长白山孤山屯泥炭沼泽活性有机碳研究

Labile Organic Carbon in the Gushantun Peat Bog in Changbai Mountains

土壤活性有机碳既是土壤微生物的活动能源,又是土壤养分循环的主要驱动力。2013年5~10月中旬,在吉林省辉南县孤山屯泥炭沼泽中,对瘤囊薹草(Carex schmidtii)—小叶章(Calamagrostis angustifolia)群落、薹草(Carex spp.)群落和薹草—柳叶绣线菊(Spiraea salicifolia)群落泥炭沼泽0~40 cm深度土壤微生物量碳和水中可溶性有机碳含量分布及其影响因素进行了研究。研究结果表明,各植物群落泥炭沼泽0~20 cm深度土层中的微生物量碳质量浓度在92.40~478.96 g/m^3范围内变化,瘤囊薹草—小叶章群落泥炭沼泽土壤中的微生物量碳含量最低;20~40 cm深度土层中的微生物量碳质量浓度在48.45~348.88 g/m^3范围内变化,在20~40 cm深度土层,各采样日都是薹草—柳叶绣线菊群落泥炭沼泽土壤的微生物量碳质量浓度相对最大,其它依次为薹草群落、瘤囊薹草—小叶章群落;各植物群落泥炭沼泽0~20 cm和20~40 cm深度水中的可溶性有机碳质量浓度的变化范围分别为28.99~53.69 mg/L和22.20~66.71 mg/L;6个采样日,薹草群落和薹草—柳叶绣线菊群落泥炭沼泽0~20 cm深度土层微生物量碳含量明显大于20~40 cm深度土层,而薹草群落泥炭沼泽20~40 cm深度水中的可溶性有机碳含量都高于上层;微生物量碳含量的对数与可溶性碳含量的对数为负相关关系;土壤微生物量碳含量的主要影响因素是土壤有机碳含量、全氮含量、全磷含量、氮磷比、硝态氮含量和水位,水中可溶性有机碳含量的主要影响因素是总氮含量、总磷含量和0 cm土壤温度。

The labile organic carbon, including dissolved organic carbon and microbial biomass carbon, is both the energy source for soil microbial activity and the main driver for soil nutrients cycle. The changes of soil carbon pool mainly occur in the labile organic carbon pool. In this study, on the 15th of May to October, 2013, at soil layers of 0-20 cm and 20-40 cm depths, the contents of dissolved organic carbon in the water and microbial biomass carbon in the soil with Carex schmidtii-Calamagrostis angustifolia, Carex spp.-Spiraea salicifolia and Carex spp. communities were investigated in the Gushantun peat bog, Jilin province. There was no significant fluctuation of the contents of the microbial biomass carbon at the bog in the sampling days. The concentrations of the microbial biomass carbon at 0-20 cm and 20-40 cm depths were 92.40 g/m3 to 478.96 g/m3 and 48.45 g/m3 to 348.88 g/m3, respectively. The concentration of the microbial biomass carbon in the soil of 20-40 cm depth with Carex schmidtii-Calamagrostis angustifolia community was the lowest significantly than those of other communities at the same depths in every sampling day. The contents of the microbial biomass carbon in the soil of the 0-20 cm depth with Carex spp. community and Carex spp.-Spiraea salicifolia community were higher than those at 20-40 cm depth. The concentrations of the dissolved organic carbon in the water at both depths were 28.99 mg/L to 53.69 mg/L and 22.20 mg/L to 66.71 mg/L, respectively. There was negative correlation relationship between the base 10 logarithm of contents of dissolved organic carbon and microbial biomass carbon at 0-40 cm depth, which indicated a trade-off relationship between them. Main environmental factors that influenced the content of dissolved organic carbon were contents of total nitrogen and total phosphorus and soil surface temperature, and the contents of organic carbon, total nitrogen and total phospho- rus, nitrogen and phosphorous ratio, nitrate nitrogen, and water level for the content of microbial biomass carbon.