Abstract:

The effects of canopy interception on nutrient cycling in the Chinese Fir plantation ecosystem was studied based on the 4 years located research data. The results indicated that the average amount of precipitation by canopy interception was 267.0 mm·a^-1 , which did not arrive onto the stand, but took part in the water cycle and nutrient cycle in the ecosystem; and the canopy interception was an important part of evapotranspiration from the Chinese Fir plantation ecosystem, which was up to 27.2 percent of the whole evapotranspiration. The evaporation from the canopy interception was an important way of drainage from the ecosystem, which was 18.97 percent of the whole amount of drainage from the watershed; The flush-eluviate of branches and leaves caused by canopy interception brought nutrient input of 143.629 kg·hm^-2a^-1, which was 74.905 kg·hm^-2a^-1 more than the input of 63.924 kg·hm^-2a^-1 from the atmospheric precipitation and was 117.2% of the latter. The decreased amount of 80.1 mm precipitation input caused by canopy interception reduced the amount of rainfall onto the stand surface and infiltration into the soil, and reduced the output with of runoff and drainage, and decreased nutrient loss through with output water. Therefore, the additional preserve of nutrient by canopy interception was 8.664 kg·hm^-2a^-1.

Key words: Chinese Fir plantation, canopy interception, intercepted evaporation, runoff, nutrition accumulation