Research Dataset Catalog and ShareScore Ratings | ScienceDex

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Body size and trophic levels explain global asymmetric response of tetrapod diversity to climate effects

Although climate-based hypotheses are widely used to explain large-scale diversity patterns, they fall short of explaining the spatial variation among taxonomic groups. Integrating food web and metabolic theories into macroecology is a promising step forward, as they allow including explicit taxon-specific traits that can potentially mediate the relationship between climate and diversity. Our investigation focuses on the role of body size and trophic structure in mediating the influence of contemporary climate and historical climate change on global tetrapods species richness. We used piecewise structural equation modeling to assess the direct effects of contemporary climate and climate instability of species richness and the indirect effects of climate on tetrapod richness mediated by community-wide species traits. We found that birds and mammals are less sensitive to the direct effect of contemporary climate than amphibians and squamates. Contemporary climate and climate instability favored the species richness in mammals and amphibians. However, for birds and squamates, this link is only associated with contemporary climate. Moreover, we demonstrated that community-wide traits favored the species richness gradients of tetrapod groups, except amphibians, but this link depends on traits and taxonomic groups. Specifically, bird communities with smaller bodies and bottom-heavy structures support higher species richness. Squamates also tend to be more diverse in communities with prevalence of smaller bodies, while mammals are correlated with top-heavy structures. Moreover, we show that higher contemporary climate and climate instability reduce the species richness of birds and mammals through community-wide traits and tend indirectly improve squamate species richness. Thus, we showed the significance of body size and trophic structure effect in driving a global asymmetric response of tetrapod diversity to climate effects highlights the limitations of applying "typical" climate-based hypotheses. Furthermore, by combining multiple theories, our research contributes to a more realistic and mechanistic understanding of diversity patterns across taxonomic groups.

opencc-zeroFeb 2024View details →

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Bottom-up effects of plant quantity and quality on arthropod diversity across multiple trophic levels in a semi-arid grassland

1. Plant quantity and quality can independently affect the diversity of the entire arthropod communities and multiple arthropod taxa in grassland ecosystems. However, it remains unclear how these effects on arthropod taxa at one trophic level propagate through food web to influence the diversity of higher trophic levels. 2. We performed a monoculture experiment with 15 herbaceous species in the Inner Mongolian grassland to investigate how natural variations in plant productivity and host leaf traits affect herbivore taxon richness, which in turn affects predator taxon richness. 3. For herbivores, plant productivity indirectly promoted herbivore taxon richness by increasing herbivore biomass, which was attributed to the increases in the richness of dominant sucking herbivores and endophytes with high food requirements. However, the high plant quality indicator (e.g. high leaf protein, phosphorus and water contents, and high leaf protein to carbohydrate ratio) directly increased, whereas the low plant quality indicator (e.g. high leaf lignin content) directly decreased herbivore taxon richness. Taxon richness of chewing and sucking herbivores with specific feeding modes (tearing or sucking mouthparts) showed strong positive responses to increasing plant quality. 4. For predators, herbivore taxon richness, rather than herbivore biomass, mainly mediated the positive effects of plant productivity and the high plant quality indicator, but the negative effect of the low plant quality indicator, on predator taxon richness. At the feeding guild level, the taxon richness of parasitoids, other predators and spiders exhibited positive responses to different herbivores, which was attributed to their different diet preferences. Predator diversity could be promoted by prey partitioning among predator guilds facilitating species coexistence. At the family level, the taxon richness of most predator families was positively correlated with that of more than one herbivore family, suggesting that high predator diversity may be caused by balanced diets owing to high prey diversity. 5. Synthesis. Natural variations in plant quantity and quality can substantially affect the diversity of herbivores and cascade up the food web to affect predators. Specificity and mechanisms of feeding have a large impact on the responses of arthropod guilds at each trophic level.

opencc-zeroAug 2022View details →

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Data from: Tree species and genetic diversity increase productivity via functional diversity and trophic feedbacks

This data was collected in the species × genetic diversity experiment of the Biodiversity–Ecosystem Functioning Experiment China Platform (BEF-China, <a href="http://www.bef-china.com/">www.bef-china.com</a>). This data set includes four species (Alniphyllum fortunei, Cinnamanum camphora, Daphniphyllum oldhamii, and Idesia polycarpa) with the mother trees of all tree individuals known, and the offspring from the same mother tree was defined as a seed family. In total, 92 subplots with 4 tree diversity levels were included: species diversity (1 or 4 species) and genetic diversity (1 or 4 seed families per species) which resulted in four tree diversity levels: one species with one seed family (1.1), one species with four seed families (1.4), four species with one seed family per species (4.1) and four species with four seed families per species (4.4). For tree functional traits, five leaf functional traits were measured in 2017 and 2018, including leaf area (LA), specific leaf area (SLA), chlorophyll content (CHL), leaf nitrogen content (LN), and leaf carbon content (LC). Herbivory was visually recorded as leaf damage in 2017. Soil fungal diversity was used as proxies for unspecified trophic interactions. Soil samples were taken on subplot level for the 1.1 and 1.4 diversity treatments, but on plot level for the 4.1 and 4.4 diversity treatments in 2017. Tree community productivity was summed by the biomass of individual trees in each subplot and individual tree biomass (kg) was calculated using the biomass equation (H × BA × CV) of the BEF-China experiment, where CV is a correction factor for stem shape and wood density.

opencc-zeroJan 2023View details →

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Data for: Ambient and substrate energy influence decomposer diversity differentially across trophic levels

The species-energy hypothesis predicts increasing biodiversity with increasing energy in ecosystems. Proxies for energy availability are often grouped into ambient energy (i.e., solar radiation) and substrate energy (i.e., non-structural carbohydrates or nutritional content). The relative importance of substrate energy is thought to decrease with increasing trophic level from primary consumers to predators, with reciprocal effects of ambient energy. Yet, empirical tests are lacking. We compiled data on 332,557 deadwood-inhabiting beetles of 901 species reared from wood of 49 tree species across Europe. Using host-phylogeny-controlled models, we show that the relative importance of substrate energy versus ambient energy decreases with increasing trophic levels: the diversity of zoophagous and mycetophagous beetles was determined by ambient energy, while non-structural carbohydrate content in woody tissues determined that of xylophagous beetles. Our study thus overall supports the species-energy hypothesis and specifies that the relative importance of ambient temperature increases with increasing trophic level with opposite effects for substrate energy.

opencc-zeroMar 2023View details →

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