EARTH SCIENCE > Biosphere > Terrestrial Ecosystems
Type of resources
Contact for the resource
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.
This dataset consists of (i) 673 red-green-blue (RGB) images, (ii) precise coordinates of ground control points and harvest plot corners, (iii) the photogrammetrically reconstructed dense point cloud (comprising of 228,315,000 points with XYZ and RGB values), (iv) four normalised difference vegetation index (NDVI) maps, (v) aboveground biomass data from harvest plots, and (vi) observations of the ground surface obtained from a walkover survey with a GNSS instrument. These data were collected over the eastern part of Qikiqtaruk - Herschel Island, in the Canadian Yukon (69.5N, 138.8W). The images were collected in July and August 2016. Further details on the image processing are provided in the lineage section. This dataset was created by Andrew Cunliffe, with support from Isla Myers-Smith, Jakob Assmann, Jeffery Kerby and Gergana Daskalova (https://teamshrub.com/), in order to inform ongoing ecological monitoring studies in this area. This research was supported by the Natural Environment Research Council (NE/M016323/1), and the NERC Geophysical Equipment Facility (GEF:1063).
Genetic variation on a spatial scale was assessed, using both DNA fingerprinting and sequencing-based approaches, in the Antarctic endemics Buellia frigida, Carbonia vorticosa and Amandinea petermananii, and in the bipolar species Caloplaca saxicola, Umbilicaria decussata and Cladonia galindezii. PCR-based (Polymerase Chain Reaction) molecular biology techniques, were used as they are ideal for working with lichens because little starting material is required. See Fabian et al. 2007 for further information on analyses and results.
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.
The fieldwork involved collection of fertile lichens from a range of sites across the Antarctic Peninsula and isolation of the lichen-forming fungi into pure culture in a laboratory at Rothera. Approximately 5,600 monospore cultures were isolated, including B frigida. Approximately 400 thalli of Usnea species, and 3 O. frigida thalli have also been collected for whole thallus analysis. Logarithmic sampling transects of B frigida were conducted at Rothera (2 transects) and on Anchorage Island (one transect) to examine the genetic variation and geographic variation. All thalli of B frigida collected from the transects were successfully used to generate viable spores from four individual apothecia from each thallus. 16 spores were subcultured and maintained from each apothecium.