华南地区4个树种叶片持水能力研究

Study on water holding capacity of leaves of four tree species in south China

采用浸泡法和喷淋法模拟林冠降雨截留,研究了构树Broussonetia papyrifera、白兰Michelia alba、木荷Schima superba、马占相思Acacia mangium等华南地区4个重要树种叶片持水率和降雨截留率及其影响因子。结果表明:采用浸泡法时,构树和白兰叶片持水率与其它树种均差异显著,马占相思和木荷差异不显著,叶片持水率从大到小依次为构树972.2%>白兰361.0%>木荷275.0%>马占相思256.3%,截留率从大到小依次为构树519.8%>白兰111.00%>木荷75.3%>马占相思62.0%,构树显著高于其它树种,白兰与其它树种均差异显著;当浸泡时间达到5 min后,植物叶片持水率和截留率基本趋于饱和;采用喷淋法时,构树持水率与其它树种持水率差异显著,马占相思、白兰、木荷差异不显著,叶片持水率从大到小依次为构树895.0%>白兰275.0%>马占相思257.7%>木荷256.7%,截留率从大到小依次为构树456.7%>木荷128.0%>白兰80.7%>马占相思80.3%,构树和木荷与其它树种均差异显著,马占相思与白兰差异不显著;2种不同方法测得构树的持水率和截留率均显著高于其它树种;叶面积、叶片长和宽、叶片长宽比和叶片粗糙度等是叶片持水能力的重要影响因子。

In order to study the leaf＇s water-holding rate, rainfall interception rate and their influencing factors of four tree species in south China, namely, Broussonetia papyrifera, Michelia alba, Schima superba and Acacia mangium, the authors investigated forest canopy rainfall interception by the method of soaking leaves in water and spraying water onto leaves. When the method of soaking leaves in water was used, the results showed that Broussonetia papyrifera and Michelia alba were significantly different from other species in leaf＇s water-holding rate, while there was no significant difference between Acacia mangium and Schima superba. The leaf＇s water holding rates followed an order of Broussonetia papyrifera 972.2% Michelia alba 361.0% Schima superba 275.0% Acacia mangium 256.3% in water-holding rate, and the rainfall interception rates exhibited an order of Broussonetia papyrifera 519.8% Michelia alba 111.00% Schima superba 75.3% Acacia mangium 62.0%. Broussonetia papyrifera had significantly higher water holding rate and rainfall interception rate than other species, and Michelia alba was significantly different from other species in water holding and rainfall interception rates. After 5 mins soaking, the leaf＇s water-holding rate and rainfall interception rate reached saturation. When the method of spraying water onto leaves were used, the leaf＇s water-holding rate of Broussonetia papyrifera was significantly different from other species, but there was no significant difference between Acacia mangium, Michelia alba and Schima superba; leaf＇s waterholding rate showed an order of Broussonetia papyrifera 895.0% Michelia alba 275.0% Acacia mangium 256.3% Schima superba256.7%, leaf rainfall interception rate revealed an order of Broussonetia papyrifera 456.7% Schima superba 128.0% Michelia alba80.7% Acacia mangium 80.3%, with Broussonetia papyrifera and Schima superba being significantly different from other species, and Acacia mangium and Michelia alba not significantly different. Broussonetia papyrifera had significantly higher water-holding rate and rainfall interception rate than other species. Leaf area, length and width, L/W, and roughness were vital factors influencing waterholding capacity.