长白山南坡苔原植被的特殊性及坡向间差异性分析

以长白山苔原带南坡植被为对象,通过植被调查,与北坡和西坡植被进行比较,研究长白山苔原植被因坡向差异导致的不同植被变化模式。结果显示:(1)长白山苔原南坡植被中灌木处于优势地位,与北坡、西坡情况一致。但在物种组成上,各坡向差异明显,为中度不相似水平;(2)在生物多样性、多度、盖度等群落特征上,南坡与西坡的差异较大、与北坡相似性较强;(3)在物种多样性的空间分布上,南坡与北坡相同,即随海拔升高呈单峰变化且峰值出现在中部,与西坡物种多样性随海拔升高呈单调递减的趋势完全不同。表明不同群落抗干扰能力以及所受干扰程度存在差异,北坡处于演替中后期,较为稳定,抗干扰能力更强。南坡因受干扰强度较小,植被处于较稳定状态;(4)长白山苔原各坡向植被变化差异较大。南坡和北坡的植被相对稳定,与西坡草本植物强烈上侵明显不同。长白山苔原带植被的坡向差异源于各坡向的本底差异、环境差异以及对全球气候变化的差异性响应,是火山、强风干扰下植被演替与响应气候变化的植被变化共同作用的结果。

Particularity of tundra vegetation and differences in slope directions on the southern slope of Changbai Mountain

Climate change in tundra areas is becoming increasingly important in the context of global climate change. In this study, we established a comprehensive monitoring system to investigate the characteristics of tundra vegetation on the Changbai Mountain, with data indicating that tremendous changes have emerged in vegetation communities. In addition, obvious differences were observed in the tundra vegetation on Changbai Mountain in regard to slope direction, with the pattern in species composition and diversity of vegetation change on the northern slope found to be quite different. Results showed that:(1) Shrubs on the southern slope were dominant among vegetation communities, consistent with that observed on the northern and western slopes. However, species composition showed obvious differences in regard to slope direction, suggesting a moderate level of dissimilarity.(2) Vegetation community characteristics (e . g. biodiversity, abundance, and coverage) on the southern and northern slopes were quite similar, but differed from those on the western slope.(3) Spatial characteristics of species diversity were the same on the southern and northern slopes, and showed a single peak at mid-altitude, whereas species diversity on the western slope increased monotonously with increasing altitude. These results indicated that distinctions existed in the anti-interference ability of the vegetation communities on the different slopes. Compared with the western slope, the southern and northern slopes shared a strong vegetation community anti-interference ability.(4) Changes in vegetation on each slope were quite different. Vegetation on the southern and northern slopes was relatively stable, which differed obviously from the strong upward invasion of herbaceous plants found on the western slope. The differences in tundra vegetation based on slope direction on Changbai Mountain were due to several reasons, including background differences of each slope, environmental differences, and different responses to global climate change. It is the combination of vegetation succession and change in response to climate change under the interference of volcanoes and strong winds.