scholarly journals Plot diversity differentially affects the chemical composition of leaves, roots and root exudates in four subtropical tree species

2020 ◽  
Author(s):  
Alexander Weinhold ◽  
Stefanie Döll ◽  
Min Liu ◽  
Andreas Schedl ◽  
Xingliang Xu ◽  
...  
Keyword(s):  
Root Exudates ◽  
Tree Species ◽  
Plant Competition ◽  
Tree Diversity ◽  
Chemical Diversity ◽  
Individual Plant ◽  
List Type ◽  
Individual Tree ◽  
Main Compound ◽  
Bef China

ABSTRACTPlants produce thousands of compounds, collectively called the metabolome, which mediate interactions with other organisms. The metabolome of an individual plant may change according to the number and nature of these interactions. We tested the hypothesis that tree diversity level affects the metabolome of four subtropical tree species in a biodiversity ecosystem-functioning experiment, BEF-China. We postulated that the chemical diversity of leaves, roots and root exudates increases with tree diversity. We expected the strength of this diversity effect to differ among leaf, root and root exudates samples. Considering their role in plant competition, we expected to find the strongest effects in root exudates.In an ecometabolomics approach, roots, root exudates and leaves of four tree species (Cinnamomum camphora, Cyclobalanopsis glauca, Daphniphyllum oldhamii, Schima superba) were sampled from selected plots in BEF-China. Samples were extracted and analysed using Liquid Chromatography-Time of Flight-Mass Spectrometry. The exudate metabolomes were normalized over their non-purgeable organic carbon level. Multivariate analyses were applied to identify the effect of both neighbouring (local) trees and plot diversity on tree metabolomes. The species and sample specific metabolites were assigned to major compound classes using the ClassyFire tool, whereas m/z features related to diversity effects were annotated manually.Individual tree species showed distinct leaf, root and root exudate metabolomes. The main compound class in leaves were the flavonoids, whereas carboxylic acids, prenol lipids and specific alkaloids were most prominent in root exudates and roots. Overall plot diversity had a stronger effect on metabolome profiles than the diversity of local, directly neighbouring trees. Leaf metabolomes responded more often to tree diversity level than exudates, whereas root metabolomes varied the least. We found not overall correlation between metabolite richness or diversity and tree diversity.Synthesis: Classification of metabolites supported initial ecological interpretation of differences among species and organs. Particularly the metabolomes of leaves and root exudates respond to differences in tree diversity. These responses were neither linear nor uniform and individual metabolites showed different dynamics. More controlled interaction experiments are needed to dissect the causes and consequences of the observed shifts in plant metabolomes.

scholarly journals Neighbourhood-based evidence of tree diversity promotion by beech in an old-growth deciduousconiferous mixed forest (Eastern Carpathians)

2021 ◽  
Vol 64 (1) ◽  
pp. 13-30
Author(s):  
Dan Gafta ◽  
Annik Schnitzler ◽  
Déborah Closset-Kopp ◽  
Vasile Cristea
Keyword(s):  
Tree Species ◽  
Species Coexistence ◽  
Mixed Forest ◽  
Spatial Segregation ◽  
Tree Diversity ◽  
Point Pattern ◽  
Old Growth ◽  
Individual Tree ◽  
Eastern Carpathians ◽  
The Individual

Neighbourhood models are useful tools for understanding the role of positive and negative interactions in maintaining the tree species diversity in mixed forests. Under such a presumption, we aimed at testing several hypotheses concerning the mechanisms of autogenic species coexistence in an old-growth, beech-fir-spruce stand, which is part of the Slătioara forest reserve (Eastern Carpathians). Univariate/bivariate spatial point pattern analyses, the individual tree species-area relationship, the species mingling analysis and generalised linear mixed models of neighbour interference were applied on data concerning the position and allometry of all saplings and trees occurring within a 0.24 ha plot. The monospecific distribution of either beech or spruce saplings did not support the spatial segregation hypothesis. There was no evidence of conspecific negative distance dependence, as no spatial segregation was detected between the saplings and trees of any species. Within 4 m-neighbourhood, the beech saplings appeared as diversity accumulators, which might be indicative of indirect facilitation (e.g., herd protection hypothesis). At tree stage, none of the three species showed either accumulator or repeller patterns in their neighbourhood with respect to sapling species richness. Signals of positive and negative interspecific association were found in tree-sized beech (at scales of 10 to 20 m) and spruce (at scales of 4 to 17 m), respectively. The former, highly interspersed pattern is in accordance with the hypothesis of positive complementary effects, whereas the latter, poorly intermingled pattern is probably linked to the unexpected, positive neighbouring effect of spruce trees on the stem growth of their conspecific saplings. Such self-favouring process might be due to a facilitative below-ground mechanism. Conversely, the beech saplings were suppressed through interference from the neighbouring conspecific trees. The beech appears to be the key promoter of tree species coexistence in the study forest stand, in contrast to the low interspersion of spruce in the overstorey leading to lower local tree diversity.

