scholarly journals Tree diversity drives associational resistance to herbivory at both forest edge and interior

2019 ◽  
Vol 9 (16) ◽  
pp. 9040-9051 ◽  
Author(s):  
Virginie Guyot ◽  
Hervé Jactel ◽  
Baptiste Imbaud ◽  
Laurent Burnel ◽  
Bastien Castagneyrol ◽  
...  
Keyword(s):  
Forest Edge ◽  
Tree Diversity ◽  
Associational Resistance ◽  
Resistance To Herbivory

scholarly journals How forest edge–center transitions in the herb layer interact with beech dominance versus tree diversity

2016 ◽  
Vol 9 (5) ◽  
pp. 498-507 ◽  
Author(s):  
Claudia Normann ◽  
Teja Tscharntke ◽  
Christoph Scherber
Keyword(s):  
Forest Edge ◽  
Tree Diversity ◽  
Herb Layer

scholarly journals Edge effects on biomass, growth, and tree diversity of a degraded peatland in West Kalimantan, Indonesia

2018 ◽  
Vol 19 (1) ◽  
pp. 272-278
Author(s):  
DWI ASTIANI ◽  
LISA M. CURRAN ◽  
MUJIMAN MUJIMAN ◽  
DESSY RATNASARI ◽  
RUSPITA SALIM ◽  
...  
Keyword(s):  
Species Composition ◽  
Edge Effects ◽  
Unit Area ◽  
Forest Biomass ◽  
Forest Edge ◽  
Tree Diversity ◽  
Biomass Growth ◽  
West Kalimantan ◽  
Abiotic Conditions ◽  
Edge Site

Astiani D, Curran LM, Mujiman, Ratnasari D, Salim R, Lisnawaty N. 2018. Edge effects on biomass, growth, and tree diversity of a degraded peatland in West Kalimantan, Indonesia. Biodiversitas 19: 272-278. Tropical forested peatlands in Indonesia are threatened by logging and clearing which reduce their ecosystem functions and degrade the environment. Land use change activities disturbed intact forests, resulted in landscape fragmentation. Scattered forest matrices resulted in forest edge areas, which will considerably affect the forest biotic and abiotic conditions, as well as forest tree dynamics within the edge sites. The goal of this study was to investigate the effect of forest edge on perimeter of the forest fragment on the forest biomass stock, growth, tree basal area as well as species composition, richness and abundance in a degraded peatland forest in West Kalimantan. A twelve-ha forest was divided into 35 plots in the interior forest and 13 at the forest edge; each plot was 50 m by 50 m in size based on their abiotic conditions such as light and temperatures. Leaf Area Index (LAI) was measured in each plot of both forest edge and interior sites using Licor-2100. The results indicated that even though the biomass levels maintained relatively moderate to high levels on both sites, forest edge significantly lowered forest biomass by 32%, reduced 23-25% of tree-biomass growth per unit area for both tree diameter of 10-20 cm and >20 cm. There was a shift of tree species composition, 76 species were found on both sites, 24 species were not found in edge site, but present in the interior site and 10 species were found only in edge site. Peatland forest matrix created forest edges that are lowering peatland forest roles in sequestering carbon per unit area and reducing species diversity. Peatland forest restoration should be conducted to reduce forest matrices and to lower the edge effects.

Forest diversity as a factor influencing Engelmann spruce resistance to beetle outbreaks

2014 ◽  
Vol 44 (11) ◽  
pp. 1369-1375 ◽  
Author(s):  
Lafe G. Conner ◽  
Michael C. Bunnell ◽  
Richard A. Gill
Keyword(s):  
Populus Tremuloides ◽  
Tree Species ◽  
Forest Type ◽  
Stand Density ◽  
Douglas Fir ◽  
Tree Diversity ◽  
Phylogenetic Distance ◽  
Associational Resistance ◽  
Engelmann Spruce ◽  
White Fir

Tree mortality because of beetle outbreaks has become substantial and widespread in conifer forests in western North America. A number of environmental and physiological factors influence patterns of mortality. Tree diversity may reduce the severity and extent of insect damage to host trees by providing associational resistance, but the existence and importance of associational resistance varies by forest type and by tree and insect species. We assessed whether plot-level tree diversity contributed to survival of Engelmann spruce (Picea engelmannii Parry ex Engelm.) following a spruce beetle (Dendroctonus rufipennis Kirby) epidemic. Our study plots comprised 2 to 5 tree species including Engelmann spruce, subalpine fir (Abies lasiocarpa (Hook) Nutt.), Douglas-fir (Pseudostuga menziesii (Mirb.) Franco), quaking aspen (Populus tremuloides Michx.), and white fir (Abies concolor (Gordon & Glend.) Hildebr.). We used a model-selection analysis to compare the importance of tree diversity with other known factors that influence spruce survival. We found lower rates of spruce survival in stands where spruce was the dominant tree species (by percent of stand density index) and higher survival in stands where nonspruce conifers (Douglas-fir, subalpine, and white fir) were dominant. We also found that tree diversity (Shannon index) did not show a positive correlation to spruce survival and that there was no additional benefit derived from the presence of aspen, which has higher phylogenetic distance from Engelmann spruce than the other trees in this study. The relationship between diversity and survival is complicated by factors that naturally co-vary with diversity, such as elevation, aspect, and stand density of spruce. Our results best support an explanation that if associational resistance does increase spruce survival during a beetle epidemic, it is due to host or resource dilution, which may be an indirect effect of higher stand diversity.

