Climate change has different predicted effects on the range shifts of
two hybridising ambush bug (Phymata) species
Abstract
A universal attribute of species is that their distributions are limited
by numerous factors that may be difficult to quantify. Furthermore,
climate change-induced range shifts have been reported in many taxa, and
understanding the implications of these shifts remains a priority and a
challenge. One approach is to employ species distribution models which
correlates species presence data with a set of predictor variables.
Here, we use MAXENT to predict current suitable habitat and to project
future distributions of two closely related Phymata species in
light of anthropogenic climate change. Using species occurrence data
from museum databases and environmental data from WorldClim, we
identified environmental variables maintaining the distribution of
Phymata americana and Phymata pennsylvanica, and created
binary suitability maps of current distributions for both species on
ArcMap. We then predicted future distributions using the same
environmental variables under different Representative Concentration
Pathways (RCP), created binary suitability maps for future
distributions, and calculated the degree of overlap between the two
species. We found that the strongest predictor to P. americana
ranges was precipitation seasonality, while precipitation of the driest
quarter and mean temperature of the coldest quarter were strong
predictors of P. pennsylvanica ranges. Future ranges for P.
americana are predicted to increase northwestward and southward at
higher CO2 concentrations. Suitable ranges for P.
pennsylvanica are initially predicted to increase, but eventually
decrease with slight fluctuations around range edges. There is an
increase in overlapping ranges in all future predictions. These
differences in optima provide evidence for different environmental
requirements for P. americana and P. pennsylvanica,
accounting for their distinct ranges. Because these species are
ecologically similar and can hybridize, climate change has potentially
important eco-evolutionary ramifications. Overall our results are
consistent with effects of climate change that is highly variable across
species, geographic regions and over time.