Earthworms and Plant Residues Modify Nematodes in Tropical Cropping Soils (Madagascar): A Mesocosm Experiment

Free-living nematodes present several characteristics that have led to their use as bioindicators of soil quality. Analyzing the structure of nematofauna is a pertinent way to understand soil biological processes. Earthworms play an important role in soil biological functioning and organic matter dynamics. Their effects on soil nematofauna have seldom been studied. We studied the effect of the tropical endogeic earthworm, Pontoscolex corethrurus, on nematode community structure in a 5-month field mesocosm experiment conducted in Madagascar. Ten different treatments with or without earthworms and with or without organic residues (rice, soybean) were compared. Organic residues were applied on the soil surface or mixed with the soil. The abundance of nematodes (bacterial and fungal feeders) was higher in presence of P. corethrurus than in their absence. The type of plant residues as well as their localisation had significant effects on the abundance and composition of soil nematodes. The analysis of nematode community structure showed that earthworm activity led to an overall activation of the microbial compartment without specific stimulation of the bacterial or fungal compartment

Appendix B. Residual effects of past land use on current ecosystem properties, vegetation composition, and productivity, as revealed by univariate ANOVA.

Residual effects of past land use on current ecosystem properties, vegetation composition, and productivity, as revealed by univariate ANOVA

Appendix D. Relationships between “soil fertility” and environmental variables related to vegetation composition, productivity, and nutrient concentrations and resorption.

Relationships between “soil fertility” and environmental variables related to vegetation composition, productivity, and nutrient concentrations and resorption

Appendix C. Residual effects of past land use on current vegetation nutrient concentrations and resorption, as revealed by univariate ANOVA.

Residual effects of past land use on current vegetation nutrient concentrations and resorption, as revealed by univariate ANOVA

A global meta‐analysis of the relative extent of intraspecific trait variation in plant communities

Recent studies have shown that accounting for intraspecific trait variation (ITV) may better address major questions in community ecology. However, a general picture of the relative extent of ITV compared to interspecific trait variation in plant communities is still missing. Here, we conducted a meta‐analysis of the relative extent of ITV within and among plant communities worldwide, using a data set encompassing 629 communities (plots) and 36 functional traits. Overall, ITV accounted for 25% of the total trait variation within communities and 32% of the total trait variation among communities on average. The relative extent of ITV tended to be greater for whole‐plant (e.g. plant height) vs. organ‐level traits and for leaf chemical (e.g. leaf N and P concentration) vs. leaf morphological (e.g. leaf area and thickness) traits. The relative amount of ITV decreased with increasing species richness and spatial extent, but did not vary with plant growth form or climate. These results highlight global patterns in the relative importance of ITV in plant communities, providing practical guidelines for when researchers should include ITV in trait‐based community and ecosystem studies181214061419CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP479083/2008‐8; 141451/2011‐4; 306573/2009‐1; 303534/2012‐5; 303714/2010‐7BEX 7913/13‐3; PNPD 14540132013/50169‐1; 2014/06453‐0We thank Mark Westoby, Ian Wright and three anonymous reviewers for providing valuable comments on an earlier version of the manuscript. AS was supported by the National Science Foundation Graduate Research Fellowship (DGE‐1247399) and NSF grant DEB‐03089. CV was supported by a Marie Curie International Outgoing Fellowship within the 7th European Community Framework Program (DiversiTraits project, no. 221060) and by the European Research Council (ERC) Starting Grant Project ‘Ecophysiological and biophysical constraints on domestication in crop plants’ (Grant ERC‐StG‐2014‐639706‐CONSTRAINTS). LC received funding from the European Research Council under the 7th European Community Framework Program FP7/2007‐2013 Grant Agreement no. 281422 (TEEMBIO). Financial support to AF came from the Chilean Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT) project No. 1120171. FdB was supported by the Czech Science Foundation, grant P505/12/1296. LWA and BSS were supported by Discovery Grants from the Natural Science and Engineering Research Council of Canada. CS was supported by the Swiss National Science Foundation (PA00P3_136474 and PZ00P3_148261). MBC, MVC, LDSD, VDP and CRF were supported by CAPES‐Brazil (grants BEX 7913/13‐3 and PNPD #1454013) and CNPq‐Brazil (grants 479083/2008‐8, 141451/2011‐4, 306573/2009‐1, 303534/2012‐5 and 303714/2010‐7). MK received support from the JSPS as a Postdoctoral Fellow for Research Abroad. VLD was supported by Sao Paulo Research Foundation (processes: 2013/50169‐1 and 2014/06453‐0). DAP, SJR and NWHM were supported by the New Zealand Ministry of Business, Innovation and Employment core funding to Crown Research Institutes and the Ministry for the Environment. YLBP was supported by the project Postdoc USB (reg.no. CZ.1.07/2.3.00/30.0006) realised through EU Education for Competitiveness Operational Programme and received funding from the European Social Fund and Czech State Budget. The Forest Dynamics Plot of Yasuni National Park has been made possible through the generous support of the Pontifical Catholic University of Ecuador, the government of Ecuador, the Andrew W. Mellon Foundation, the Smithsonian Tropical Research Institute and the University of Aarhus of Denmar

A global meta-analysis of the relative extent of intraspecific trait variation in plant communities

International audienceRecent studies have shown that accounting for intraspecific trait variation (ITV) may better address major questions in community ecology. However, a general picture of the relative extent of ITV compared to interspecific trait variation in plant communities is still missing. Here, we conducted a meta-analysis of the relative extent of ITV within and among plant communities worldwide, using a data set encompassing 629 communities (plots) and 36 functional traits. Overall, ITV accounted for 25% of the total trait variation within communities and 32% of the total trait variation among communities on average. The relative extent of ITV tended to be greater for whole-plant (e.g. plant height) vs. organ-level traits and for leaf chemical (e.g. leaf N and P concentration) vs. leaf morphological (e.g. leaf area and thickness) traits. The relative amount of ITV decreased with increasing species richness and spatial extent, but did not vary with plant growth form or climate. These results highlight global patterns in the relative importance of ITV in plant communities, providing practical guidelines for when researchers should include ITV in trait-based community and ecosystem studies