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Species and functional plant diversity enhance ecosystem functions in the central Monte desert
Author(s) -
Chaves Jimena E.,
Aranibar Julieta N.,
Gatica Gabriel
Publication year - 2020
Publication title -
journal of vegetation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 115
eISSN - 1654-1103
pISSN - 1100-9233
DOI - 10.1111/jvs.12952
Subject(s) - species evenness , species richness , ecosystem , edaphic , environmental science , ecology , species diversity , soil organic matter , biodiversity , plant community , soil water , biology
Abstract Questions Niche complementarity has been proposed as the underlying mechanism for optimizing resource use of plants in diverse ecosystems, usually associated with their functional traits and not with the species number per se. Our main questions were: (a) does species diversity optimize the use of resources in arid ecosystems; (b) is there redundancy of species in the use of water and nutrients; and (c) what diversity components most affect ecosystem functions of water regulation and material cycling? Location Central Monte desert, Argentina. Methods We selected vegetation patches with different species ( SD ) and functional diversities ( FD ), where we measured indicators of water regulation and material cycling. At two soil depths, we measured soil nitrate, phosphate, organic matter, chloride, electrical conductivity, and pH. We also determined decomposition, plant water use efficiency (foliar δ 13 C of C3 plants), and nitrogen use (δ 15 N). These variables were used as response variables, while total plant cover, species richness, Shannon, Simpson, evenness, and Rao's functional diversity indexes were used as predictors. Results At the soil surface, response variables were better explained by models that included diversity ( SD , FD or both) instead of evenness, total plant cover or null model. A diversity effect was not detected in deeper soil layers for most variables, except for electric conductivity, which had a positive effect on FD . Richness explained plant δ 13 C but had no influence on plant δ 15 N. Conclusions Diversity of plant community influences ecosystem processes, as it increases decomposition, soil organic matter, and nutrient availability at the surface, and decreases water losses to the subsoil and plant water use efficiency. Both SD and FD explained one or more ecosystem processes of water regulation and material cycling, suggesting that individual species contribute to ecosystem functioning, with a low redundancy for arid areas.