Relationships at the Aboveground–belowground Interface: Plants, Soil Biota, and Soil Processes

Abstract

Interactions at the aboveground-belowground interface provide important feedbacks that regulate ecosystem processes. Organisms within soil food webs are involved in processes of decomposition and nutrient mineralization, and their abundance and activity have been linked to plant ecophysiological traits such as species identity and the quality and quantity of plant tissue. We tested aboveground-belowground diversity relationships in a naturally developed plant community of native tallgrass prairie by taking soil samples from beneath naturally established grass tillers of chosen characteristics (e.g., homogeneous vs. heterogeneous plant combinations or C 4 vs. C 3 photosynthetic pathway) without imposing any disturbances to existing plant-soil relationships. The goal of this study was to elucidate the consequences, for soil microbiota (microflora phospholipid fatty acids, protozoa, and nematode functional groups) and for C and N mineralization, of plant community properties such as species richness, resource quality, resource heterogeneity, species identity, and presence of exotics. None of the biotic or abiotic soil variables was related to plant resource heterogeneity. Protozoa were not responsive to any of the plant community traits. Some bacterial and nematode groups were affected by plant characteristics specific to a particular plant species, but no uniform pattern emerged. Invasive and native plants generally were similar with respect to soil variables tested in this study. The lack of clear responses of soil variables to plant community traits indicates that idiosyncratic effects dominate both at the plant and soil biotic level and that generalized plant and soil diversity effects are hard to predict.

Nonlinear dynamics in ecosystem response to climatic change: Case studies and policy implications

“…Infilling of spruce and/or shrubs will change ecosystem nutrient status, snowfall retention, and hydrology (Sturm et al, 2001). Such shifts will likely alter both above-and below-ground biodiversity (Kennedy et al, 2002;Porazinska et al, 2003;Heemsbergen et al, 2004). In addition, the expansion of white spruce into tundra will alter fire frequency and distribution so fire suppression may become an important policy issue in natural resource planning (Flannigan and Van Wagner, 1991).…”

Linking Species Richness, Biodiversity and Ecosystem Function in Soil Systems

“…In an extensive experiment carried out under field conditions, Porazinska et al (2003) tested aboveground-belowground diversity relationships in a naturally developed tallgrass prairie ecosystem by comparing soil biota and soil processes occurring in homogeneous and heterogeneous C3-and C4 plant combinations. Some bacterial and nematode groups were affected by plant characteristics specific to a given plant species, but no uniform patterns emerged.…”

Tree diversity and species identity effects on soil fungi, protists and animals are context dependent

“…Through resource availability and niche differentiation, increase in plant biomass and species richness favours the accumulation of soil microbial and faunal biomass and abundance that accommodate greater number of species. Such bottom-up relationships among diversity of food-web organisms occur both aboveground and belowground and are reflected along the trophic cascades (Scherber et al, 2010;Eisenhauer et al, 2013; but see Porazinska et al, 2003). Recent studies on natural grassland plants showed that plant species richness is positively correlated with that of several major fungal groups on a local scale (Hiiesalu et al, 2014;Pellissier et al, 2014).…”