uBio - Personalized RSS Alerts

	[login \| help \| signup \| show feeds]	[RSS 1 \| RSS 2]

1 2 3 4 5 6 7 8 9 10 11 12 13 ... |Next

Catalog of Life

Show results from:

Results 1 - 50 of 228608

All
Animalia
Archaea
Bacteria
Chromista
Fungi
Plantae
Protozoa
Viruses

This classification is based on the Species 2000 and ITIS Catalogue of Life 2007 Annual Checklist

Only show results from:

2012-02-05

Easter Lilies: Thinking "Spring" on a Winter's Day

2012-02-05

Identification of Avian Wax Synthases

2012-02-05

Genomic mapping by fingerprinting random clones: a mathematical analysis.

2012-02-05

MetaMerge: scaling up genome-scale metabolic reconstructions, with application to Mycobacterium tuberculosis

2012-02-05

In-feed antibiotic effects on the swine intestinal microbiome

CiteULike: Everyone's library
	Proceedings of the National Academy of Sciences, Vol. 109, No. 5. (31 January 2012), pp. 1691-1696. Antibiotics have been administered to agricultural animals for disease treatment, disease prevention, and growth promotion for over 50 y. The impact of such antibiotic use on the treatment of human diseases is hotly debated. We raised pigs in a highly controlled environment, with one portion of the littermates receiving a diet containing performance-enhancing antibiotics [chlortetracycline, sulfamethazine, and penicillin (known as ASP250)] and the other portion receiving the same diet but without the antibiotics. We used phylogenetic, metagenomic, and quantitative PCR-based approaches to address the impact of antibiotics on the swine gut microbiota. Bacterial phylotypes shifted after 14 d of antibiotic treatment, with the medicated pigs showing an increase in Proteobacteria (1–11%) compared with nonmedicated pigs at the same time point. This shift was driven by an increase in Escherichia coli populations. Analysis of the metagenomes showed that microbial functional genes relating to energy production and conversion were increased in the antibiotic-fed pigs. The results also indicate that antibiotic resistance genes increased in abundance and diversity in the medicated swine microbiome despite a high background of resistance genes in nonmedicated swine. Some enriched genes, such as aminoglycoside O-phosphotransferases, confer resistance to antibiotics that were not administered in this study, demonstrating the potential for indirect selection of resistance to classes of antibiotics not fed. The collateral effects of feeding subtherapeutic doses of antibiotics to agricultural animals are apparent and must be considered in cost-benefit analyses. Torey Looft, Timothy Johnson, Heather Allen, Darrell Bayles, David Alt, Robert Stedtfeld, Woo Sul, Tiffany Stedtfeld, Benli Chai, James Cole, Syed Hashsham, James Tiedje, Thad Stanton
	Keywords: Escherichia coli, Proteobacteria

2012-02-05

Untangling Genomes from Metagenomes: Revealing an Uncultured Class of Marine Euryarchaeota

2012-02-05

Chronic pneumonia in calves after experimental infection with Mycoplasma bovis strain 1067: Characterization of lung pathology, persistence of variable surface protein antigens and local immune response

BioMed Central - Latest articles
	Background:Mycoplasma bovis is associated with pneumonia in calves characterized by the development of chronic caseonecrotic lesions with the agent persisting within the lesion. The purposes of this study were to characterize the morphology of lung lesions, examine the presence of M. bovis variable surface protein (Vsp) antigens and study the local immune responses in calves after infection with M. bovis strain 1067.Methods:Lung tissue samples from eight calves euthanased three weeks after experimental infection with M. bovis were examined by bacteriology and pathology. Lung lesions were evaluated by immunohistochemical (IHC) staining for wide spectrum cytokeratin and for M. bovis Vsp antigens and pMB67 antigen. IHC identification and quantitative evaluation of CD4+ and CD8+ T lymphocytes and immunoglobulin (IgG1, IgG2, IgM, IgA)-containing plasma cells was performed. Additionally, expression of major histocompatibility complex class II (MHC class II) was studied by IHC.Results:Suppurative pneumonic lesions were found in all calves. In two calves with caseonecrotic pneumonia, necrotic foci were surrounded by epithelial cells resembling bronchial or bronchiolar epithelium. In all calves, M. bovis Vsp antigens were constantly present in the cytoplasm of macrophages and were also present extracellularly at the periphery of necrotic foci. There was a considerable increase in numbers of IgG1- and IgG2-positive plasma cells among which IgG1-containing plasma cells clearly predominated. Statistical evaluation of the numbers of CD4+ and CD8+ T cells, however, did not reveal statistically significant differences between inoculated and control calves. In M. bovis infected calves, hyperplasia of bronchus-associated lymphoid tissue (BALT) was characterized by strong MHC class II expression of lymphoid cells, but only few of the macrophages demarcating the caseonecrotic foci were positive for MHC class II.Conclusions:The results from this study show that infection of calves with M. bovis results in various lung lesions including caseonecrotic pneumonia originating from bronchioli and bronchi. There is long-term persistence of M. bovis as demonstrated by bacteriology and immunohistochemistry for M. bovis antigens, i.e. Vsp antigens and pMB67. The persistence of the pathogen and its ability to evade the specific immune response may in part result from local downregulation of antigen presenting mechanisms and an ineffective humoral immune response with prevalence of IgG1 antibodies that, compared to IgG2 antibodies, are poor opsonins.
	Keywords: Mycoplasma bovis, Mycoplasma bovis variable

2012-02-05

Visual fields and eye morphology support color vision in a color-changing crab-spider

ScienceDirect Search: species
	Publication year: 2012 Source: Arthropod Structure & Development, Available online 4 February 2012 Teresita C. Insausti, Jérémy Defrize, Claudio R. Lazzari, Jérôme Casas Vision plays a major role in many spiders, being involved in prey hunting, orientation or substrate choice, among others. InMisumena vatia, which experiences morphological color changes, vision has been reported to be involved in substrate color matching. Electrophysiological evidence reveals that at least two types of photoreceptors are present in this species, but these data are not backed up by morphological evidence. This work analyzes the functional structure of the eyes of this spider and relates it to its color-changing abilities. A broad superposition of the visual field of the different eyes was observed, even between binocular regions of principal and secondary eyes. The frontal space is simultaneously analyzed by four eyes. This superposition supports the integration of the visual information provided by the different eye types. The mobile retina of the principal eyes of this spider is organized in three layers of three different types of rhabdoms. The third and deepest layer is composed by just one large rhabdom surrounded by dark screening pigments that limit the light entry. The three pairs of secondary eyes have all a single layer of rhabdoms. Our findings provide strong support for an involvement of the visual system in color matching in this spider. Highlights ► A broad superposition of visual fields was observed in the crab-spiderM. vatia. ► The frontal space is simultaneously analyzed by receptors of four different eyes. ► The retina of the AM eyes is arranged in three layers with three receptor types. ► The deeper layer of the retina in AM eyes has just one large rhabdom. ► Our findings provide support to the hypothesis of color vision inM. vatia.
	Keywords: Arachnida, Araneae, Chelicerata, Copepods, Cupiennius salei, Dendryphantinae, Leucorchestris arenicola, Metaphidippus aeneolus, Metaphidippus vatia, Misumena vatia, Phidippus johnsoni, Philodromidae, Salticidae, Spartaeinae, Thomisidae

2012-02-05

Cross-species transferability of 86 cucumber (Cucumis sativusL.) microsatellite markers to gherkin (C.anguriaL.)

ScienceDirect Search: species
	Publication year: 2012 Source: Scientia Horticulturae, Volume 136, 1 March 2012, Pages 110-114 Yuichi Matsumoto, Nobuyoshi Watanabe, Tsutomu Kuboyama Gherkin (Cucumis anguriaL.), also known as West Indian gherkin, burr gherkin, and maxixe, is mainly cultivated and consumed in Brazil and the United States. Marker-assisted selection (MAS) would be a highly desirable tool for breeding of gherkin as gherkin cultivation generally requires considerable time, labor, and space. However, DNA markers available for gherkin have rarely been reported, although many microsatellite linkage maps have been constructed for cucumber and whole genomic sequences have been reported. In this study, we attempted to transfer 86 microsatellite markers derived from cucumber to gherkin and assess amplification and polymorphism between two gherkin accessions to enable the use of the microsatellite markers in gherkin. In PI 320052 and PI 364475, 58 (67.4%) and 55 (64.0%) microsatellite markers were successfully amplified, respectively. Of the amplified markers, the polymorphism number between the two accessions was 40. Thus, an adequate number of cucumber microsatellite markers can be transferred to gherkin. Current polymorphic microsatellite markers could then be made available for the study of landmarks in linkages, genomic structures, evolutionary ecology, and MAS in gherkin and Cucurbitaceae. Highlights ► We attempted to transfer 86 microsatellite markers derived from cucumber to gherkin. ► In two gherkin accession, PI 320052 and PI 364475, 58 and 55 markers were successfully amplified, respectively. ► Of the amplified markers, the polymorphism number between the two accessions was 40. ► These will be useful in the study of genetic relationships and maker assisted selection in gherkin.
	Keywords: Actinidia chinensis, Allium sativum, Benincasa hispida, Citrullus lanatus, Cucumis anguria, Cucumis melo, Cucumis sativus, Cucurbita maxima, Cucurbita moschata, Cucurbitaceae, Erysiphe cichoracearum, Fusarium oxysporum, Lagenaria siceraria, Momordica charantia, Praecitrullus fistulosus, Prunus serotina, Sphaerotheca fuliginea, Trichosanthes cucumeroides

2012-02-05

Parthenocarpic genetic resources and gene expression related to parthenocarpy among four species in pear (Pyrusspp.)

