鹤山不同植被类型土壤惰性碳含量及其季节变化特征

Variation of Soil Non-labile Carbon under Different Forest Types in Heshan

摘要:

为探讨植被恢复下森林土壤惰性碳(Non-labile carbon, NLC)的分布和季节动态,对鹤山6种不同植被类型(灌草、马尾松、桉树、乡土树种、马占相思、季风常绿阔叶林)不同土层(0～10 cm、10～20 cm和20～40 cm)NLC进行研究。结果表明: 6种植被类型土壤NLC含量均以表层(0～10 cm)最高,且随土层深度增加有下降趋势。表层土壤NLC含量受植被类型的影响显著,马占相思林的土壤NLC含量显著高于其他林型;马尾松林的土壤NLC含量最低,与其他林型差异显著。马占相思林深层土壤(10～20 cm和20～40 cm)的NLC含量显著高于其它植被类型,其它植被类型间无显著差异。不同植被类型的土壤NLC含量具有不同的干湿季动态变化,湿季土壤NLC占土壤总有机碳(Soil organic carbon, SOC)的比值高于干季。从不同土层NLC占SOC的比例可见,马占相思林和灌草林能显著提高土壤不同层次的NLC含量,马尾松林、桉树林、乡土树林和季风常绿阔叶林则有利于提高深层土壤SOC稳定性。

Abstract:

In order to determine the vertical contents and the seasonal variations of none-labile carbon (NLC) under different forest types, soils samples at 0～10, 10～20 and 20～40 cm depth were collected from six forests, including shrub-grass forest, masson pine forest, Eucalyptus forest, native-species forest, Acacia forest and monsoon evergreen broad-leaved forest, respectively, in Heshan. The results showed that soil NLC declined with the soil depth in the six types of forest with the highest NLC contents at the surface layer (0～10 cm depth). At the surface layer soil, the contents of NLC were significantly different among the forest types with the highest level in Acacia forest and the lowest level in masson pine forest. At the deeper layers (10～20 cm and 20～40 cm depth), the Acacia forest had the highest NLC while the other 5 forest types had the contents of NLC without significant differences. Among the six forest types, there were seasonal patterns of soil NLC with the higher ratios of NLC to soil organic carbon (SOC) in wet season than in dry season. The ratios of NLC/SOC among the six forest types indicated that Acacia forest and shrub-grass forest were helpful to increase the contents of soil NLC at all layers,while masson pine forest, Eucalyptus forest, native-species forest, and monsoon evergreen broad-leaved forest were helpful to stabilize the contents of SOC at deeper soils.