Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950.
Proc Natl Acad Sci U S A. 1985 Jun;82(11):3707-11. doi: 10.1073/pnas.82.11.3707.
Field studies demonstrate that the population structure of the barnacle Balanus glandula differs between locations of high and low larval settlement rate. These observations, together with results from a model for the demography of an open, space-limited population, suggest that the settlement rate may be a more important determinant of rocky intertidal community structure than is presently realized. Locations with a low larval settlement rate exhibit a generally low abundance of barnacles that varies slightly within years and greatly between years, reflecting yearly differences in settlement. Locations with a high-settlement rate exhibit a generally high abudance of barnacles. However, the abundance varies greatly within years with a significant oscillatory component (period, 30 weeks) and only slightly between years regardless of yearly differences in settlement. At the low-settlement location mortality of barnacles is independent of the area occupied by barnacles. At the high-settlement location mortality is cover-dependent due to increased predation by starfish on areas of high barnacle cover. In both locations the cover-independent component of mortality does not vary with age during the first 60 weeks. As assumed in the demographic model, the kinetics of larval settlement can be described as a process in which the rate of settlement to a quadrat is proportional to the fraction of vacant space within the quadrat. Generalizations that the highest species diversity in a rocky intertidal community is found at locations of intermediate disturbance, and that competition causes zonation between species of the barnacle genera Balanus and Chthamalus, seem to apply only to locations with high-settlement rates.
野外研究表明，藤壶的种群结构在幼虫附着率高和低的地点存在差异。这些观察结果，以及一个开放的、空间有限的种群的人口统计学模型的结果表明，幼虫附着率可能是潮间带岩石群落结构的一个比目前认识更为重要的决定因素。幼虫附着率低的地点通常藤壶的丰度较低，而且每年的变化幅度较小，这反映了每年附着的差异。附着率高的地点通常藤壶的丰度较高。然而，丰度在每年的变化幅度很大，有一个显著的波动成分（周期为 30 周），而与每年的附着差异无关。在低附着率的地点，藤壶的死亡率与藤壶占据的面积无关。在高附着率的地点，死亡率与藤壶的覆盖率有关，因为海星对高覆盖率的藤壶区域的捕食增加了。在这两个地点，死亡率的非覆盖依赖成分在第 60 周之前的年龄期间不会随年龄而变化。如人口模型中所假设的，幼虫附着的动力学可以描述为一个过程，其中在一个四分体中的附着率与四分体中空位的分数成正比。在一个潮间带岩石群落中，物种多样性最高的地点位于中等干扰的地点，以及竞争导致藤壶属和 Chthamalus 属的物种在带状分布的一般推论，似乎只适用于附着率高的地点。
