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The big picture from small landscapes

investigations of spatial patterns and processes using a model metacommunity

Åström, Jens (2011). The big picture from small landscapes. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2011:60
ISBN 978-91-576-7604-7
[Doctoral thesis]

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Habitat fragmentation is a major current threat to natural environments. Still, fundamental questions of what influences ecological communities in spatially structured habitats are unanswered. In this thesis, microarthropods in moss patches were used in a model system, where both biotic and abiotic factors could be manipulated. In four studies, I investigated how isolation distance, connectivity, habitat size, dispersal barriers, matrix quality, and environmental quality influenced the occurrence, abundance and diversity of mites (Acari), and springtails (Collembola). First, I show that the effects of habitat fragmentation was profound and species specific. Inter-patch dispersal between isolated patches was low in natural settings compared to mainland-island dispersal, and populations in the mainland had a large influence even on distant communities. Secondly, I show that connecting fragmented patches by habitat corridors increased the dispersal throughout the landscape, but that this had complex and unpredictable results. Habitat corridors interacted with the surrounding matrix which led to counterintuitive patterns. For predatory mites and collembolans, habitat corridors had a negative impact when the corridors intersected a matrix of poor quality, severely reducing their abundance, probably due to increased edge effects. Moreover, oribatid mites decreased in landscapes with corridors, likely due to increased predation, caused by increased connectivity, favoring predators. Thirdly, I show that community assembly following a disturbance event was predictable, based on random colonization of individuals from the surrounding pool of individuals. In contrast, community disassembly following habitat fragmentation was highly unpredictable, and could not be explained by a random loss of individuals. The fourth study examined natural situations and show that while the spatial factors connectivity and distance had a lasting influence on local communities, habitat area was the major determining factor for both density and species richness.

Authors/Creators:Åström, Jens
Title:The big picture from small landscapes
Subtitle:investigations of spatial patterns and processes using a model metacommunity
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2011
Number of Pages:45
IJens Åström and Jan Bengtsson (2011). Patch size matters more than dispersal distance in a mainland-island metacommunity. Oecologia (in press). DOI: 10.1007/s00442-011-2024-y
IIJens Åström and Tomas Pärt. Matrix quality and trophic interactions determine response to corridors in an experimental metacommunity. (manuscript).
IIIJens Åström. Predictable community assembly and unpredictable disassembly in a spatially structured landscape. (manuscript).
IVJens Åström, Niklas Lindberg and Jan Bengtsson. Lasting influence of space and environment on community composition in a naturally fragmented moss patch ecosystem. (manuscript).
Place of Publication:Uppsala
Publisher:Institutionen för ekologi, Sveriges lantbruksuniversitet
ISBN for printed version:978-91-576-7604-7
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L20 Animal ecology
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Ecology
Agrovoc terms:habitats, ecology, landscape, acarina, collembola, cryptostigmata, predation
Keywords:Metacommunity ecology, Fragmentation, Dispersal, Connectivity, Disturbance, Microarthropods, Acari, Collembola, Oribatida
Permanent URL:
ID Code:8169
Department:(NL, NJ) > Dept. of Ecology
(S) > Dept. of Ecology
External funders:Swedish Research Council
Deposited By: Jens Åström
Deposited On:13 Jun 2011 07:44
Metadata Last Modified:02 Dec 2014 10:46

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