Dauphin Island Sea Lab, Dauphin Island, AL, United States of America.
University of South Alabama, Marine Science Department, Mobile, AL, United States of America.
PLoS One. 2019 Jan 7;14(1):e0210144. doi: 10.1371/journal.pone.0210144. eCollection 2019.
The expansion of black mangrove Avicennia germinans into historically smooth cordgrass Spartina alterniflora-dominated marshes with warming temperatures heralds the migration of the marsh-mangrove ecotone northward in the northern Gulf of Mexico. With this shift, A. germinans is expected to outcompete S. alterniflora where it is able to establish, offering another prevalent food source to first order consumers. In this study, we find A. germinans leaves to be preferable to chewing herbivores, but simultaneously, chewing herbivores cause more damage to S. alterniflora leaves. Despite higher nitrogen content, A. germinans leaves decomposed slower than S. alterniflora leaves, perhaps due to other leaf constituents or a different microbial community. Other studies have found the opposite in decomposition rates of the two species' leaf tissue. This study provides insights into basic trophic process, herbivory and decomposition, at the initial stages of black mangrove colonization into S. alterniflora salt marsh.
随着温度的升高，黑榄李（Avicennia germinans）在历史上较为平滑的互花米草（ Spartina alterniflora ）占主导地位的沼泽中扩张，预示着墨西哥湾北部的沼泽-红树林生态交错带向北迁移。随着这种转变，黑榄李有望在其能够建立的地方与互花米草竞争，为第一级消费者提供另一种普遍的食物来源。在这项研究中，我们发现黑榄李的叶子更受咀嚼食草动物的喜爱，但同时，咀嚼食草动物也会对互花米草的叶子造成更大的损害。尽管黑榄李叶子的氮含量较高，但它的分解速度却比互花米草叶子慢，这可能是由于其他叶子成分或不同的微生物群落。其他研究发现，这两种植物叶片组织的分解速率正好相反。这项研究为黑榄李侵入互花米草盐沼的初始阶段的基本营养过程、食草和分解提供了一些见解。