ScienceDirect Search: species
	Publication year: 2012 Source: Scientia Horticulturae, Volume 136, 1 March 2012, Pages 101-109 Chikako Nishitani, Ayako Yamaguchi-Nakamura, Fumiko Hosaka, Shingo Terakami, Tokurou Shimizu, ... Parthenocarpy—the production of seedless fruits without fertilization—is very useful for fruit cultivation, especially in self-incompatible species such as pears. To search for parthenocarpic genetic resources in pear, 31 pear accessions [20 Chinese pears (13Pyrus bretschneideri, sevenPyrus ussuriensis), five European pears (Pyrus communis), two Japanese pears (Pyrus pyrifolia), and four interspecific hybrids] were subjected to flower emasculation and left unpollinated, and then the fruit-set ratio and fruit enlargement were investigated. All European pears examined had a stable and high degree of fruit set, and ‘La France’ had high fruit enlargement. The possibility of stenospermocarpy was ruled out, because the emasculated flowers were left unpollinated in paper bags and the absence of seed was confirmed in the enlarged fruits. Neither Chinese nor Japanese pears treated with emasculation and no pollination showed consistently stable fruit set and fruit enlargement. An analysis of parthenocarpy in the offspring of ‘La France’ suggested that both high fruit set and fruit enlargement were inherited and that it should be possible to introduce parthenocarpy into Japanese pears. Although parthenocarpic ‘La France’ fruits weighed slightly less than those from cross-pollinated flowers, their cortex enlargement compared favorably with that seen with cross-pollinated ones. By using a customized pear cDNA microarray, we compared the gene expression profiles of highly and weakly parthenocarpic cultivars before flowering. Expression of several phenylpropanoid-related genes and photosystem-related genes differed significantly between the two groups. Some of these genes were putatively encoded in the chloroplast genome. These genes might be candidates of DNA markers for achievement of parthenocarpy in Japanese pear breeding. Highlights ► Parthenocarpy is a very important characteristic for pear cultivation with stable fruit set. ► We found that European pear ‘La France’ had especially stable and high levels of automatic parthenocarpy. ► Parthenocarpy was partially inherited by the offspring of ‘La France’. ► Microarray analysis showed that the phenylpropanoid and photosystem pathways were associated with parthenocarpy.
	Keywords: Acer pseudoplatanus, Actinidia chinensis, Arabidopsis thaliana, Cucumis sativus, Cucurbita pepo, Cucurbitaceae, Gossypium hirsutum, Pyrus bretschneideri, Pyrus communis, Pyrus pyrifolia, Pyrus serotina, Pyrus ussuriensis, Solanaceae, Vaccinium corymbosum

2012-02-05

Lipoic acid attenuates high-fat-diet–induced oxidative stress and B-cell–related immune depression

ScienceDirect Search: species
	Publication year: 2012 Source: Nutrition, Volume 28, Issue 3, March 2012, Pages 275-280 Jue Cui, Ying Xiao, Yong-Hui Shi, Bin Wang, Guo-Wei Le ObjectiveThis study investigated whether spleen oxidative stress induced by a high-fat diet (HFD) influences the expression of genes involved in B-cell activation, thus leading to B-cell–related immunosuppression.MethodsMale C57BL/6 mice were randomly assigned to one of three groups with eight mice in each group. The control group consumed an ordinary diet (4.9% fat, w/w). The other two groups were fed an HFD (21.2% fat) and an HFD plus 0.1% lipoic acid (LA). After 10 wk, plasma and spleen oxidative stress biomarkers including superoxide dismutase, catalase, glutathione peroxidase, total antioxidant capacity, reduced glutathione/oxidized glutathione ratio, and malondialdehyde were examined. The B-cell–related immune function was evaluated by examining the number of B cells, and the apoptotic percentages of splenic lymphocytes were determined by flow cytometry. Furthermore, the B-cell activation and reactive oxygen species scavenger-related genes differentially expressed between mice fed an HFD and those fed an HFD supplemented with LA were identified through complementary DNA microarray.ResultsThe HFD induced marked decreases in the number of B cells and significantly increased the apoptotic percentages of splenic lymphocytes, accompanied by oxidative stress and increased oxidative damage, in the plasma and spleen. In addition, complementary DNA array analysis results showed that the HFD induced the decreased expression of genes associated with antioxidant defense, such as superoxide dismutase-3 (1.5-fold), metallothionein-1 (3.03-fold), glutathione peroxidase-5 (17.15-fold), and peroxiredoxin-4 (1.5), and B-cell activation, such as immunoglobulin heavy chain 6 (2.46-fold), immunoglobulin κ-chain (1.74-fold), Fc receptor (1.41-fold), and RAS-related C3 botulinum substrate-1 (7.46). The LA supplement prevented the buildup of oxidative stress and upregulated related gene expressions.ConclusionThese results indicate a role for LA as a possible effective supplement with an HFD to prevent the development of oxidative stress and to attenuate B-cell damnification by increasing the gene expression of the B-cell receptor signaling pathway.
	Keywords: Macaca mulatta

2012-02-05

The role of probiotics in gastrointestinal surgery

2012-02-05

Optimization of plant coverage in relation to water balance in the Loess Plateau of China

ScienceDirect Search: species
	Publication year: 2012 Source: Geoderma, Volumes 173–174, March 2012, Pages 134-144 Wei Fu, Mingbin Huang, Jacques Gallichand, Mingan Shao A series of revegetation practices have been implemented to improve the environmental quality and to reduce water and soil losses in the wind and water erosion transitional belt of China's Loess Plateau. An incompatibility exists between the limited water availability and the extensive plant coverage needed to protect the soil from accelerated erosion. The objective of this study was to investigate the relationship between plant coverage and soil water to determine the optimal plant coverage for the two dominant shrubs (Caragana korshinkii KomandSalix psammophila) in this area. Experiments were performed with four coverage treatments (T0, T1, T2, and T3) for each shrub during the growing seasons of 2008, 2009 and 2010. Soil water content was measured with a neutron probe. The Simultaneous Heat and Water Transfer (SHAW) model was used to simulate soil water content variations for a critical climatic year, i.e. the one-in-ten dry year. The soil and plant parameters of the SHAW model were calibrated using the measured soil water content in the 0–200 cm soil layer of the T2 coverage for each species. The calibrated model was verified using measurements for T0, T1, and T3 plant coverages. The results indicated that soil water storage in the 0–200 cm soil layer decreased with increasing plant coverage. Soil desiccation occurred at various depths in the 0–200 cm soil layer for the different plant coverages. The degree of soil desiccation was greater for the two shrubs when plant coverage was more extensive. The SHAW model, calibrated for soil and plant parameters, accurately simulated soil water variations in the 0–200 cm profile under different plant coverages. During the verification phase, the root mean square error (RMSE) between the measured and simulated soil water contents ranged from 0.022 to 0.033 cm cmand the relative root mean square error (RRMSE) ranged from 14.4% to 24.6%. Based on the observed and modeled interactions of soil water depletion and plant growth, the optimal plant coverage corresponds to a maximum LAI of 1.27 forC. korshinkiiand 0.70 forS. psammophila. Highlights ► The relationship between plant coverage and soil water was studied for two shrubs. ► Soil water storage in the root zone decreased with increasing plant coverage. ► The soil desiccation occurred in the root zone for different coverages. ► A numerical model was calibrated and verified using the field measurements. ► The optimal plant coverage was determined for each shrub at a 10% risk probability.
	Keywords: Salix psammophila, Sinapis alba

2012-02-05

Allocation of carbon to mycorrhiza in the grassesKoeleria glaucaandCorynephorus canescensin sandy grasslands

ScienceDirect Search: species
	Publication year: 2012 Source: Applied Soil Ecology, Volume 54, March 2012, Pages 55-62 Linda-Maria Mårtensson, Tim Krone Schnoor, Pål Axel Olsson By investigating both semi-natural and experimentally implemented pH variation in nutrient-poor sandy grasslands, we examined how soil decalcification may influence the arbuscular mycorrhizal (AM) fungal biomass in plant roots and in the soil, as well as the allocation of carbon (C) to AM fungal biomass. We estimated the amount of AM fungal mycelium, by using the fatty acid 16:1ω5, in the roots and in the soil surrounding the roots of two grass species in a pH gradient, and in one grass in an experimental area. We investigated the allocation of C to the AM fungi by usingin situC labelling. Contrary to our expectations, we found a decrease in AM fungal mycelium in the soil with increasing soil pH, and no significant relationship between soil pH and the amount of AM fungi in the roots. We also found that the allocation of C below ground was very small in the grasses investigated; the excess ofC in the roots after five days was only between 0.06 and 1.2% of the excess ofC in the shoots directly after labelling. The allocation of C to the extraradical AM mycelium also decreased with increasing pH, ranging from not detectable to 1.2 μgC gdry soil in the range of soil pH from 5.5 to 8.5. Experimental manipulation of decalcification through soil perturbation further supported the finding that AM fungal density is higher in decalcified areas, although it was not statistically significant in this case. We conclude that the amount of AM fungi is very low in this type of nutrient and drought stressed habitat, and that a high pH in the topsoil does not leads to higher AM fungal biomass. Highlights ► In semi-natural and experimentally implemented pH variation in nutrient-poor sandy grasslands, the specific biomarker NLFA 16:1w5 decreased with increasing soil pH. ►In situCO2pulse labelling of aboveground biomass followed the same pattern. ► Mycorrhizal fungi and their potential for storage of carbon are reduced in erosion slopes and in intensive disturbance regimes.
	Keywords: Anisantha tectorum, Corynephorus canescens, Koeleria glauca, Littorella uniflora, Lobelia dortmanna, Phaseolus vulgaris, Plantago lanceolata, Rumex acetosella, Viscaria vulgaris

2012-02-05

Trace elements inCoralliumspp. as indicators for origin and habitat

2012-02-05

Three dimensional temporal and spatial distribution of adultOryzaephilus surinamensisandSitophilus oryzaein stored wheat under different temperatures, moisture contents, and adult densities

