东北东部山区8个主要树种耐旱性评价研究

Evaluation on Drought Tolerance of the Major Tree Species in the Eastern Mountain Region of Northeast China

耐旱性对于树木存亡具有一定的指示作用。该研究以东北东部山区野外自然生长的8个树种——白桦、黄菠萝、胡桃楸、水曲柳、蒙古栎、春榆、兴安落叶松和红松为研究对象,通过测定各树种PV曲线水分参数(7个),同时结合蒸腾速率、枝叶清晨和中午水势、初始致死含水率和持水力等5个实测水分指标,对比分析以单个水分指标、综合水分指标评价耐旱性的差异。结果表明:(1)分别以PV曲线水分参数ψ_(tlp)和ψ_(sat)等衡量8个树种的耐旱性,发现单个水分指标对8个树种的耐旱性强弱排序有所不同,有的甚至完全相反;但通过PV曲线获取的水分参数ψ_(sat)-ψ_(tlp)、RWC_(tlp)、ROWC_(tlp)、ε_(max)和b值排序基本一致,其耐旱性强弱依次为:红松>胡桃楸>黄菠萝>白桦>兴安落叶松>蒙古栎>春榆>水曲柳。(2)以PV曲线7个水分参数综合评价结果显示,8个树种的耐旱性强弱依次为:红松>胡桃楸>黄菠萝>兴安落叶松>蒙古栎>白桦>春榆>水曲柳;以实测5个水分指标综合评价结果显示,8个树种的耐旱性强弱依次为:红松>蒙古栎>兴安落叶松>黄菠萝>水曲柳>春榆>白桦>胡桃楸;两者之间存在一定差异,特别是胡桃楸、蒙古栎和水曲柳位置发生了较大变化。(3)采用12个指标进行综合评价,结果发现8个树种的耐旱性强弱依次为:红松>黄菠萝>蒙古栎>兴安落叶松>胡桃楸>春榆>白桦>水曲柳。研究认为,12个指标的综合评价结果比较符合东北东部山区8个树种天然分布的生态特征。

Severe droughts have been associated with regional-scale forests mortality worldwide.Drought tolerance for tree species would be an important indicator for tree survival.Temperate forest in northeastern China plays a vital role in economic development and ecological environment construction of China.However,this forest is suffering project climate warming and drought.Therefore,it is urgent to assess the drought tolerance of trees in this forest.This study selected 8 tree species,which included Betula platyphylla ,Phellodendron amurense ,Juglans mandshurica ,Fraxinus mandshurica ,Quercus mongolica ,Ulmus japonica ,Larix gmelinii ,and Pinus koraiensis trees in a natural environment at Maoershan Forest Research Station in the eastern mountain region of northeast China,and simultaneously measured the 7 water parameters derived from the PV curves and 5 actual water indices including transpiration rate,twig / leaf predawn and midday water potential,water content at incipient injury and water-retaining capability.The difference of drought tolerance was evaluated by single water index and comprehensive water index.The results showed that:(1) water parameters by PV curves ψ tlp and ψ sat measure drought tolerance of eight species,respectively,drought tolerance evaluation by single water index was different or even completely contradictory with each other,but by PV curve water parameters including ψ sat -ψ tlp ,RWC tlp ,ROWC tlp ,ε max and b values are basically identical.The order of drought tolerance was as follows:P.koraiensis > J.mandshurica > P.amurense > B.platyphylla > L.gmelinii > Q.mongolica > U.japonica > F.mandshurica.(2) According to the comprehensive evaluation results of 7 PV curve water parameters,the order of drought tolerance of 8 tree species was as following:P.koraiensis > J.mandshurica > P.amurense > L.gmelinii > Q.mongolica > B.platyphylla > U.japonica > F.mandshurica;according to the comprehensive evaluation results of 5 actual water indices,the order of drought tolerance of 8 tree species was as following:P.koraiensis > Q.mongolica > L.gmelinii > P.amurense > F.mandshurica > U.japonica > B.platyphylla > J.mandshurica;there were some differences between them,especially the positions of J.mandshurica ,Q.mongolica and F.mandshurica changed greatly.(3) The order of comprehensive drought tolerance based on 12 water indices was as following:P.koraiensis > P.amurense > Q.mongolica > L.gmelinii > J.mandshurica > U.japonica > B.platyphylla > F.mandshurica .The study considers that the comprehensive evaluation results of 12 water indices have good agreement with the natural distribution of species in the eastern mountain region of northeast China.