Frontiers in soil ecology—Insights from the World Biodiversity Forum 2022

Global change is affecting soil biodiversity and functioning across all terrestrial ecosystems. Still, much is unknown about how soil biodiversity and function will change in the future in response to simultaneous alterations in climate and land use, as well as other environmental drivers. It is crucial to understand the direct, indirect and interactive effects of global change drivers on soil communities and ecosystems across environmental contexts, not only today but also in the near future. This is particularly relevant for international efforts to tackle climate change like the Paris Agreement, and considering the failure to achieve the 2020 biodiversity targets, especially the target of halting soil degradation. Here, we outline the main frontiers related to soil ecology that were presented and discussed at the thematic sessions of the World Biodiversity Forum 2022 in Davos, Switzerland. We highlight multiple frontiers of knowledge associated with data integration, causal inference, soil biodiversity and function scenarios, critical soil biodiversity facets, underrepresented drivers, global collaboration, knowledge application and transdisciplinarity, as well as policy and public communication. These identified research priorities are not only of immediate interest to the scientific community but may also be considered in research priority programmes and calls for funding

The TeaComposition Initiative: Unleashing the power of international collaboration to understand litter decomposition

Collected harmonized data on global litter decomposition are of great relevance for scientists, policymakers, and for education of the next generation of researchers and environmental managers. Here we describe the TeaComposition initiative, a global and open research collaborative network to study organic matter decomposition in a standardized way allowing comparison of decomposition rate and carbon turnover across global and regional gradients of ecosystems, climate, soils etc. The TeaComposition initiative today involves 570 terrestrial and 300 aquatic ecosystems from nine biomes worldwide. Further, we describe how to get involved in the TeaComposition initiative by (a) implementing the standard protocol within your study site, (b) joining task forces in data analyses, syntheses and modelling efforts, (c) using collected data and samples for further analyses through joint projects, (d) using collected data for graduate seminars, and (e) strengthening synergies between biogeochemical research and a wide range of stakeholders. These collaborative efforts within/emerging from the TeaComposition initiative, thereby, will leverage our understanding on litter decomposition at the global scale and strengthen global collaborations essential for addressing grand scientific challenges in a rapidly changing world.This work was performed within the TeaComposition and TeaComposition H2O initiatives, carried by 290 institutions worldwide. We thank to UNILEVER for sponsoring the Lipton tea bags. The initiative is supported by the following grants: ILTER Initiative Grants, ClimMani Short-Term Scientific Missions Grants, INTERACT Remote Transnational Access and an Alfred Deakin Postdoctoral Research Fellowship. Nico Eisenhauer gratefully acknowledges the support of iDiv funded by the German Research Foundation (DFG– FZT 118, 202548816). ST-T was supported by the ARC DE210101029 and Deakin University’s ADPR Fellowship. Fernando T. Maestre acknowledges support from the European Research Council (ERC Grant agreement 647038 [BIODESERT]) and Generalitat Valenciana (CIDEGENT/2018/041)

Frontiers in soil ecology—Insights from the World Biodiversity Forum 2022

17 páginas.- 3 figuras.- 194 referenciasGlobal change is affecting soil biodiversity and functioning across all terrestrial ecosystems. Still, much is unknown about how soil biodiversity and function will change in the future in response to simultaneous alterations in climate and land use, as well as other environmental drivers. It is crucial to understand the direct, indirect and interactive effects of global change drivers on soil communities and ecosystems across environmental contexts, not only today but also in the near future. This is particularly relevant for international efforts to tackle climate change like the Paris Agreement, and considering the failure to achieve the 2020 biodiversity targets, especially the target of halting soil degradation. Here, we outline the main frontiers related to soil ecology that were presented and discussed at the thematic sessions of the World Biodiversity Forum 2022 in Davos, Switzerland. We highlight multiple frontiers of knowledge associated with data integration, causal inference, soil biodiversity and function scenarios, critical soil biodiversity facets, underrepresented drivers, global collaboration, knowledge application and transdisciplinarity, as well as policy and public communication. These identified research priorities are not only of immediate interest to the scientific community but may also be considered in research priority programmes and calls for funding.Funding information Deutsche Forschungsgemeinschaft, Grant/Award Numbers: DFG– FZT 118, 202548816, 493345801, DFG, FOR 5000, 192626868, 326061700, MO 412/54‐2; DFG, Grant/Award Numbers: Ei 862/29‐1, Ei 862/ 31‐1; GlobNet project, Grant/Award Number: ANR‐16‐CE02‐0009; Investissement d'Avenir, Grant/Award Numbers: Trajectories: ANR‐15‐ IDEX‐02, Montane: OSUG@2020: ANR‐10‐ LAB‐56; Saxon State Ministry for Science, Culture and Tourism (SMWK), Germany, Grant/Award Number: 3‐7304/35/6‐2021/ 48880; sDiv, Grant/Award Number: SFW9.02; ERC‐StG SHIFTFEEDBACK, Grant/Award Number: 851678; European Union's Horizon 2020 research and innovation programme, Grant/Award Numbers: 864287— THRESHOLD—ERC‐2019‐COG, 817946; Swedish Research Council Formas, Grant/Award Number: 2020‐00807; German Federal Environmental Foundation, Grant/Award Number: DBU, 20021/752Peer reviewe

