Scott Abigail L, York Paul H, Duncan Clare, Macreadie Peter I, Connolly Rod M, Ellis Megan T, Jarvis Jessie C, Jinks Kristin I, Marsh Helene, Rasheed Michael A
Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University, Cairns, QLD, Australia.
College of Science and Engineering, James Cook University, Townsville, QLD, Australia.
Front Plant Sci. 2018 Feb 12;9:127. doi: 10.3389/fpls.2018.00127. eCollection 2018.
Seagrass meadows support key ecosystem services, via provision of food directly for herbivores, and indirectly to their predators. The importance of herbivores in seagrass meadows has been well-documented, but the links between food webs and ecosystem services in seagrass meadows have not previously been made explicit. Herbivores interact with ecosystem services - including carbon sequestration, cultural values, and coastal protection. Interactions can be positive or negative and depend on a range of factors including the herbivore identity and the grazing type and intensity. There can be unintended consequences from management actions based on a poor understanding of trade-offs that occur with complex seagrass-herbivore interactions. Tropical seagrass meadows support a diversity of grazers spanning the meso-, macro-, and megaherbivore scales. We present a conceptual model to describe how multiple ecosystem services are influenced by herbivore pressure in tropical seagrass meadows. Our model suggests that a balanced ecosystem, incorporating both seagrass and herbivore diversity, is likely to sustain the broadest range of ecosystem services. Our framework suggests the pathway to achieve desired ecosystem services outcomes requires knowledge on four key areas: (1) how size classes of herbivores interact to structure seagrass; (2) desired community and management values; (3) seagrass responses to top-down and bottom-up controls; (4) the pathway from intermediate to final ecosystem services and human benefits. We suggest research should be directed to these areas. Herbivory is a major structuring influence in tropical seagrass systems and needs to be considered for effective management of these critical habitats and their services.
海草草甸提供关键的生态系统服务，通过直接为食草动物提供食物，并间接为它们的捕食者提供食物。食草动物在海草草甸中的重要性已有充分记录，但此前海草草甸食物网与生态系统服务之间的联系尚未明确。食草动物与生态系统服务相互作用——包括碳固存、文化价值和海岸保护。相互作用可能是积极的或消极的，取决于一系列因素，包括食草动物的种类以及放牧类型和强度。基于对海草 - 食草动物复杂相互作用中权衡的理解不足而采取的管理行动可能会产生意想不到的后果。热带海草草甸支持着从中型、大型到巨型食草动物等多种食草动物。我们提出了一个概念模型，以描述热带海草草甸中食草动物压力如何影响多种生态系统服务。我们的模型表明，一个包含海草和食草动物多样性的平衡生态系统，可能会维持最广泛的生态系统服务。我们的框架表明，实现期望的生态系统服务结果的途径需要关于四个关键领域的知识：（1）不同大小类别的食草动物如何相互作用以构建海草结构；（2）期望的群落和管理价值；（3）海草对自上而下和自下而上控制的反应；（4）从中级生态系统服务到最终生态系统服务和人类福祉的途径。我们建议研究应针对这些领域。食草作用是热带海草系统中的一种主要结构影响因素，对于有效管理这些关键栖息地及其服务需要加以考虑。
