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opencc-by-4.0May 2022View details →

Decomposition, topology, properties, and graphs of 14 individuals of Cenostigma pyramidale (Tul.) Gagnon & G.P. Lewis, a Caatinga tree species

Data were obtained from the observation of 14 individuals of the tree species Cenostigma pyramidale (Tul.) Gagnon & G.P. Lewis growing in a semiarid area in Caatinga vegetation under natural conditions in the Northeast of Brazil in Paraiba State, located at the Fazenda Pocinho (7º29'46" S, 35º58'12" W) in the municipality of Barra de Santana. The woody crowns were drawn (skeletonized) in the 2-D format as rooted trees resulting in networks with nodes and connectors named woody crown networks. The data of decomposition, topology, and some properties are captured by skeletonized crowns following the methodology described by Prado et al. (2020, <a href="https://doi.org/10.1016/j.jtbi.2020.110318">https://doi.org/10.1016/j.jtbi.2020.110318</a>).

Morphometric data of two tree frog species and their hybrids from a hybrid zone in Poland

Under incomplete reproductive isolation, secondary contact of diverged allopatric lineages may form hybrid zones that allow to study recombinants over several generations as excellent systems of genomic interactions, resulting from the evolutionary forces, acting on certain genes and phenotypes. Hybrid phenotypes are expected to either exhibit intermediacy or, alternatively, transgressive traits, which exceed the extremes of their parents due to epistasis and segregation of complementary alleles. While transgressive morphotypes have been examined in fish, reptiles, birds, and mammals, studies in amphibians are rare. Here, we associate microsatellite-based genotypes and morphometrics-based morphotypes of two European tree frog species of the Hyla arborea group, sampled across a hybrid zone in Poland, to understand whether the genetically differentiated parental species also differ in morphology between each other and their hybrids, and whether secondary contact leads to the evolution of intermediate or transgressive morphotypes. Using univariate approaches, explorative multivariate methods (Principal Component Analyses) as well as techniques with prior grouping (Discriminant Function Analyses), we find that morphotypes of both parental species and hybrids differ from each other. Importantly, hybrid morphotypes are neither intermediate nor transgressive but found to be more similar to H. orientalis than to H. arborea. Our study presents one of the rare datasets, in which genotypes along with morphotypes examined the occurrence or absence of transgressive morphologies in wild amphibians.

Data from: Species tree estimation and the impact of gene loss following whole-genome duplication

Whole-genome duplication (WGD) has been demonstrated to occur broadly and repeatedly in the evolutionary history of eukaryotes, and is recognized as a prominent evolutionary force, especially in plants. Immediately following WGD, most genes are present in two copies as paralogs. Due to this redundancy, one copy of a paralog pair commonly undergoes pseudogenization and is eventually lost. When speciation occurs shortly after WGD, however, differential loss of paralogs may lead to spurious phylogenetic inference resulting from the inclusion of pseudoorthologs – paralogous genes mistakenly identify as orthologs because they are present in single copes within each sampled species. The influence and impact of including pseudoorthologs versus true orthologs as result of gene extinction (or incomplete laboratory sampling) in a phylogenetic context is only recently starting to gain empirical attention. Moreover, few of these studies have yet to investigate this phenomenon in an explicit coalescent framework. Here, using mathematical models, numerous simulated data sets, and two newly assembled empirical data sets, we assess the effect of pseudoorthologs on species tree estimation under varying levels of incomplete lineage sorting (ILS) and different patterns of gene loss following WGD. When gene loss occurs in the terminal branches of the species tree, the alignment-based (BPP) and gene-tree-based (ASTRAL, MP-EST, and STAR) coalescent methods are adversely affected as the level of ILS increases. This can be greatly improved by sampling a sufficiently large number of genes. Under the same circumstances, however, concatenation methods consistently estimate incorrect species trees as the number of sampled genes increases. Furthermore, pseudoorthologs can mislead species tree inference if gene loss occurs in the internal branches of the species tree, where both coalescent and concatenation methods are prone to produce inconsistent results. However, pseudoorthologs are problematic when filtering only for single-copy genes in phylogenomic data sets. Pruning orthologs or even randomly selecting a copy from multi-copy genes can avoid most of those pseudoorthologs. These results underscore the importance of understanding the influence of pseudoorthologs in the phylogenomics era.

