基于最大熵模型的真藓属植物在新疆的潜在分布预测

Potential Distribution of Bryum in Xinjiang Based on Maxent Model

真藓属植物(Bryum Hedw.)是耐干旱的藓类,也是生物结皮层的优势成分,对生物结皮层的形成和维持起着重要的生态作用。本文基于最大熵(Maxent)模型,利用真藓属在新疆的137个实际分布样点并结合当前20个环境因子预测该属在新疆的潜在分布区域,分析影响其分布的主导环境因子。结合基于RCP45 CO_(2)排放情景下2050年和2070年的6个气候数据,模拟预测该属在新疆的分布情况。结果表明:(1)预测效果较理想,与实际分布区域相似度较高。真藓属在新疆的分布受最干季降雨量等6个主要气候因子影响。(2)该属主要分布在阿尔泰地区、塔城地区、伊犁地区、昌吉回族自治州、乌鲁木齐和克孜勒苏柯尔克孜自治州,在阿尔金山和伊犁地区部分区域及阿克苏地区西北部也有少量分布。在未来气候情境下,真藓属在天山中部地区和阿尔金山国家级自然保护区东南部区域将丧失部分适生区面积,在西天山、昆仑山北坡地区将获得新生境,21世纪50年代和70年代,该属植物分布面积将比当代气候条件下扩增3.36%和3.67%。

Bryum Hedw.is a drought tolerant moss and a dominant component of the biological crust layer,and it plays an important ecological role for the formation and maintenance of biological crust layer.Based on the Maxent model,137 distributional records of Bryum in Xinjiang and 20 environmental factors were used to predict the potential distribution of this genus in Xinjiang,and the dominant environmental factors were analyzed.Combined with six climate data in 2050 and 2070 based on RCP45 CO_(2) emission scenario,the distribution of this genus in Xinjiang was simulated and predicted.The results showed that:(1)The prediction effect was ideal,and the similarity to the actual distribution area was high.The distribution of Bryum in Xinjiang was affected by six main climatic factors,including rainfall in the driest season.(2)The genus was mainly distributed in Altai region,Tacheng,Yili,Changji Huizu autonomous prefecture,Urumqi region and Kizilsu autonomous prefecture,and a small amount is also distributed in part of Altun mountain and Yili regions and the northwest of Aksu region.In the future climate scenario,the regions in the central area of the Tianshan Mountains and the southeast corner of the Altun National Nature Reserve would lose some of the area of the habitat;new habitats would be obtained in the West Tianshan Mountains and in the north slope of Kunlun Mountains.In 2050 s and 2070 s,the distribution area of the genus would be amplified by 3.36%and 3.67%compared with the contemporary climatic conditions.