摘要
[目的]探讨不同发育阶段对马尾松人工林土壤团聚体及养分含量的影响,为马尾松人工林合理利用土壤提供参考依据.[方法]采用时空替代法,以黔中不同发育阶段(幼龄林→中龄林→近熟林→成熟林→过熟林)的马尾松人工林为研究对象,基于团聚体粒径分组对 0～80 cm土层内团聚体的质量分数、稳定性(平均质量直径MWD、平均几何直径GMD)、C、N含量以及相互间的关系进行分析.[结果]1)不同发育阶段0～80 cm土层内团聚体质量分数均表现为大团聚体(45.57%～91.20%)＞微团聚体(7.24%～32.87%)＞粉黏团聚体(1.09%～21.56%),大团聚体质量分数整体随土层加深而降低,微团聚体和粉黏团聚体则升高,在发育的后期大团聚质量分数较低,而微团聚体和粉黏团聚体则相反;2)不同发育阶段 0～80 cm土层内MWD和GMD的范围分别为 0.57～1.04 和 0.30～0.92 mm,团聚体稳定性随土层加深而降低,在幼龄林至近熟林阶段无显著差异,在成熟林阶段显著降低,在过熟林阶段有一定升高;3)不同发育阶段大团聚体、微团聚体、粉黏团聚体C、N的平均含量分别为 18.47～32.61、1.20～1.98、21.99～38.42、1.12～1.80、14.49～29.39 和0.94～2.45 g∙kg-1,各团聚体C、N基本随土层的加深而降低,大团聚体和微团聚体C、N随正向发育先升高后降低,粉黏粒团聚体C降低,N则呈现波动的趋势;4)大团聚体质量分数、各团聚体C、N分别与MWD和GMD之间呈极显著正相关,同一团聚体C与N之间、不同团聚体C与C、C与N、N与N之间也呈极显著正相关.[结论]在黔中马尾松人工林发育的后期,土壤团聚体的稳定性及对养分的固持能力降低.
Abstract
[Objective]Investigate the effects of development stages on soil aggregate and its nutrient contents of Pinus massoniana plantation so as to provide a insights for the rational use of soil in P.massoniana plantation.[Method]Using the method of space instead of time,P.massoniana plantation at different development stages in central Guizhou province(young-aged forest→middle-aged forest→near-mature forest→mature forest→overripe forest)was selected as research material,and then based on the method of aggregate size fractionation,the composition,stability,carbon and nitrogen concentrations of soil aggregate and their correlation with each other were analyzed.[Result]1)The mass percentage of aggregate in the 0-80 cm soil layer at different development stages was as macroaggregate(45.57%-91.20%)＞microaggregate(7.24%-32.87%)＞slit-clay aggregate(1.09%-21.56%),the mass percentage of macroaggregate decreased with the deepening of the soil layer,while the microaggregate and slit-clay aggregate increased,the mass percentage of macroaggregate decreased in the later development stages,while the microaggregate and silt-clay aggregate was the opposite;2)The values of MWD and GMD in the 0-80 cm soil layers at different development stages were 0.57-1.04 and 0.30-0.92 mm,respectively,the MWD and GMD decreased significantly with deepening of the soil layer,there was no significant difference in MWD and GMD from young-aged to near-mature stage,which decreased significantly in mature stage and increased to some extent in overripe stage;3)The average contents of C and N in macroaggregate,microaggregate and silt-clay aggregate at different development stages were 18.47-32.61,1.20-1.98,21.99-38.42,1.12-1.80,14.49-29.39 and 0.94-2.45 g∙kg-1,respectively,the contents of C and N in each aggregate basically decreased with the deepening of soil layer,the contents of C and N in macroaggregate and micro-aggregate first increased and then decreased with forward development,while the contents of C in slit-clay aggregate decreased,N contents showed a fluctuating trend;4)The mass percentage of macroaggregate,C and N contents in each aggregate were positively correlated with MWD and GMD,there were significant positive correlation between C and N of the same aggregates,as well as C and C,C and N,N and N of different aggregates.[Conclusion]In the later development stages of P.massoniana plantation in central Guizhou province,the stability and the nutrients contents of soil aggregates decreased.
基金项目
贵州省科技厅计划项目(黔科合基础-ZK[2022]一般241)
NETL
NSTL
万方数据