Plant invasion modifies isohydricity in Mediterranean tree species

Understanding of plant hydraulic strategies (i.e., the degree of iso-/anisohydricity) is crucial to predict the response of plants to changing environmental conditions such as climate-change induced extreme drought. Several abiotic factors, including evaporative demand, have been shown to seasonally modify the isohydricity of plants. However, the impact of biotic factors such as plant-plant interactions on hydraulic strategies has seldom been explored. Here, we investigated adaptations and changes in hydraulic strategies of two woody species in response to seasonal abiotic conditions, experimental drought, and plant invasion in a Mediterranean cork oak (Quercus suber) ecosystem with a combined shrub invasion (Cistus ladanifer) and rain exclusion experiment. From the dry to wet season, Q. suber shifted from a partial isohydric to an anisohydric behaviour while C. ladanifer shifted from strict anisohydric to partial isohydric. During drought, water competition by plant invasion significantly modified the hydraulic strategy of invaded Q. suber, which was accompanied by lower pre-dawn leaf water potentials, sap flow density, leaf area index, and trunk increment rates. This altered isohydricity of invaded Q. suber trees was most likely caused by interspecific competition for water resources by water spending C. ladanifer shrubs. Both species do have the highest proportion of fine roots in the topsoil and thus, an additional water consumer, such as C. ladanifer can lead to more stressful conditions for Q. suber during times of water scarcity. Further underlying mechanisms of the altered isohydricity of Q. suber, such as potential allelopathic effects of C. ladanifer exudates on root growth of Q. suber, have to be investigated in the future. In conclusion, we demonstrate that the degree of isohydricity of two woody Mediterranean plant species is dynamically determined by the interplay of species-specific hydraulic traits and their abiotic and biotic environment.

A dataset of 5 million city trees from 63 US cities: species, location, nativity status, health, and more.

Sustainable cities depend on urban forests. City trees -- a pillar of urban forests -- improve our health, clean the air, store CO2, and cool local temperatures. Comparatively less is known about urban forests as ecosystems, particularly their spatial composition, nativity statuses, biodiversity, and tree health. Here, we assembled and standardized a new dataset of N=5,660,237 trees from 63 of the largest US cities. The data comes from tree inventories conducted at the level of cities and/or neighborhoods. Each data sheet includes detailed information on tree location, species, nativity status (whether a tree species is naturally occurring or introduced), health, size, whether it is in a park or urban area, and more (comprising 28 standardized columns per datasheet). This dataset could be analyzed in combination with citizen-science datasets on bird, insect, or plant biodiversity; social and demographic data; or data on the physical environment. Urban forests offer a rare opportunity to intentionally design biodiverse, heterogenous, rich ecosystems.

Climate and mycorrhizae mediate the relationship of tree species diversity and carbon stocks in subtropical forests

1. It is increasingly being recognized that tree species diversity has positive effects on forest ecosystem carbon (C) stock. However, at broad spatial scales this relationship may depend on climate conditions and species mycorrhizal associations. 2. Here, observations from 667 forest plots in subtropical China, were used to investigate the effects of species diversity, mean annual precipitation (MAP), mean annual temperature (MAT) and mycorrhizal type (arbuscular or ectomycorrhizal) on the forest C stock and its components (tree C stock, shrub layer C stock, herb layer C stock, litter layer C stock, root C stock and soil C stock). 3. We found positive effect of tree species diversity on total forest C stock. MAP had positive effects on total forest C stock and its components, while MAT had consistently negative effects on total forest C stock and most of its components. Different levels of MAP and MAT did modulate the strength of effect of species diversity on forest C stock and its components. In addition, species diversity, MAT and MAP showed a significant positive relationship with arbuscular mycorrhiza-associated tree C stock but had no or negative relationship with ectomycorrhiza-associated tree C stock. 4. Synthesis. Our results indicate that maintaining high level of species diversity may support the buffering of negative effects resulting from climate warming. Furthermore, under climate warming the specific C stock of AM trees can increase, which can potentially promote forest C stock. Taken together, our study suggests that afforestation policies should consider not only tree species diversity to increase forest C stock but also the effects of different tree mycorrhizal types.

