瀑布沟水库干热河谷消落带土壤氮时空分布特征

以瀑布沟水库消落带土壤为研究对象,以海拔、土地利用与土地覆盖(LULC)、地形与时间为影响因子,对消落带0—40cm土壤进行采样。采样时间分别为2017年4月25日、2017年7月5日和2018年4月25日,从时间上探讨了消落带雨热同期的夏季与1年轮回对土壤全氮与碱解氮含量的影响。结果表明:(1)消落带全氮和碱解氮含量随土层深度的增加而降低。(2)消落带低海拔地区全氮和碱解氮含量高于高海拔地区。(3)消落带全氮和碱解氮含量平均值大小为淤泥>草地>旱地>裸地。(4)消落带全氮和碱解氮含量与地形因子LS值呈反比。(5)夏季采集的土壤样本全氮与碱解氮含量显著低于2次4月采集的样本。从时间和空间上解释瀑布沟消落带土壤全氮与碱解氮含量的分布特征,为瀑布沟消落带的生态环境治理提供科学的数据支撑。

Spatial and Temporal Distribution Characteristics of Soil Nitrogen of the Dry-hot Valley in the Hydro-fluctuation Belt of the Pubugou Reservoir

In this paper, the 0-40 cm soil in the hydro-fluctuation belt of the Pubugou reservoir was collected in the study area according to different land use and land cover (LULC), elevation, topography and time. The sampling time was April 25, 2017, July 5, 2017 and April 25, 2018, the influence of summer and annual cycle on soil total nitrogen and alkali-hydrolyzed nitrogen content was analyzed. The results showed that:(1) The contents of total nitrogen and alkali-hydrolyzed nitrogen decreased with the increase of soil depth. (2) The contents of soil total nitrogen and alkali-hydrolyzed nitrogen in low altitude area was higher than that in high altitude area. (3) The average contents of soil total nitrogen and alkali-hydrolyzed nitrogen was:sludge > grassland > dry land > bare land. (4) The contents of soil total nitrogen and alkali-hydrolyzed nitrogen was inversely proportional to the terrain factor LS. (5) The contents of total nitrogen and alkali-hydrolyzed nitrogen in soil samples collected in summer were significantly lower than that in April. This study explored the distribution characteristics of soil total nitrogen and alkali-hydrolyzable nitrogen contents in the hydro-fluctuation belt of the Pubugou reservoir from time and space, which could provide scientific data support for the ecological environment management of the Pubugou reservoir.