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EARTH SCIENCE > Biosphere > Ecological Dynamics > Food-web Dynamics

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  • The Antarctic food webs represent two entire above-belowground communities from Signy Island Reference Sites on Signy Island, one of the South Orkney Islands in the Maritime Antarctic. The two communities are a dry moss community (Antarctic dry tundra) and a wet moss community (Antarctic wet tundra). These two communities were the focus of intensive biological study by personnel from the British Antarctic Survey over the course of a decade in the 1970''s, of which the results were finally compiled into a meta-analysis by Davis (1981). The Jacobians of the dry and wet tundra were calculated by Neutel and Thorne (2014) using the empirical biomass and flow data of the respective systems from Davis'' analysis. The Jacobians represent the interaction strengths of the species in the two food webs, evaluated at equilibrium.

  • Among all possible interaction types, trophic interactions are easily observable and essential in terms of energy transfer, and thus binary networks have arisen as the most straightforward method to describe complex ecological communities. These food-web models also inform on the ecosystem dynamics and function, and the patterns arising from food web topology can be indicators for ecosystem stability. We present a comprehensive pelagic network for the Scotia Sea underpinned by surveys and dietary studies conducted in the Scotia Sea in the last century. Selection of the trophic links followed a protocol based on taxonomy and geographic location, and was further refined based on the consumer and resource depth ranges and their body size ratios. The resulting network consists on 228 nodes and 10880 links which represent the main trophic paths in the Scotia Sea ecosystem and can serve as a basis for ecosystem modelling in the Scotia Sea or comparison with other ecosystems. Funding was provided by NERC Highlight Topic grant NE/N005937/1 and NERC Fellowship NE/L011840/1.

  • The soil food webs in this collection represent a total of 32 belowground communities studied by Neutel et al. (2007), from two natural successions in sandy dune soils: one on the Waddensea Island of Schiermonnikoog in the north of the Netherlands and the other at Hulshorsterzand, on the Veluwe, in the central Netherlands. The study sites, which constitute the two gradients, represent four consecutive stages in chronosequences of early primary vegetation succession, increasing in aboveground and below-ground productivity. The Jacobians of the 32 food webs (two series, four stages with four replicates per stage) were calculated by Neutel et al. (2007) from observed average biomass data of the respective systems, and inferring steady-state biomass flow data using a procedure described by Hunt et al. (1987). The Jacobians represent the interaction strengths of the species in the two food webs, evaluated at equilibrium.

  • The soil food webs in this collection represent seven belowground communities from native and agricultural soils. The seven communities are from experimental research sites in the USA, Sweden and the Netherlands. The Jacobians of the seven food webs were calculated by de Ruiter et al. (1995) using the empirical biomass data of the respective systems, and inferring steady-state biomass flow data using a procedure described by Hunt et al. (1987), see further references below. The Jacobians represent the interaction strengths of the species in the two food webs, evaluated at equilibrium.

  • This dataset comprises conventional stomachs contents data for the biomass-dominant species of mesopelagic fish, particularly myctophid fish (Family Myctophidae) in the Scotia Sea. The data were collected by depth-discrete RMT25 net trawls deployed between 0-1000 m between the Antarctic Polar Front and the South Orkney Islands. Samples were collected repeatedly at nominal sampling stations during austral autumn 2004, spring 2006, summer 2008 and autumn 2009 for analyses examining the trophodynamics of Southern Ocean mesopelagic fish and their role in the food web. The data are the quantitative measures of diet composition (prey abundance, frequency and mass) observed from microscope analyses of individual fish stomachs per species.