Supplementary material for: Impact of ghost introgression on coalescent-based species tree inference and estimation of divergence time

The species studied in any evolutionary investigation generally constitute a small proportion of all the species currently existing or that have gone extinct. It is therefore likely that introgression, which is widespread across the tree of life, involves "ghosts," i.e., unsampled, unknown, or extinct lineages. However, the impact of ghost introgression on estimations of species trees has rarely been studied and is poorly understood. Here, we use mathematical analysis and simulations to examine the robustness of species tree methods based on the multispecies coalescent model to introgression from a ghost or extant lineage. We found that many results originally obtained for introgression between extant species can easily be extended to ghost introgression, such as the strongly interactive effects of incomplete lineage sorting (ILS) and introgression on the occurrence of anomalous gene trees (AGTs). The relative performance of the summary species tree method (ASTRAL) and the full-likelihood method (*BEAST) varies under different introgression scenarios, with the former being more robust to gene flow between non-sister species whereas the latter performing better under certain conditions of ghost introgression. When an outgroup ghost (defined as a lineage that diverged before the most basal species under investigation) acts as the donor of the introgressed genes, the time of root divergence among the investigated species generally was overestimated, whereas ingroup introgression, as commonly perceived, can only lead to underestimation. In many cases of ingroup introgression that may or may not involve ghost lineages, the stronger the ILS, the higher the accuracy achieved in estimating the time of root divergence, although the topology of the species tree is more prone to be biased by the effect of introgression.

opencc-zeroJul 2022View details →

Impact of warmer and drier conditions on tree photosynthetic properties and the role of species interactions

Increased temperature and prolonged soil moisture reduction have distinct impacts on tree photosynthetic properties. Yet, our knowledge of their combined effect is limited. Moreover, how species interactions alter photosynthetic responses to warming and moisture reduction remains unclear. Using mesocosms, we studied how photosynthetic properties of European beech and downy oak were impacted by multi-year warming and moisture reduction alone or combined, and how species interactions (intra- vs. interspecific interactions) modulated these effects. Warming of +5°C enhanced photosynthetic properties in oak but not beech, while moisture reduction decreased them in both species. Combined warming and moisture reduction reduced photosynthetic properties for both species, but no exacerbated effects were observed. Oak was less impacted by combined warming and moisture reduction when interacting with beech than in intraspecific stands. For beech, species interactions had no impact on the photosynthetic responses to warming and moisture reduction, alone or combined. Warming had either no or beneficial effects on the photosynthetic properties, while moisture reduction and their combined effects strongly reduced photosynthetic responses in both species. However, interspecific interactions can mitigate the negative impacts of the combined warming and moisture reduction in oak, thereby highlighting the need to deepen our understanding of interspecific interactions under climate change.

opencc-by-4.0Jul 2022View details →

Drought resistance enhanced by tree species diversity in global forests

The species diversity effect (theta) on drought resistance for global forest ecoregions. The species diversity effect was estimated based on a global analysis of the relationship between species richness and drought-induced changes in forest productivity, using a database that contains more than 0.7 million forest plots and satellite-based estimation of drought resistance.

opencc-zeroAug 2022View details →

Tropical tree species differ in damage and mortality from lightning

Lightning is an important agent of mortality for large tropical trees with implications for tree demography and forest carbon budgets. We evaluated interspecific differences in susceptibility to lightning damage using a unique dataset of systematically located lightning strikes on Barro Colorado Island, Panama. We measured differences in mortality among trees damaged by lightning and related those to damage frequency and tree functional traits. Eighteen of 30 focal species had lightning mortality rates that deviated from null expectations. Several species showed little damage and 3 species had no mortality from lightning, whereas palms were especially likely to die from strikes. Species that were most likely to be struck also showed the highest survival. Interspecific differences in tree tolerance to lightning suggest that lightning-caused mortality shapes compositional dynamics over time and space. Shifts in lightning frequency due to climatic change are likely to alter species composition and carbon cycling in tropical forests.

