Describing spatial variation in species richness and understanding its links to ecological mechanisms are complementary approaches for explaining geographical patterns of richness. The study of elevational gradients holds enormous potential for understanding the factors underlying global diversity. This paper investigates the pattern of species richness and range‐size distribution of epiphytic bryophytes along an elevational gradient in Marojejy National Park, northeast Madagascar. The main objectives are to describe bryophyte species composition and endemism in Marojejy National Park, to describe the species richness and distribution patterns of epiphytic bryophytes along an elevational gradient from 250 m to 2050 m and to evaluate the explanatory value of environmental variables for the observed patterns. Bryophyte samples were collected following a nested design with four hierarchical levels: elevational belts, plots, quadrats, and microplots. In total, 254 epiphytic bryophyte species were recorded, comprising 157 liverworts and 97 mosses. Twenty‐three of these are endemic to Madagascar. Species richness exhibits a hump‐shaped pattern along the elevational gradient, peaking at 1,250 m. Eighty‐seven percent of the total recorded species have a range distribution lower than 1,000 m, at which point 36% are restricted to these single elevations. Our results suggest that mean temperature, relative humidity, and vapor pressure deficit play important roles in shaping the richness pattern observed in this study. While the liverwort richness pattern did not correlate to vapor pressure deficit and responded only weakly to relative humidity, the richness pattern shown by mosses correlates well with mean temperature, relative humidity, and vapor pressure deficit.

中文翻译：

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马达加斯加Marojejy附生苔藓植物的多样性和沿海拔梯度的范围分布

描述物种丰富度的空间变化并理解其与生态机制的联系是解释丰富度地理模式的补充方法。海拔梯度的研究具有巨大的潜力，可以理解全球多样性背后的因素。本文研究了马达加斯加东北部Marojejy国家公园沿海拔的附生苔藓植物的物种丰富度和范围大小分布模式。主要目的是描述Marojejy国家公园的苔藓植物物种组成和特有度，描述沿250 m至2050 m海拔梯度的附生苔藓植物的物种丰富度和分布格局，并评估环境变量对观测格局的解释价值。按照以下四个层次的嵌套设计收集苔藓植物样品：高程带，样地，方形样和微样。总共记录了254种附生苔藓植物，包括157种艾蒿和97种苔藓。其中有23种是马达加斯加特有的。物种丰富度沿海拔梯度呈驼峰状，最高峰为1,250 m。在记录的全部物种中，有百分之八十七的范围分布小于1,000 m，此时，只有36％的范围仅限于这些单一海拔。我们的结果表明，平均温度，相对湿度和蒸气压赤字在塑造本研究中观察到的富集模式方面起着重要作用。虽然地草的丰富度模式与蒸气压不足无关，而对相对湿度的响应却微弱，