Biodiversity and decomposition in experimental grassland ecosystems

Abstract

We examined the impact of biodiversity on litter decomposition in an experiment that manipulated plant species richness. Using biomass originating from the experimental species richness gradient and from a species used as a common substrate, we measured rates of decomposition in litterbags in two locations: in situ in the experiment plots and in an adjacent common garden. This allowed us to separate the effects of litter quality and decomposition location on decomposition. We found that plant species richness had a significant, but minor negative effect on the quality (nitrogen concentration) of the biomass. Neither litter type nor location had a consistent effect on the rate of carbon and nitrogen loss over a 1-year period. Thus, the increased productivity and corresponding lower soil available nitrogen levels observed in high diversity plots do not lead to faster litter decomposition or faster nitrogen turnover. This supports the hypothesis that increased productivity corresponding with higher species richness results in increased litter production, higher standing litter pools and a negative feedback on productivity, because of an increased standing nitrogen pool in the litter.

A Survey of Roadside Soil Arthropod Communities from Three Elevations in Mauritius

“…According to Knops et al [14], plant species richness may affect soil processes by influencing microclimate. An increase in plant diversity can lower the soil temperature by 3˚C [15].…”

Intercropping affects the rate of decomposition of soil organic matter and root litter

“…Diversity effects on the decomposition environment may be explored by incubating a standard substrate in soils from different diversity treatments. Grassland biodiversity experiments have shown inconsistent effects of plant diversity on decomposition of standard substrates (e.g., senesced leaves), ranging from faster decomposition (Hector et al 2000;Knops et al 2001;Spehn et al 2005;Vogel et al 2013), no effect (Spehn et al 2000;Scherer-Lorenzen 2008) to slower decomposition (Fornara et al 2009). Plant diversity has frequently been found to affect the soil microbial decomposer community, either through a more diverse litter composition (Chung et al 2007), or through higher biomass production (Zak et al 2003), or through soil fauna-driven effects on soil structure (Stephan et al 2000).…”

Functional diversity, soil features and community functioning: a test in a cerrado site

“…Most studies on the relationships between biodiversity and community functioning have been carried out in temperate regions (Cornelissen and Thompson, 1997;Fortunel, 2009;Hector et al, 2000;Knops et al, 2001;Scherer-Lorenzen, 2008;Scherer-Lorenzen et al, 2003Spehn, 2000). Moreover, on a fine scale, only studies by experimental manipulation of diversity were developed Knops et al, 2001;Scherer-Lorenzen, 2008;Scherer-Lorenzen et al, 2003;Spehn, 2000).…”

“…Moreover, on a fine scale, only studies by experimental manipulation of diversity were developed Knops et al, 2001;Scherer-Lorenzen, 2008;Scherer-Lorenzen et al, 2003;Spehn, 2000). Manipulative experiments allow controlling variation in environmental conditions , but tend to oversimplify the processes.…”