鼎湖山森林演替和海拔梯度上的土壤微生物生物量碳氮变化

发布时间：2018-03-23 11:47

本文选题：土壤微生物　切入点：森林凋落物　出处：《生态学杂志》2017年02期

【摘要】：在广东鼎湖山选取演替(马尾松林、针阔混交林和季风阔叶林)和海拔(沟谷阔叶林、季风阔叶林和山地阔叶林)梯度上的两组森林,采集凋落物层(未分解L层和半分解/腐殖化F/H层)和矿质土层(0~15 cm)的森林土壤样品,测定微生物生物量碳(MBC)和氮(MBN)及其潜在影响因子(包括含水量、总碳、总氮、总磷、可溶性有机碳和可溶性有机氮),探讨演替和海拔对凋落物层和矿质土层微生物生物量的影响及其机理。结果表明,MBC、MBN、MBC/MBN比值以及碳氮磷总量整体上均随有机质分解程度的增加(L层→F/H层→矿质土层)而降低。随演替进行(马尾松林→混交林→季风林),F/H层和矿质土层的MBC和MBN显著增加,而L层的MBC和MBN在混交林显著低于在马尾松林和季风林。随海拔上升(沟谷林→季风林→山地林),L层的MBC和MBN显著减少,而F/H层和矿质土层的MBC和MBN无显著变化。相关分析表明,在L层中MBC和MBN与含水量呈显著正相关;在F/H层中MBC和MBN与总磷和可溶性有机氮含量呈显著正相关;在矿质土层中MBC和MBN与土壤含水量、碳氮磷总量以及可溶性有机氮含量呈显著正相关。本研究表明,演替和海拔梯度上的土壤微生物生物量变化因土层而异,与不同土层的有机质分解程度、空间位置和养分有效性差异有关。
[Abstract]:Two groups of forests on the gradient of succession (Pinus massoniana forest, mixed coniferous broadleaved forest and monsoon broadleaved forest) and elevation (gully broad-leaved forest, monsoon broad-leaved forest and mountainous broad-leaved forest) were selected in Dinghu Mountain, Guangdong Province. Forest soil samples from litter layer (undecomposed L layer and semi-decomposed / humifying F / H layer) and mineral soil layer (0 ~ 15 cm) were collected to determine microbial biomass (MBC) and nitrogen (MBN) and their potential impact factors (including water content, total carbon, total nitrogen, total phosphorus, total phosphorus, total water content, total carbon, total nitrogen, total phosphorus). The effects of succession and altitude on microbial biomass in litter layer and mineral soil layer were studied. The results showed that the ratio of MBC / MBN / MBN and the total amount of carbon, nitrogen and phosphorus increased with the increase of decomposition degree of organic matter. 鈫扚 / H layer. 鈫扺ith succession (Pinus massoniana forest). 鈫扢ixed forest. 鈫扵he MBC and MBN of F / P H layer and mineral soil layer increased significantly in monsoon forest, while MBC and MBN in L layer were significantly lower in mixed forest than in Pinus massoniana forest and monsoon forest. 鈫扢onsoon forest. 鈫扢BC and MBN in L layer of mountain forest decreased significantly, but MBC and MBN in F / H layer and mineral soil layer did not change significantly. Correlation analysis showed that MBC and MBN were positively correlated with water content in L layer. In F / H layer, MBC and MBN were positively correlated with total phosphorus and soluble organic nitrogen, and MBC and MBN were positively correlated with soil water content, total carbon, nitrogen and phosphorus content and soluble organic nitrogen content in mineral soil. The variation of soil microbial biomass in succession and elevation gradient varies with soil layer, which is related to the degree of organic matter decomposition, spatial location and nutrient availability of different soil layers.
【作者单位】：中国科学院华南植物园退化生态系统植被恢复与管理重点实验室;中国科学院大学;中国科学院华南植物园广东省应用植物学重点实验室;
【基金】：国家自然科学基金项目(41401326)资助
【分类号】：S714

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