Soil properties are not adversely impacted by fire, a positive outcome for the soil-dwelling American burying beetle. Extreme prescribed fire restores ABB habitat and herbaceous plant communities that were lost to woody encroachment. Soil compaction and infiltration rates are similar between restored grasslands and uninvaded grasslands. Herbaceous species richness and basal cover in grasslands restored with extreme fire are comparable to uninvaded grasslands. ABB are positively associated with perennial forbs/grasses, and negatively associated with trees at >10% cover and cropland at 0.5% cover. This study is the first to document increases in the ABB due to management with fire. The abundance and distribution of the ABB in the Loess Canyons is mapped with the four landcover types. We apply an NMDS analysis to examine changes in functional groups over time among sites. We sample herbaceous plant richness, basal percent cover, soil compaction, and infiltration rates in grasslands restored with fire, uninvaded grasslands, and unburned woodland. We apply a space-for-time substitution design across the Loess Canyons to allow sampling across a time-since-fire gradient of 17 years. We use the Bayesian latent indicator scale selection method to select the best-performing spatial scale for each landcover type in the model. We use 13 years of beetle monitoring data and multi-spatial landcover data of perennial forbs/grasses, trees, croplands, and litter in a Bayesian N-mixture model to estimate the relative abundance of ABB at permanent trapping locations. The Nebraska Natural Legacy Project established the Loess Canyons ecoregion as a Biologically-Unique Landscape in 2005 with the state’s wildlife action plan to stop habitat loss due to woody encroachment and prevent reductions in the federally-threatened American burying beetle. Our study site is the Loess Canyons Experimental Landscape, a long-term, ecoregion-scale experiment to apply prescribed fire across the region to restore grasslands. This fire is considered “extreme” because it is capable of changing the structure and function of an ecosystem. Prescribed burn associations have utilized prescribed fire to collapse invading woodlands and allow the restoration of grasslands. Grasslands are declining in the Great Plains due to land use changes, woody plant encroachment, and loss of historic fire cycles. Studies like ours provide a way for conservation efforts to shift focus from managing individual species to preserving ecosystem functions so that management can meet their stated goals. Insects should be a greater focus of conservation efforts due to their high level of biodiversity, integral role in many ecosystem functions, and the recent documentation of global insect declines.
While it is expected that differing land cover composition will result in different insect communities, we demonstrated how these different communities are directly tied to ecosystem function. Decomposition rates of a small mammal carcass also exhibited a negative correlation with the proportion of urban landscape and positive correlation with sage scrub cover. Beetle families (Silphidae, Staphylinidae, Histeridae) and a fly family (Phoridae) exhibited a negative relationship with urban land cover and a positive relationship with sage scrub within 5 km of trapping locations. To address the conservation of ecosystem functions, we 1) described the insect community associated with the decomposition of small mammal carcasses, 2) assessed correlations between insects (abundance and community composition) and landscape cover types, and 3) quantified decomposition rates of a small mammal carcass in Mediterranean shrublands and grasslands of San Diego County, CA USA.
Conservation typically has dual objectives of preserving both biodiversity and ecosystem functioning however, management of ecosystems is challenging.
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