We explore the connection between the observed spatial patterns of trees and shrubs in the rainforest and the ecological processes that shape these patterns. In particular we study the information that is captured by within-species aggregation and between species co-association. In the first part of this thesis, we introduce an individual-based model of the reproduction and death of trees of a single species. We use this as a null-model to compare within-species aggregation under idealised conditions with those found in the field. We show that the within-species aggregation of a species is expected to be strongly dependent on its local abundance. Based on this result we examine the effect of dioecy and recent changes in local abundance. We find that within-species aggregation maintains information on recent changes in local abundance. In the second part of this thesis, we examine the pair-wise cross-species spatial co-associations. In this work we do not focus on the spatial co-variation of individual species pairs, but on all pairwise combinations of a large group of species. We introduce a novel technique to normalise the cross-species co-association values that helps to make them comparable between different pairs of species, taking into account the different local abundances and within-species spatial patterns of the species. We use these normalised co-association values to find sub-communities of species that are co-located within the same spatial regions. Based on those sub-communities of species, we then investigate the effect of habitat and shade-tolerance in structuring the ecosystem.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:602920 |
| Date | January 2014 |
| Creators | Flügge, A. J. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1426727/ |
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