秦岭南麓油松林水分利用效率的边缘效应研究

Edge Effect of Water Use Efficiency in Pinus tabuliformis Forest in Southern Qinling Mountains

为了研究油松(Pinus tabuliformis)内在耗水机制和水分利用策略,以秦岭南麓油松天然林为研究对象,利用稳定碳同位素法研究了油松叶片的δ^(13)C值,分析了方位对油松叶片水分利用效率(WUE)的影响及到林缘不同距离叶片的WUE差异。结果表明,油松在各个方位上WUE的变化分布范围为0.62~57.08μmol/mol。叶片WUE在不同方位线上具有显著的差异,其中西向样线的油松叶片WUE最高,南向样线的油松叶片WUE最低。从林缘至林内的叶片WUE总体呈先升后降的趋势,但变化未达到显著水平,这可能与植被WUE影响因素的多样性有关。方位是影响油松WUE的重要因素,准确掌握本区植被的水分利用策略,需要更加全面深入地研究。

Pinus tabuliformis is a unique species and the dominant tree species in the Chinese boreal forest.To further understand its internal water consumption mechanism and water use strategy,our study analyzed the influence of aspects on Chinese pine foliar stable carbon isotope content(δ^(13)C)by using carbon isotope method.The results showed that the water use efficiency(WUE)in Pinus tabuliformis ranged from 0.62 to 57.08μmol/mol.There were significant differences in leaf WUE of different aspects,with the western aspect was the highest while that on the southern aspect was the lowest.Leaf WUE increased first and then decreased from the edge of forest to the inner forest,but the change was not significant different,which may be related to the diversity of influence factors of vegetation WUE.Direction is an important factor affecting WUE of Pinus tabuliformis.More comprehensive and further study is needed to understand the WUE of vegetation in this region.