东北4种林木干基腐朽病原真菌潜在分布范围预测及其生态位分析

Potential distribution and ecological niches of four butt-rot pathogenic fungi in Northeast China

东北地区木生真菌物种资源丰富,包括了数十种林木干基腐朽病原真菌。过去对该类真菌曾进行多次调查,获取了大量物种分布数据,但对于非重点调查区域是否存在某种真菌物种却不明确。本文选取东北地区具有代表性的4种林木干基腐朽病原真菌,即红缘拟层孔菌(Fomitopsis pinicola)、落叶松锈迷孔菌(Porodaedalea laricis)、桦剥管孔菌(Piptoporus betulinus)和香栓孔菌(Trametes suaveolens),根据其地理分布数据和分布地的环境因子数据,以最大熵模型(MaxEnt)对这些种类在东北地区可能的分布范围进行了模拟预测,以曲线下面积(area under the receiver operating characteristic curve,AUC)对模型有效性进行评价,并对各物种的生态位进行了分析。结果显示,以MaxEnt方法获得的各物种预测模型均获得了较高的AUC值,分别为0.990,0.990,0.989和0.967,表明4种林木干基腐朽病原真菌预测模型的有效性较高。物种分布模型涉及的环境变量对模型的贡献率显示,最暖季降水量(Bio18)、温度的年较差(Bio7)、最干季均温(Bio9)等变量对各物种模型贡献率较高。该研究结果为预测4种病原真菌在东北地区的分布范围和科学防治该类病原真菌提供了依据。

Lignicolous fungi,including dozens of butt-rot pathogenic fungi,are abundant in Northeast China.In the past decades,many investigations have been carried out on fungal species diversity,and thus plentiful species distribution data has been obtained.However,it is not clear whether there remains a region that has yet to be investigated for the presence of fungal species.In this study,four representative butt-rot pathogenic fungi,Fomitopsis pinicola,Porodaedalea laricis,Piptoporus betulinus and Trametes suaveolens,of Northeast China were selected.Their geographical distribution data and the correlating environmental factors were used to model their potential distribution using the maximum entropy model(MaxEnt).The area under the receiver operating characteristic curve(AUC)was examined to evaluate the model performance.Thus,the ecological niches of these species were analyzed.The results showed that all the species prediction models obtained high AUC values(0.990,0.990,0.989 and 0.967),which suggests that the prediction models were effective for the four species.The most effective environmental variables,which were the precipitation of warmest quarter(Bio18),the temperature annual range(Bio7)and the mean temperature of driest quarter(Bio9),were shown to contribute more to the species distribution models than other factors.The results delineate possible distribution ranges for the four pathogenic fungi in Northeast China,thereby offering forest managers a guide for where to focus prevention and treatment efforts for these pathogenic fungi.