scholarly journals Body size and tree species composition determine variation in prey consumption in a forest-inhabiting generalist predator

2020 ◽  
Author(s):  
Irene M. van Schrojenstein Lantman ◽  
Eero J. Vesterinen ◽  
Lionel R. Hertzog ◽  
An Martel ◽  
Kris Verheyen ◽  
...  
Keyword(s):  
Body Size ◽  
Species Composition ◽  
Tree Species ◽  
Tree Diversity ◽  
Prey Consumption ◽  
Generalist Predator ◽  
List Type ◽  
Large Prey ◽  
Tree Species Composition ◽  
Predator Size

AbstractDue to physiological, behavioural or ecological mechanisms, generalist predators may show individual variation in prey consumption. This individual specialization can result from both environmental and trait variation, with especially body size strongly connected to diet. Environmental variation can thus affect consumer-predator interactions by the joint action of changes in prey community composition and predator size.We studied whether and how changes in forest environmental conditions, such as variation in tree species identity and forest fragmentation, affect predator-prey interactions. More specifically we anticipate tree diversity or spatial context to impact the predator diet directly via prey availability and prey size, but also indirectly through shifts in predator size. We used the orb-weaving spider Araneaus diadematus inhabiting forest fragments differing in edge distance, tree diversity and tree species as a model species. The species’ diet was quantified by an unprecedented metabarcoding campaign. A total of 983 spiders were subjected to molecular diet analysis, from in total of 53 forest plots.A. diadematus showed to be a generalist predator, with 298 prey items detected in total. At the individual level, we found large spiders to consume less different species, but consistently larger species. Tree species composition affected both prey species richness and size in the spider’s diet, although tree diversity per se had no influence on the consumed prey. Edges had an indirect effect on the spider diet as spiders closer to the forest edge were larger and therefore consumed larger prey.We attribute the structural complexity of the understory related to tree species composition as a driver of prey composition and its size distribution as reflected in the predator’s diet. Although large spiders may specialize on large prey, we found no firm evidence for either ecological opportunism or strong specialization. Finally, we conclude that intraspecific size variation and tree species composition define the consumed prey of this generalist predator, and that the many feeding interactions of this spider underlie the species’ success in a large diversity of habitats.

scholarly journals Classification of Tree Species as Well as Standing Dead Trees Using Triple Wavelength ALS in a Temperate Forest

2019 ◽  
Vol 11 (22) ◽  
pp. 2614 ◽  
Author(s):  
Nina Amiri ◽  
Peter Krzystek ◽  
Marco Heurich ◽  
Andrew Skidmore
Keyword(s):  
Tree Species ◽  
Feature Selection Method ◽  
Silver Fir ◽  
Maximum Point ◽  
Individual Tree ◽  
Dead Trees ◽  
Multi Wavelength ◽  
Standing Dead ◽  
Standing Dead Trees ◽  
532 Nm

