摘要:
研究小气候变化对植被恢复的响应机制可为喀斯特地区石漠化综合防治提供理论依据.文章选取喀斯特高原山地和高原峡谷石漠化综合防治示范区4种土地利用类型为研究对象,通过常规的小气候监测方法,在雨季前(4月)、雨季(8月)、雨季后(12月)对4种土地利用类型的大气温度、光照强度、相对湿度、土壤温度日变化进行监测和对比分析.结果表明:(1)4种土地利用方式中,大气温度、光照强度和土壤温度均表现为石漠化裸地>农耕地>灌木林>林地,而相对湿度的变化规律则反之:林地>灌木林>农耕地>石漠化裸地,说明林地的小气候调节作用最优,而石漠化裸地最差,与其石漠化治理和植被恢复效果相对应;(2)高原峡谷的大气温度、光照强度和相对湿度在不同的季节和不同土地利用方式下都显著高于高原山地,不同土层的土壤温度是高原山地显著低于高原峡谷;(3)各土地利用方式的小气候季节差异明显,大气温度、土壤温度均为:雨季(8月)>雨季前(4月)>雨季后(12月),而光照强度、相对湿度为:雨季(8月)>雨季后(12月)>雨季前(4月),8月各小气候指标值最高,且不同土地利用方式和治理区间的差异亦最大,因此,选取8月进行小气候监测以比较各土地利用方式和治理区之间的差异要优于其他两个月份.
Abstract:
Different land use types on two typical geomorphological units of karst,plateau mountain and plateau valley,were studied,which can help to reveal the relationship between vegetation restoration and microclimate change by different land use types,and to provide the theoretical basis for in tegrated control of rocky desertification in karst region.Data were collected by regular microclimate monitoring.Daily variation of atmospheric temperature,light intensity,relative humidity and soil temperature on four land use types were analyzed before the rainy season (April),during the rainy season (August) and after the rainy season (December) in the two study areas.The results showed that,(1) Among the four land use types,atmospheric temperature,light intensity and soil temperature were in the order of rocky desertification bare land > farmland > shrubbery > forest land,while the relative humidity was on the contrary,i.e.forest land > shrubbery > farmland > rocky desertification bare land.This indicated that the forest land performs the best in microclimate regulation,and the rocky desertification bare land performs the worst,which corresponds to the rocky desertification control and vegetation restoration.(2)In the plateau mountain,atmospheric temperature,light intensity and relative humidity were significantly higher than the plateau valley in all seasons and land use types,while soil temperature of different soil layers in the plateau mountain was significantly lower than the plateau valley.(3)Seasonal differences on microclimate of different land use types was clear.Atmospheric temperature and soil temperature were in the order of rainy season (August) > before the rainy season (April) > after the rainy season (December),while the light intensity and relative humidity were in the order of the rainy season (August) > after the rainy season (December) > before the rainy season (April).Each index of microclimate reached to the highest value in August.The discrepancy of these values among the different land use types and different control areas was also the most significant in August.Therefore,microclimate monitoring in August to compare the difference among the different land use tvpes and different control areas is more effective than the other two months,i.e.April and December.
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