Dynamics of Rocky Intertidal Communities: Analyses of Long Time Series from South African Shores
Dynamics of Rocky Intertidal Communities: Analyses of Long Time Series from South African Shores
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岩石潮间带群落的动态：南非海岸的长期序列分析
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发表时间：
1998
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影响因子：
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通讯作者：
A. Dye
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作者：
A. Dye
摘要对南非东海岸三个岩石岸边未受干扰和经过实验清理的样方中底栖无脊椎动物的丰度进行了13年的季度监测。在11个常见物种中，大多数都表现出明显的季节性周期，尽管年际变异性很大，但有证据表明两年一次的周期丰富。对于许多物种来说，长期趋势是显而易见的。帽贝的数量普遍减少，而长吻牡蛎和岩石牡蛎增加。随着时间的推移，两种数量占优势的藤壶呈现出相反的关系，在某些地点，一个物种被另一个物种取代。在小尺度上，种间和种内的相关性都很高，但在几十至数百公里的尺度上，这种相关性减弱。许多时间序列表现出明显的不连续性，丰度变化最多可达三个数量级。这种不连续通常标志着持续3-4年的年际变化变化周期的开始。在某些情况下，这导致时间序列被划分为具有完全不同的潜在动力学的阶段。经过长达3年的初步恢复期后，开垦区域表现出许多与对照相同的特征，但有增加年际变化的趋势。一个有趣的发现是，在春季和夏季清理的区域没有表现出未受干扰地区的两年一次的周期特征，而在秋季和冬季清理的区域保留了这一特征。潮间带无脊椎动物丰度的波动明显地表现出复杂的动力学，这是根据可能的外部强迫函数来讨论的。
Abstract The abundance of benthic invertebrates in undisturbed and experimentally cleared quadrats on three rocky shores on the east coast of South Africa was monitored quarterly for 13 years. Most of the 11 commonly occurring species exhibited significant seasonal cycles and, although interannual variability was high, there was evidence of biennial cycles in abundance. Long-term trends were evident for many species. Limpets generally decreased in abundance, while periwinkles and rock oysters increased. The two numerically dominant barnacles exhibited an inverse relationship over time, and at some sites one species was replaced by the other. There was a high degree of both inter- and intraspecific correlation at small scales, but this was attenuated at scales of tens to hundreds of kilometres. Many of the time series exhibited significant discontinuities in which changes in abundance of up to three orders of magnitude were evident. Such discontinuities usually marked the start of periods of altered interannual variability lasting for 3–4 years. In some cases, this resulted in time series divided into phases with completely different underlying dynamics. After an initial recovery period of up to 3 years, the cleared areas exhibited many of the same characteristics as the controls, but with a tendency for increased interannual variability. An interesting finding was that areas cleared in spring and summer did not exhibit the biennial cycles characteristic of undisturbed areas, while those cleared in autumn and winter retained this characteristic. Fluctuations in abundance of intertidal invertebrates clearly exhibit complex dynamics, which are discussed in terms of possible external forcing functions.