Significant local-scale plant-insect species richness relationship independent of abiotic effects in the temperate Cape Floristic Region biodiversity hotspot
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Public Library of Science
Abstract
Globally plant species richness is a significant predictor of insect richness. Whether this is
the result of insect diversity responding directly to plant diversity, or both groups responding
in similar ways to extrinsic factors, has been much debated. Here we assess this relationship
in the Cape Floristic Region (CFR), a biodiversity hotspot. The CFR has higher plant
diversity than expected from latitude (i.e., abiotic conditions), but very little is known about
the diversity of insects residing in this region. We first quantify diversity relationships at multiple
spatial scales for one of the dominant plant families in the CFR, the Restionaceae, and
its associated insect herbivore community. Plant and insect diversity are significantly positively
correlated at the local scales (10±50 m; 0.1±3 km), but not at the regional scales (15±
20 km; 50±70 km). The local scale relationship remains significantly positively correlated
even when accounting for the influence of extrinsic variables and other vegetation attributes.
This suggests that the diversity of local insect assemblages may be more strongly influenced
by plant species richness than by abiotic variables. Further, vegetation age and plant
structural complexity also influenced insect richness. The ratio of insect species per plant
species in the CFR is comparable to other temperate regions around the world, suggesting
that the insect diversity of the CFR is high relative to other areas of the globe with similar abiotic
conditions, primarily as a result of the unusually high plant diversity in the region.
Introduction
Description
CITATION: Kemp, J. E. & Ellis, A. G. 2017. Significant local-scale plant-insect species richness relationship independent of abiotic effects in the temperate Cape Floristic Region biodiversity hotspot. PLoS ONE, 12(1):1-16, doi:10.1371/journal.pone.0168033.
The original publication is available at http://journals.plos.org/plosone
Publication of this article was funded by the Stellenbosch University Open Access Fund.
The original publication is available at http://journals.plos.org/plosone
Publication of this article was funded by the Stellenbosch University Open Access Fund.
Keywords
Plant insect relationships, Abiotic effects -- Cape Floristic Region, Biodiversity conservation, Insects -- Cape Floristic Region -- Diversity
Citation
Kemp, J. E. & Ellis, A. G. 2017. Significant local-scale plant-insect species richness relationship independent of abiotic effects in the temperate Cape Floristic Region biodiversity hotspot. PLoS ONE, 12(1):1-16, doi:10.1371/journal.pone.0168033