Mechanisms of benthic algal succession in lotic environments
Mechanisms of benthic algal succession in lotic environments
复制标题
海水环境中底栖藻类演替机制
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
R. Stevenson
中科院分区：
文献类型：
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作者：
P. Mccormick;R. Stevenson
虽然藻类演替的季节性模式受到了相当大的关注，很少有研究试图阐明的过程，有助于短期藻类演替后的干扰。本研究围绕四种一般演替机制展开，旨在探讨种特异性自体生态学和种间相互作用对美国肯塔基州三级河流中藻类短期演替模式的影响。在不同的当前环境中的流在连续两个冬天的观测被用来分类优势种的早期或晚期演替的基础上，通过时间的相对丰度的变化，在新曝光的基板。相同年龄但不同的早期和晚期演替物种的相对丰度的组合是在河边通道中开发的，重建了当前的环境，以测量生长参数（例如，繁殖）的优势种，并测试种间的相互作用。在冬季组合中的五种优势藻类中，有三种始终被归类为早期演替（即，相对丰度随组合年龄的增加而降低）和2种为晚期演替。早期演替的物种不同的生长形式和战略，最初占主导地位的基板，具有高密度的水柱，高概率的附着，或快速的早期繁殖率。演替后期的物种表现出更广泛的增长形式，并有最高的人均繁殖率在后期的增长。后期演替的物种减少了早期物种的繁殖率，在目前的环境中进行的继承，但本身并没有抑制生物量的增加。虽然早期和晚期演替物种之间的增长策略的差异表明的重要性，被动的耐受性机制的继承，密度依赖的相互作用在社会发展过程中是一致的主动耐受机制。在陆地植物群落中，底栖藻类组合的演替模式似乎是由几个过程引起的，无法用单一的机械模型来解释。
Although seasonal patterns of algal succession have received considerable attention, few studies have attempted to elucidate the processes that contribute to short- term algal succession following disturbance. We framed the present study around four general mechanisms of succession in order to investigate the contribution of species-specific autecologies and interspecific interactions to observed short-term patterns of algal succes- sion in a productive third-order stream in Kentucky, USA. Observations in different current environments in the stream during two consecutive winters were used to classify dominant species as early or late successional based on changes in relative abundance through time on newly exposed substrates. Assemblages of the same age but differing in the relative abundance of early- and late-successional species were developed in streamside channels recreating both current environments to measure growth parameters (e.g., reproduction) of dominant species and to test for interspecific interactions. Of the five dominant species of algae in the winter assemblage, three species were consistently classified as early successional (i.e., decreased in relative abundance with in- creasing assemblage age) and two species as late successional. Early-successional species differed in their growth form and strategy for initially dominating the substrate, having high densities in the water column, high probabilities of attaching, or fast early reproductive rates. Late-successional species exhibited a more extended growth form and had the highest per capita reproductive rates during later growth. Late-successional species reduced the reproductive rate of early species as succession proceeded in both current environments but were not themselves inhibited by biovolume increases. While differences in growth strategies between early- and late-successional species indicated the importance of passive tolerance mechanisms of succession, density-dependent interactions during community development were consistent with active tolerance mechanisms. As in terrestrial plant communities, successional patterns in benthic algal assemblages appear to result from several processes that defy explanation by a single mechanistic model.