opencc-zeroSep 2022View details →

Intraspecific trait variation in a dryland tree species corresponds to regional climate gradients

Aim: Intraspecific trait variation is fundamental to understanding a species' adaptive capacity. Assessing phenotypic variation at different ecological scales is useful for evaluating species' vulnerability to changing environmental conditions. Here we quantify the ecological scale of variation of phenotypic functional traits for a widespread dryland tree species in the western United States, Pinus monophylla, and evaluate the strength of trait-environment relationships across spatial gradients and in response to interannual variability in weather conditions. Location: Western United States Taxon: Conifer tree (Pinaceae): Pinus monophylla Methods: Nine reproductive and foliar morphological traits were measured from 23 sampling locations in nine mountain ranges, stratified across broad-scale gradients of precipitation timing and quantity and local gradients of elevation. We partitioned trait variation within and among nested ecological scales (mountain range, site, tree, and tree growth year). We then used multivariate methods to quantify the association between environmental variables and ecological trade-offs associated with both reproductive and foliar traits. Results: Most variation was explained at the scale of individual trees (18–46%) and between growth years (20–30%), with smaller but variable contributions at the scale of sites (8–25%) and mountain ranges (0–15%). Trait values had low correlation with environmental variables (13%); however, 94% of the trait-environment covariance was explained by two major axes of variation: (1) the drought-stress gradient covarying with reproductive traits, and (2) precipitation patterns covarying with foliar morphology. Main conclusions: High levels of individual trait variation indicate within-population adaptive capacity. Consistent relationships among range-wide patterns of foliar and reproductive traits and broad-scale climate gradients provide indirect evidence of local adaptation and may inform seed sourcing for restoration or the potential for assisted migration efforts. Quantification of intraspecific trait variation across multiple ecological scales is important for understanding the potential climate change response of dryland tree species.

opencc-zeroDec 2021View details →

Reciprocal bark exchange helps to disentangle tree species dependent bark and wood trait effects on invertebrate diversity

1. Previous studies showed that bark cover at early-decay stage had profound control on the invertebrate assemblages of bark and wood, with possible consequence for the decomposition process. However, previous experimental designs could not disentangle how bark versus wood traits affect the invertebrate assemblage process in bark and/or wood separately because wood traits of different tree species may vary independently from bark traits. Furthermore, we do not know whether such tree species specific bark trait effects are still influential at mid-decay stage. 2. To unravel whether and how bark and wood traits influence invertebrate communities in tree logs at mid-decay stage, we introduce reciprocal bark transplantation within pairs of different tree species as a new method. We applied this method to two pairs of phylogenetically contrasting species of gymnosperms (pair I: Araucaria araucana and Cryptomeria japonica, pair II: Picea abies and Thuja plicata) and another gymnosperm (Chamaecyparis lawsoniana) set as disturbance control to test for potential bark manipulation artefacts on invertebrate community composition. 3. Our bark exchange experiment revealed that both bark and wood host abundant and divergent subsets of invertebrates on mid-decay logs of different tree species. We further documented that the invertebrate community composition was predominantly shaped by the traits of host tissue per se, while also being significantly but less strongly affected by the traits of the other tissue, i.e. the adjacent bark or wood. Our results indicated that bark trait effects faded with time and how long bark trait effects persist greatly depends on bark thickness. 4. Synthesis. Our study suggests that maintaining deadwood heterogeneity related to variation between tree species, and to bark versus wood, is important for nursing a large biodiversity of invertebrates. Combined with bark removal methodology, our bark exchange method can be further extended to more decay stages and more forest biomes to track bark trait effects and bark induced priority effects on deadwood decomposition, and its associated invertebrate and microbial communities.

opencc-by-4.0Oct 2022View details →

Dataset: Selecting tree species to restore forest under climate change conditions: complementing species distribution models with field experimentation

