Intertidal organisms distributed in different zones experience strong environmental stress due to various biotic and abiotic factors. Environmental stress model (ESM) predicted that overall species richness and diversity should follow a unimodal trend along the vertical elevation gradient. In the present study, species richness and diversity of macroinvertebrates (molluscs and crustaceans) were measured on a rocky shore of Mumbai, the west coast of India. Data on species abundance were collected for two years (January 2005 to December 2006) after fixing three transects from high-to-low-shore zones based on the tidal heights. Quadratic regression analysis was applied to examine the pattern of variation in overall species richness and diversity across the stress gradient. The analysis revealed that both the variables followed unimodal trends across elevations and suggested that ESM predictions can also be applied to taxonomic groups besides different functional groups of intertidal organisms. It was also found that ESM can be useful in predicting local species richness and diversity as a function of environmental stress and helpful in providing a better understanding of distribution and dynamics of communities at local scale.

中文翻译：

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在印度孟买的岩石潮间带高程梯度上，对大型无脊椎动物多样性的环境压力模型进行的预测检验

由于各种生物和非生物因素，分布在不同区域的潮间生物受到强烈的环境压力。环境压力模型（ESM）预测，总体物种丰富度和多样性应沿垂直海拔梯度遵循单峰趋势。在本研究中，在印度西海岸孟买的岩石海岸上测量了大型无脊椎动物（软体动物和甲壳类动物）的物种丰富度和多样性。在根据潮高确定了从高到低海岸带的三个样带后，收集了两年（2005年1月至2006年12月）物种丰富度的数据。应用二次回归分析来研究整个物种丰富度和整个应力梯度的多样性的变化模式。分析表明，这两个变量都遵循跨海拔的单峰趋势，并建议除了潮间带生物的不同功能组外，ESM预测也可以应用于分类组。还发现，ESM可以根据环境压力来预测当地物种的丰富度和多样性，并有助于更好地了解当地规模的社区分布和动态。