Primary assembly of soil communities: disentangling the effect of dispersal and local environment

Abstract

It has long been recognised that dispersal abilities and environmental factors are important in shaping invertebrate communities, but their relative importance for primary soil community assembly has not yet been disentangled. By studying soil communities along chronosequences on four recently emerged nunataks (ice-free land in glacial areas) in Iceland, we replicated environmental conditions spatially at various geographical distances. This allowed us to determine the underlying factors of primary community assembly with the help of metacommunity theories that predict different levels of dispersal constraints and effects of the local environment. Comparing community assembly of the nunataks with that of non-isolated deglaciated areas indicated that isolation of a few kilometres did not affect the colonisation of the soil invertebrates. When accounting for effects of geographical distances, soil age and plant richness explained a significant part of the variance observed in the distribution of the oribatid mites and collembola communities, respectively. Furthermore, null model analyses revealed less co-occurrence than expected by chance and also convergence in the body size ratio of co-occurring oribatids, which is consistent with species sorting. Geographical distances influenced species composition, indicating that the community is also assembled by dispersal, e.g. mass effect. When all the results are linked together, they demonstrate that local environmental factors are important in structuring the soil community assembly, but are accompanied with effects of dispersal that may "override" the visible effect of the local environment.

Oribatid mite communities on the bark of dead wood vary with log type, surrounding forest and regional factors

“…However, the structure of bark and the type of tree logs also affected the oribatid mite community structure (deterministic niche-based species assemblage). Hence, our data support the conclusion that similar to the soil Ingimarsdóttir et al, 2012) oribatid mite communities on the bark of dead wood are assembled by both neutral and niche based processes.…”

Animal Successional Pathways for about 200 Years Near a Melting Glacier: A Norwegian Case Study

“…On Iceland, springtails and oribatid mites easily colonised recently emerged nunataks, and isolation of a few kilometres did not affect the colonisation [16]. These results strongly indicate aerial dispersal, and our study supports this.…”

“…In addition to the present case study, there are studies on arthropod succession in glacier forelands from the Alps [5,[7][8][9][10][11], from Svalbard [12][13][14][15], from Iceland [16] and from Norway [17][18][19][20][21][22][23].…”

If we build it, will they colonize? A test of the field of dreams paradigm with soil macroinvertebrate communities

“…With a few notable exceptions (Berg and Hemerik, 2004;Ingimarsdóttir et al, 2012), soil invertebrate reassembly is rarely studied and the factors influencing their recovery are even less understood. This study documents the role of time since cessation of cultivation coinciding with perennial plant community development on soil macroinvertebrate recovery during tallgrass prairie restoration.…”