关键词: 藓类生长速率, 蒸汽压亏缺, 辐射, 采伐迹地, 云杉原始林

Abstract:

Aims Mosses constitute major ground cover of the subalpine forests in the eastern Tibetan Plateau. Moss leaves have one layer of cells and are highly sensitive to environment changes. This attribute of mosses can be used to monitor environment conditions and guide restoration. However, moss growth and especially variables affecting moss growth in subalpine forest ecosystems are poorly known. Even worldwide, the growth rate of mosses has been rarely studied because of time-consuming, inaccurate measuring methods.
Methods Two plots, one in old-growth spruce forest and the other in nearby clear-cut land in subalpine western Sichuan, were selected. We labeled and measured mosses on May 7, 2001 and remeasured on August 7, 2001 and simultaneously recorded microclimate measurements.
Important findings The growth rate of mosses varied among species and habitats. Hylocomium splendens had the highest growth rate, while Dicranum assamicum had the lowest. The growth of H. splendens, D. assamicum, and Thuidium lepidoziaceum was faster in forest than in clear-cut land, where it was inversely correlated with distance to forest. Actinothuidium hookeri and Rhytidiadelphus triquetrus had moderate growth rates nearly independent of habitat. From May to July, the forest almost always had lower radiation level and vapor pressure deficit (VPD) favorable for moss growth. For habitat-insensitive species, microtopographic factors might have offset the effect of habitat. Moss growth rate and habitat VPD were strongly negatively correlated. Moss growth rate can be used to suggest favorable habitat.

Key words: moss growth rate, vapor pressure deficit (VPD), clear-cut, spruce forest