This repository contains the files associated with the following article: Jesús Sandoval-Martínez, Ernesto I. Badano, Francisco A. Guerra-Coss, Jorge A. Flores Cano, Joel Flores, Sandra Milena Gelviz-Gelvez, Felipe Barragán-Torres, “Selecting tree species to restore forest under climate change conditions: complementing species distribution models with field experimentation”, submitted to Journal of Environmental Management. Supplementary material 01 is a compressed file that contains two Microsoft Excel files with data that support the results of the study. A file correspond to Vachellia pennatula and the another file correspond to Prosopis laevigata. In both files, the first spreadsheet shows the occurrence data (latitude and longitude) used to calibrate the distribution model (SDM) of the corresponding species, the current values of the 19 bioclimatic variables associated with these coordinates and the Spearman correlation coefficients used to select the variables included in the SDM (selected variables are indicated in green). The second spreadsheet shows the current habitat occupancy probabilities of the target species estimated with the SDM at the geographic coordinates of occurrence points, while the table on the side shows the fraction of true presences dropping at the following probability categories: (1) habitat occupancy probabilities below 0.1 = unsuitable spatial units for the species, (2) habitat occupancy probabilities between 0.1 and 0.4 = barely suitable spatial units for the species, (3) habitat occupancy probabilities between 0.4 and 0.7 = moderately suitable spatial units for the species, and (4) habitat occupancy probabilities above 0.7 = highly suitable spatial units for the species. The third spreadsheet shows the one-thousand random geographic coordinates and the corresponding current and future habitat occupancy probabilities of each species. Future habitat occupancy probabilities are provided for three time periods (2041-2060, 2061-2080 and 2081-2100) at four radiative forcing levels each (2.6, 4.5, 7.0 and 8.5 W/m2). Supplementary material 02 is a compressed file that contains a folder for Vachellia pennatula and another folder for Prosopis laevigata. Each of these folders contains the summaries of the MaxEnt outputs that support the results of the corresponding SDM. Supplementary material 03 is a compressed Keyhole Markup Language file (KMZ) that contains interactive maps that are optimized for the desktop version of Google Earth. To accelerate visualization of maps, we recommend installing this software in a computer meeting the following requirements: CPU Intel Core i5 9th generation or higher, CPU clock speed 1.8 GHz or higher, random-access memory (RAM) 8 GB or higher, and video random access memory (VRAM) 1 GB or higher. Otherwise, opening this file may take several minutes. These maps are organized in a folder for Vachellia pennatula and another folder for Prosopis laevigata, which must be expanded for accessing the following information (click on the arrow on the left of folders to expand them): <ul> <li>Current climate – Activating this folder (click the fox on the left of the folder) display the map of habitat occupancy probabilities of species across Mexico under the current climate.</li> <li>Period 2041-2060, 2061-2080  and 2081-2100 – Expanding each of these folders (click on the arrow on the left of folders) shows four subfolders that correspond to different radiative forcing levels (2.6, 4.5, 7.0 and 8.5 W/m2). Activating each of these sub folders (click the fox on the left of subfolders) display the map of habitat occupancy probabilities of species across Mexico expected on the corresponding time period and radiative forcing level. These maps also show the areas classified as climatically unsuitable in the multivariate environmental similarity surface (MESS) analysis. Clicking on the names of subfolders displays a figure showing the relationship between current and future habitat occupancy probabilities of the species on the corresponding time period and radiative forcing level. In these figures, the red line is the empirical relationship between these variables and the solid blue line is the theoretical relationship with intercept = 0 and slope = 1. The statistical results that support these relationships are also shown in these figures.</li> </ul> Supplementary material 04 is a compressed file that contains two Microsoft Excel files with data that support the results of the study. the file labeled as “Microclimate data” contains two spreadsheets, which correspond to the temperature and rainfall values measured in controls under the current climate and climate change simulation plots located of the field experiments. The file levelled as “Seedling emergence and survival” contains a spreadsheet for Vachellia pennatula and another one for Prosopis laevigata, which contains the data used to estimate the seedling emergence and survival rates in controls and climate change simulation plots.

