Chin J Plant Ecol ›› 2013, Vol. 37 ›› Issue (4): 306-316.DOI: 10.3724/SP.J.1258.2013.00030

• Research Articles • Previous Articles     Next Articles

Effect of snow patches on leaf litter mass loss of two shrubs in an alpine forest

HE Wei, WU Fu-Zhong, YANG Wan-Qin*(), WU Qi-Qian, HE Min, ZHAO Ye-Yi   

  1. Key Laboratory of Ecological Forestry Engineering of Sichuan Province, Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu 611130, China
  • Received:2012-10-22 Accepted:2013-02-25 Online:2013-04-01 Published:2013-04-09
  • Contact: YANG Wan-Qin

Abstract:

Aims Litter decomposition of understory species is one of the essential components in material cycling and other important processes in alpine/subalpine forest ecosystems. Natural snow patches with different snow depths in winter could play an important role in litter decomposition due to significantly different freeze-thaw characters, but little information has been available. Therefore, our objective was to understand the effects of snow patches on litter decomposition of dwarf bamboo (Fargesia nitida) and salix (Salix paraplesia), two representative understory shrubs in alpine forest.
Methods A field experiment using litterbags was conducted in an alpine forest in western Sichuan, China. Samples of air-dried leaf litter were placed in nylon litterbags, and the litterbags were placed on the forest floor along a snow depth gradient from forest gap to canopy cover. Five snow patches with different snow depths were selected: thickest snow cover patch (SP1), thicker snow cover patch (SP2), middle thick snow cover patch (SP3), thinner snow cover patch (SP4) and no snow cover patch (SP5). Mass loss was measured at five critical periods as decomposition proceeded (onset of soil freezing period, soil freezing period, soil thawing period, early growth period and later growth period) of the first year of decomposition.
Important findings Mass loss of dwarf bamboo and salix litters in the freeze-thaw season accounted for (48.78 ± 2.35)% and (46.60 ± 5.02)% of the first year of litter decomposition, respectively. Both litters displayed higher mass loss rate under the patches with snow cover compared with no snow patch in the freeze-thaw season, but showed higher mass loss rate under SP5 in the growth season. Over the first year of decomposition, although mass loss rate of bamboo litter increased with the increase of winter-snow depth, salix litter showed the highest value under SP4 and lowest value under SP5. In addition, correlation analysis indicated that mass loss rate in the freeze-thaw season was positively related to daily mean temperature and negative cumulative temperature, whereas mass loss rate in the growth season was not related to any investigated temperature factors. However, 1-year mass loss rate was significantly related to daily mean temperature and negative/positive cumulative temperature. These results indicated that change of snow pattern would have significant effects on understory litter decomposition in the alpine forest in the scenario of warmer winters, but the effects could be various in different kinds of litter.

Key words: alpine forest, shrub leaf litter decomposition, snow patches, warm winter