10.5061/DRYAD.6PP21NP
Simmonds, Jeremy S.
University of Queensland
van Rensburg, Berndt J.
University of Queensland
University of Johannesburg
Tulloch, Ayesha I. T.
University of Sydney
Australian National University
Maron, Martine
University of Queensland
Data from: Landscape-specific thresholds in the relationship between
species richness and natural land cover
Dryad
dataset
2019
habitat loss
Manorina
natural land cover
<i>Manorina</i>
2019-01-18T21:55:33Z
2019-01-18T21:55:33Z
en
https://doi.org/10.1111/1365-2664.13320
11468 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
1. Thresholds in the relationship between species richness and natural
land cover can inform landscape-level vegetation protection and
restoration targets. However, landscapes differ considerably in
composition and other environmental attributes. If the effect of natural
land cover on species richness depends on (i.e. interacts with) these
attributes, and this affects the value of thresholds in this relationship,
such dependencies must be considered when using thresholds to guide
landscape management. 2. We hypothesised that the amount of natural land
cover at which a threshold occurs would differ in predictable ways with
particular anthropogenic, abiotic and biotic attributes of landscapes. To
test this, we related woodland bird species richness in 251 landscapes,
each 100 km 2, to natural land cover in south-east Australia. We compared
the fit of exponential and threshold models of the richness-natural land
cover relationship, focussing on the extent of natural land cover at which
thresholds presented among landscapes that differed in matrix land use
intensity, heterogeneity, productivity and the prevalence of strong biotic
interactors. We used linear mixed modelling to examine how interactions
between natural land cover and the various landscape attributes affected
the fit of models of species richness. 3. Threshold models of the
richness-natural land cover relationship were always a better fit than
exponential models. Threshold values did not vary consistently with
specific landscape attributes, with the exception of landscapes that were
classified by the prevalence of strong biotic interactors
(hypercompetitive native birds of the genus Manorina). 4. Natural land
cover had a more positive effect on species richness in landscapes when
Manorina prevalence was higher. This positive interaction provided the
biggest improvement in explanatory power of models of species richness. 5.
Synthesis and applications. While we detected an interaction between
Manorina prevalence and the area of natural land cover, generalities
relating to the underlying nature of thresholds in the richness-natural
land cover relationship remain elusive. Complex interactions, relating to
various landscape attributes and associated ecological processes, likely
underpin variation in threshold values. Until these complexities are
better understood, the use of thresholds for informing landscape
management and conservation target setting should be approached with
caution.
Simmonds_etal_JAE_thresholdsFile provides the data used to examine
thresholds in the richness-natural land cover relationship, among
landscape with different attributes.