TITLE: Diagrams to explain niche complementarity
DATE: 2021-07-31
AUTHOR: John L. Godlee
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I've just finished writing the background chapter for my PhD
thesis. I've been writing about how competing species co-exist by
occupying different niche space. To visualise nice complementarity,
I made these schematic diagrams, which I've included below along
with the length caption I included in the chapter.
Schematic diagrams demonstrating niche occupation and secondary
controls on the mechanism of niche complementarity. Each density
plot shows a number of species, each represented by the species
functional contribution (productivity) under different
environmental conditions (niche space) within the larger
environmental niche volume (dashed line). a) shows how the degree
of overlap in functional niche of two species affects the total
utilisation of the environmental niche volume (area under all
species curves). When species are functionally distinct (left),
more of the environmental niche volume is utilised. Removal of a
species in this case would result in a large reduction in ecosystem
productivity, while on the right, where functional redundancy is
high, removal of a single species would have negligible effects. b)
shows the effect of adding a functionally distinct species to an
ecosystem. c) shows the effect of niche breadth on niche volume
utilisation. On the left, three generalist species overlap in their
functional niche. While each species has relatively incomplete
utilisation of the environmental niche volume, this is offset as
each species may occupy a wide range of environmental conditions.
If the red species was removed, there would be only a marginal
reduction in ecosystem productivity. On the right, three specialist
species have a narrower niche breadth but a more complete
utilisation of the environmental niche under ideal conditions. If a
species was removed from this ecosystem, there would be a much
greater reduction in ecosystem productivity.
