Data from: Spatio-temporal dynamics of a tree-killing beetle and its predator

Resolving linkages between local-scale processes and regional-scale
patterns in abundance of interacting species is important for
understanding long-term population stability across spatial scales.
Landscape patterning in consumer population dynamics may be largely the
result of interactions between consumers and their predators, or driven by
spatial variation in basal resources. Empirical testing of these
alternatives has been limited by the lack of suitable data. In this study,
we analyzed an extensive network of spatially replicated time series to
characterize the local and regional processes affecting spatio-temporal
dynamics of a tree-killing bark beetle (Dendroctonus frontalis or SPB) and
its key predator (Thanasimus dubius) across the southeastern United
States. We first used a mechanistic model to evaluate factors affecting
the stability of 95 predator-prey time series and then conducted spatial
analyses to evaluate scale dependence in the factors affecting the
geographical patterning of this system. Across the region, population
fluctuations of both species were correlated in space beyond 400 km but
there was notable spatial variation in the deterministic and stochastic
processes influencing forest-scale (local) fluctuations. Time series
analyses indicated that local dynamics of SPB and T. dubius are not
cyclical. Instead, the abundance of T. dubius responded almost
instantaneously to changes in SPB abundance. Spatial variation in
long-term forest-scale abundance of both species was linked most strongly
to the abundance of pine habitat indicating a stronger role for resource
availability in SPB population dynamics than top–down effects. Our results
are consistent with other studies indicating that animal populations tend
to be synchronized in space via spatially correlated processes such as
weather; yet local dynamics tend to be linked to smaller-scale host
patterns. Our study provides a rare empirical assessment of how local
processes scale up to produce landscape patterns that influence forest
ecology and forest management.