冀北辽河源阔叶混交林与油松林土壤呼吸及其影响因子

Soil Respiration and Impact Factors of Pinus tabulaeformis Forest and Mixed Broad-leaved Forest in Liaoheyuan Nature Reserve of Northern Hebei

对生长季内阔叶混交林和油松林的土壤呼吸速率进行研究,探讨冀北辽河源地区土壤呼吸与地下5cm土壤湿度、地下5、10、15 cm土壤温度(T5、T10、T15)、近地面大气温度、土壤微生物量碳、土壤理化性质的关系。结果表明:阔叶混交林和油松林的土壤呼吸速率的季节变化呈明显的单峰曲线,平均值分别为4.28、3.69μmol·m-2·s-1,与土壤温度的季节变化曲线大致相同,而滞后于大气温度。阔叶混交林、油松林的各温度与土壤呼吸均呈显著的正相关关系(P<0.01);而土壤湿度和各土层的阔叶混交林与土壤呼吸的相关性不显著,但群落间土壤有机碳、w(C)/w(N)、全氮、全磷、土壤微生物量碳均达到显著差异。综合分析,地下5 cm土壤温度为该地区森林土壤呼吸速率季节变化的主要影响因子;而土壤微生物量碳、凋落物种类及土壤理化性质的综合影响可能是引起两种群落的土壤呼吸速率差异的原因。

We studied the soil respiration of mixed broad-leaved forest（ MBF） and Pinus tabulaeformis forest（ YF） within the growing season,and discussed the relationships between soil respiration rate and soil moisture at 5 cm depth（ W）,soil temperature at 5 cm,10 cm,15 cm depth（ T5,T10,T15）,near-surface air temperature（Ta）,soil microbial biomass carbon（ MBC）,soil physical and chemical properties in Liaoheyuan Nature Reserve of Northern Hebei. The seasonal variations of YF and MBF＇s soil respiration rate represented a single peak curve with the means of 4. 28 and 3. 69 μmol·m-2·s-1,respectively. It was the same with the seasonal variation of soil temperature curve,but laged behind atmospheric temperature. T5,T10,T15,Taand corresponding soil respiration of MBF,YF showed a significant positive correlation（P 0.01）,and the relationship between W,each layer of MBC and soil respiration were not significant. But significance between communities of soil organic carbon,w（ C） / w（ N）,total nitrogen,total phosphorus,soil microbial biomass carbon reached significant levels. By comprehensive analysis,T5 was the main factor leading forest soil respiration seasonal variations in this area,and the combined effects of MBC,litter type and soil physical and chemical properties in all probability caused the differences between the soil respirations of two communities.