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Spatial resilience of a soil microarthropod community on disturbed areas

2012Spatial resilience of a soil microarthropod community on disturbed areasCASTILLO SANUDO Diana Maria (Colombia)dianamariacastillo@gmail.com
Organisation:University of Coimbra, Coimbra (PT) - Federal University of Rio Grande do Sul, Porto Alegre RS (Brazil)Supervisor :José Paulo Sousa (UC) & Paula Araújo (UFRGS)
Summary: The recovery of soil fauna communities in disturbed areas implies the recolonization of those areas and the subsequent establishment and growth of the different populations. A successful recolonization depends not only from the existence of suitable habitat conditions in these disturbed areas and from the dispersal ability of the organisms, but also from the spatial configuration of disturbed and non-disturbed (donor) patches. In principle, an interspersion of disturbed and donor patches will increase the spatial resilience of these communities, i.e., recolonization will be faster and, assuming minimum habitat conditions are met, community will recover faster on a spatial basis. This study aims to analyse the spatial resilience of Collembola on disturbed areas, focusing on the influence of number of donor patches (non-disturbed habitat) within a disturbed matrix. The experiment consisted of four treatments comprising different numbers of donor patches inside a disturbed matrix, but maintaining the total donor area: 0, 1, 2 and 4 patches. Each treatment was replicated 3 times following a block design. The disturbance was applied to cause a decrease of the number of Collembola in the matrix, but trying to have a low impact on habitat structure. Both soil and litter layers were defauned. Leaf litter was removed and dried at 70°C and placed again. soil was showered with water at 80ºC. Soil cores were collected immediately after and six weeks after disturbance. Soil microarthropods were extracted from these soil corers using the Tullgren funnel method. Extracted Collembola were classified to morphotype level according to Vanderwalle’s scoring traits (mainly related to the dispersal ability of the organisms). Data is still being treated, but we hypothesize that (1) an intermediate number of donor patches originate a faster recolonization of the disturbed matrix. (2) a very low number will decrease recolonization due to the low perimeter/area ratio of the donor areas, whereas (3) a higher number of patches will have a similar effect mainly due to the small area of each patch and the possible extinction of local populations.
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