opencc-zeroOct 2022View details →

Beetle diversity in dead wood is lower in non-native than native tree species, especially those more distantly related to native species

1. Non-native tree species are widely used in forest plantations. This may have negative consequences for biodiversity. Hitherto, most studies have compared species diversity between native and non-native forest stands, which makes it difficult to separate the impact of tree species per se from stand characteristics. Our study, conducted in the south of Sweden, compares saproxylic beetle diversity across different nutritional groups, in dead wood of two native and four non-native tree species in a block design after one and three seasons. Such an approach allows analysis of the impact of non-native tree species per se. 2. Mean species richness (±SD) per log was lower in non-native than in native tree species (non-native trees: lodgepole pine: 10.7 (± 5.3); Sitka spruce: 8.5 (± 4.3), Douglas fir: 7.1 (± 4.3), Japanese larch 9.4 (± 4.6); native trees: Norway spruce: 12.0 (± 6.0), Scots pine: 12.3 (± 5.2)). Sample-based rarefaction revealed that when only native tree species were pooled, the species richness was higher than for all tree species combined. The difference in species composition among tree species was strongly driven by bark and wood consumers in the first season, while for predators and fungivores, the differences were smaller. Species composition differed more after one season. 3. Dissimilarity in beetle species composition was positively correlated with phylogenetic distances of the tree species. Species richness was lower in non-native tree species that are only remotely related to native trees species. Of the studied non-native tree species, lodgepole pine was more closely related to native tree species and consistently harboured higher species richness. 4. Synthesis and applications. Although non-native tree species also harbour saproxylic beetle communities, the use of non-native tree species, especially those only remotely related to native tree species, reduces local diversity of saproxylic beetles. Thus, for biodiversity conservation, an extensive use of non-native tree species is not recommended as this increases the risk of losing forest biodiversity, especially when they are only distantly related to native tree species.

opencc-zeroOct 2022View details →

Host preference of a tree-killing bark beetle across a geographic boundary separating host species

The life cycles of bark beetles are intimately linked to their host species. Therefore, bark beetle species are expected to show traits that vary among different host species and across geographic ranges. The taxonomic proximity of host tree species can also influence host selection. Abies species native to Japan are genetically classified into three phylogenetic groups. Their natural distributions are separated by a distinct biogeographic boundary in Japan (i.e. the Tsugaru Strait, also referred to as Blakiston's Line). Especially, A. sachalinensis is the only species native to Hokkaido, north of the Tsugaru Strait. I, therefore, investigated the host preference of Polygraphus proximus Blandford within four allopatrically distributed Abies species across the north and south of the Tsugaru Strait through field surveys and field choice experiments. Field observations and field host-choice bioassays showed that A. sachalinensis was less severely attacked by P. proximus than was A. veitchii on both sides of the Tsugaru Strait. The beetles also preferred to attack A. firma (which belongs to a genetically distinct group (i.e., the section Momi) from that of A. veitchii and A. sachalinensis (i.e., the section Balsamea)), over A. sachalinensis in both Hokkaido and Honshu. Although A.homolepis also belongs to the section Momi, A. firma and A. veitchii had more attacks than A. homolepis. The results provide evidence that P. proximus does not show specialization across the different parts of their geographic range where the host species are different, and there is no positive correlation between taxonomic proximity and host preference for P. proximus.

opencc-zeroApr 2024View details →

Intraspecific plant-soil feedback in four tropical tree species is inconsistent in a field experiment

