南极菲尔德斯半岛植被土壤N_2O排放特征

Characteristics of N_2O Emissions from Vegetal Soils on Fildes Peninsula, Antarctica

应用密闭箱法首次测定了南极菲尔德斯半岛苔藓、地衣植被土壤N2 O的排放通量 ,并估算了该半岛植被区土壤在夏季 2个月内N2 O的排放总量 .结果表明 :在晴天和雨天 ,苔藓土壤N2 O的排放通量与温度有较好的响应关系 ,呈现单峰型变化趋势 ;但在雪天 ,与温度的变化不一致 ;苔藓、地衣这 2种不同的植被土壤N2 O排放通量日变化基本一致 ;温度是影响苔藓土壤N2 O的排放通量季节变化的主要因子 ,同时还受降水的影响 ,干湿交替有利于N2 O的排放 ;苔藓土壤N2 O的排放总量为 3 .71 52kg ;地衣土壤N2 O的排放总量为 2 .53 4 4kg .由此可见 ,南极菲尔德斯半岛苔藓、地衣植被土壤N2 O排放量虽然很小 ,但仍起着大气N2

The N 2O fluxes from the vegetal soils were first measured on the Fildes peninsula, Antarctica, and the total N 2O emission was also estimated in the summer 2 months. The daily variations of N 2O fluxes appeared single peak trend under the sunshine or rainy weather conditions but they were irregular under the snow weather conditions and inconsistent with the atmospheric temperatures. The seasonal variations of the N 2O fluxes were affected by the temperature and rainfall. The conditions during the transitions between dry and wet seasons improved the N 2O emission. The total N 2O emissions from moss and lichen soils were 3.7152kg and 2.5344kg, respectively. It follows that the vegetal soils are the sources for the atmospheric N 2O on the Fildes peninsula, Antarctica.