scholarly journals Tree diversity reduces pest damage in mature forests across Europe

2016 ◽  
Vol 12 (4) ◽  
pp. 20151037 ◽  
Author(s):  
Virginie Guyot ◽  
Bastien Castagneyrol ◽  
Aude Vialatte ◽  
Marc Deconchat ◽  
Hervé Jactel
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Tree Diversity ◽  
Insect Herbivores ◽  
Forest Pest ◽  
Associational Resistance ◽  
Pest Damage ◽  
Tree Defoliation ◽  
Tree Species Richness ◽  
Total Tree

Forest pest damage is expected to increase with global change. Tree diversity could mitigate this impact, but unambiguous demonstration of the diversity–resistance relationship is lacking in semi-natural mature forests. We used a network of 208 forest plots sampled along two orthogonal gradients of increasing tree species richness and latitudes to assess total tree defoliation in Europe. We found a positive relationship between tree species richness and resistance to insect herbivores: overall damage to broadleaved species significantly decreased with the number of tree species in mature forests. This pattern of associational resistance was frequently observed across tree species and countries, irrespective of their climate. These findings confirm the greater potential of mixed forests to face future biotic disturbances in a changing world.

Données LiDAR aériennes: pertinence de l'interprétation visuelle pour la foresterie

2017 ◽  
Vol 168 (3) ◽  
pp. 127-133
Author(s):  
Matthew Parkan
Keyword(s):  
Cross Sections ◽  
Forest Edge ◽  
Airborne Lidar ◽  
Visual Interpretation ◽  
Individual Tree ◽  
Small Areas ◽  
Interactive 3D ◽  
The Individual ◽  
Airborne Lidar Data ◽  
Stem Position

Airborne LiDAR data: relevance of visual interpretation for forestry Airborne LiDAR surveys are particularly well adapted to map, study and manage large forest extents. Products derived from this technology are increasingly used by managers to establish a general diagnosis of the condition of forests. Less common is the use of these products to conduct detailed analyses on small areas; for example creating detailed reference maps like inventories or timber marking to support field operations. In this context, the use of direct visual interpretation is interesting, because it is much easier to implement than automatic algorithms and allows a quick and reliable identification of zonal (e.g. forest edge, deciduous/persistent ratio), structural (stratification) and point (e.g. tree/stem position and height) features. This article examines three important points which determine the relevance of visual interpretation: acquisition parameters, interactive representation and identification of forest characteristics. It is shown that the use of thematic color maps within interactive 3D point cloud and/or cross-sections makes it possible to establish (for all strata) detailed and accurate maps of a parcel at the individual tree scale.

scholarly journals Recombination and Gene Conversion in a 170-kb Genomic Region of Arabidopsis thaliana

Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1269-1278 ◽  
Author(s):  
Bernhard Haubold ◽  
Jürgen Kroymann ◽  
Andreas Ratzka ◽  
Thomas Mitchell-Olds ◽  
Thomas Wiehe
Keyword(s):  
Genetic Diversity ◽  
Arabidopsis Thaliana ◽  
Linkage Disequilibrium ◽  
Gene Conversion ◽  
Genomic Sequence ◽  
Genomic Region ◽  
Resistance To Herbivory ◽  
Linkage Disequilibria ◽  
Coalescent Simulations ◽  
The Mean

Abstract Arabidopsis thaliana is a highly selfing plant that nevertheless appears to undergo substantial recombination. To reconcile its selfing habit with the observations of recombination, we have sampled the genetic diversity of A. thaliana at 14 loci of ~500 bp each, spread across 170 kb of genomic sequence centered on a QTL for resistance to herbivory. A total of 170 of the 6321 nucleotides surveyed were polymorphic, with 169 being biallelic. The mean silent genetic diversity (πs) varied between 0.001 and 0.03. Pairwise linkage disequilibria between the polymorphisms were negatively correlated with distance, although this effect vanished when only pairs of polymorphisms with four haplotypes were included in the analysis. The absence of a consistent negative correlation between distance and linkage disequilibrium indicated that gene conversion might have played an important role in distributing genetic diversity throughout the region. We tested this by coalescent simulations and estimate that up to 90% of recombination is due to gene conversion.

Fire enhances forest degradation within forest edge zones in Africa

2021 ◽  
Author(s):  
Zhe Zhao ◽  
Wei Li ◽  
Philippe Ciais ◽  
Maurizio Santoro ◽  
Oliver Cartus ◽  
...  
Keyword(s):  
Forest Degradation ◽  
Forest Edge
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