摘要
本文研究了黑石顶自然保护区南亚热带常绿阔叶林的凋落量及其季节动态,并对现存凋落量和凋落物分解速率进行了初步测定。 小凋落物[叶、D(直径)<lcm枝、花果、杂物]总量为5.230t·ha^(-1)a^(-1)(2年平均),其中叶3.550(68.22％),枝0.837(15.81％),花果0.582(10.97％)。凋落物的季节变化明显,叶凋落量雨季较多,干季较少,一般以4月为凋落高峰,花果凋落量则以秋冬季节较多。大枝(D≥1cm)凋落量为0.340t·ha^(-1)(2年平均),年际变化较大。 现存凋落量为5.545t·ha^(-1),其中叶3.275(59.06％),枝1.618(29.18％),花果0.131(2.36％)。 叶凋落量约为叶生物量的1/4,叶现存凋落量约为叶生物量的1/5。 凋落物分解至原重量一半约需5个月左右(雨季),一年半后重量减至原重的19％。
Litterfall and its monthly variation, litter standing crop, and the litter decomposition rate in the lower subtropical evergreen broad- leaved forest of Heishiding Natural Reserve, Province Guangdong, were studied from Aug. 1989 to Aug. 1991. the forest is at 400 m above sea level , which was dominated by Ixonanthes chinensis, Artocarpus styracifolins, Ormosia glaberrima, Crypto-carya cancinna, Calamus rhabdocladus, Cibotium, barametz, etc. As measured, amount of small litter-fall including leaves, branches less than one centimeter in diameter, flowers and fruits, and trash was 5. 230 t · ha-1 per year (mean for 2 yrs. ) among which leaves, branches, and flowers and fruits were 3. 550(68. 22%), 0. 837(15. 81%), and 0. 582(10. 97%) respectively. It was obvious that the litterfall varied monthly. Greater leaf litterfall occured in the wet season, with a peak in April, while flower and fruit litterfall was more in Autumn and Winter. Big branch (diameter over 1 cm) litterfall was 0. 34 t · ha-1per year (mean for 2 yrs. ), with significant yearly variation. Litter standing crop amounted to 5. 545 t · ha-1, among which leaves, branches, and flowers and fruits were 3.275 (59.06%), 1. 618(29. 18%), and 0. 131(2. 36%) respectively. Leaf litteffall and standing crop of leaf litter were about 1/4 and 1 /5 of the leaf biomass respectively. It took about 5 months for the litter to lose half of its weight in wet season. The lit ter decreased to 19 % of the original weight in 18 months.
