地下水位变化对鄂西南亚高山泥炭藓湿地物种多样性和生物量的影响

Effects of Groundwater Level Fluctuations on Species Diversity and Biomass in Subalpine sphagnum Wetlands of Southwest Hubei, China

摘要:

为了探讨地下水位变化对鄂西南亚高山泥炭藓湿地植物群落物种多样性和生物量的影响，通过设置自然、排水和蓄水三种不同水位梯度处理，研究水位变化对湿地植被的影响。结果表明：天然湿地的物种丰富度和多样性指数均显著高于排水和蓄水湿地，表明适中且稳定的地下水位有利于物种的多样化。相比之下，排水湿地灌木层生物量最高，而蓄水湿地苔藓层生物量显著增加，但群落多样性较低，单一物种占据竞争优势。此外，地下水位变化显著影响植物群落的优势种分布：排水湿地主要以耳叶杜鹃、多齿长尾槭等灌木为优势种，天然湿地则以耳叶杜鹃与泥炭藓共存为特征，而蓄水湿地中齿缘吊钟花占据主导地位。研究结果揭示了地下水位对泥炭藓湿地植物多样性与生物量影响的非线性响应模式，指出维持地下水位在适宜范围（-10～-5 cm）对湿地生态系统的保护和恢复具有关键作用。

Abstract:

In order to explore the effects of groundwater level fluctuations on plant species diversity and biomass in alpine Sphagnum wetlands of southwestern Hubei, China, three groundwater level treatments（natural, drainage, and water storage）were applied to examine their influence on wetland vegetation.Results indicated that species richness and diversity indices were significantly higher in natural wetlands compared to drainage and water-storage wetlands, suggesting that moderate and stable groundwater levels are beneficial for species diversification.In contrast, shrub biomass was highest in drained wetlands, whereas moss biomass significantly increased in water-storage wetlands, which exhibited lower community diversity characterized by single-species dominance.Additionally, groundwater fluctuations significantly affected dominant species distribution patterns: shrub species such as Rhododendron auriculatum and Acer caudatum dominated drained wetlands, natural wetlands were characterized by the coexistence of Rhododendron auriculatum and Sphagnum palustre, and water-storage wetlands were dominated by Enkianthus serrulatus.These findings demonstrate a nonlinear response of species diversity and biomass to groundwater level variations and highlight the critical importance of maintaining groundwater levels within an optimal range（approximately -10 to -5cm）for the conservation and ecological restoration of wetland ecosystems.