@article {4295, title = {Soil nematode abundance and functional group composition at a global scale}, journal = {Nature}, volume = {572}, year = {2019}, month = {08/2019}, abstract = {

Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, few quantitative, spatially explicit models of the active belowground community currently exist. In particular, nematodes are the most abundant animals on Earth, filling all trophic levels in the soil food web. Here we use 6,759 georeferenced samples to generate a mechanistic understanding of the patterns of the global abundance of nematodes in the soil and the composition of their functional groups. The resulting maps show that 4.4 \± 0.64 \× 1020 nematodes (with a total biomass of approximately 0.3 gigatonnes) inhabit surface soils across the world, with higher abundances in sub-Arctic regions (38\% of total) than in temperate (24\%) or tropical (21\%) regions. Regional variations in these global trends also provide insights into local patterns of soil fertility and functioning. These high-resolution models provide the first steps towards representing soil ecological processes in global biogeochemical models and will enable the prediction of elemental cycling under current and future climate scenarios.

}, keywords = {LTER-MCM}, doi = {10.1038/s41586-019-1418-6}, url = {https://www.nature.com/articles/s41586-019-1418-6}, author = {van den Hoogen, Johan and Geisen, Stefan and Routh, Devin and Ferris, Howard and Traunspurger, Walter and Wardle, D and de Goede, Ron G. M. and Byron Adams and Ahmad, Wasim and Andriuzzi, Walter S. and Richard D. Bardgett and Bonkowski, Michael and Campos-Herrera, Raquel and Cares, Juvenil E. and Caruso, Tancredi and de Brito Caixeta, Larissa and Chen, Xiaoyun and Costa, Sofia R. and Creamer, Rachel and Mauro da Cunha Castro, Jos{\'e} and Dam, Marie and Djigal, Djibril and Escuer, Miguel and Griffiths, Bryan S. and Guti{\'e}rrez, Carmen and Hohberg, Karin and Kalinkina, Daria and Kardol, Paul and Kergunteuil, Alan and Korthals, Gerard and Krashevska, Valentyna and Kudrin, Alexey A. and Li, Qi and Liang, Wenju and Magilton, Matthew and Marais, Mariette and Mart{\'\i}n, Jos{\'e} Antonio Rodr{\'\i}guez and Matveeva, Elizaveta and Mayad, El Hassan and Mulder, Christian and Mullin, Peter and Neilson, Roy and Nguyen, T. A. Duong and Uffe N. Nielsen and Okada, Hiroaki and Rius, Juan Emilio Palomares and Pan, Kaiwen and Peneva, Vlada and Pellissier, Lo{\"\i}c and Carlos Pereira da Silva, Julio and Pitteloud, Camille and Powers, Thomas O. and Powers, Kirsten and Quist, Casper W. and Rasmann, Sergio and Moreno, Sara S{\'a}nchez and Scheu, Stefan and Set{\"a}l{\"a}, Heikki and Sushchuk, Anna and Tiunov, Alexei V. and Trap, Jean and van der Putten, W and Vesterg{\r a}rd, Mette and Villenave, Cecile and Waeyenberge, Lieven and Diana H. Wall and Wilschut, Rutger and Wright, Daniel G. and Yang, Jiue-in and Crowther, Thomas Ward} } @article {4107, title = {Spatial and temporal patterns of microbial mats and associated invertebrates along an Antarctic stream}, journal = {Polar Biology}, volume = {41}, year = {2018}, month = {10/2018}, pages = {1911{\textendash}1921}, abstract = {

Microbial biofilms are biological hotspots in many alpine and polar ecosystems, but the controls on and functional significance of their fauna are little known. We studied cyanobacterial mats and the underlying sediment in a glacial meltwater stream in the McMurdo Dry Valleys, Antarctica. We investigated mat biomass (total and phototrophic), diatoms, and micro-meiofauna (nematodes, rotifers, and tardigrades) at nine sites along a 1670 m stream reach in a cold, low-flow growing season, and in a warmer growing season in which peak flows (above 100 L s\−1) scoured the mats. Diatom and invertebrate communities were not related, but mat biomass in the low-flow year was negatively related to nematode abundance, including that of the omnivore\ Eudorylaimus. In the high-flow year that followed, invertebrate abundance was reduced in the mats, diatom community structure was altered, and mat biomass was higher. The difference in invertebrate abundance between years was greater in mats in upstream reaches, where the greatest increases in flow velocity may have occurred, and was negligible in mats in downstream reaches as well as in the sediment beneath the mats. Integrating our results with previous findings, we generate two predictive hypotheses to be tested in glacial meltwater streams: (1) under peak flows invertebrates decline in the microbial mats, while (2) the sediment beneath the mats is a refuge from the flow disturbance. Our results also suggest that, under stable flow conditions, microinvertebrate grazers could exert top-down control on microbial mat biomass.

}, keywords = {LTER-MCM, diatoms, Disturbance, Dry valleys, Epilithon, Microfauna, Stream flow}, doi = {10.1007/s00300-018-2331-4}, url = {http://link.springer.com/10.1007/s00300-018-2331-4}, author = {Andriuzzi, Walter S. and Lee F. Stanish and Breana L. Simmons and Chris Jaros and Byron Adams and Diana H. Wall and Diane M. McKnight} }