Knowledge about forest structures, particularly of deadwood, is fundamental for understanding, protecting, and conserving forest biodiversity. While individual tree-based approaches using single wavelength airborne laserscanning (ALS) can successfully distinguish broadleaf and coniferous trees, they still perform multiple tree species classifications with limited accuracy. Moreover, the mapping of standing dead trees is becoming increasingly important for damage calculation after pest infestation or biodiversity assessment. Recent advances in sensor technology have led to the development of new ALS systems that provide up to three different wavelengths. In this study, we present a novel method which classifies three tree species (Norway spruce, European beech, Silver fir), and dead spruce trees with crowns using full waveform ALS data acquired from three different sensors (wavelengths 532 nm, 1064 nm, 1550 nm). The ALS data were acquired in the Bavarian Forest National Park (Germany) under leaf-on conditions with a maximum point density of 200 points/m 2 . To avoid overfitting of the classifier and to find the most prominent features, we embed a forward feature selection method. We tested our classification procedure using 20 sample plots with 586 measured reference trees. Using single wavelength datasets, the highest accuracy achieved was 74% (wavelength = 1064 nm), followed by 69% (wavelength = 1550 nm) and 65% (wavelength = 532 nm). An improvement of 8–17% over single wavelength datasets was achieved when the multi wavelength data were used. Overall, the contribution of the waveform-based features to the classification accuracy was higher than that of the geometric features by approximately 10%. Our results show that the features derived from a multi wavelength ALS point cloud significantly improve the detailed mapping of tree species and standing dead trees.

scholarly journals Urbanization pressures alter tree rhizosphere microbiomes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Carl L. Rosier ◽  
Shawn W. Polson ◽  
Vincent D’Amico ◽  
Jinjun Kan ◽  
Tara L. E. Trammell
Keyword(s):  
Organic Matter ◽  
Relative Abundance ◽  
Tree Species ◽  
High Throughput Sequencing ◽  
Regional Climate ◽  
Keystone Species ◽  
Fagus Grandifolia ◽  
Yellow Poplar ◽  
Individual Tree ◽  
Structural Formation

AbstractThe soil microbial community (SMC) provides critical ecosystem services including organic matter decomposition, soil structural formation, and nutrient cycling. Studies suggest plants, specifically trees, act as soil keystone species controlling SMC structure via multiple mechanisms (e.g., litter chemistry, root exudates, and canopy alteration of precipitation). Tree influence on SMC is shaped by local/regional climate effects on forested environments and the connection of forests to surrounding landscapes (e.g., urbanization). Urban soils offer an ideal analog to assess the influence of environmental conditions versus plant species-specific controls on SMC. We used next generation high throughput sequencing to characterize the SMC of specific tree species (Fagus grandifolia [beech] vs Liriodendron tulipifera [yellow poplar]) across an urban–rural gradient. Results indicate SMC dissimilarity within rural forests suggests the SMC is unique to individual tree species. However, greater urbanization pressure increased SMC similarity between tree species. Relative abundance, species richness, and evenness suggest that increases in similarity within urban forests is not the result of biodiversity loss, but rather due to greater overlap of shared taxa. Evaluation of soil chemistry across the rural–urban gradient indicate pH, Ca+, and organic matter are largely responsible for driving relative abundance of specific SMC members.

scholarly journals Long-Term Projections of the Natural Expansion of the Pine Wood Nematode in the Iberian Peninsula

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 849
Author(s):  
Begoña de la Fuente ◽  
Santiago Saura
Keyword(s):  
Iberian Peninsula ◽  
Tree Species ◽  
Average Rate ◽  
Limiting Factor ◽  
Pine Wood Nematode ◽  
Individual Tree ◽  
Pine Wood ◽  
Pine Tree ◽  
Informative Content

The invasive pine wood nematode (PWN), Bursaphelenchus xylophilus, causal agent of pine wilt disease, was first reported in Europe, near Lisbon, in 1999, and has since then spread to most of Portugal. We here modelled the spatiotemporal patterns of future PNW natural spread in the Iberian Peninsula, as dispersed by the vector beetle Monochamus galloprovincialis, using a process-based and previously validated network model. We improved the accuracy, informative content, forecasted period and spatial drivers considered in previous modelling efforts for the PWN in Southern Europe. We considered the distribution and different susceptibility to the PWN of individual pine tree species and the effect of climate change projections on environmental suitability for PWN spread, as we modelled the PWN expansion dynamics over the long term (>100 years). We found that, in the absence of effective containment measures, the PWN will spread naturally to the entire Iberian Peninsula, including the Pyrenees, where it would find a gateway for spread into France. The PWN spread will be relatively gradual, with an average rate of 0.83% of the total current Iberian pine forest area infected yearly. Climate was not found to be an important limiting factor for long-term PWN spread, because (i) there is ample availability of alternative pathways for PWN dispersal through areas that are already suitable for the PWN in the current climatic conditions; and (ii) future temperatures will make most of the Iberian Peninsula suitable for the PWN before the end of this century. Unlike climate, the susceptibility of different pine tree species to the PWN was a strong determinant of PWN expansion through Spain. This finding highlights the importance of accounting for individual tree species data and of additional research on species-specific susceptibility for more accurate modelling of PWN spread and guidance of related containment efforts.