ScienceDirect Search: species
	Publication year: 2012 Source: Journal of Stored Products Research, Volume 49, April 2012, Pages 155-165 Fuji Jian, Ron Larson, Digvir S. Jayas, Noel D.G. White Three dimensional temporal and spatial distributions of adultOryzaephilus surinamensisat densities of 0.1, 1.0, and 5.0 adults/kg wheat (referred to as A/kg) and adultSitophilus oryzaeat densities of 1.0, 5.0, and 10.0 A/kg were determined in bins filled with 1.5 t wheat having 11.0 ± 0.8, 13.0 ± 0.6, or 15.0 ± 0.5% moisture content at 20 ± 1, 25 ± 1 or 30 ± 1 °C. At each of the five sampled locations, wheat was separated into three 15 kg vertical layers and the number of adults in each layer was counted.Less than 30% of adultO. surinamensiswere recovered in the top layer, while more than 80% of adultS. oryzaewere recovered in the top layer. Adults ofO. surinamensispreferred the center locations in each layer and adults ofS. oryzaepreferred the top layer. Densities of both species at adjacent locations in the horizontal direction were autocorrelated with each other. The temporal continuous property might not exist for the adults ofO. surinamensisbut exists for the adults ofS. oryzae. Even though both species had aggregated and clumped distribution at any temperature, moisture content and adult density, adults ofO. surinamensishad a more homogeneous distribution thanS. oryzae. These characterized patterns of distribution of adult insects could be used to effectively estimate their density inside stored grain-bins. Highlights ► The two adults had different preferences in their distribution in a 1.5 t wheat bin. ► More than 80% ofSitophilus oryzaewere recovered in the top layer. ► Less than 30% ofOryzaephilus surinamensiswere recovered in the top layer. ► Densities ofS. oryzaein the horizontal direction were autocorrelated. ► The temporal continuous property might not exist for the adults ofO. surinamensis.
	Keywords: Acari, Chrysomelidae, Coleoptera, Cryptolestes ferrugineus, Cucujidae, Culicidae, Diptera, Ixodidae, Laemophloeidae, Oryzaephilus surinamensis, Sitophilus oryzae, Tribolium castaneum

2012-02-05

Hydrocarbon-utilizing bacteria associated with biofouling materials from offshore waters of the Arabian Gulf

ScienceDirect Search: species
	Publication year: 2012 Source: International Biodeterioration & Biodegradation, Volume 69, April 2012, Pages 10-16 H. Al-Awadhi, N. Dashti, M. Kansour, N. Sorkhoh, S. Radwan Biofouling materials from 30 offshore substrates in eight sites along the Kuwaiti coast harbored 3 × 10–28 × 10bacterial cells g, as counted microscopically. Using culture-based methods, 7 × 10–4.1 × 10colony forming units (CFU's) were counted on a nitrogen-containing mineral medium with oil vapor as a sole carbon source. According to their 16S rDNA sequences, those bacteria were affiliated with species belonging to the generaAlcanivorax, Dietzia, Gordonia, Hoyosella, Kocuria, Marinobacter, Micrococcus, Mycobacterium, Planococcus, Planomicrobium, Pseudoalteromonas, Salinivibrio, and Vibrio. Similar numbers of CFUs appeared on the nitrogen-free mineral media; the predominant species were affiliated with most of the genera recorded above, in addition toAgrobacterium, Labrenzia, Microbacterium, Nitratireductor, Pseudomonas, and Rhodococcus. Isolates of these bacteria grew on a wide range of individual alkanes, phenanthrene, naphthalene, and biphenyl as sole carbon sources. Quantitative determinations showed that individual bacteria could attenuate crude oil, puren-octadecane, and pure naphthalene in batch cultures. Also microbial consortia associated with fresh environmental samples attenuated oil in batch cultures in the presence and absence of NaNO3. It was concluded that bacteria associated with biofouling materials probably contribute to hydrocarbon bioremediation in the Arabian Gulf. Highlights ► Marine biofouling materials harbored hydrocarbon-utilizing bacteria. ► Predominant genera:Alcanivorax, Dietzia, Gordonia, Hoyosella, Pseudoalteromonas. ► Most of the isolates were also diazotrophic. ► Inoculation with biofouling materials attenuated hydrocarbons in culture.
	Keywords: Actinobacteria, Agrobacterium ferrugineum, Agrobacterium tumefaciens, Alcanivorax borkumensis, Alcanivorax jadensis, Alcanivorax venustensis, Alphaproteobacteria, Dietzia cinnamea, Dietzia maris, Dietzia natronolimnaea, Firmicutes, Gammaproteobacteria, Gordonia amarae, Gordonia lacunae, Hoeflea marina, Kocuria flavus, Kocuria palustris, Kocuria rosea, Marinobacter hydrocarbonoclasticus, Microbacterium arborescens, Microbacterium jejuense, Micrococcus yunnanensis, Mycobacterium chlorophenolicum, Planococcus citreus, Planococcus maritimus, Planomicrobium psychrophilum, Pseudoalteromonas prydzensis, Pseudomonas mendocina, Rhodococcus rhodochrous, Rhodococcus ruber, Salinivibrio costicola, Vibrio alginolyticus, Vibrio azureus, Vibrio brasiliensis, Vibrio communis, Vibrio fortis, Vibrio parahaemolyticus, Vibrio shilonii, Vibrio sinaloensis

2012-02-05

Long-term effects of deer browsing: Composition, structure and productivity in a northeastern Minnesota old-growth forest

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 222-228 Mark A. White Although the immediate impacts of elevated deer (Odocoileusspp.) browsing on forest regeneration have been well documented, few studies have examined the longer term consequences. A deer exclosure experiment was initiated in 1991 in an old-growth northern mixed mesic forest in northeastern Minnesota, and resampled in 2008 to examine changes in composition, structure and productivity. Decades of overbrowsing by white-tailed deer have led to almost complete recruitment failure in size classes >2.5 cm dbh for preferred deer browse speciesThuja occidentalisandPinus strobusin unprotected plots. Other palatable browse species have been severely limited in understory development (Populus tremuloides,Betula papyrifera,Fraxinus nigra). Within exclosures,P. strobusgained in all size classes <20 cm dbh, whileF. nigra,B. papyrifera,T. occidentalisall showed significant gains. Non-preferredPicea glaucaincreased outside exclosures, but has also gained within exclosures. The increase inP. glaucaacross treatments indicates a long-term legacy effect of preferential browsing. Browsing induced suppression of subcanopy density of preferred species and failure of canopy tree replacement may lead to a more open woodland structure dominated byP. glauca. Browsing pressure may negatively impact productivity, as whole tree biomass in exclosures increased at a rate twice that of unprotected plots. The low biomass levels recorded in 2008 (unprotected: 98.0 mg/ha, exclosure: 104 mg/ha) are approximately 1/2 of values typically recorded in later successional forests in this region indicating lower productivity may be another longer-term legacy of elevated deer population. Continued high browsing pressure is one of many factors contributing to the restructuring of northern Great Lakes forests away from historical variability conditions towards a novel and more homogeneous forested landscape. These simplified forests may be less resilient to the suite of emerging stressors such as climate change and less able to provide ecosystem services such as carbon storage, biological diversity and forest products. Sustained restoration efforts, along with reductions in deer density will be needed to restore species and structural diversity. Highlights ► In unfenced plots, preferred browse species did not recruit into the sapling layer. ► In fenced plots, preferred browse species gained in sapling and subcanopy layers. ► Non-preferred white spruce gained in fenced and unfenced plots. ► Productivity doubled in protected plots compared to unprotected. ► Forests may be shifting to a spruce dominated woodland state.
	Keywords: Abies balsamea, Acer saccharum, Alces alces, Betula allegheniensis, Betula papyrifera, Fraxinus nigra, Lepus americanus, Odocoileus virginianus, Parelaphostrongylus tenus, Picea glauca, Pinus resinosa, Pinus strobus, Populus strobus, Populus tremuloides, Quercus rubra, Thuja occidentalis

2012-02-05

Invasion of alienAcacia dealbataon SpanishQuercus roburforests: Impact on soils and vegetation

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 214-221 N. González-Muñoz, M. Costa-Tenorio, T. Espigares Invasive treeAcacia dealbatawas introduced in the Iberian Peninsula in the 19th century. Nowadays, it is spreading in wide areas in which native vegetation has been altered or removed by human-activities, as in the case ofQuercus roburforests in the northwest of Spain. In this article we assess the impact ofA. dealbatainvasion on soil properties (pH, organic matter, total N,and), light characteristics (direct and diffuse photon flux density and leaf area index) and soil seed bank and established vegetation. We selected three sites where nativeQ. roburforests andA. dealbatainvaded patches grow nearby. Before 2008 autumn rains, we took soil samples under five trees per species (A. dealbataandQ. robur) and site to determine soil seed bank floristic composition and soil properties. In spring 2009 we monitored the floristic composition of the vegetation growing under the same trees. Our results show thatA. dealbatapresence increases total N,andand decreases pH in soils but does not affect light characteristics.Acacia dealbatamodifies soil seed bank composition by decreasing species richness, seed density and the percentage of bryophyte and fern spores, and by increasing the percentage ofAsteraceaeand exotic species. Understorey of invadedA. dealbataforests shows a decrease in species richness and plant cover. Finally,A. dealbatareduces the similarity between the soil seed bank and the established vegetation. These results suggest thatA. dealbatainvasion produces a deep impact onQ. roburforests that hampers their regeneration, even afterA. dealbataremoval. Highlights ► Acacia dealbataincreases nitrogen in soils but decreases pH. ► It decreases species richness and seed density in the seed bank. ► In the seed bank, it increasesAsteraceaeand exotic species presence. ► It decreases species richness and plant cover of established vegetation. ► This invasion deeply impactsQuercus roburforest, hampering native forest regeneration.
	Keywords: Acacia dealbata, Acacia longifolia, Acacia saligna, Anagallis arvensis, Anagallis dealbata, Arbutus dealbata, Arbutus unedo, Asteraceae, Castanea sativa, Centaurea nigra, Coleoptera, Crataegus monogyna, Digitalis purpurea, Fabaceae, Fallopia japonica, Gunnera tinctoria, Hedera helix, Heracleum mantegazzianum, Ilex aquifolium, Laurus nobilis, Lithodora prostrata, Mimosaceae, Mimosoideae, Myrica faya, Oxalis pes-caprae, Pinus pinaster, Poaceae, Pseudarrhenatherum longifolium, Pyracantha angustifolia, Quercus ilex, Quercus pyrenaica, Quercus robur, Quercus suber, Rhamnus alaternus, Rubus ulmifolius, Rumex acetosa, Rumex ulmifolius, Ruscus aculeatus, Sonchus oleraceus, Stellaria holostea, Tamus communis, Teucrium scorodonia, Ulex minor, Viola riviniana

