ABSTRACT

Successful plant recruitment is crucial for maintaining forest ecosystems, but knowledge of the responses of early life stages of tropical montane tree species to complex environmental factors is still limited across the Himalayas. Vegetation was surveyed along an altitudinal gradient (2450–3070 m) in six altitudinal bands in a tropical montane forest of Myanmar. We examined the effects of microclimate, soil, and microsite conditions on seedling and sapling recruitment in three dominant tree species (Quercus semecarpifolia, Rhododendron arboreum, and Symplocos lucida). We found that densities of R. arboreum and Q. semecarpifolia were higher in high and mid-altitudinal bands (2800–3000 m), whereas density of S. lucida was higher in lower altitudinal bands (2600–2700 m). Seedlings showed better recruitment in humid conditions and more sensitive to soil properties than saplings. R. arboreum and S. lucida preferred debris microsites, followed by shrub and grass microsites, whereas Q. semecarpifolia showed no significant microsite preference. Seedling recruitment mainly depended on soils and microsites, whereas sapling recruitment depended on microclimate and altitude. The study provides information on species-specific preferences and responses of montane tree species to complex environmental factors, which may contribute to restoration and sustainable forest conservation.

摘要

成功的植物补充对于维持森林生态系统至关重要，但关于热带山地树种早期生命阶段对复杂环境因素的反应的知识在整个喜马拉雅山脉仍然有限。在缅甸热带山地森林的六个海拔带中，沿海拔梯度（2450-3070 米）对植被进行了调查。我们研究了小气候、土壤和微型场地条件对三种优势树种（Quercus semecarpifolia、Rhododendron arboreum和Symplocos lucida）的幼苗和树苗补充的影响。我们发现R. arboreum和Q. semecarpifolia在高海拔和中海拔（2800-3000 m）的密度较高，而S. lucida在较低的海拔带（2600-2700 m）中较高。幼苗在潮湿条件下表现出更好的补充，并且比树苗对土壤性质更敏感。R. arboreum和S. lucida偏好碎屑微网站，其次是灌木和草的微网站，而Q. semecarpifolia没有显示出显着的微网站偏好。幼苗补充主要取决于土壤和微型场地，而幼苗补充则取决于小气候和海拔。该研究提供了有关山地树种对复杂环境因素的物种特定偏好和反应的信息，这可能有助于恢复和可持续森林保护。