The Effects of Canopy Shadings on Algal Recruitment and Growth in a Giant Kelp Forest
The Effects of Canopy Shadings on Algal Recruitment and Growth in a Giant Kelp Forest
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树冠遮荫对巨型海带森林中藻类补充和生长的影响
DOI：
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发表时间：
1984
期刊：
影响因子：
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通讯作者：
M. Foster
中科院分区：
文献类型：
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作者：
D. Reed;M. Foster
加州卡梅尔湾静水湾相对隐蔽的巨型海带森林中的潮下带（10-15 m）组合由形成三个主要垂直层的多年生物种组成：Macrocystis pyrifera表层冠层、另一种海带Pterygophora californica的致密次表层冠层和下层的关节和结壳珊瑚藻。海带冠层单独或组合可以减少底部光到表面流入的<3%（通常<1%）。光减少这些植被层的藻类招聘和随后的增长的影响，确定通过删除各种组合的树冠超过2年的时间，并随后的变化相对于适当的控制。把两个M。pyrifera和P. californica冠层导致这些物种的适度招聘，以及每年的棕色叶甲Desmarestia ligulata var.舌形。没有这些藻类招募到控制区，其中一个或两个树冠保持完整。最高的棕色和红色的藻类招聘发生时，海带冠层加林下珊瑚分支被删除。单独去除后者没有显著影响。一年中的时间，当藻类冠层被删除的组合物的影响不大，随后的藻类殖民化，招聘noncalcareous物种主要发生在春季的一个短时期内。这些结果表明，静水湾的物理和生物干扰水平相对较低，允许建立一些多年生藻类物种，抑制自己的招聘，以及其他物种的入侵，阴影。这与附近的海带森林受到更大和更频繁的干扰，其特点是一年生藻类物种的多样性组合。
The subtidal (10-15 m) assemblage in the relatively sheltered giant kelp forest at Still- water Cove in Carmel Bay, California, consists of perennial species forming three major vertical layers: a Macrocystis pyrifera surface canopy, a dense subsurface canopy of another kelp, Pterygophora californica, and an understory of articulated and encrusting coralline algae. The kelp canopies alone or in combination can reduce bottom light to <3% (usually <1%) of surface influx. The effects of light reduction by these vegetation layers on algal recruitment and subsequent growth were determined by removing various combinations of canopies over a 2-yr period, and following subsequent changes relative to appropriate controls. Removing both M. pyrifera and P. californica canopies resulted in moderate recruitment of these species as well as of the annual brown alga Desmarestia ligulata var. ligulata. None of these algae recruited into control areas where one or both canopies were left intact. Highest brown and red algal recruitment occurred when both kelp canopies plus understory coralline branches were removed. Removal of the latter alone had no significant effect. The time of year when algal canopies were removed had little effect on the composition of subsequent algal colonization, as the recruitment of noncalcareous species occurred primarily during a short period in the spring. These results indicate that the relatively low levels of both physical and biological disturbance in Stillwater Cove allow the establishment of a few perennial algal species that inhibit their own recruitment, as well as invasion of other species, by shading. This contrasts with nearby kelp forests subjected to greater and more frequent disturbance, and characterized by a diverse assemblage of annual algal species.