【摘要】 研究了季节雨林0~20 cm土层中≤2 mm细根的生物量、分解量、死亡量、生长量和周转率,并比较了0~10 cm和10~20 cm土层细根生物量的差异。结果表明:0~10 cm的细根生物量明显多于10~20 cm的细根生物量;在0~20 cm土层中,季节雨林活细根和死细根生物量分别为5 418 kg.hm-2和707 kg.hm-2;细根生物量的季节变化显著,其中活细根生物量的最大值出现在5月,最小值出现在8月;年分解量、年死亡量、年生长量和年周转率分别为391 kg.hm-2,1 061 kg.hm-2,3 776 kg.hm-2和0.70 times.a-1。更多还原

【Abstract】 Xishuangbanna, with remarkable seasonal climate variations, is located in the north edge of tropical rain forest in the world. The tropical rain forest there is different from those in other tropical regions. One-year measurement of fine roots turnover was carried out in a tropical seasonal rain forest in Nature Reserve （21°57′N,101°12′E）, 5 km away from Xishuangbanna Tropical Botanical Garden in Xishuangbanna, Yunnan.The objectives of this study are: （1） to measure the biomass of live and dead fine roots （diameter≤2 mm） at the depth of 0～20 cm in soil, （2） to compare fine roots biomass at the depth of 0～10 cm and 10～20 cm, （3） to calculate decomposition, mortality, production and turnover rate of fine roots.Soil corer was used to investigate the biomass of live and dead fine roots. A traditional method of nylon litter bag was used to measure the decomposition and percentage of dry mass loss of fine roots. Based on one-year data and McClaugherty’s formulas, we calculated production and turnover rate of fine roots. The results showed that （1） The mean biomass of fine roots at the depth of 0～20 cm was 6 125 kg·hm^-2, the mean biomass of live and dead fine roots were 5 418 kg·hm^-2 and 707 kg·hm^-2, respectively （88.46% and 11.54% of total, respectively ）. Fine roots biomass at the depth of 0～10 cm was higher than that of 10～20 cm （P <0.01）, which was similar to other regions in the word. （2） The biomass of live fine roots was maximum in May and minimum in August. （3） Based on the theory of Olson, the relationship between leftover after decomposition and decomposition time was negative correlation, calculated decomposition coefficient （k） and percentage of dry mass loss （R） were 0.001 9 and 49.01%, respectively. （4） Decomposition, mortality, production and turnover rate were 391 kg·hm^-2,1 061 kg·hm^-2,3 776 kg·hm^-2 and 0.70 times·a^-1, respectively.更多还原