2012-02-05

Heterotrophic respiration and nitrogen mineralisation in soils of Norway spruce, Scots pine and silver birch stands in contrasting climates

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 197-205 Bengt A. Olsson, Karna Hansson, Tryggve Persson, Egbert Beuker, Heljä-Sisko Helmisaari Different tree species are often associated with different soil properties. Earlier studies have shown that Norway spruce (Picea abies(L.) Karst.) and Scots pine (Pinus sylvestrisL.), the two dominant tree species in Fennoscandia, often generate soils with larger carbon (C) and nitrogen (N) pools than silver birch (Betula pendulaRoth.). Consequently, we hypothesised that spruce and pine would create soils with slower turnover rates than birch. To test this, C and N pools and C and N mineralisation rates were determined in different soil layers (humus, 0–10 cm, 10–20 cm mineral soil) at two sites with contrasting climatic conditions. One site (Tönnersjöheden) was located in the temperate zone in SW Sweden and one (Kivalo) in the north boreal zone in N Finland. At both sites, experimental plots with the three tree species had been established more than 50 years before the study. Samples from the different soil layers were incubated at 15 °C in the laboratory for 30 days, and C and N mineralisation rates were determined. In addition, earthworm abundance was estimated at Tönnersjöheden but not at Kivalo (no sign of bioturbation). At Tönnersjöheden, soil C and N pools (g C or N m) were ranked spruce > pine > birch. C mineralisation rate (mg CO2–C g C d) was higher in the birch plots than in the other plots, but because of larger C pools in the spruce plots, field C mineralisation (g CO2–C m year) was higher for spruce than for pine and birch. Field net N mineralisation (80–90 kg N ha year) did not differ significantly between tree species, but nitrification rates (μg NO3–N g C d) in the topsoil were higher in the birch plots than in the other plots. The birch plots had larger populations of earthworms and a higher degree of bioturbation than any of the coniferous plots, which probably explains the higher turnover rate of birch soil organic matter (SOM). At Kivalo, C and N soil pools were significantly larger in spruce than in birch plots, and C mineralisation rate was higher in birch and spruce humus than in pine humus. Net N mineralisation rate and annual field net N mineralisation (<4 kg N ha year) were estimated to be very low, with no effect of tree species. Thus, the hypothesis of a ‘birch effect’ was supported at Tönnersjöheden, but only partly at Kivalo. The main difference seemed to be that the earthworms at Tönnersjöheden accelerated SOM decomposition under birch, whereas earthworm stimulation was negligible at Kivalo, probably because of climate-related limitations. Highlights ► Spruce, pine and birch soils were compared at two contrasting sites. ► Respiration mwas highest under spruce due to high C pools. ► Respiration rate (g C) was highest under birch. ► Higher earthworm abundance under birch.
	Keywords: Agrostis capillaris, Betula papyrifera, Betula pendula, Betula pubescens, Calluna vulgaris, Dendrobaena octaedra, Deschampsia flexuosa, Fagus sylvatica, Frangula alnus, Hypnum cupressiforme, Lumbricidae, Lumbricus rubellus, Oligochaeta, Picea abies, Picea glauca, Pinus abies, Pinus banksiana, Pinus sylvestris, Pleurozium schreberi, Pseudotsuga menziesii, Quercus petraea, Quercus robur, Sorbus aucuparia, Vaccinium myrtillus, Vaccinium vitis-idaea

2012-02-05

Quantification of the effects of aboveground and belowground competition on growth of seedlings in a conifer–angiosperm forest

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 188-196 Fiona E. Carswell, James E. Doherty, Robert B. Allen, Melissa E. Brignall-Theyer, Sarah J. Richardson, ... Differential shade-tolerance is thought one of the critical components of coexistence of conifer and angiosperm canopy tree species in temperate forests. However, belowground competition for nutrients may also change along light gradients, confounding apparent differences in shade tolerance. Despite this co-variation in light and nutrients,in situmanipulation of belowground competition along a light gradient has not been previously used to investigate conifer–angiosperm seedling performance. In this study we selected conifer–angiosperm seedlings along a light gradient and used trenching to reduce belowground competition for half of the seedlings. The forest is currently dominated by an angiosperm (Beilschmiedia tawa) that is more shade-tolerant than the co-occurring conifersPrumnopitys ferrugineaand shade-intolerantDacrydium cupressinum. Diameter and height growth rates of the fastest growing seedlings (top 25%) across all species were greater for seedlings with reduced belowground competition – increased light did not significantly alter growth rates. For these fast-growing seedlings the diameter growth rates of the coniferousP. ferrugineaandD. cupressinumwere superior to that of the angiospermB. tawa. Of the fastest growing seedlings, height growth was also greatest forD. cupressinumacross the gradient of light availability. This species was most responsive to light, shoot growth showing a positive interaction between increased light and trenching. Approximately 30% of its seedlings occurred at >10% full sun, and rates of both diameter and shoot growth were increased approximately threefold at the highest light levels, compared with the lowest (c. 2% full sun). Despite the angiosperm’s current dominance of the study forest, the superior performance of the fastest growing conifer seedlings, coupled with their longevity, suggests the conifer species will persist even under current conditions. Highlights ► Seedlings of shade-tolerant angiosperm grew more slowly than co-occurring conifers. ► Across all seedlings growth was more responsive to light than trenching. ► Fastest growing seedlings more responsive to trenching than light. ► Conifers will persist even under prevailing current conditions.
	Keywords: Anthoxanthum odoratum, Beilschmiedia tawa, Blechnaceae, Blechnum tawa, Cinnamomum verum, Cyatheaceae, Dacrydium cupressi, Dacrydium cupressinum, Dicksonia cupressinum, Dryopteridaceae, Elaeocarpaceae, Elaeocarpus dentatus, Hemiphaga novaeseelandiae novaeseelandiae, Knightia excelsa, Lauraceae, Metrosideros robusta, Myrtaceae, Pinus radiata, Plantago lanceolata, Podocarpaceae, Podocarpus latifolius, Polystichum ferruginea, Proteaceae, Prumnopitys ferruginea, Urewera

2012-02-05

Roles of thinning intensity in hardwood recruitment and diversity in a conifer,Criptomeria japonicaplantation: A 5-year demographic study

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 177-187 Kenji Seiwa, Yukino Etoh, Masahiro Hisita, Kazuhiko Masaka, Aya Imaji, ... To evaluate the role of thinning intensity in increasing hardwood diversity in managed coniferous forests, we investigated the effects of environmental changes caused by thinning on the seedling demography (i.e. seedling emergence, survival, and growth) of hardwood species for 5 years after thinning in 67% thinned (Intensive), 33% thinned (Weak), and unthinned treatments (Control) in aCryptomeria japonicaplantation in northern Japan. Intensive thinning strongly increased light and soil temperature but reduced litter accumulation, thus facilitating seed germination, seedling emergence, and seedling survival of primarily early- and mid-successional species compared to late-successional species. As a result, more early- and mid-successional species were observed in Intensive compared to Weak and Control, whereas the number of late-successional species did not differ among thinning intensities. Thus, the number of species was greatest in Intensive but lowest in Control throughout the 5 years. However, Shannon’s diversity index (H′)did not strongly differ among thinning intensities, largely due to the predominance of the mid-successional speciesCornus controversa, particularly in Intensive. In Control and Weak, both seedling survival and height were often greater for advance regeneration than for seedlings newly emerged in the year following thinning, whereas neither variable differed between advance regeneration and seedlings newly emerged in Intensive, mainly due to selective predation of advance regeneration by mammalian herbivores. These results suggest that the future composition of hardwoods can be roughly predicted by the composition of advance regeneration in Weak but by the composition of both advance regeneration and seedlings newly emerged in Intensive. When comparing large individuals (height >1.5 m), the number of species was greatest in Intensive in 2008, 5 years post-thinning, primarily due to rapid vertical growth regardless of successional status. These results suggest that within aC. japonicaplantation, a canopy-level mixed conifer-hardwood forest would be more probable and occur more rapidly in Intensive compared to Weak. In Weak, enhanced species diversity would likely be restricted to the understorey layer because of the slower growth rate and lower survival rate of hardwood seedlings caused by the more rapid deterioration of favourable environmental conditions. Highlights ► We evaluated the role of thinning intensity in species diversity in a conifer plantation. ► Intensive thinning (67%) strongly increases environmental conditions. ► Environmental improvement facilitates establishment of pioneer species. ► More early- and mid-successional species are observed in Intensive thinning. ► Number of species is greatest in Intensive but lowest in Control.
	Keywords: Acer mono, Acer rufinerve, Alnus hirsuta, Alnus rubra, Aralia errata, Betula maximowicziana, Betula papyrifera, Betula pendula, Carpinus laxiflora, Caryophyllaceae, Castanea crenata, Chamaecyparis japonica, Chamaecyparis obtusa, Clethra barbinervis, Clethra japonica, Clethra obtusa, Cornus controversa, Cornus crenata, Cornus japonica, Cornus laxiflora, Cryptomeria controversa, Cryptomeria crenata, Cryptomeria japonica, Enkianthus perulatus, Hydrangea paniculata, Larix kaempferi, Paulownia tomentosa, Picea abies, Picea glehnii, Picea mariana, Pinus densiflora, Pinus resinosa, Pinus strobus, Pinus sylvestris, Prunus densiflora, Prunus grayana, Prunus tomentosa, Prunus verecunda, Pterocarya rhoifolia, Quercus serrata, Rhododendron kaempferi, Rhus javanica, Rubus palmatus, Salix bakko, Salix hultenii, Salix vulpine, Viburnum dilatatum, Viburnum furcatum, Weigela hortensis

