千烟洲人工针叶林对温湿环境的调节作用

The regulating effects of coniferous plantation on temperature and humidity in Qianyanzhou

森林对气候有调节作用是森林生态服务功能的体现之一。森林小气候研究有助于深入了解森林生态系统对气候调节的特征及其机制,进而为农林生产提供理论指导。本研究以千烟洲亚热带人工针叶林为对象,以2005—2014年林外与林内平行观测数据为基础,通过对比林内外的温度、湿度差异,研究中亚热带人工林对小气候中的温度、湿度要素的调节作用,并进一步研究了10年时间尺度上森林对温湿环境调节作用的时间动态特征。结果表明,该人工林对温湿环境表现出了显著的调节作用。林内气温多年平均值低于林外0.5℃,林内月最高气温低于林外2.0℃,月最低气温高于林外0.4℃。随着林龄从20年增长到30年,夏季的降温效应显著增强,对最高气温和最低气温的调节作用显著增强。该人工林林内水汽压高于林外,表现出明显的增湿效应。从2005—2014年,林内水汽压呈显著升高趋势。森林对土壤温度的调节作用大于对气温的调节作用,林内5 cm深土壤温度多年均值比林外低3.6℃。炎热的夏季表现为极显著的降温作用,冬季表现出极显著的保温作用;对土壤温度的调节作用没有随着林龄的增长呈现出明显的变化趋势,而是受到土壤含水量的影响。

Forests can regulate climate to some extent, which is an aspect of the ecological services of forests. Studies on forest microclimates can help us understand the regulations and mech- anism of how the forests affect climate and provide theoretical guides to agricultural and forest production managements. We conducted ten-year parallel measurements of temperature and water vapor pressure both outside and inside a coniferous plantation in subtropical China from 2005 to 2014. To examine the effects of the coniferous plantation on microclimate, air temperature, soil temperature and water vapor pressure inside the forest were compared with those outside of the forest. The results showed that forest can significantly affect temperature and humidity in the forest. At annual scale, the multi-year mean air temperature inside the forest was 0.5 ℃ lower than that outside the forest. The multi-year mean monthly maximum air temperature inside the forest was 2.0 ℃ lower than that outside the forest. Moreover, the multi-year mean monthly minimum air temperature inside the forest was 0.4 ℃ higher forest increased from 20 years to 30 years, the increased. In addition, the regulating effects than that outside the forest. As the age of the cooling effects of the forest in summer significantly on maximum and minimum air temoerature wereenhanced. The water vapor pressure inside the forest was generally higher than that outside the forest, which indicated a humidifying effect of forest. From 2005 to 2014, accompanying with the growth of the forest, water vapor pressure inside the forest significantly increased. The regulating effects of forest on soil temperature were greater than that on air temperature. The multi-year mean annual soil temperature at 5 cm depth inside the forest was 3.6 ℃ lower than that outside the forest. The forest showed significant cooling effects in the hot summers, while it showed heat preservation effects in winter. These effects did not show obvious increase or decrease trends with increasing forest age, but might be affected by soil water contents.