Global mismatches in aboveground and belowground biodiversity

Human activities are accelerating global biodiversity change and have resulted in severely threatened ecosystem services. A large proportion of terrestrial biodiversity is harbored by soil, but soil biodiversity has been omitted from many global biodiversity assessments and conservation actions, and understanding of global patterns of soil biodiversity remains limited. In particular, the extent to which hotspots and coldspots of aboveground and soil biodiversity overlap is not clear. We examined global patterns of these overlaps by mapping indices of aboveground (mammals, birds, amphibians, vascular plants) and soil (bacteria, fungi, macrofauna) biodiversity that we created using previously published data on species richness. Areas of mismatch between aboveground and soil biodiversity covered 27% of Earth's terrestrial surface. The temperate broadleaf and mixed forests biome had the highest proportion of grid cells with high aboveground biodiversity but low soil biodiversity, whereas the boreal and tundra biomes had intermediate soil biodiversity but low aboveground biodiversity. While more data on soil biodiversity are needed, both to cover geographic gaps and to include additional taxa, our results suggest that protecting aboveground biodiversity may not sufficiently reduce threats to soil biodiversity. Given the functional importance of soil biodiversity and the role of soils in human well-being, soil biodiversity should be considered further in policy agendas and conservation actions by adapting management practices to sustain soil biodiversity and considering soil biodiversity when designing protected areas.Peer reviewe

Large-scale drivers of relationships between soil microbial properties and organic carbon across Europe

[Aim] Quantify direct and indirect relationships between soil microbial community properties (potential basal respiration, microbial biomass) and abiotic factors (soil, climate) in three major land-cover types.[Location] Europe.[Time period] 2018.[Major taxa studied] Microbial community (fungi and bacteria).[Methods] We collected 881 soil samples from across Europe in the framework of the Land Use/Land Cover Area Frame Survey (LUCAS). We measured potential soil basal respiration at 20 ºC and microbial biomass (substrate-induced respiration) using an O2-microcompensation apparatus. Soil and climate data were obtained from the same LUCAS survey and online databases. Structural equation models (SEMs) were used to quantify relationships between variables, and equations extracted from SEMs were used to create predictive maps. Fatty acid methyl esters were measured in a subset of samples to distinguish fungal from bacterial biomass.[Results] Soil microbial properties in croplands were more heavily affected by climate variables than those in forests. Potential soil basal respiration and microbial biomass were correlated in forests but decoupled in grasslands and croplands, where microbial biomass depended on soil carbon. Forests had a higher ratio of fungi to bacteria than grasslands or croplands.[Main conclusions] Soil microbial communities in grasslands and croplands are likely carbon-limited in comparison with those in forests, and forests have a higher dominance of fungi indicating differences in microbial community composition. Notably, the often already-degraded soils of croplands could be more vulnerable to climate change than more natural soils. The provided maps show potentially vulnerable areas that should be explicitly accounted for in future management plans to protect soil carbon and slow the increasing vulnerability of European soils to climate change.The LUCAS Soil sample collection is supported by the Directorate-General Environment (DG-ENV), Directorate-General Agriculture and Rural Development (DG-AGRI), Directorate-General Climate Action (DG-CLIMA) and Directorate-General Eurostat (DG-ESTAT) of the European Commission. F. Bastida thanks the Spanish Ministry and European Regional Development Fund (FEDER) funds for the project AGL2017–85755-R (AEI/FEDER, UE), the i-LINK+ 2018 (LINKA20069) from CSIC, and funds from ‘Fundación Séneca’ from Murcia Province (19896/GERM/15). M.C.R. acknowledges support from an European Research Commission (ERC) Advanced Grant (694368). This project was funded by the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig of the German Research Foundation (FZT 118-202548816).Peer reviewe

