哀牢山中山湿性常绿阔叶林土壤养分的时间及空间变化规律

Temporal and Spatial Variations of Soil Nutrients in the Montane Moist Evergreen Broad-leaved Forest in Ailao Mountains

为探索中山湿性常绿阔叶林土壤养分的年际、年内及空间变化规律,以中国科学院哀牢山亚热带森林生态系统研究站固定样地2005—2015年土壤长期定位土壤养分观测的数据为研究材料,进行统计分析。结果显示:(1)土壤有机质和全氮含量随着土层深度的增加下降趋势明显;土壤全磷含量下降趋势不明显,在0~60 cm土层呈缓慢下降趋势,60~100 cm土层则有所上升;土壤全钾含量在0~60 cm土层呈逐渐上升趋势,60~100 cm土层则呈明显下降趋势。(2)与2005年相比,2015年0~10 cm土层的有机质、全氮、全磷和全钾含量均有不同幅度的下降,其中,土壤全磷含量下降幅度最大,为23.45%;有机质含量下降幅度最小,为8.76%;全氮和全钾的含量下降幅度分别为15.40%和14.30%。(3)土壤有机质和全氮在3—8月份呈下降趋势,8—11月份又逐渐增加。土壤有效磷在冬春干旱期(12月—翌年6月)逐渐增加,雨季(7—11月)快速下降。土壤速效钾在1—5月份呈缓慢平稳增长状态,5—8月份快速下降,9—12月份又快速上升。研究结果可为哀牢山中山湿性常绿阔叶林土壤养分供应状况及循环研究提供参考。

In order to explore the interannual,intra annual and spatial changes of soil nutrients in montane moist evergreen broad-leaved forest in Ailao Mountains,this study analyzed the long-term soil positioning observation data of Ailaoshan Station for Subtropical Forest Ecosystem Studies,Chinese Academy of Sciences from 2005 to 2015.The results showed that:(1)The contents of soil organic matter and total nitrogen decreased obviously with the increase of soil depth.The decrease trend of soil total phosphorus is not obvious,it decreased slowly at 0-60 cm,and then increased slowly at 60-100 cm.The total potassium of soil increased gradually in 0-60 cm,and then decreased obviously in 60-100 cm.(2)Compared with 2005,the content of organic matter,total nitrogen,total phosphorus and total potassium in 0-10 cm soil decreased by different ranges in 2015,among them,the maximum decrease of soil total phosphorus was 23.45%,the minimum decrease of soil organic matter was 8.76%,and the decrease of soil total nitrogen and total potassium was 15.40%and 14.30%respectively.The main reason is that the increase of forest volume leads to the gradual increase of forest trees’consumption of soil nutrition;Secondly,forest degradation and soil erosion will also aggravate nutrient loss.(3)Soil organic matter and total nitrogen decreased from March to August,and increased gradually from August to November.Soil available P increased gradually in the dry period of winter and spring(December to June of the next year),and decreased rapidly in the rainy season(July to November).Soil available potassium increased slowly and steadily from January to may,decreased rapidly from May to August,and increased rapidly from September to December.The results can provide a reference for the study of soil nutrient supply and cycle of montane moist evergreen broad-leaved forest in Ailao Mountains.