2012-02-05

Soil and plant legacies associated with harvest trails in boreal black spruce forests

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 168-176 Miren Lorente, William F.J. Parsons, Robert L. Bradley, Alison D. Munson The practice of careful logging has been mandated in northeastern Canada’s coniferous and mixedwood forests as a means of protecting natural regeneration while minimizing soil disturbance by machinery. This practice imposes evenly spaced, parallel trails for circulation of harvesting machinery, while most of the understory and soil is left intact in wide protection strips between the trails. The objective of this study was to examine soil physico-chemical and microbial properties, and ericaceous shrub performance (aboveground biomass) following careful logging and with or without subsequent scarification. By sampling 32 cutover forest sites (formerly black spruce-dominated) in the Abitibi-Temiscamingue region of boreal northwestern Quebec, we evaluated how (a) the presence of alternating bands of protection strips and skid trails (on non-scarified sites), and (b) a scarification treatment consisting of mixing the soil organic layer with the surface mineral soil, influenced soil and vegetation properties over time (4–15 years after careful logging). On non-scarified sites, careful logging showed a differential compaction pattern consisting of bands of disturbed zones or trails alternating with protection zones. Both soil properties and ericaceous shrub biomass estimates tracked these alternating compacted and non-compacted areas on the cutover. Soil N (Nt), soil percentage microbial C to total C (Cmic/Ct), andKalmia angustifolia(Kalmia) andVacciniumspp. (Vaccinium) aboveground biomass differed on strips and trails 8 and 15 years after harvest. The observed differences in ericaceous shrub biomass between strips and trails, and correlations between biomass and soil variables, suggest potential shrub interference with soil processes. These observations suggest that ericaceous species may promote differences in soil properties and plant communities that result in a long-term spatial signature perpetuating the trail pattern. Scarification reducedKalmiaandVacciniumaboveground biomass and had a negative effect on Cmic/Nmicand Cmic/Ct, 15 years after harvest. Forest understory plants, such as ericaceous shrubs, may play a key role in driving belowground properties, forest regeneration, and long-term succession on these sites. Understanding the ecology and spatial distribution of these species may thus have important implications for ecosystem structure and function as well as timber production. Highlights ► We examine soil and ericad properties 15 years after careful logging and scarification. ► These properties differed on trails and protection strips after careful logging. ► Ericad-induced changes in soil properties contributed to perpetuate the trail pattern. ► Scarification had a positive effect on ericad reduction but altered C and N availability.
	Keywords: Abies balsamea, Betula papyrifera, Empetrum hermaphroditum, Ericales, Hylocomium spendens, Kalmia angustifolia, Ledum groenlandicum, Picea abies, Picea mariana, Pinus banksiana, Pinus radiata, Pinus sylvestris, Pleurozium schreberi, Rhododendron groenlandicum, Vaccinium angustifolium, Vaccinium myrtilloides, Vaccinium myrtillus

2012-02-05

Windthrow after group and dispersed tree retention in eastern Canada

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 158-167 Sébastien Lavoie, Jean-Claude Ruel, Yves Bergeron, Brian D. Harvey Although green tree retention has been proposed as a means of maintaining forest structural attributes normally found after stand replacing disturbances, there is some concern about mortality and fall rates of residual trees. Very little data regarding windthrow after green tree retention is currently available for Quebec, eastern Canada. The present study documents windthrow after two types of retention in two regions with contrasting biophysical characteristics, and identifies the most influential factors. A retrospective survey of windthrow was conducted in dispersed and group retention cuts conducted two to five years previously. In the Abitibi region of northwestern Quebec, the level of windthrow was comparable between group and dispersed tree retention. In the North Shore region of eastern Quebec, windthrow was higher in dispersed retention and levels of mortality were generally lower than in the Abitibi region. Windthrow probability was best explained by edaphic variables, tree species, slenderness ratio, tree height or diameter at breast height, and sapling abundance. Variables such as regional mean wind speed, retained group area, simple fetch and topographical exposure (Topex to distance) were not included in the best models. Although mortality rates increased after green tree retention, it remains to be established whether this increase has detrimental effects in terms of maintaining biodiversity. Highlights ► Windthrow after green tree retention can be significant. ► Windthrow can be especially high after green tree retention in old even-aged stands. ► Windthrow probability generally increases with tree size and varies with species and soil characteristics.
	Keywords: Abies balsamea, Betula papyrifera, Choristoneura fumiferana, Picea abies, Picea glauca, Picea mariana, Pinus banksiana, Pinus strobus, Populus tremula, Populus tremuloides

2012-02-05

Changes in soil organic C and N stocks after forest transformation from Norway spruce and Scots pine into Douglas fir, Douglas fir/spruce, or European beech stands at different sites in Southern Germany

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 134-148 Jörg Prietzel, Sven Bachmann At 18 sites in Bavaria (Germany) with substantial difference in elevation, parent material, climate, and stand age, which encompass most variance of site properties to be found in Central Europe, the effects of a replacement of Norway spruce (Picea abiesL. Karst.; 16 sites) or Scots pine (Pinus sylvestrisL.; two sites) by Douglas fir (Pseudotsuga menziesii, spp.menziesii) and European beech (Fagus sylvatica) stands on humus form as well as soil organic carbon (OC) and nitrogen (N) concentrations and stocks were investigated by single-site analysis and meta-analysis. At each study site, which comprised adjacent stands of the investigated tree species with similar age, soil samples were taken down to the solid bedrock or 80 cm depth at six representative locations of each stand. Replacement of spruce or pine by Douglas fir or beech resulted in a considerable, in most cases significant decrease of the forest floor C/N ratio in the order spruce, pine > mixture of spruce or pine with Douglas fir > Douglas fir > beech. Additionally we noticed a significant decrease of forest floor OC (on average: −38% to −45%) and N stocks (on average: −24% to −29%) in the same order. After replacement of spruce or pine by Douglas fir or beech, we observed insignificant changes of mineral soil OC stocks, but significantly increased (on average: +5% to +8%) mineral soil N stocks. For the total soil, including the forest floor and the mineral soil down to 50 cm depth, replacement of spruce with Douglas fir or beech resulted in significantly decreased soil OC stocks (average of all sites: −7% and −11%, respectively). Only two sites with original Scots pine stands located at poorer sites were included in the study: here, the changes of soil C and N stocks as induced by transformation into Douglas fir stands were in the same direction and order of magnitude as for the spruce stands. Replacement of pure spruce by 50%/50%-mixtures of spruce with Douglas fir resulted in statistically insignificant, slight increases of the soil OC stock (average +4%), and significantly increased soil N stocks (average: +7%). The magnitude of replacement effects was dependent on stand age and site properties, such as site N or moisture status. The circumstance that mixtures of Douglas fir with Norway spruce seem to be particularly effective in sequestrating C and N in the soil emphasizes the benefit of mixed stands not only with regard to ecosystem stability, but also with regard to mitigation of atmospheric CO2enrichment, and minimization of N exports into groundwater aquifers. Our study demonstrates the potential of meta-analysis to (i) identify and quantify small, but significant changes of soil variables with considerable spatial variation, and (ii) reveal site factors which affect these changes. Highlights ► Decreased soil OC stocks after replacement of spruce or pine by Douglas fir or beech. ► Increased soil N stocks after replacement of spruce by Douglas fir/spruce mixture. ► Douglas fir/spruce mixtures: particularly effective to sequestrate C and N in soil.
	Keywords: Dendrobaena octaedra, Fagus sylvatica, Lumbricus terrestris, Picea abies, Pinus sylvestris, Pseudotsuga menziesii

2012-02-05

Species abundance in floor vegetation of managed coppice and abandoned forest

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 99-105 H. Itô, T. Hino, D. Sakuma The species abundance in floor vegetation was compared among three developmental stages (early, middle and late) of managed coppices and two types of abandoned forest (broadleaved and pine). The studied coppices, which mainly consisted ofQuercus acutissima, were maintained to produce charcoal, and had been cut periodically about once every decade. The abandoned forests appeared to have been left for at least 30 years. A hierarchical Bayesian model was constructed to estimate the probability distributions of presence for each species and each condition (forest type, management, stand age, and floor cleaning). The results showed that species abundance was higher in the managed coppices than in the abandoned forests and higher before floor cleaning (early and middle stages) than after clearing (late stages) within the coppices. In the coppices, a number of deciduous shrub, grass and herbaceous species were highly likely to be present while evergreen understory and shrub species were likely to be present in the abandoned forests. A simulation using the results of the model was conducted to estimate which management plan would maintain the abundance of floor species in coppices. The simulation showed that keeping a mosaic structure consisting of at least two levels of stand age would maintain a stable and rich abundance of species. Highlights ► Periodical clear cutting would prevent the dominance of evergreen subtree species. ► Periodical partial clear cutting would form shifting mosaics. ► Coppice management can contribute to keep floor species abundance.
	Keywords: Abelia spathulata, Acer crataegifolium, Aphananthe aspera, Aster semiamplexicaulis, Asteraceae, Callicarpa japonica, Callicarpa mollis, Camellia japonica, Carex stenostachys, Celtis sinensis, Clethra barbinervis, Cleyera japonica, Crassocephalum crepidioides, Cymbidium goeringii, Deutzia crenata, Dioscorea japonica, Elaeagnus pungens, Erechtites hieracifolia, Eurya japonica, Fraxinus sieboldiana, Ilex crenata, Ilex macropoda, Ilex pedunculosa, Illicium anisatum, Lindera glauca, Lindera obtusiloba, Lindera umbellata, Lyonia ovalifolia, Miscanthus sinensis, Neolitsea sericea, Oplismenus undulatifolius, Osmanthus heterophyllus, Padus grayana, Paederia scandens, Pertya scandens, Pieris japonica, Pinus densiflora, Platanthera minor, Pourthiaea vilosa, Quercus acutissima, Quercus aliena, Quercus glauca, Quercus serrata, Quercus variabilis, Reynoutria japonica, Rhododendron macrosepalum, Rhododendron reticulatum, Rosa paniculigera, Rubus hirsutus, Smilax china, Styrax japonica, Torreya nucifera, Tylophora aristolochioides, Viburnum dilatatum, Viburnum erosum, Weigela hortensis, Wisteria floribunda, Wisteria japonica