Blind spots in global soil biodiversity and ecosystem function research

Soils harbor a substantial fraction of the world’s biodiversity, contributing to many crucial ecosystem functions. It is thus essential to identify general macroecological patterns related to the distribution and functioning of soil organisms to support their conservation and consideration by governance. These macroecological analyses need to represent the diversity of environmental conditions that can be found worldwide. Here we identify and characterize existing environmental gaps in soil taxa and ecosystem functioning data across soil macroecological studies and 17,186 sampling sites across the globe. These data gaps include important spatial, environmental, taxonomic, and functional gaps, and an almost complete absence of temporally explicit data. We also identify the limitations of soil macroecological studies to explore general patterns in soil biodiversity-ecosystem functioning relationships, with only 0.3% of all sampling sites having both information about biodiversity and function, although with different taxonomic groups and functions at each site. Based on this information, we provide clear priorities to support and expand soil macroecological research.This manuscript developed from discussions within the German Centre of Integrative Biodiversity Research funded by the German Research Foundation (DFG FZT118). CAG and NE acknowledge funding by iDiv (DFG FZT118) Flexpool proposal 34600850. C.A.G., A.H.B., J.S., A.C., N.G.R., S.C., L.B., M.C.R., F.B., J.O., G.P., H.R.P.P., M.W., T.W., K.K., and N.E. acknowledge funding by iDiv (DFG FZT118) Flexpool proposal 34600844. N.E. acknowledges funding by the DFG (FOR 1451) and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 677232). Finally we would like to acknowledge the contribution of all the authors that provided their datasets for analysis within this paper. Open access funding provided by Projekt DEAL

Temporal Asynchrony of Trophic Status Between Mainstream and Tributary Bay Within a Giant Dendritic Reservoir: The Role of Local-Scale Regulators

Limnologists have regarded temporal coherence (synchrony) as a powerful tool for identifying the relative importance of local-scale regulators and regional climatic drivers on lake ecosystems. Limnological studies on Asian reservoirs have emphasized that climate and hydrology under the influences of monsoon are dominant factors regulating seasonal patterns of lake trophic status; yet, little is known of synchrony or asynchrony of trophic status in the single reservoir ecosystem. Based on monthly monitoring data of chlorophyll a, transparency, nutrients, and nonvolatile suspended solids (NVSS) during 1-year period, the present study evaluated temporal coherence to test whether local-scale regulators disturb the seasonal dynamics of trophic state indices (TSI) in a giant dendritic reservoir, China (Three Gorges Reservoir, TGR). Reservoir-wide coherences for TSICHL, TSISD, and TSITP showed dramatic variations over spatial scale, indicating temporal asynchrony of trophic status. Following the concept of TSI differences, algal productivity in the mainstream of TGR and Xiangxi Bay except the upstream of the bay were always limited by nonalgal turbidity (TSICHL−TSISD <0) rather than nitrogen and phosphorus (TSICHL−TSITN <0 and TSICHL−TSITP <0). The coherence analysis for TSI differences showed that local processes of Xiangxi Bay were the main responsible for local asynchrony of nonalgal turbidity limitation levels. Regression analysis further proved that local temporal asynchrony for TSISD and nonalgal turbidity limitation levels were regulated by local dynamics of NVSS, rather than geographical distance. The implications of the present study are to emphasize that the results of trophic status obtained from a single environment (reservoir mainstream) cannot be extrapolated to other environments (tributary bay) in a way that would allow its use as a sentinel site

The regional and global significance of nitrogen removal in lakes and reservoirs

Author Posting. © The Author(s), 2008. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Biogeochemistry 93 (2009): 143-157, doi:10.1007/s10533-008-9272-x.Human activities have greatly increased the transport of biologically available N through watersheds to potentially sensitive coastal ecosystems. Lentic water bodies (lakes and reservoirs) have the potential to act as important sinks for this reactive N as it is transported across the landscape because they offer ideal conditions for N burial in sediments or permanent loss via denitrification. However, the patterns and controls on lentic N removal have not been explored in great detail at large regional to global scales. In this paper we describe, evaluate, and apply a new, spatially explicit, annual-scale, global model of lentic N removal called NiRReLa (Nitrogen Retention in Reservoirs and Lakes). The NiRReLa model incorporates small lakes and reservoirs than have been included in previous global analyses, and also allows for separate treatment and analysis of reservoirs and natural lakes. Model runs for the mid-1990s indicate that lentic systems are indeed important sinks for N and are conservatively estimated to remove 19.7 Tg N yr-1 from watersheds globally. Small lakes (< 50 km2) were critical in the analysis, retaining almost half (9.3 Tg N yr-1) of the global total. In model runs, capacity of lakes and reservoirs to remove watershed N varied substantially (0-100%) both as a function of climate and the density of lentic systems. Although reservoirs occupy just 6% of the global lentic surface area, we estimate they retain approximately 33% of the total N removed by lentic systems, due to a combination of higher drainage ratios (catchment surface area : lake or reservoir surface area), higher apparent settling velocities for N, and greater N loading rates in reservoirs than in lakes. Finally, a sensitivity analysis of NiRReLa suggests that, on-average, N removal within lentic systems will respond more strongly to changes in land use and N loading than to changes in climate at the global scale.The NSF26 Research Coordination Network on denitrification for support for collaboration (award number DEB0443439 to S.P. Seitzinger and E.A. Davidson). This project was also supported by grants to J.A. Harrison from California Sea Grant (award number RSF8) and from the U.S. Geological Survey 104b program and R. Maranger (FQRNT Strategic Professor)