Search results for "Trophic species"
showing 5 items of 5 documents
A modified niche model for generating food webs with stage‐structured consumers: The stabilizing effects of life‐history stages on complex food webs
2021
Abstract Almost all organisms grow in size during their lifetime and switch diets, trophic positions, and interacting partners as they grow. Such ontogenetic development introduces life‐history stages and flows of biomass between the stages through growth and reproduction. However, current research on complex food webs rarely considers life‐history stages. The few previously proposed methods do not take full advantage of the existing food web structural models that can produce realistic food web topologies.We extended the niche model developed by Williams and Martinez (Nature, 2000, 404, 180–183) to generate food webs that included trophic species with a life‐history stage structure. Our me…
Functional diversity of decomposer organisms in relation to primary production
1998
Abstract The term `biodiversity' is claimed to lack connections to a serious scientific background. In this work, we approached the concept of biodiversity from a functional point of view by asking: “At what level of the ecological organization (species, trophic species/feeding guilds, trophic levels etc.) should reduction in biodiversity matter to bring about visible changes in ecosystem performance?” We investigate the concepts of `functional diversity' and `ecosystem performance' in relation to feeding habits (such as fungivory, detritivory etc.) of soil fauna and plant growth. After analysing the results of a number of microcosm studies, we came into the following conclusions: (i) troph…
Sensitivity of ecosystem functioning to changes in trophic structure, functional group composition and species diversity in belowground food webs
2002
The objective of the present paper, using decomposer food webs as a tool, is to explore the levels of the ecological hierarchy (trophic groups, feeding guilds, species populations) at which reduction in complexity brings about significant changes in ecosystem performance. A review is given of various mini-ecosystem studies that have recently been conducted at the University of Jyvaskyla. It is hypothesized that the typical features of soils as a habitat, and the peculiarities of belowground food webs, such as the commonness of indirect interactions (mediated through abiotic resources) among the biota, together with the high frequency of polyphagy/omnivory among soil organisms, produce a div…
A modified niche model for generating food webs with stage-structured consumers : The stabilizing effects of life-history stages on complex food webs
2021
1. Almost all organisms grow in size during their lifetime and switch diets, trophic positions, and interacting partners as they grow. Such ontogenetic development introduces life-history stages and flows of biomass between the stages through growth and reproduction. However, current research on complex food webs rarely considers life-history stages. The few previously proposed methods do not take full advantage of the existing food web structural models that can produce realistic food web topologies. 2. We extended the niche model by Williams & Martinez (2000) to generate food webs that included trophic species with a life-history stage structure. Our method aggregated trophic species …
Exposing the structure of an Arctic food web
2015
15 pages; International audience; How food webs are structured has major implications for their stability and dynamics. While poorly studied to date, arctic food webs are commonly assumed to be simple in structure, with few links per species. If this is the case, then different parts of the web may be weakly connected to each other, with populations and species united by only a low number of links. We provide the first highly resolved description of trophic link structure for a large part of a high-arctic food web. For this purpose, we apply a combination of recent techniques to describing the links between three predator guilds (insectivorous birds, spiders, and lepidopteran parasitoids) a…