摘要
切根贴膜简单易行,是减轻林带胁地效应的有效方法,但可能会对林带造成不良影响.本文以黑龙江省黑土区农田防护林为研究对象,以不切根贴膜为对照,研究距树干0.5、1、2、3 m切根贴膜处理对杨树光合特性的影响.结果表明:切根贴膜对杨树叶片含水率的影响较小.处理后杨树净光合速率峰、谷值出现的时间在7月较对照提前,日均值明显低于对照,各处理间差异显著.8—9月,处理后杨树净光合速率日均值仍低于对照,但降低幅度有所减小,距树干3 m处切根贴膜的杨树净光合速率与对照相比无显著差异.处理后杨树蒸腾曲线出现多种形式,距树干2、3 m处切根贴膜杨树蒸腾速率日均值较对照无显著变化,而距树干0.5、1 m处切根贴膜的杨树蒸腾速率在7月下降幅度比光合速率下降幅度更大,导致水分利用效率高于对照.切根贴膜处理没有改变杨树叶片水分利用效率的日变化趋势,但对杨树叶片水分利用效率的日均值产生了明显影响,且这种影响可能是负向的.综合分析,在距树干3 m处切根贴膜对杨树的光合特性影响较小,明显优于其他处理.
Root excision mulched with film is an effective method which can minimize decrease in crop production in negative-effect area. However, the measure may have adverse effects on the cropland shelterbelt. Taking no treatment as CK, the effects of root excisions mulched with film at distance 0.5, 1, 2 and 3 m from the trunk on photosynthesis characteristics of poplar shelterbehs in black soil region were discussed. The results indicated that root excision mulched with film had no significant effect on poplar leaf water content. Early in July, the time of peak and trough in the treatments were earlier than CK. Different treatments of root excision mulched with film made daily average value of net photosynthetic rate of poplar leaves significantly lower than CK, and there were significant difference among different treatments. During August to September, root excision mulched with film induced daily average value of net photosynthetic rate of poplar leaves still lower than CK, but the lowered range was somewhat reduced, root excision mulched with film at the dis- tance 3 m from the trunk had no significant difference from CK. After root excision mulched with film, transpiration curve appeared in many forms. At the distances 2 and 3 m from the trunk, daily average value of transpiration rate of poplar leaves had no significant difference from CK. At the dis- tances 0.5 and 1 m from the trunk, the decrease in transpiration rate in July was greater than that of photosynthetic rate, resulting in the significantly high water use efficiency than CK. Compared with CK, daily dynamics of water use efficiency in the other treatments had no change, however, daily average value of water use efficiency in the other treatments had significant change, and some of the changes were adverse. Comprehensive comparison indicated that root excision mulched with film at the distance 3 m from the trunk had no significant effect on the photosynthetic characteristics of poplar leaves, and this treatment was significantly superior to others.
出处
《应用生态学报》
CAS
CSCD
北大核心
2017年第1期47-54,共8页
Chinese Journal of Applied Ecology
基金
林业公益性行业科研专项(201404202-01)资助~~
关键词
断根
含水率
水分利用效率
光合特性
光合日变化
root excision
moisture content
water use efficiency
photosynthetic characteristics
diurnal photosynthetic variation.