Soil microbes can influence patterns of diversity in plant communities via plant-soil feedbacks. Intraspecific plant-soil feedbacks occur when plant genotype causes variation in soil microbial composition, resulting in differences in the performance of seedlings growing near their maternal plants versus seedlings growing near non-maternal conspecific plants. How consistently such intraspecific plant-soil feedbacks occur in natural plant communities is unclear, especially under variable field conditions. We conducted an in situ experiment with four native tree species on Barro Colorado Island (BCI), Panama. Seedlings of each species were transplanted beneath their maternal tree or another conspecific tree in the BCI forest. Mortality and growth were assessed at the end of the wet season (~4 months post-transplant) and at the end of the experiment (~7 months post-transplant). Differences in seedling performance among field treatments were inconsistent among species and eroded over time. Effects of field environment were detected at the end of the wet season in two of the species: Virola surinamensis seedlings had higher survival beneath their maternal tree than other conspecific trees, while the opposite pattern was found in Ormosia macrocalyx. However, these differences disappeared by the end of the experiment. Our results suggest that intraspecific plant-soil feedbacks may not occur consistently under field conditions in tropical tree species and may have a limited role in determining seedling performance in tropical tree communities. Future studies are needed to elucidate the environmental and genetic factors that determine the incidence and direction of intraspecific plant-soil feedbacks in plant communities.

opencc-by-sa-4.0Apr 2024View details →

Data for: "Different dry-wet pulses favor different functional strategies: a test using tropical dry forest tree species" by Vega-Ramos, Flor, Cifuentes Gómez, Lucas, Pineda-García, Fernando, Dawson, Todd, Paz, Horacio

These data represent those published in "Different dry-wet pulses favor different functional strategies: a test using tropical dry forest tree species" by Vega-Ramos, Flor, Cifuentes Gómez, Lucas, Pineda-García, Fernando, Dawson, Todd, Paz, Horacio

opencc-zeroApr 2024View details →

Fruiting trees provide fruit and insect resources for four tropical deer species

Fruiting trees provide important fruit and seed resources for various animal species, but rarely are they considered to be rich sources of insects as well. During a study of seed dispersal of Trewia nudiflora (Euphorbiaceae) using camera-traps in Nepal, we observed four tropical deer species (Axis axis, Muntiacus vaginalis, Rusa unicolor, Axis porcinus) foraging for insects, rather than fruits under the trees. These herbivorous deer are proven seed dispersers of Trewia, but 8-38% of video captures (across each species) were of insectivory, rather than frugivory. The deer chased and consumed red cotton bugs (Dysdercus sp. family Pyrrhocoridae), which were seed predators that hoarded Trewia seeds. It is likely that other unidentified insect species were also consumed. Tropical deer species are considered to be fully herbivorous, so our observations extend their known diets and possibly indicate a seasonal requirement for protein. These findings also highlight tri-trophic interactions among deer, insects, and fruits that could have important implications for seedling recruitment if seed predators are being consumed by seed dispersers (in addition to fruit consumption).

opencc-zeroJun 2024View details →

Data from: A trait-based root acquisition-defence-decomposition framework in angiosperm tree species

Plants make trade-offs between root resource acquisition and defence ability, for adapting to the complex belowground environment. This includes forming partnerships with different types of root associating microorganisms, such as arbuscular mycorrhizal and ectomycorrhizal fungi. These trade-offs, by mediating root chemistry, exert legacy effects on nutrient release during decomposition, which may, in turn, affect the ability of new roots to re-acquire resources, thereby generating a feedback loop. However, the linkages at the basis of this potential feedback loop remain largely unquantified. Here, we propose a trait-based root 'acquisition-defence-decomposition' conceptual framework and test the strength of relevant linkages across 90 angiosperm tree species. We show that, at the plant species level, the root-fungal symbiosis gradient within the root economics space, root chemical defence (condensed tannins), and root decomposition rate are closely linked, providing support to this framework. Beyond the dichotomy between arbuscular mycorrhizal-dominated versus ectomycorrhizal-dominated systems, we suggest a continuous shift in feedback loops, from "high arbuscular mycorrhizal symbiosis-low defence-fast decomposition-inorganic nutrition" by evolutionarily ancient taxa to "high ectomycorrhizal symbiosis-high defence-slow decomposition-organic nutrition" by more modern taxa. This 'acquisition-defence-decomposition' framework provides solid foundation for testable hypotheses on the multidimensional linkages between species' belowground strategies and ecosystem nutrient cycling in evolutionary context.