Variable modes of facilitation in the upper intertidal: goose barnacles and mussels
Variable modes of facilitation in the upper intertidal: goose barnacles and mussels
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DOI：
10.3354/meps272203
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发表时间：
2004-01-01
影响因子：
2.5
通讯作者：
Tokeshi, M
中科院分区：
文献类型：
--
作者：
Kawai, T;Tokeshi, M
两个固着滤食动物相似的身体大小，鹅藤壶Capitulum mitella和贻贝Septifer virgatus，发生在补丁上的一个适度的波浪暴露的岩石海岸南日本在西太平洋。他们的共存模式进行了调查，通过实地观察和实验操作，特别是侧重于季节性变化的模式，在恶劣的环境条件下，在潮间带发现的便利。田间观察和相互迁移实验表明，C. mitella在两个混合斑（包含C. mitella和S. virgatus）和仅Capitulum补丁。相反，S. virgatus在混合环境中的存活率明显高于单一环境，表明S. virgatus受到C. mitella，而后者不受前者在潮间带上部的存在。人工补片移植实验表明，C。无论是在夏季温度胁迫较强时，还是在冬季波浪作用引起的物理干扰较强时，小刺藻都能促进虎尾藻的存活和生长。人工遮阴处理提高了S.弗吉尼亚只在夏天存活。在夏季，热条件（温度和斑块内的间隙湿度）是苛刻的，在无遮荫（S。virgatus-only）比混合（C. mitella + S. virgatus）和阴影处理（S. virgatus with artificial shade）。与此相反，严重的身体状况的影响，证明了贝壳磨损的程度在贻贝更明显的阴影和unshaded治疗比在混合治疗在冬季。这些结果表明C. Mitella具有两种不同的生境改变功能：（1）改善热应激和（2）改善物理应激;人工遮荫仅执行其中的第一种。
Two sessile filter-feeders of similar body sizes, the goose barnacle Capitulum mitella and mussel Septifer virgatus, occur in patches on a moderately wave-exposed rocky shore of south Japan in the western Pacific. Their pattern of coexistence was investigated through field observations and experimental manipulation, focusing in particular on seasonally variable modes of facilitation under harsh environmental conditions found in the upper intertidal. Field observations and reciprocal-removal experiments showed a high survivorship of C. mitella in both mixed patches (containing C. mitella and S. virgatus) and Capitulum-only patches. In contrast, S. virgatus exhibited a substantially higher survivorship in the mixed than in single situations, indicating that S. virgatus was positively affected by the presence of C. mitella, while the latter was not influenced by the presence of the former in the upper intertidal. An artificial patch transplant experiment demonstrated that C. mitella enhanced S, virgatus survivorship and growth both in summer when thermal stress was severe and in winter when physical disturbance caused by wave action was strong. In contrast, the artificial shade treatment enhanced S. virgatus survivorship only in summer. In summer, thermal conditions (temperature and interstitial humidity within patches) were harsher in the unshaded (S. virgatus-only) than in the mixed (C. mitella + S. virgatus) and shaded treatments (S. virgatus with artificial shade). In contrast, the effect of severe physical condition as evidenced by the extent of shell wear in mussels was more pronounced in the shaded and unshaded treatments than in the mixed treatment in winter. These results suggest that C. mitella had 2 different habitat-modifying functions: (1) amelioration of thermal stress and (2) amelioration of physical stress; the artificial shade performed only the first of these.