RUI: Size: Field Tests of the Impacts of Sea Urchin Grazingand Sediment Disturbance Herbivory, Bioturbation and the Regulation of Seagrass Meadow

在之前的工作中，赫克博士和他的合作者评估了海胆短期放牧的重要性，以及沙子对墨西哥湾北部海草栖息地生物扰动的重要性。根据这项工作的结果和最新公布的信息，他们现在将在墨西哥湾北部启动更多的野外实验，以及在佛罗里达州南部的一个地点进行研究，以更准确地确定永久创造无植物沙地所需的海胆密度和食草动物的持续时间。这两个地点加在一起代表了美国一些最广泛的海草栖息地的北部和南部范围，面积约为14,000平方公里。此外，他们将继续评估沙尘暴对海草根际生物扰动的作用，以及沙尘暴生物扰动和海胆食草性之间在限制海草栖息地分布方面的潜在相互作用。他们将进行第一次实验测试，以测试串鱼和穴居蟹在适合海草的栖息地创造和维护未生长植物的沙洲的能力。这项工作将提高我们对维持栖息地和马赛克所涉及的变量的理解，以及那些促进替代群落状态(例如海草草甸和沙洲)之间变化的变量，这些变量反过来可能导致初级和次级生产力的急剧变化。

In previous work, Dr. Heck and collaborators assessed the importance of short-term grazing by sea urchins, and bioturbation by sand dollars in a seagrass habitat in the northern Gulf. Based on results of this effort and newly published information, they will now initiate additional field experiments in the northern Gulf of Mexico, as well as studies at a south Florida site, to identify more precisely the densities of sea urchins and the duration of herbivory required to permanently create unvegetated sand flats. Together these two sites represents the northern and southern extents of some of the most extensive seagrass habitats in the United States, encompassing some 14,000 Km2. Additionally, they will continue assessing the role of bioturbation of the seagrass rhizosphere by sand dollars, and the potential interaction between sand dollar bioturbation and sea urchin herbivory in limiting the distribution of seagrass habitats. They will carry out the first experimental examination of the ability of stringrays and burrowing crabs to create and maintain unvegetated sand flats within otherwise suitable habitat for seagrasses. The work will improve our understanding of the variables involved in maintaining habitat and mosaics, and those that facilitate changes between alternative community states (e.g. seagrass meadows and sand flats) which in turn can lead to drastic shifts in primary and secondary productivity.