Diversifying stocking practices within rangelands supports diverse plant-pollinator communities and interactions

Abstract

Understanding how management alters species' biodiversity and interactions is critical for sustainable agriculture. This can be especially important for rangelands, grasslands used for livestock grazing that cover 30% of land worldwide. In rangelands, ranchers need to maximize livestock production while supporting healthy ecosystems. Grazing management can alter the impact of livestock by varying grazing timing and intensity, but its ecological impacts remain poorly understood. One critical function that may be supported in these systems is pollination; how rangeland management may alter this ecosystem service is not systematically understood. We investigated how rotational stocking, where livestock are rotated among pastures, affected plant and pollinator communities and plant-pollinator interactions using working ranches in the Southern Great Plains. Sites were managed through continuous stocking or rotation with low or high frequency. We found that high-frequency livestock rotation supported greater flower abundance, and consequently greater pollinator abundance. Pollinator orders varied in their responses to management with Hymenoptera directly responding to management, and Coleoptera and Lepidoptera responding indirectly via changes in flower abundance. Community-level changes produced more specialized interaction networks that, along with species turnover, led to high interaction turnover across rangeland sites. This suggests that a mosaic of management strategies likely diversifies habitat and helps support plant and pollinator biodiversity at the landscape scale. This study demonstrates that rangelands can support plants, pollinators, and their interactions, particularly when managed with high-frequency rotational stocking.