2012-02-05

Residual vegetation importance to net CO2uptake in pine-dominated stands following mountain pine beetle attack in British Columbia, Canada

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 82-91 Rebecca Bowler, Arthur L. Fredeen, Mathew Brown, T. Andrew Black An unprecedented epidemic of mountain pine beetle (MPB:Dendroctonus ponderosae) has resulted in extensive mortality of lodgepole pine (Pinus contortavar.latifolia) across British Columbia. The goal of this study was to quantify the contribution of residual live vegetation to forest-level daytime gross ecosystem photosynthesis (GEP) as measured by EC flux-towers in two lodgepole pine-dominated forests during and/or after MPB-attack. Diurnal foliar net photosynthesis (pn) of residual live herb, shrub, and tree foliage was measured periodically at both sites throughout the growing seasons of 2007, 2008, and 2009. There were no consistent trends inpnacross years at either site for conifer or broadleaf components. The weighted average growing seasonpnof all components, normalized for LAI of the component, were similar to the average growing-season flux-tower estimates of GEP. Non-rectangular hyperbolic relationships between instantaneous values ofpnand photosynthetically active radiation (Q) provided the best-fit models forpn. These relationships were used to scale up to stand level by using half-hourly values ofQ, and measurements of the leaf area of vegetation components to provide modelled estimates of the vertical stand components and their summed ecosystem-scale net photosynthesis (PN ECOSYSTEM). PN ECOSYSTEMwas similar to GEP at MPB-06 for both half-hourly and daily averages. At MPB-03, daily average estimates of PN ECOSYSTEMagreed very well with GEP estimates, but half-hourly averages were consistently underestimated in the morning compared to GEP in all 3 years. Understory non-tree species (termed broadleaf vegetation component) were responsible for the majority (65–68%) of PNECOSYSTEMat MPB-03, and about one-third (33–35%) at MPB-06. Thus, residual vegetation, and particularly broadleaf species, is very important to growing-season CO2uptake in MPB-attacked pine stands in central British Columbia and cannot be neglected in larger scale modelling of forest carbon dynamics in these locations. Management of forests in this region should take into account the importance of CO2uptake by live residual vegetation in helping to mitigate forest management impacts on rising atmospheric CO2concentrations. Highlights ► Mountain pine beetle-attacked pine forests of central British Columbia. ► Growing-season foliar gas-exchange was successfully up-scaled to forest level. ► Live trees and understory vegetation were responsible for CO2-uptake.
	Keywords: Abies lasiocarpa, Alnus incana, Arceuthobium americanum, Arctostaphylos uva-ursi, Dendroctonus ponderosae, Endocronartium harknessii, Lycopodium complanatum, Picea engelmannii, Picea glauca, Pinus contorta, Pinus elliottii, Pinus palustris, Pinus ponderosa, Pinus sylvestris, Populus tremuloides, Pseudotsuga menziesii, Quercus douglasii

2012-02-05

Do thinning and/or burning treatments in western USA ponderosa or Jeffrey pine-dominated forests help restore natural fire behavior?

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 68-81 Peter Z. Fulé, Joseph E. Crouse, John Paul Roccaforte, Elizabeth L. Kalies We carried out a systematic review and meta-analysis of the effects of forest thinning and burning treatments on restoring fire behavior attributes in western USA pine forests. Ponderosa pine (Pinus ponderosa) and Jeffrey pine (Pinus jeffreyi), with co-occurring species, are adapted to a disturbance regime of frequent surface fires, but extended fire exclusion and other factors have led to historically uncharacteristically dense stands and high fuel loadings, supporting high-severity fires. Treatments to begin to reverse these changes and reduce fuel hazards have been tested experimentally and observations of wildfire behavior in treated stands have also been reported. Using a systematic review methodology, we found 54 studies with quantitative data suitable for meta-analysis. Combined treatments (thinning + burning) tended to have the greatest effect on reducing surface fuels and stand density, and raising modeled crowning and torching indices, as compared to burning or thinning alone. However, changes in canopy base height and canopy bulk density were not consistently related to treatment intensity, as measured by basal area reduction. There are a number of qualifications to the findings. First, because it is not feasible to subject treated areas to severe fire experimentally, inferences about potential fire behavior rely on imperfect modeling techniques. Second, research has not been carried uniformly over the ranges of the pine forests, although we found no significant differences in treatment effects between regions or forest types. Overall, however, meta-analysis of the literature to date strongly indicates that thinning and/or burning treatments do have effects consistent with the restoration of low-severity fire behavior. Highlights ► Systematic review and meta-analysis of forest thinning and burning treatments. ►Pinus ponderosaandPinus jeffreyidense stands and high fuels, severe fires. ► Fifty four studies with quantitative data on treatments. ► Combined thinning + burning had the greatest effect. ► There are a number of qualifications to the findings.
	Keywords: Abella, Neotamias speciosus, Pinus coulteri, Pinus jeffreyi, Pinus lambertiana, Pinus ponderosa, Populus tremuloides

2012-02-05

Nest-site selection by old boreal forest cavity excavators as a basis for structural retention guidelines in spatially-aggregated harvests

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 37-51 Hilary A. Cooke, Susan J. Hannon Cavity excavators (woodpeckers, chickadees, nuthatches) are vulnerable to loss of old forest associated with traditional harvest practices. In the boreal plains of Canada, old forest excavators are retained in the short term in small (<100 ha) and large (1000s ha) harvests with residual trees and patches. Information on habitat selection can be used to guide “what, where, and how much” structure to retain and ensure excavators, and the secondary species that use their cavities, are conserved in harvests in the short term. We examined multi-scale nest-site use and selection by excavators in intact old upland forest and spatially-aggregated harvests with structural retention and developed guidelines for the types and spatial arrangement of trees, patches, and stands retained during forest planning (i.e. planned residuals) and harvesting (i.e. operator residuals). In both intact and harvest landscapes, live large (>35 cm) and tall (>25 m) trembling aspen (Populus tremuloides) with multiple (∼20) conks of a heartrot fungus (Phellinus tremulae) were the preferred cavity trees for yellow-bellied sapsucker (Sphyrapicus varius), hairy woodpecker (Picoides villosus), and pileated woodpecker (Dryocopus pileatus). Short (∼10 m), broken-top aspen snags of medium (>20 cm) and large (>35 cm) diameter were preferred by black-capped chickadees (Poecile atricapillus) and northern flickers (Colaptes auratus), respectively. In the harvests, sapsuckers, hairy woodpeckers, and flickers selected cavity trees in clumps with other medium- and large-diameter aspen with conks. Black-capped chickadees selected trees with no live large conifers within ∼10 m. Sapsuckers selected old aspen and mixedwood stands in intact landscapes. In harvest landscapes, sapsuckers selected trees in or near planned patches greater than 5 ha and composed of mature and old aspen and mixedwood stands. Sapsuckers tended to nest in areas with ∼50% residual forest cover whereas flickers selected open areas of cutblocks away from planned patches. We recommend harvest operators retain several live, large (>35 cm dbh) aspen with numerous (∼20) fungal conks in clumps that are adjacent to or near (<60 m) large (>5 ha) patches. Planned patches should have one to two thirds of their area derived from mature and old aspen and mixedwood stands and should be at least 5 ha, with most greater than 15 ha. These prescriptions will facilitate retention of the cavity-using assemblage of old upland forest in aggregated harvests in the short term. However, regional strategies for old forest conservation may be necessary to conserve cavity users in managed forest landscapes over the long term. Highlights ► Large-diameter, decaying live aspen with conks were preferred woodpecker nest trees. ► Yellow-bellied sapsuckers nested in large patches of old forest in harvests. ► Retention recommendations include large aspen and old aspen forest patches >15 ha.
	Keywords: Colaptes auratus, Dryocopus pileatus, Falco sparverius, Fomes igniarius, Glaucomys sabrinus, Phellinus tremulae, Picea glauca, Picea mariana, Picoides arcticus, Picoides dorsalis, Picoides pubescens, Picoides tridactylus, Picoides villosus, Pinus banksiana, Poecile atricapillus, Poecile hudsonica, Populus balsamifera, Populus tremula, Populus tremuloides, Pteromys volans, Rangifer tarandus caribou, Sitta canadensis, Sphyrapicus nuchalis, Sphyrapicus varius, Tachycineta bicolor, Tamiasciurus hudsonicus

2012-02-05

Effects of resin tapping and tree size on the purity, germination and storage behavior ofBoswellia papyrifera(Del.) Hochst. seeds from Metema District, northwestern Ethiopia