scholarly journals Individual Tree Species Classification by Illuminated—Shaded Area Separation

2009 ◽  
Vol 2 (1) ◽  
pp. 19-35 ◽  
Author(s):  
Eetu Puttonen ◽  
Paula Litkey ◽  
Juha Hyyppä
Keyword(s):  
Tree Species ◽  
Species Classification ◽  
Individual Tree ◽  
Tree Species Classification

scholarly journals Phenotyping Architecture Traits of Tree Species Using Remote Sensing Techniques

2021 ◽  
Vol 64 (5) ◽  
pp. 1611-1624
Author(s):  
Worasit Sangjan ◽  
Sindhuja Sankaran
Keyword(s):  
Remote Sensing ◽  
Structure From Motion ◽  
Tree Species ◽  
Tree Height ◽  
Tree Canopy ◽  
System Structure ◽  
List Type ◽  
Canopy Architecture ◽  
Chemical Application ◽  
Canopy Volume

HighlightsTree canopy architecture traits are associated with its productivity and management.Understanding these traits is important for both precision agriculture and phenomics applications.Remote sensing platforms (satellite, UAV, etc.) and multiple approaches (SfM, LiDAR) have been used to assess these traits.3D reconstruction of tree canopies allows the measurement of tree height, crown area, and canopy volume.Abstract. Tree canopy architecture is associated with light use efficiency and thus productivity. Given the modern training systems in orchard tree fruit systems, modification of tree architecture is becoming important for easier management of crops (e.g., pruning, thinning, chemical application, harvesting, etc.) while maintaining fruit quality and quantity. Similarly, in forest environments, architecture can influence the competitiveness and balance between tree species in the ecosystem. This article reviews the literature related to sensing approaches used for assessing architecture traits and the factors that influence such evaluation processes. Digital imagery integrated with structure from motion analysis and both terrestrial and aerial light detection and ranging (LiDAR) systems have been commonly used. In addition, satellite imagery and other techniques have been explored. Some of the major findings and some critical considerations for such measurement methods are summarized here. Keywords: Canopy volume, LiDAR system, Structure from motion, Tree height, UAV.

scholarly journals Entwicklung klimasensitiver Wachstumsfunktionen für das Szenariomodell «Massimo»

2015 ◽  
Vol 166 (6) ◽  
pp. 389-398 ◽  
Author(s):  
Brigitte Rohner ◽  
Esther Thürig
Keyword(s):  
Tree Ring ◽  
Tree Growth ◽  
Tree Species ◽  
Climatic Factors ◽  
Climate Variables ◽  
Individual Tree ◽  
Climate Effects ◽  
Growth Functions ◽  
Tree Ring Data ◽  
Scenario Model

Development of climate-dependent growth functions for the scenario model “Massimo” Tree growth is substantially influenced by climatic factors. In the face of climate change, climate effects should therefore be included in estimations of Switzerland's future forest productivity. In order to include climate effects in the growth functions of the “Massimo” model, which is typically applied to project forest resources in Switzerland, we statistically modelled climate effects on tree growth representatively for Switzerland by simultaneously considering further growth-influencing factors. First, we used tree ring data to evaluate how climate variables should be defined. This analyses showed that for modelling multi-year tree growth we should use averages of whole-year variables. Second, we fitted nonlinear mixed-effects models separately for the main tree species to individual-tree growth data from the Swiss National Forest Inventory. In these models, we combined climate variables defined according to the results of the tree ring study with various further variables that characterize sites, stands and individual trees. The quantified effects were generally plausible and explained convincingly the physiological differences between the species. The statistical growth models for the main tree species will now be included in the forest scenario model “Massimo”. This will allow for founded analyses of scenarios which assume changing climatic conditions.

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