Quantifying seascape structure: extending terrestrial spatial pattern metrics to the marine realm

Spatial pattern metrics have routinely been applied to characterize and quantify structural features of terrestrial landscapes and have demonstrated great utility in landscape ecology and conservation planning. The important role of spatial structure in ecology and management is now commonly recognized, and recent advances in marine remote sensing technology have facilitated the application of spatial pattern metrics to the marine environment. However, it is not yet clear whether concepts, metrics, and statistical techniques developed for terrestrial ecosystems are relevant for marine species and seascapes. To address this gap in our knowledge, we reviewed, synthesized, and evaluated the utility and application of spatial pattern metrics in the marine science literature over the past 30 yr (1980 to 2010). In total, 23 studies characterized seascape structure, of which 17 quantified spatial patterns using a 2-dimensional patch-mosaic model and 5 used a continuously varying 3-dimensional surface model. Most seascape studies followed terrestrial-based studies in their search for ecological patterns and applied or modified existing metrics. Only 1 truly unique metric was found (hydrodynamic aperture applied to Pacific atolls). While there are still relatively few studies using spatial pattern metrics in the marine environment, they have suffered from similar misuse as reported for terrestrial studies, such as the lack of a priori considerations or the problem of collinearity between metrics. Spatial pattern metrics offer great potential for ecological research and environmental management in marine systems, and future studies should focus on (1) the dynamic boundary between the land and sea; (2) quantifying 3-dimensional spatial patterns; and (3) assessing and monitoring seascape change.

The activity pattern of Tegula funebralis

The activity pattern of the black turban snail, Tegula funebralis (A. Adams, 1854) at Pacific Grove, California, is the subject of this article. Field studies were carried out to follow the locomotory and feeding activities of individuals of T. funebralis, to determine how much of each animal's time was spent in each of these activities, and when and under what environmental conditions they occurred.

东灵山地区辽东栎群中植物种群的时空格局研究

在北京东灵山地区以辽东栎（Quercus liaotungensis Koidz.）林群落为主要对象，研究了辽东栎种群和主要伴生种的空间格局、种间联结以及辽东栎种子雨的时间格局，井对空间格局的表达方法进行尝试性的探讨。 对辽东栎林群落中主要乔木树种辽东栎、大叶白蜡（Fraxinus thynchophylla）和五角枫（Acer mono）种群空间格局与动态的考察结果显示：各种群大多表现出聚集分布的趋势;辽东栎种群在各个龄级层均显示出较强优势，但种群内竞争激烈，龄级结构相对稳定;人叶白蜡的幼苗对环境适应能力较强，在成熟林中呈现出较五角枫种群更明显的增长型趋势：幼林中3个种群均呈衰退型趋势。 种间联结性的测定结果较好地反映了植物对环境的适应性，用关联分析法作出的树状图利用临界种将样方划分为若干组，体现出小生境之间的差异，反映了植物对其生境亦具有一定指示作用。 辽东栎种子雨的时间格局研究结果表明：种群种子雨密度随时间的变化呈正态分布趋势，种群水平利个体水平的种子雨累积随时间变化均符台Logistic曲线，具有很高的相关性。 空间格局表达方法的探讨显示：可以用集合论的方法对数学模型进行形象表达。

Circulation pattern of the Egyptian Mediterranean waters during winter and summer seasons

The water circulation of the Egyptian Mediterranean waters was computed during winter and summer seasons using the dynamic method. The reference level was set at the 1000db surface. The results showed that the surface circulation is dominated by the Atlantic water inflow along the North African coast and by two major gyres, the Mersa Matruth anticyclonic gyre and El-Arish cyclonic gyre. The results showed a seasonal reversal of El-Arish gyre, being cyclonic in winter and anticyclonic in summer. El-Arish gyre had not been previously measured. The geostrophic current velocity at the edges of the Mersa Matruth gyre varied between 12.5 and 29.1cm/sec in winter and between 6.5 and 13.1cm/sec in summer. The current velocity reached its maximum values (>40cm/sec) at El-Arish gyre. The current velocity at the two gyres decreased with increasing depth. The North African Current affects the surface waters down to a depth of 100m, and that its mean velocity varies between 6 and 38cm/sec.