关键词: 长期氮磷钾肥配施, 相对产量, 黄壤, 土壤养分可持续性指数

Abstract: Forest microclimate monitoring is of great importance in evaluating the responses and feedbacks of forest to global climate change. One-year meteorological data in 2010, namely temporal patterns of air temperature, relative humidity, soil temperature and soil moisture at two sites from a mixed coniferous and broadleaf forest and an open land without forest in the Dinghushan Biosphere Reserve were analyzed and compared. The results showed that the annual average air temperature, relative humidity, soil temperature in the mixed forest were 19.8 ℃, 86.5%, and 20 ℃, respectively, while those in the open land were 22.1 ℃, 79.1%, and 24 ℃, respectively. Soil volumetric water content was significantly higher in the mixed forest, suggesting a cooling, humidifying and waterconserving function of this forest. Differences in air temperature, relative humidity and soil temperature during the daytime (10:00-17:00) between the two sites were much higher than that at nighttime, supporting the above assertion of better cooling and humidifying functions of the mixed forest at daytime. Differences in monthly air and soil temperature between the two sites were higher during the rainy season than in dry season, while the difference in monthly relative humidity was more apparent in dry season, indicating better cooling effects in rainy season and better humidifying effects in dry season. The pattern of microclimate in the mixed forest was controlled by local climate and vegetation type in lower subtropical China.

Key words: relative yield, yellow soil, long-term application of NPK fertilizer, sustainability index of soil nutrients.