Ecosystem service trade-offs resulting from woody plant removal vary with biome, encroachment stage and removal method.
Abstract
Plant removal is used widely to restore systems encroached by woody plants and to improve ecosystem health and human well-being. However, the effects of removal are rarely consistent, with a mixture of positive and negative outcomes for ecosystems, making it difficult to develop consistent prescriptions for achieving sustainable management of woody dominated systems. We complied a global database of 5086 records on the impacts of woody plant removal from 204 studies to explore where (biome; grassland, savanna, shrubland, woodland), when (encroachment stage; low, medium, high encroachment) and how (removal method; physical, chemical, browsing, burning, multiple removal techniques) woody plant removal would affect eight ecosystem services (forage value, soil stability, hydrological regulation, nutrient cycling, carbon sequestration, animal diversity, plant diversity and primary productivity). Removing woody plants in grasslands enhanced forage value, but woody removal in shrublands reduced hydrological regulation. Conversely, chemical removal enhanced hydrological regulation and forage value, but at the expense of plant diversity. In grasslands, interactions between encroachment stage and removal method also regulated service responses, with burning enhancing nutrient cycling under low encroachment, but reducing it in heavily encroached stands. The effectiveness of removal in promoting ecosystem services varied with removal method, with burning suppressing the long-term effectiveness on carbon sequestration, but browsing exacerbating the negative effect on soil stability.