Vegetation responses and trade-offs with soil-related ecosystem services after shrub removal: A meta-analysis

Abstract

Aim: To assess the sustainability of different shrub control practices (fire, mechanical, and chemical) based on their efficacy to control shrubs and their effects on multiple ecosystem service provisions, including possible trade-off and/or synergy. Methods: Using a meta-analysis approach, this study synthesized results from global shrub removal experiments. Log response ratio (lnR) between the outcome of shrub removal and that of the untreated control was used to estimate proportional changes in soil and vegetation properties resulting from each shrub control practice. Results: When forage provisioning is the only service considered, shrub removal could achieve this desirable outcome as indicated by increasing herbaceous biomass. However, observable decreases in litter, biological crust cover, and soil nutrients, as well as increases in bare soil indicated long-term potential trade-offs with other ecosystem services (e.g., erosion control service and nutrient cycling); the degree was influenced by different shrub control methods. Synergistic properties were probably limited to a short-term boost of herb productivity resulting from short-term increase in herb biomass and diversity as well as nutrient availability. Conclusion: Human-induced drivers manifested in shrub control practices changed vegetation response. However, management also changed non-targeted processes, generating potential reduction in several regulating ecosystem services. Continuous monitoring to assess landscape conditions should therefore become the key for adaptive management. Sustainable forage production should focus on strategies to maintain multiple ecosystem services because consideration of those services can lead to long-term protection of the landscape and provide a broader range of environmental benefits.