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 31-36 Abeje Eshete, Demel Teketay, Mulugeta Lemenih, Frans Bongers Boswellia papyrifera(Del.) Hochst. is one of the tree species in dry woodlands of Ethiopia that provides several goods and services. Despite its wide economic and ecological importance, its area coverage is dwindling from time to time, and its natural regeneration is hampered. Hence, long-term prospect for a sustained supply of the goods and services from the species is becoming questionable. The objectives of this study were to investigate: (i) the effect of resin tapping and tree size (DBH) on seed susceptibility to insect attack and the production of viable seeds; and (ii) seed longevity and germination ecology of the seeds ofB. papyrifera. We collected seeds from tapped and untappedB. papyriferastands at Lemlem Terara in Metema District, northwestern Ethiopia. The result showed that both tapped and untapped stands produced comparable insect attacked seeds (tapped stands = 16.6%; untapped stands = 15.8%). Untapped trees yielded significantly (P < 0.0001) higher viable seeds (59%) than continuously tapped trees (49.3%), and trees with medium size (20 cm DBH) provided more viable seeds than bigger (30 cm DBH) and younger trees (10 cm DBH). Longevity ofB. papyriferaseeds indicated significant difference in viability under three different temperature regimes (5, 15 and 21 °C), three storage periods (6, 9 and 12 months) and two tapping regimes (tapped and untapped populations). Fire that produced temperatures above 100 °C was lethal to the seeds as it caused complete loss of germinability regardless of exposure time. However, heat with temperatures less than 100 °C did not cause loss of germinability even after an hour of exposure. We also found that light conditions had no significant impact on the germination percentage. In general, viability of the seeds was affected by tapping and tree size but not by storage conditions and period, modest temperature and light conditions. Highlights ► Current tapping contributes to loss of seed viability, increased susceptibility to insect attack and lower seed longevity. ► Trees with larger diameters were more susceptible to effect of tapping. ► Seeds can be stored for at least one year with no loss in germination capacity. ► Fire generating more than 100 °C can have lethal effects on seeds.
	Keywords: Acacia senegal, Boswellia papyrifera, Sterculia urens

2012-02-05

Tree regeneration in black ash (Fraxinus nigra) stands exhibiting crown dieback in Minnesota

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 26-30 Brian J. Palik, Michael E. Ostry, Robert C. Venette, Ebrahim Abdela Crown dieback and mortality of black ash (Fraxinus nigra) has been noted across the range of the species in North America for several decades. Causes of dieback and mortality are not definitive, but may be related to spring drought or excessive moisture. Where black ash is the dominant tree species in the forest, continued dieback and mortality may result in open, non-forest systems in the future. There is only limited research that has examined tree regeneration in black ash-dominated forests and none in stands experiencing dieback and mortality. Such studies are needed to better understand likely successional dynamics of impacted stands. Our objective was to quantify tree regeneration of black ash and other species in stands with and without crown dieback and mortality, to elucidate potential successional trajectories with decline and loss of black ash. We assessed 54 stands in Minnesota exhibiting a range of black ash crown dieback and mortality. Dieback and mortality in the black ash sapling layer were positively correlated with the same condition in the overstory, suggesting that saplings may not replace dead overstory trees. The next most abundant sapling-sized species was speckled alder, a non-canopy species, indicating that replacement tree species for black ash are not currently abundant. Black ash seedling densities were generally low, suggesting that a pool of advance regeneration is not available to replace black ash. Other canopy potential species were limited in the seedling layer, while abundance of shrubs was generally high. Our results suggest a high potential for loss of a tree layer in these stands and conversion to open, shrub dominated systems. Highlights ► We studied regeneration of black ash in stands with dieback and mortality. ► There was no emerald ash borer infestation in these stands. ► Dieback of saplings were positively correlated with the same in the overstory. ► Healthy ash saplings are not replacing dead trees and seedling numbers are low. ► Conversion to shrubs is likely, which also may occur with emerald ash borer invasion.
	Keywords: Acer spicatum, Agrilus planipennis, Alnus incana, Betula alleghaniensis, Corylus cornuta, Fraxinus nigra, Prunus serotina

2012-02-05

Forest restoration in a surface fire-dependent ecosystem: An example from a mixed conifer forest, southwestern Colorado, USA

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 269, 1 April 2012, Pages 10-18 Julie E. Korb, Peter Z. Fulé, Michael T. Stoddard Over a century of fire suppression in warm/dry mixed conifer forests of southwestern Colorado, USA has resulted in changes that have disrupted feedback interactions between vegetation composition and structure and the accompanying natural fire regime. The ecosystem is now more susceptible to high intensity crown fires that were previously rare or absent in this forest type, which can lead to novel ecosystems. We established four replicated blocks of (1) thin/burn, (2) burn alone and (3) control treatments, each approximately 16-ha, to quantify the effects of restoration treatments on forest structure. We sampled in 2003 (pre-treatment) and in 2009 (post-treatment). There were no significant changes in the control and burn alone treatments for tree density, basal area, canopy cover and tree regeneration between pre- and post-treatment. Significant changes in the thin/burn treatments included: tree density declining 82% (582.7 trees ha), principally white fir and Douglas-fir; tree canopy cover decreasing 36%; basal area declining 49% (12.5 m ha), primarily from white fir; aspen tree regeneration increasing by 362% (582.7 trees ha), and white fir regeneration decreasing by 94% (249.1 trees ha). Overstory trees that died tended to be younger, shorter, and/or smaller in diameter. Multivariate analysis of tree basal area by species in the thin/burn treatments in 2009 showed a strong directional shift away from 2003 pre-treatment data towards the reconstructed historical (1870) forest structure. Burn alone treatments were distinct from controls after treatment in 2009 but did not resemble reconstructed 1870 forest structure. Thin/burn treatments moved warm/dry mixed conifer forests in southwestern Colorado rapidly along the trajectory toward historical reference conditions by altering forest composition and structure. Burn alone treatments were less effective but also less costly. Forest restoration will make forests more resilient to stand-replacing fires and subsequent transitions to novel ecosystems under a warmer, drier climate. Highlights ► Fire suppression in mixed conifer has resulted in biotic changes that have disrupted the natural fire regime. ► We established replicated blocks of thin/burn, burn and control treatments to quantify restoration. ► Burn treatments were distinct from controls but did not resemble reconstructed 1870 forest structure. ► Thin/burn treatments moved forests rapidly along the trajectory toward historical reference conditions. ► These changes will make forests more resilient to stand-replacing fires under a warmer, drier climate.
	Keywords: Abella, Abies concolor, Amelanchier alnifolia, Juniperus scopulorum, Picea engelmannii, Picea pungens, Pinus edulis, Pinus ponderosa, Populus tremuloides, Pseudotsuga menziesii, Quercus gambelii, Symphoricarpus rotundifolius

2012-02-05

A flavonoid survey ofFraxinus(Oleaceae) in eastern Asia, and the overlooked speciesFraxinushopeiensisT. Tang in northern China

ScienceDirect Search: species
	Publication year: 2012 Source: Biochemical Systematics and Ecology, Volume 41, April 2012, Pages 150-156 Heung Su Lee, Si Hyung Park, Eva Wallander, Chin-Sung Chang From a survey of 14 flavonoids of 19 Asian taxa of Fraxinus, flavonols were present in most taxa of sects.Ornus,Fraxinus, andSciadanthus, while flavones were only detected inFraxinuslanuginosain Japan andFraxinushopeiensisin China of sect.OrnusandFraxinuschiisanensisin Korea (asincertae sedia sensuWallander). The present data failed to clearly distinguish many taxa within the genus because of the extreme monotony of flavonoid content. However, the dichotomy on a smaller scale was observed inFraxinus, where this chemical approach was useful in the determination of natural groupings of the overlooked taxonF. hopeiensisin China,F. lanuginosain Japan, andF. chiisanensisin Korea. The gain of O-flavone appears to be a significant evolutionary step; however, the sporadic occurrence of O-flavone in some species is the result of chemical advancement. The present study demonstrated that flavonoid chemistry may indeed be as variable as the morphological features, with no significant flavonoid differences observed at the species level. However,F. hopeiensis, found in the mountain regions of Hebei in northern China, has petals likeFraxinussieboldianaandF. lanuginosaand is clearly different from other related taxa, includingFraxinusrhynchophyllaandFraxinuschinensis. This study shows thatF. hopeiensisis morphologically, chemically, and geographically distinct and should be treated as a distinct species. Highlights ► A survey of 14 flavonoids of 19 Asian taxa showed two chemical groups. ► This chemical approach was useful in the determination of natural groupings of the overlooked Chinese taxon. ►Fraxinus hopeiensisof Hebei has petals and is clearly different fromFraxinusrhynchophyllaandFraxinuschinensis. ►F. hopeiensisshould be treated as a distinct species.
	Keywords: Compositae, Fraxinus americana, Fraxinus augustifolia, Fraxinus baroniana, Fraxinus bungeana, Fraxinus caroliniana, Fraxinus chiisanensis, Fraxinus chinensis, Fraxinus floribunda, Fraxinus griffithi, Fraxinus griffithii, Fraxinus hopeiensis, Fraxinus hupehensis, Fraxinus insularis, Fraxinus japonica, Fraxinus lanuginosa, Fraxinus longicuspis, Fraxinus malacophylla, Fraxinus mandschurica, Fraxinus mandshurica, Fraxinus papillosa, Fraxinus paxiana, Fraxinus pennsylvanica, Fraxinus platypoda, Fraxinus profunda, Fraxinus rhynchophylla, Fraxinus sieboldiana, Fraxinus sogdiana, Fraxinus spaethiana, Fraxinus stylosa, Fraxinus szaboana, Fraxinus velutina, Fraxinus xanthoxyloides, Loganiaceae, Myrsinaceae, Oleaceae

