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Penelope A. Luckens 《新西兰海洋与淡水研究杂志》2013,47(4):637-654
When grazing animals are excluded from any intertidal area algae grow unchecked. In screened frames on the shore where predation experiments are in progress such growth is undesirable. A number of shore herbivores were tested for their ability to remove such algal growth and prevent its reformation without interfering with the main experiments. Only the browsing species Lunella smaragda and Melagraphia aethiops were capable of removing large algal growths, and these species were acceptable food for some of the predatory species. The complex inter‐relationship between grazing species and shore zonation at several places near Auckland is discussed. 相似文献
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This study examined whether buried organic matter in the form of seagrass influenced colonization by the corophiid amphipod Paracorophium excavatum in an intertidal sandflat. Laboratory manipulations were compared to results from field studies to determine the role of hydrodynamics in mediating the effects of the organic matter. At levels of organic loading greater than 1% of sediment dry weight, size frequency effects and decreases in numbers of colonizers occurred in still water conditions. In the field, however, at levels of organics up to 2% of sediment dry weight, only size-frequency effects were observed. A change in hydrodynamic conditions and the influence of this on sediment geochemistry is suggested as the most reasonable explanation for the disparity in colonization both between sites in the field and between laboratory and field manipulations. Two effects of organics upon corophiid amphipod colonization are proposed: a lower level of organic loading that can lead to a greater proportion of juveniles in the colonizing population and a higher level of organics that can lead to a decrease in the numbers of amphipods colonizing. The threshold at which these effects take place is modulated by the hydrodynamics of the environment. The same organic addition can therefore have different effects upon colonization across a tidal flat, which is dependent upon the variation in hydrodynamics 相似文献
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