Dissertation Research: Interactions of Controlled Nutrient Enrichment, Plant Growth, and Insect Herbivory in Red Mangrove (Rhizophora mangle)

红树林的初级生产力是邻近海洋系统的重要营养来源。生产力水平不仅受到环境因素的影响，还受到红树林群落其他组成部分的影响。营养物质的富集可能通过增加红树林的初级生产力对水生食物网产生直接影响，但对沿海水域的富集可能会减轻，因为多达20%的红树林叶片物质被食草动物去除。本研究的目的是在控制沉积物中养分有效性的对照实验中，确定营养富集对红树林主要物种根藻（Rhizophora mangle）初级生产力的影响，以及对昆虫食草率的影响。以下假设将被检验：1。富营养化可增加叶片和顶芽的产生、节间伸长和开花。2. 红树林组织的营养品质（如CNP比率、含水量）随着沉积物的营养富集而增加。3. 红树林组织的营养质量与食叶昆虫（叶食动物）和蛀枝昆虫（木食动物）的取食率相关。4. 昆虫及其近亲（如捕食者、寄生虫、筑巢蚁等）对山竹枝的二次利用随着初次食草率的增加而增加。5. 随着营养物的富集，白杨取食枝条的种类比例发生了变化。本研究将有助于建立红树林生态学知识库，并为红树林保护提供重要信息。//

Primary productivity of mangroves is an important source of nutrients for adjacent marine systems. The level of productivity is affected not only by environmental factors but also by other components of the mangrove community. Nutrient enrichment might have direct impact on aquatic food webs by increasing primary productivity of mangroves, but enrichment to coastal waters might be mitigated because as much as 20% of mangrove leaf material is removed by herbivores. The objective of this study is to determine the effects of nutrient enrichment on primary productivity of the key mangrove species, Rhizophora mangle, and on rates of insect herbivory in a controlled experiment in which nutrient availability in sediment is manipulated. The following hypotheses will be tested: 1. Nutrient enrichment causes increased leaf production and terminal branch production, internodal elongation, and flowering. 2. Nutritional quality (e.g., CNP ratio, water content) of mangrove tissues increases following nutrient enrichment of the sediment. 3. Nutritional quality of mangrove tissues correlates with rates of insect herbivory by both leaf feeders (folivores) and twig borers (xylovores). 4. Secondary use of R. mangle twigs by insects and their kin, e.g., predators, parasites, twig-nesting ants, etc., increases with rate of primary herbivory. 5. Proportions of species in the twig-feeding guild of R. mangle change following nutrient enrichment. This research will contribute to the knowledge base on mangrove ecology and may provide important information useful in conservation of mangroves.//