Aim The Madrean Sky Island Archipelago is a North American biodiversity hotspot composed of similar to 60 isolated mountains that span the Cordilleran Gap between the Rocky Mountains and the Sierra Madre Occidental. Characterized by discrete patches of high-elevation montane habitat, these "sky islands" serve as stepping stones across a "sea" of desert scrub/grassland. Over this coming century, the region is expected to shift towards a warmer and drier climate. We used species distribution modelling to predict how the spatial distribution of montane habitat will be affected by climate change. Location Madrean Sky Island Archipelago, south-west United States and north-west Mexico (latitude, 29-34 degrees N; longitude, 107-112 degrees W). Methods To approximate the current distribution of montane habitat, we built species distribution models for five high-elevation species (Ceanothus fendleri, Pinus strobiformis, Quercus gambelii, Sciurus aberti, and Synuchus dubius). The resulting models were projected under multiple climate change scenarios-four greenhouse gas concentration trajectories (RCP 2.6, 4.5, 6.0, and 8.5) for each of three climate models (CCSM4, MPI-ESM-LR, and NorESM1-M)-to generate predicted distributions for the years 2050 and 2070. We performed chi-squared tests to detect any future changes to total montane habitat area, and Conover-Iman tests to evaluate isolation among the discrete montane habitat patches. Results While the climate models differ with respect to their predictions as to how severe the effects of future climate change will be, they all agree that by as early as year 2050, there will be significant montane habitat loss and increased montane habitat patch isolation across the Madrean Archipelago region under a worst-case climate change scenario (RCP 8.5). Main conclusions Our results suggest that under 21st-century climate change, the Madrean Sky Islands will become increasingly isolated due to montane habitat loss. This may affect their ability to serve as stepping stones and have negative implications for the region's biodiversity.

The heteropteran fauna of Illinois is diverse and well-surveyed, comprising approximately 680 species distributed among 40 of the 57 families represented in the Nearctic region (Henry and Froeschner, 1988; Swanson, unpublished). This diversity arises, in part, from the state’s latitudinal extent, as well as from the varied habitats present in the state, ranging from dune land bordering Lake Michigan in the northeast to large tracts of old growth forest in the Shawnee National Forest and bald cypress/tupelo swamps in the south. Also present is a generous array of riparian, lentic and lotic zones, seep springs, cave systems, and various discrete tall grass, sand, hill, and floodplain prairie ecosystems (White and Madany, 1978; Schwegman, 1987; Taylor et al., 2009). Consequently, the early development of natural history programs catalyzed the accumulation of knowledge regarding the region’s biota (Post, 1991). Despite Illinois’ strong history of biotic surveys extending back into the first half of the 19th century, new records of native species are still being discovered within its borders (e.g., Tin erella et al., 2009; McPherson et al., 2011). In the fall of 2012, as part of a larger insect bioinventory, two of the authors (ADY and SJT) collected a specimen of a minute, rarely encountered lygaeoid in a pitfall trap laid in the Braidwood Dunes and Savanna Nature Preserve (Will County, northeastern Illinois). Discovered in the lot of Braidwood heteropteran samples sent to DRS, the specimen (Fig. 1), a single adult male, was identified as Sisamnes claviger (Uhler, 1895), a species previously unknown from Illinois. This individual, preserved in ethanol, has been deposited in the Illinois Natural History Survey Insect Collection, University of Illinois at Urbana-Champaign, Champaign, Illinois (INHS), and bears the following label data: ILLINOIS: Will Co., Braidwood Dunes & Savanna Nature Preserve, 1.5 km SE of Braidwood on IL 113, 41.25290N -88.19970W, Site 189 (mesic sand prairie), Pitfall trap: B, 18 August 2011–2 September 2011, Sample Number: 5010, Lot Number: BRD 32204, Collectors: A. D. Yanahan, S. J. Taylor, det. D. R. Swanson 2013, INHS Insect Collection 780,190. Details of the collecting event, including a discussion of the habitat, are treated later in the text. Volume 124, Number 5, April 2015 357

Accurately measuring biodiversity is essential for successful conservation planning. Due to biodiversity’s complexity, specific taxa are often chosen as indicators of patterns of diversity as a whole. Such taxa can include vegetation which can inform conservation decisions by demarcating land units for management strategies. For land units to be useful, they must be accurate spatial representations of the species assemblages present on the landscape. In this study, we determined whether land units classified by vegetative communities predicted the community structure of a diverse group of invertebrates—the ground beetles (Coleoptera: Carabidae). Specifically, that (1) land units of the same classification contained similar carabid species assemblages and that (2) differences in species structure were correlated with variation in land unit characteristics, including canopy and ground cover, vegetation structure, tree density, leaf litter depth, and soil moisture. The study site, the Braidwood Dunes and Savanna Nature Preserve in Will County, Illinois is a mosaic of differing land units. Carabid beetles were sampled continuously with pitfall trapping for 1 year (excluding winter) from September 2011 to November 2011 and from March 2012 to September 2012. Land unit characteristics were measured in July 2012. Nonmetric multidimensional scaling (NMDS) ordinated the land units by their carabid species assemblages into five ecologically meaningful clusters: disturbed, marsh, prairie, restoration, and savanna. The subset of land unit characteristics with the highest rank correlation with the NMDS ordination included soil moisture, leaf litter depth, percentage of canopy cover, and percentage of grass ground cover. Land units classified by vegetative communities effectively represented carabid species assemblages.

The extensive land use conversion expected to occur to meet demands for bioenergy feedstock production will likely have widespread impacts on agroecosystem biodiversity and ecosystem services, including carbon sequestration. Although arthropod detritivores are known to contribute to litter decomposition and thus energy flow and nutrient cycling in many plant communities, their importance in bioenergy feedstock communities has not yet been assessed. We undertook an experimental study quantifying rates of litter mass loss and nutrient cycling in the presence and absence of these organisms in three bioenergy feedstock crops-miscanthus (Miscanthus x giganteus), switchgrass (Panicum virgatum), and a planted prairie community. Overall arthropod abundance and litter decomposition rates were similar in all three communities. Despite effective reduction of arthropods in experimental plots via insecticide application, litter decomposition rates, inorganic nitrogen leaching, and carbon-nitrogen ratios did not differ significantly between control (with arthropods) and treatment (without arthropods) plots in any of the three community types. Our findings suggest that changes in arthropod faunal composition associated with widespread adoption of bioenergy feedstock crops may not be associated with profoundly altered arthropod-mediated litter decomposition and nutrient release.