生态系统服务是指人类从生态系统获得的所有惠益，包括供给服务、调节服务、支持服务和文化服务。人口数量增加、经济发展和全球消耗量的增长正在改变着生态系统的结构、生态过程，进而影响其生态功能和服务。在众多生态系统类型中，草地生态系统一直以来受到人类活动的严重影响，高强度的利用率改变了草地生态系统的植被构成，草地大量转化为灌木，尽管采取大量措施砍伐灌木，草地恢复只能维持较短时间，长期来看，环境恶化、养分和碳库流失，需要对多种生态系统服务进行权衡。
本研究对灌丛化土地的生态系统服务权衡进行量化，对保护措施能否提供生态系统服务进行了识别。第一章强调了草地生态系统作为多种生态系统服务的供给方的重要性，而不是仅仅关注它的畜牧生产力，即供给服务这单一的方面。第二 解释方法，包括本报告中使用的荟萃分析统计数据、第三, 第四, 第五章分析了对灌丛化的草地采取不同措施时，生态系统特征和相关生态系统服务的变化。第六章对灌丛化草地可持续管理提出了建议，第七章为本研究结论，采取保护措施可以增加灌丛化草地的供给服务。

Ecosystem services are defined as benefits that we obtain from the ecosystems, including provisioning, regulating, supporting and cultural services. However, increasing human population size, economic growth and global consumption have changed ecosystem structures and placed tremendous pressure on ecosystem processes and functions, including the delivery of ecosystem services. Of the different ecosystem types that humans have recognized, grassland represent an ecosystem which is heavily-influenced by humans since its utilization has started over millennia. Over-utilization of grasslands as a single ecosystem service provider (livestock production) has led to changes in vegetation composition, from grasses to shrubs. Despite numerous attempts to remove shrubs, grass recovery is usually limited to short-term period, but in the long-term, there are often multiple trade-offs with increasing environmental degradation such as increasing soil erosion, reduced nutrient cycling and loss of carbon stock. My research thus tried to quantify those tradeoffs and identify whether conservation practices that utilize the benefits of shrubs can be used to the provision of different ecosystem services. Chapter 1 provides an overview of the importance of grasslands as the provider of ecosystem services other than production, which usually become the characteristics of human-dominated ecosystems. Chapter 2 explains the methodology, including meta-analysis statistics used in this report. Chapters 3, 4, 5 examine the changes in ecosystem properties and the associated ecosystem services with shrub encroachment and shrub control methods. Chapter 6 suggests sustainable policy approach for managing shrub-encroached lands. Finally, chapter 7 provides a conclusion which showing that the provision of ecosystem services from shrub-encroached ecosystems can be made possible with the adoption of conservation practices.