Ecological Implications of Converting Cropland to Permanent-Cover for Four Native Prairie Taxa

Habitat loss due to human activities is one of the main causes of wildlife population declines and threats to global biodiversity. The grasslands of North America are one of the most human-altered ecosystems on earth, with agriculture replacing approximately 80% of all native grasslands. As a result, populations of many grassland species are in decline and threatened with extinction. To improve habitat quality for native species, some habitat enhancement programs have converted cropland into permanent-cover (grass planted for hay or livestock grazing). The ecological effects of permanent-cover on songbird communities have been investigated, but little has been done to examine the responses of other taxa. In addition, previous studies have rarely included comparisons between multiple habitat types and have been conducted on relatively small spatial scales. To gain a broader ecological perspective, I examined the impacts of converting cropland into permanent-cover across two eco-regions, among three habitat types, and among multiple taxa. In the moist-mixed and mixed grassland eco-regions of southern Saskatchewan, I compared Shannon-Weiner diversity indices and abundance measures for native species of grasshoppers, small mammals (i.e. mice, voles, shrews), fossorial mammals, and raptors among permanent-cover, cropland, and native prairie habitats. To determine how permanent-cover influences these taxa more specifically, I analysed the abundance of the most frequently captured or detected species, and burrows made by fossorial mammals which could potentially benefit other prairie species (i.e. burrowing owls, Athene cunicularia). I analysed grasshopper, small mammal and burrow diversity and densities using mixed-model multiple regressions, paired with small sample Akaike's Information Criterion. Raptor data were pooled between eco-regions and analysed using logistic generalized linear mixed models.;In general, I found that permanent-cover supports a higher diversity of animal species than cropland, and higher abundances of animals than native prairie. Specifically, grasshopper biomass and species density were greater in permanent-cover and cropland than in native prairie, but this varied between eco-regions. Small mammal diversity was unaffected by habitat type. Small mammal biomass and species density were greater on permanent-cover and cropland than in native prairie and this trend was consistent between eco-regions. Permanent-cover had a greater number of all burrow types and ground squirrel burrows compared to cropland, but only in the mixed grassland eco-region. The abundance of badger burrows was unaffected by permanent-cover. The number of potential burrowing owl nest burrows was greatest in native prairie, followed by permanent-cover and then cropland. Raptors were detected more frequently over permanent-cover and native prairie compared to cropland, and their presence was also negatively affected by increasing vegetation height. Overall, converting cropland into permanent-cover appears to be a beneficial conservation tool to enhance habitat quality for a variety of native prairie species.