Ma Kevin C K, Redelinghuys Suzanne, Gusha Molline N C, Dyantyi Siphelele B, McQuaid Christopher D, Porri Francesca
Department of Zoology and Entomology Rhodes University Grahamstown South Africa.
South African Institute for Aquatic Biodiversity Grahamstown South Africa.
Ecol Evol. 2021 Aug 9;11(17):11930-11944. doi: 10.1002/ece3.7958. eCollection 2021 Sep.
We hypothesized congruence in the spatial structure of abundance data sampled across multiple scales for an ecological guild of consumers that exploit similar nutritional and habitat resources. We tested this hypothesis on the spatial organization of abundance of an herbivorous guild of sea urchins. We also examined whether the amount of local along-shore rocky habitat can explain the observed spatial patterns of abundance. Standardized estimates of abundance of four intertidal sea urchins- cf. , , , and were determined by six observers at 105 sites across 2,850 km of coast of South Africa. For each species and observer, wavelet analysis was used on abundance estimates, after controlling for potential biases, to examine their spatial structure. The relationship between local sea urchin abundance and the amount of upstream and downstream rocky habitat, as defined by the prevailing ocean current, was also investigated. All species exhibited robust structure at scales of 75-220 km, despite variability among observers. Less robust structure in the abundances of three species was detected at larger scales of 430-898 km. Abundance estimates of sympatric populations of two species (. cf. and ) were positively correlated with the amount of rocky habitat upstream of the site, suggesting that upstream populations act as larval sources across a wide range of scales. No relationship between abundance and habitat size was found for or . . Within the range of scales examined, we found robust congruence in spatial structure in abundance at the lower, but not the larger, range of scales for all four species. The relationship between abundance and upstream habitat availability in two species suggests that larval supply from upstream populations was probably the mechanism linking habitat size and abundance.
我们假设，对于利用相似营养和栖息地资源的一个消费者生态群落而言，跨多个尺度采样的丰度数据的空间结构具有一致性。我们针对食草性海胆群落的丰度空间组织对这一假设进行了检验。我们还研究了当地沿岸岩石栖息地的面积是否能够解释所观察到的丰度空间格局。南非2850公里海岸线上105个地点的6名观察者确定了4种潮间带海胆（即 cf. 、 、 和 ）的标准化丰度估计值。对于每个物种和观察者，在控制潜在偏差之后，对丰度估计值进行小波分析，以研究其空间结构。我们还研究了当地海胆丰度与上游和下游岩石栖息地面积（由盛行洋流定义）之间的关系。尽管观察者之间存在差异，但所有物种在75 - 220公里的尺度上均呈现出明显的结构。在430 - 898公里的较大尺度上，检测到3个物种的丰度结构不太明显。两种同域分布物种（ cf. 和 ）的丰度估计值与该地点上游岩石栖息地的面积呈正相关，这表明上游种群在广泛的尺度上充当幼体来源。对于 或 ，未发现丰度与栖息地大小之间存在关系。在所研究的尺度范围内，我们发现所有4个物种在较低尺度而非较大尺度上，丰度的空间结构具有明显的一致性。两种物种的丰度与上游栖息地可利用性之间的关系表明，上游种群的幼体供应可能是将栖息地大小与丰度联系起来的机制。
