Ecological Drivers of Species Distributions and Niche Overlap for Three Subterranean Termite Species in the Southern Appalachian Mountains, USA

Abstract

In both managed and unmanaged forests, termites are functionally important members of the dead-wood-associated (saproxylic) insect community. However, little is known about regional-scale environmental drivers of geographic distributions of termite species, and how these environmental factors impact co-occurrence among congeneric species. Here we focus on the southern Appalachian Mountains—a well-known center of endemism for forest biota—and use Ecological Niche Modeling (ENM) to examine the distributions of three species of Reticulitermes termites (i.e., R. flavipes, R. virginicus, and R. malletei). To overcome deficiencies in public databases, ENMs were underpinned by field-collected high-resolution occurrence records coupled with molecular taxonomic species identification. Spatial overlap among areas of predicted occurrence of each species was mapped, and aspects of niche similarity were quantified. We also identified environmental factors that most strongly contribute to among-species differences in occupancy. Overall, we found that R. flavipes and R. virginicus showed significant niche divergence, which was primarily driven by dry-season precipitation. Also, all three species were most likely to co-occur in the mid-latitudes of the study area (i.e., northern Alabama and Georgia, eastern Tennessee and western North Carolina), which is an area of considerable topographic complexity. This work provides important baseline information for follow-up studies of local-scale drivers of these species’ distributions. It also identifies specific geographic areas where future assessments of the frequency of true syntopy vs. micro-allopatry, and associated interspecific competitive interactions, should be focused.

Belowground community turnover accelerates the decomposition of standing dead wood

“…Posts were scored for presence or absence of termite and borer activity in the buried, interface, and aerial sections of the post. Although multiple termite species are found in the region (Hyseni and Garrick 2019), all termites in the posts we observed belonged to the species R. flavipes , an observation consistent with an earlier survey of termites at both locations (King et al. 2013).…”

The role of glacial‐interglacial climate change in shaping the genetic structure of eastern subterranean termites in the southern Appalachian Mountains, USA

“…Accordingly, if high precipitation was important for facilitating range expansion, these conditions seem to have been in place at a time that coincides with colonization of the central region. Furthermore, seasonal differences in precipitation between the southern and northern portions of the study region (Hyseni & Garrick, ) may have led to different flight phenologies and thus seasonal isolation and niche partitioning. Consistent with this, dbRDA revealed that in addition to spatial structuring of genetic variation, wet‐season precipitation accounted for the remainder of genetic differentiation of the Southern cluster compared to the other two.…”

Ecological Niche Modeling to Calculate Ideal Sites to Introduce a Natural Enemy: The Case of Apanteles opuntiarum (Hymenoptera: Braconidae) to Control Cactoblastis cactorum (Lepidoptera: Pyralidae) in North America

“…A strategy developed to select appropriate sites for the natural enemy’s liberation based on prioritizing its environmental requirements could increase the success of biological control agents [ 32 ]. Ecological niche modeling is a tool widely used for estimating environmental suitability for organisms, building ecological models for successful prediction in specific geographic areas of interest [ 33 , 34 , 35 , 36 ]. In this study, we calculated the ecological niche model for A. opuntiarum and C. cactorum to define regions of environmental suitability and determine niche overlap for the purpose of predicting areas of successful establishment of this parasitoid in North America.…”