摘要
阐明不同生态系统土壤呼吸碳排放特征及其影响因子,对于评估陆地生态系统碳平衡具有重要作用。当前,人们对不同生态系统土壤呼吸对施氮或氮沉降的响应的认识还很不一致。虽然目前已对橡胶(Hevea brasiliensis)林土壤呼吸进行了较多的研究,但对施氮对橡胶林土壤呼吸的影响还了解得不多。采用静态碱液吸收法,研究了4种施氮水平下(不施氮,N0;低氮100 kg·hm^(-2),N100;中氮230 kg·hm^(-2),配施有机肥氮30 kg·hm^(-2),N230;高氮400 kg·hm^(-2),N400)海南橡胶林土壤呼吸的碳排放速率、通量及其影响因子。结果表明,橡胶林土壤呼吸的碳排放速率具有明显的季节变化特征,全年呈多峰型曲线。土壤呼吸碳排放速率与施氮量、土壤湿度和土壤温度均存在显著或极显著相关性。不同施氮处理土壤碳排放速率介于1.27~1.96 g·m^(-2)·d^(-1),年排放通量介于4.62~7.12 Mg·hm^(-2)·a^(-1)。与不施氮处理相比,较低的施氮水平(N100)并没有显著影响土壤呼吸,而继续增施氮肥则显著激发了橡胶林土壤碳排放。与N100和N400相比,N230化肥配施有机肥并没有引起土壤碳排放的显著增加。综上所述,施氮能促进橡胶林土壤呼吸碳排放,但其促进程度与施氮量有关。
Illuminating carbon （C） emission characteristic and impact factors of soil respiration in different ecosystems is important for accurately assessing C balance of terrestrial ecosystems. At present, the knowledge about responses of soil respiration in different ecosystems to nitrogen （N） fertilization or N deposition are controversial. Many studies about soil respiration were carried out in rubber （Hevea brasiliensis） plantations, but few for the effects of N fertilization on soil respiration. In this study, the alkali absorption method was used to investigate the carbon emission rates, fluxes and impact factors of soil respiration in rubber plantation of Hainan under four N fertilization levels （no N, N0; 100 kg·hm^-2, N100; 230 kg·hm^-2, organic N 30 kg·hm^-2, N230; 400 kg·hm^-2, N400）. The results showed that the C emission rate from soil respiration in rubber plantation was characteristics of obvious seasonal variation, and showed a multiple-peak curve during the whole year. The C emission rates were significantly positive correlated with, N rate, soil moisture and soil temperature. The C emission rates varied between 1.27 and 1.96 g·m^-2·d^-1 in different N treatments, and the annual C emission fluxes varied between 4.62 and 7.12 Mg·hm^-2·a^-1. Compared with N0, low N rate （N100） had no obvious effect on soil respiration. But if the N fertilizer rates continue to increase, the C emission was stimulated greatly. Compared with N100 and N400, N230 consisted of organic and inorganic fertilizers did not cause the soil emissions increase significantly. Our results suggest that N fertilization could promote the C emission from soil respiration in rubber plantation, and it depends on the rate of N fertilization to a great degree.
出处
《生态环境学报》
CSCD
北大核心
2016年第7期1134-1139,共6页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(31400529)
海南省自然科学基金项目(314143)
关键词
橡胶林
施氮
土壤呼吸
碳排放
海南
rubber plantation
nitrogen fertilization
soil respiration
carbon emission
Hainan
