Biology subjects

Tiunov, A.

Publications and source records attributed to Tiunov, A..

4 recordsLinked to original sources

bioRxiv2024

Body size is a better predictor of intra- than interspecific variation of animal stoichiometry across realms

Animal stoichiometry affects fundamental processes ranging from organismal physiology to global element cycles. However, it is unknown whether animal stoichiometry follows predictable scaling relationships with body mass and whether adaptation to life on land or water constrains patterns of elemental allocation. To test both interspecific and intraspecific body-size scaling relationships of the nitrogen (N), phosphorus (P), and N:P content of animals, we used a subset of the StoichLife database encompassing 9,933 individual animals (vertebrates and invertebrates) belonging to 1,543 species spanning 10 orders of magnitude of body size from terrestrial, freshwater, and marine realms. Across species, body mass did not explain much variation in %N and %P composition, although the %P of invertebrates decreased with size. The effects of body size on species elemental content were small in comparison to the effects of taxonomy. Body size was a better predictor of intraspecific than interspecific elemental patterns. Between 42 to 45% in intraspecific stoichiometric variation was explained by body size for 27% of vertebrate species and 35% of invertebrate species. Further, differences between organisms inhabiting aquatic and terrestrial realms were observed only in invertebrate interspecific %N, suggesting that the realm does not play an important role in determining elemental allocation of animals. Based on our analysis of the most comprehensive animal stoichiometry database, we conclude that (i) both body size and realm are relatively weak predictors of animal stoichiometry across taxa, and (ii) body size is a good predictor of intraspecific variation in animal elemental content, which is consistent with tissue-scaling relationships that hold broadly across large groups of animals. This research reveals a lack of general scaling patterns in the elemental content across animals and instead points to a large variation in scaling relationships within and among lineages.

ecology↗

bioRxiv2022

Global monitoring of soil animal communities using a common methodology

Here we introduce the Soil BON Foodweb Team, a cross-continental collaborative network that aims to monitor soil animal communities and food webs using consistent methodology at a global scale. Soil animals support vital soil processes via soil structure modification, direct consumption of dead organic matter, and interactions with microbial and plant communities. Soil animal effects on ecosystem functions have been demonstrated by correlative analyses as well as in laboratory and field experiments, but these studies typically focus on selected animal groups or species at one or few sites with limited variation in environmental conditions. The lack of comprehensive harmonised large-scale soil animal community data including microfauna, mesofauna, and macrofauna, in conjunction with related soil functions, limits our understanding of biological interactions in soil communities and how these interactions affect ecosystem functioning. To provide such data, the Soil BON Foodweb Team invites researchers worldwide to use a common methodology to address six long-term goals: (1) to collect globally representative harmonised data on soil micro-, meso-, and macrofauna communities; (2) to describe key environmental drivers of soil animal communities and food webs; (3) to assess the efficiency of conservation approaches for the protection of soil animal communities; (4) to describe soil food webs and their association with soil functioning globally; (5) to establish a global research network for soil biodiversity monitoring and collaborative projects in related topics; (6) to reinforce local collaboration networks and expertise and support capacity building for soil animal research around the world. In this paper, we describe the vision of the global research network and the common sampling protocol to assess soil animal communities and advocate for the use of standard methodologies across observational and experimental soil animal studies. We will use this protocol to conduct soil animal assessments and reconstruct soil food webs on the sites included in the global soil biodiversity monitoring network, Soil BON, allowing us to assess linkages among soil biodiversity, vegetation, soil physico-chemical properties, and ecosystem functions. In the present paper, we call for researchers especially from countries and ecoregions that remain underrepresented in the majority of soil biodiversity assessments to join us. Together we will be able to provide science-based evidence to support soil biodiversity conservation and functioning of terrestrial ecosystems.

ecology↗

bioRxiv2018

Adaptive radiation of barbs of the genus Labeobarbus (Cyprinidae) in the East African river

Large African barbs of the genus Labeobarbus are widely distributed in African freshwaters, and exhibit profound phenotypic plasticity that could be a prerequisite for adaptive radiation. Using morphological, molecular, and stable isotope analyses, we investigated whether an adaptive radiation has occurred in a riverine assemblage of the L. gananensis complex. This complex is composed of six phenotypically distinct sympatric forms inhabiting the Genale River (Ethiopian highlands, East Africa). Of the six forms, five were divergent in their mouth morphology, corresponding to generalized, lipped, scraping (two forms) and large-mouthed phenotypes. Stable isotope analysis revealed differences in 15N and 13C among these forms, representing different foraging strategies (omnivorous, scraping and piscivorous). Phylogenetic analysis of two mtDNA markers confirmed the monophyly of L. gananensis, suggesting an intra-riverine radiation. However, the Genale assemblage appears to have originated through a combination of allopatric and sympatric events. Some of the specialized forms within this drainage originated independently from the local generalized forms in three different river regions within local mini-flocks composed of two to three sympatric forms. Our study shows that adaptive radiation in rivers can be enhanced by a combination of sympatric speciation and temporal geographic isolation, leading to local sympatric speciation followed by migration.

evolutionary biology↗

bioRxiv2018

Trophic consistency of supraspecific taxa in belowground invertebrate communities

1. Animals that have similar morphological traits are expected to share similar ecological niches. This statement applies to individual animals within a species and thus species often serve as the functional units in ecological studies. Species are further grouped into higher-ranked taxonomic units based on their morphological similarity and thus are also expected to be ecologically similar. On the other hand, theory predicts that strong competition between closely related species can lead to differentiation of ecological niches. Due to a high diversity and limited taxonomic expertise, soil food webs are often resolved using supraspecific taxa such as families, orders or even classes as functional units.\n\n2. Here we for the first time empirically tested the trophic consistency of supraspecific taxa across major lineages of temperate forest soil invertebrates: Annelida, Chelicerata, Myriapoda, Crustacea and Hexapoda. Published data on stable isotope compositions of carbon and nitrogen were used to infer basal resources and trophic level, and explore the relationship between taxonomic and trophic dissimilarity of local populations.\n\n3. Genera and families had normal and unimodal distributions of isotope niches, suggesting that supraspecific taxa are trophically consistent. The isotopic niche of populations across different localities is better predicted by species than by supraspecific taxa. However, within the same genus, the effect of species identity on stable isotope composition of populations was not significant in 92% of cases. The link to basal resources, i.e. plants or detritus, was convergent in different lineages, while trophic levels followed the Brownian motion taxonomic model. Virtually none of the studied taxa showed pronounced trophic niche conservatism within a lineage.\n\n4. Supraspecific taxa are meaningful as functional units in ecological studies, but the consistency varies among taxa and thus the choice of taxonomic resolution depends on the research question; generally, identification of taxa should be more detailed in more diverse taxonomic groups. We compiled a comprehensive list of mean {Delta}13C and {Delta}15N values of invertebrate taxa from temperate forest soils allowing to refine soil food-web models when identification to species level is not feasible.

ecology↗