Journal ArticleDOI
The dual importance of competition and predation as regulatory forces in terrestrial ecosystems: evidence from decomposer food-webs.
David A. Wardle,Gregor W. Yeates +1 more
TLDR
Top predatory nematodes were sometimes strongly related to the microbial but not microbial-feeding trophic levels, indicating that microbial biomass may directly influence top predator numbers, and that the intermediate level may simply serve as a conduit by which resources pass from the bottom to top trophIC levels.Abstract:
The relative importance of predation and competition (resource limitation) in influencing the components of a below-ground food-web consisting of three trophic levels (bacteria and fungi; bacterial-feeding and fungal-feeding nematodes; and top predatory nematodes) was estimated using microbial biomass and nematode frequency data collected throughout a 1-year period in two agro-ecosystems. The study suggested that bacterial and fungal biomass were likely to be regulated by grazing and competition respectively, and that these differences were likely to be attributed to the biological (probably morphological) differences between bacteria and fungi, in contrast to the predictions of the hypothesis of Hairston et al. (1960). Top predatory nematodes were sometimes strongly related to the microbial but not microbial-feeding trophic levels, indicating that microbial biomass may directly influence top predator numbers, and that the intermediate level may simply serve as a conduit by which resources pass from the bottom to top trophic levels. This study also suggests that the detritus food-web acts as two distinct (bacterial-and fungal-based) compartments.read more
Citations
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Journal ArticleDOI
A framework for soil food web diagnostics : extension of the nematode faunal analysis concept
TL;DR: This work enhances the resolution of faunal analyses by providing a weighting system for the indicator importance of the presence and abundance of each functional guild in relation to enrichment and structure of the food web.
Journal ArticleDOI
Interactions between Aboveground and Belowground Biodiversity in Terrestrial Ecosystems: Patterns, Mechanisms, and Feedbacks
David U. Hooper,David E. Bignell,Valerie K. Brown,Lijbert Brussard,J. Mark Dangerfield,Diana H. Wall,David A. Wardle,David C. Coleman,Ken E. Giller,Patrick Lavelle,Wim H. van der Putten,Peter C. de Ruiter,Josef Rusek,Whendee L. Silver,James M. Tiedje,Volkmar Wolters +15 more
TL;DR: For example, the authors of the paper as discussed by the authors presented the results of a study at the Netherlands Institute of Terrestrial Ecology (ZG Heteren) and the University of Utrecht (UTHeteren).
Journal ArticleDOI
Protozoa and plant growth: the microbial loop in soil revisited
TL;DR: Because the regulation of root architecture is a key determinant of nutrient- and water-use efficiency in plants, protozoa provide a model system that may considerably advance the understanding of the mechanisms underlying plant growth and community composition.
Journal ArticleDOI
The influence of biotic interactions on soil biodiversity.
TL;DR: An improved understanding of what drives the diversity of life in the soil, incorporated within appropriate conceptual frameworks, should significantly aid the understanding of the structure and functioning of terrestrial communities.
Book ChapterDOI
Impacts of Disturbance on Detritus Food Webs in Agro-Ecosystems of Contrasting Tillage and Weed Management Practices
TL;DR: While disturbances in CT systems may exert predictable negative effects on most groups of soil organisms, the responses of species assemblages are less predictable, and individual taxonomic species are undoubtedly a more sensitive indicator of ecosystem disturbance than are entire functional groups, and is therefore a more appropriate unit for biomonitoring purposes.
References
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Journal ArticleDOI
Community Structure, Population Control, and Competition
TL;DR: Populations of producers, carnivores, and decomposers are limited by their respective resources in the classical density-dependent fashion and interspecific competition must necessarily exist among the members of each of these three trophic levels.
Journal ArticleDOI
A comparative assessment of factors which influence microbial biomass carbon and nitrogen levels in soil
TL;DR: Relationship with soil chemical factors and macroclimate and global distribution of microbial biomass are studied.
Journal ArticleDOI
Species Diversity Gradients: Synthesis of the Roles of Predation, Competition, and Temporal Heterogeneity
TL;DR: It is suggested that the "predation" and "competition" hypotheses of community organization and species diversity are complementary, and that Predator-mediated escapes by primary producers from herbivores may explain the apparent importance of interspecific competition in certain primary producer associations.
Journal ArticleDOI
Interactions of Bacteria, Fungi, and their Nematode Grazers: Effects on Nutrient Cycling and Plant Growth
TL;DR: The results support claims in the literature that microbial grazers may perform important regulatory functions at critical times in the growth of plants and support a conceptual model proposed in which microfloral grazers were considered as separate state variables.