华南丘陵人工马占相思林下灌木湿润季节蒸腾与小气候的关系

Relationship between transpiration of shrubs under artificial Acacia mangium stand on hilly land of South Chin and its microclimate during wet season

在湿润季节测定了广东丘陵常见的人工马占相思林内６种灌木的蒸腾日变化， 描述其蒸腾日变化的规律．并分析叶片蒸腾与林内的光、气温、湿度等小气候因子及叶温、 叶片气孔扩散阻力的回归关系．所有被观测灌木的蒸腾耗水日变化格局相似，阳性种类桃 金娘在人工林的隐蔽条件下生长良好．其蒸腾速率最高，山苍子的蒸腾速率次之，其它种 类的蒸腾表现较为适中．回归分析结果表明，灌木蒸腾变化与空气相对湿度呈负相关，与 林内气温、全光照、光合有效辐射呈正相关．叶温和叶片气孔扩散阻力与灌木蒸腾变化分 别呈正、负相关．

The diurnal patterns of transpiration of 6 kinds of understory shrubs in an artificial Acaia mangium stand which is common in Guangdong hilly lands are measured, and the relation between leaf transpiration and microclimatic factors such as light, temperature, heredity inside the feat is analysed. The shrubs have a similar diurnal variation of water consumption through transpiration. Among the shrubs measured. Rhodomyrtus tomentosa, a sunny species which can still pew well in shady environment, exhibits the highest transpiration rate. Another sunny species Litsea cubeba takes the second place. Other shrubs transpire modestly. The transpiration of all shrubs is negatively correlated with air humidity and positively with air temperature, full radiation, and photosynthetically active radistion in forest. Two ecophysiolo- gical factores, leaf temperature and stomatal diffusive resistance, are positively and negatively correlated with iran8Piratbo, respectivesy.