2012-02-05

Partial cutting can enhance epiphyte conservation in temperate oak-rich forests

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 270, 15 April 2012, Pages 35-44 Björn Nordén, Heidi Paltto, Christina Claesson, Frank Götmark The strongly increasing demand for biofuel from forests poses new challenges for biodiversity conservation. Methods that may combine biofuel production with conservation goals need to be tested for various forest types. One possible conservation-oriented management alternative is partial cutting of closed canopy oak-rich forests (may also be called conservation thinning). Such cutting may counteract succession and restore a semi-open canopy structure, which may favor epiphytes. We evaluated this possibility by surveying the epiphyte community of lichens and bryophytes on large oaks in 24 oak-rich temperate forests in southern Sweden. Treatment plots, and reference plots with no cutting, were surveyed before, and 6 years after cutting. In the treatment plots, about 25% of the basal area was harvested, and mainly small and intermediate sized successional trees were removed. We detected significant positive effects of partial cutting on species density for both lichens and bryophytes. The additional variation in light influx at tree level (after the cutting) could not explain the change in species density. The increase in density of lichen species was highest on oaks with small trunk diameter and on oaks with deep bark crevices. The pooled frequency of species of conservation concern increased after the cutting, but the change in species composition was weak; colonization events occurred over mean minimum distances of 63.5 m to the nearest potential source tree (n = 22 events and 9 species). Overall, we found significantly higher colonization rates, and significantly lower extinction rates per tree for lichens in the treatment plots. We conclude that partial cutting influenced epiphytes of large oaks positively, as was the case for several other organism groups at the same study sites (previous studies). A mild form of biofuel harvesting may represent sustainable resource-use in these forests, compatible with conservation. However, part of the forest should be kept untouched for species vulnerable to changes in microclimatic conditions, and for evaluation of long-term effects. Highlights ► We tested the effects of conservation-oriented partial cutting on oak forest epiphytes. ► Species density increased for both lichens and bryophytes, also species of conservation concern. ► Our BACI design also revealed higher colonization and lower extinction for lichens in managed plots. ► Lichens of conservation concern dispersed more than 60 m over 8 years. ► A mild form of biofuel harvesting may represent sustainable resource-use in these forests.
	Keywords: Arthonia vinosa, Ascomycetes, Biatora efflorescens, Buellia violaceofusca, Caliciaceae, Calicium adspersum, Calicium viride, Caloplaca lucifuga, Chaenotheca chlorella, Chaenotheca hispidula, Chaenotheca phaeocephala, Chrysothrix candelaris, Cladonia coniocraea, Cliostomum corrugatum, Cliostomum hispidula, Cliostomum lucifuga, Cyphelium inquinans, Evernia prunastri, Hypnum cupressiforme, Hypogymnia physodes, Lepraria incana, Lobaria pulmonaria, Lobaria quercizans, Micarea prasina, Ochrolechia androgyna, Opegrapha vermicellifera, Parmelia sulcata, Pertusaria amara, Pertusaria coccodes, Phlyctis argena, Populus tremula, Pseudocyphellaria crocata, Quercus petraea, Quercus robur, Quercus virginiana, Ramalina farinacea, Schismatomma decolorans, Schismatomma pericleum, Trentepohlia umbrina, Usnea longissima

2012-02-05

California black oak responses to fire severity and native conifer encroachment in the Klamath Mountains

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 270, 15 April 2012, Pages 25-34 Matthew I. Cocking, J. Morgan Varner, Rosemary L. Sherriff Fire exclusion in forests across the western United States has resulted in widespread vegetation change, often with notable increases in density and cover of fire-sensitive species. In California oak woodlands, encroachment by the more shade-tolerant native Douglas-fir (Pseudotsuga menziesii) is particularly common, and results in the piercing and eventual overtopping of crowns of shade-intolerant trees. We investigated canopy competition, paired tree ages, and post-fire effects in a recently burned, encroached California black oak (Quercus kelloggii) woodland. Pre-fire woodland overstory was heavily dominated by Douglas-fir, which commonly pierced and overtopped California black oak crowns. Trees that pierced overstory oak crowns were younger (mean difference = 43.6 years,p < 0.001) than their paired oaks. Fire effects were variable, leaving some areas unchanged and others with complete above-ground stem mortality. Although above-ground stem-kill was often high for California black oak, the majority (82%) re-sprouted from the root collar. Logistic modeling revealed a significant relationship between California black oak mortality and neighboring Douglas-fir height and plot heat load index. The probability of California black oak mortality increased as neighboring Douglas-fir height increased and decreased with increasing heat load index. Probability of mortality for Douglas-fir decreased with increasing tree size, while the probability of California black oak top-kill was much higher than that for 20–30 cm dbh Douglas-fir across a continuous measure of char height. Results indicate that competitive pressure from encroaching trees may compromise California black oak’s ability to survive fire while resilience of encroaching Douglas-fir improves with greater size. Caution should be taken when planning and implementing restoration activities in California black oak woodlands to minimize loss of compromised, remnant oaks while still achieving adequate removal of encroaching conifers. Highlights ► We model effects of encroaching trees on California black oak post-fire mortality. ► The dominant encroaching species surrounding focal oaks was Douglas-fir. ► Proximate Douglas-fir height was significantly related to post-fire oak mortality. ► Heat load index was significantly related to post-fire oak mortality. ► Restoration may not be achieved with conventional approaches.
	Keywords: Abies concolor, Acer macrophyllum, Arbutus menziesii, Calocedrus decurrens, Cornus nuttallii, Dacrycarpus dacrydioides, Pinus echinata, Pinus jeffreyi, Pinus lambertiana, Pinus ponderosa, Pseudotsuga menziesii, Quercus agrifolia, Quercus alba, Quercus chrysolepis, Quercus douglasii, Quercus garryana, Quercus kelloggii, Quercus velutina, Quercus virginiana

2012-02-05

Can mixed species stands enhance arthropod diversity in plantation forests?

ScienceDirect Search: species
	Publication year: 2012 Source: Forest Ecology and Management, Volume 270, 15 April 2012, Pages 11-18 Anne Oxbrough, Veronica French, Sandra Irwin, Thomas C. Kelly, Patrick Smiddy, ... Tree species composition is a key driver of forest biodiversity, influencing structural components of the environment from soil and litter to vegetation layers and the canopy, and ecosystem processes, such as nutrient cycling. Single species stands, particularly intensively managed monoculture plantations, are typically more homogenous in habitat structure and the biotic communities supported, than mixed stands. Thus, international forest policy increasingly promotes the establishment of mixed stands as an alternative to enhance biodiversity in plantations. Forests represent around 10% of the land area of Ireland, with most being monocultures of non-native conifers. By contrast, natural forest cover, primarily comprised of deciduous species, is just 1%. In recent years there has been an increase in mixed plantations; however, optimum tree species combinations, which aim to promote biodiversity under sustainable forest management, have yet to be established. Arthropods (ground-dwelling spiders and Carabid beetles, and night-flying macrolepidoptera) were examined in twenty mixed and monoculture plantations in Ireland (Norway spruce–oak mix, Norway spruce–Scots pine mix, Norway spruce monoculture). Both oak and Scots pine were secondary mix components, comprising between 15% and 40% of stems. Spiders and Carabid beetles were sampled using pitfall traps during summer 2008 and moths using light traps during summer and autumn 2008 and spring 2009.There was no evidence for an influence of oak or Scots pine on the arthropod fauna when they were a secondary component in a mix. Overall, arthropod communities were similar in species richness, assemblage structure and habitat specialists among the forest types. Furthermore, the mixed stands exhibited similar environmental conditions to monocultures in terms of stand structure, vegetation and litter cover. This suggests that there is limited biodiversity value from an additional canopy species comprising 15–40% of the mix, at least for the taxa and tree species studied here. This has implications for forest policy, where recommendations are often based on the proportion of each mix component, at least in terms of the potential biodiversity value of additional canopy species. Further research is required to determine the proportion at which oak or Scots pine begin to influence the arthropod fauna. Highlights ► Spider, beetle and moth diversity was compared in mixed and monoculture plantations. ► Mixed stands comprised two species with the second varying in cover from 15% to 40%. ► Mixed and monocultures were similar in arthropod assemblages and forest structure. ► Canopy species comprising <40% cover do not influence the arthropod community.
	Keywords: Abax parallelepipedus, Arachnida, Araneae, Carabidae, Coleoptera, Collembola, Diarsia latifrons, Diarsia mendica, Diplocephalus latifrons, Fagus sylvatica, Fraxinus excelsior, Gymnoscelis rufifasciata, Hepialus fusconebulosa, Lepidoptera, Lepthyphantes flavipes, Lepthyphantes tenebricola, Lepthyphantes zimmermanni, Noctuidae, Picea abies, Pinus sylvestris, Pterostichus madidus, Ptilodon capucina, Quercus robur, Thera britannica, Thera fermata, Thera firmata, Thyatiridae

2012-02-05

Effects of herbicides on Behr's metalmark butterfly, a surrogate species for the endangered butterfly, Lange's metalmark

2012-02-05

Litterfall mercury deposition in Atlantic forest ecosystem from SE – Brazil

2012-02-05

Clubroot management of highly infested soils

2012-02-05

Geospatial analysis of management areas implemented for protection of the North Atlantic right whale along the northern Atlantic coast of the United States

2012-02-05

Beach and demersal spawning in capelin (Mallotus villosus) on the northeast Newfoundland coast: egg developmental rates and mortality

2012-02-05

Incorporating behavior-based indices of connectivity into spatially explicit population models

2012-02-05

Multiple factors limit use of local sites by Elliot’s short-tailed shrews (Blarina hylophaga) in tallgrass prairie

2012-02-05

Genetically modified growth affects allometry of eye and brain in salmonids

2012-02-05

Ionic regulation and shell mineralization in the bivalve Anodonta cygnea (swan mussel) following heavy-metal exposure

2012-02-05

Prolonged life span among endemic Gasterosteus populations

2012-02-05

Incubation patterns of a shorebird with rapid multiple clutches, the Mountain Plover (Charadrius montanus)

2012-02-05

Proportional underwater call type usage by Weddell seals (Leptonychotes weddellii) in breeding and nonbreeding situations

2012-02-05

Effects of supplementation with preferred foods on the reproductive axis of American Goldfinches (Spinus tristis)

2012-02-05

The Monitor's 2012 Pro Football Hall of Fame picks

Top 10 Species

1)	Escherichia coli
2)	Arabidopsis thaliana
3)	Drosophila melanogaster
4)	Saccharomyces cerevisiae
5)	Homo sapiens
6)	Caenorhabditis elegans
7)	Zea mays
8)	Pseudomonas aeruginosa
9)	Glycine max
10)	Oryza sativa

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights

Highlights