我国大陆黄檗潜在分布区及分布适宜性评价

Suitability assessments of potential distribution areas for Amur corktree in China's Mainland

黄檗为我国国家二级重点保护野生植物,多散生于阔叶林中,数量稀少,近年来,无论是从国家层面,还是地方政府层面都采取了一系列保护措施,人为破坏大大减少,然而其种群数量仍没有显著增加,拟从生态学的角度分析我国黄檗的潜在分布区,并进行了适宜性评价,为我国野生黄檗种群的就地保护和迁地保护提供技术支撑。通过实地调查和文献资料整理,获得69个包括准确经纬度信息的分布点,同时在世界气候数据库(World-Clim)中下载中国大陆的3个地形变量(alt、slo、asp),5个土壤变量(grav、pH、radi、rub、oc)和19个生物气候变量(bio1—bio19),利用多重共线性分析来检验环境因子之间的相关性,剔除出部分相关性高的环境因子,最终得到包括6个气候变量(bio1、bio3、bio4、bio12、bio15、prec1)、3个地形变量(alt、asp、slo)及5个土壤变量(grav、pH、radi、rub、oc)的14个环境因子作为环境变量,进而应用最大熵模型(MaxEnt)和地理信息系统(GIS)的空间分析功能,预测了黄檗在我国的潜在分布区,并评价分布区的适宜等级;分析了影响黄檗分布和适生性的关键因子及其适生区间。1)黄檗潜在分布区主要集中在我国东北地区和京津冀大部分区域,以及河南北部、内蒙古东南部等区域,黄檗潜在分布区总面积为117.51万km^2,占全国总面积的12.27%,其中高度适宜分布区面积为189400 km^2,占全国总面积的1.97%,主要包括黑龙江中东部,吉林大部分区域,辽宁东南部和北京大部分区域。2)温度季节性变化的标准差(35.7%)、年均降水量(28%)、坡度(6.5%)、年均温(6.7%)和有机碳含量(5.8%)是影响黄檗分布的5个最主要的环境因子,总的贡献率为82.7%。温度季节性变化标准差在14000—16000范围内,年均降水量在600—800 mm范围内,坡度在2°—8°范围内,年均温在1—7℃范围内,土壤有机碳含量在25—65 g/kg范围内为黄檗适宜分布的环境因子区间。我国野生黄檗分布还远远没有达到其潜在的分布范围,山东、山西、河南、内蒙古等目前资料显示分布并不广泛的省份也是进行野生黄檗迁地保护和人工种植的可选区域。对影响黄檗分布和适生性的关键因子进行分析后表明,温度季节性变化标准差越大其适生程度越高(14000—16000),说明黄檗对于温度的承受范围较大;年均降水量处于700 mm左右其适生程度最高,说明黄檗对于水分要求为中等水平;坡度为2°—8°范围内野生黄檗的适生程度最高,说明黄檗多分布在缓坡地带,年均温在4℃其适生程度最高;土壤有机碳含量在50 g/kg左右其适生程度最高。

Amur corktree （Phellodendron amurense Rupr. ） is listed as a second-class protected species in national key protected plant lists. They are commonly scattered in broad-leaved forest in small populations. In recent years, a series of protective measures have been taken at the national or local government level, and man-made damage to the species has been greatly reduced. However, the population of Amur cork has not increased significantly from these measures. In this paper, potential distribution areas for Amur corktree in China were analyzed from an ecological point of view, and their suitabilities were evaluated to provide technical support for in situ and ex situ conservation of the wild Amur corktree population. According to the field investigation and literature review, which included accurate geographic information, we obtained 69 distribution points of Amur corktree. Simultaneously, three topographic variables （alt, slo, asp）, five soil variables （gray, pH, radi, rub, oc）, and 19 bioclimatic variables （biol--biol9） were downloaded from the world climate database （world-clim）. We tested the correlations between these environmental factors by multiple collinearity analysis, and some environmental factors with high correlations were excluded, The final results include six climatic variables （biol, bio3, bio4, biol2, biol5, and precl）, three topographic variables （alt, ASP, SLO）, and five soil variables （grav, pH, radi, rub, oc） for a total of 14 environmental factors as environmental variables, and we predicted the potential distribution areas of Amur corktree in China. A suitable grade for each area was determined by using the maximum entropy model （MaxEnt） and GIS; meanwhile, we analyzed the key factors that influence the distribution and growth of the Amur corktree, and the appropriate ranges of these factors. 1 ） The potential suitable distribution areas of Amur corktree in China are mainly concentrated in the northeastern regions and most areas of Beijing, Tianjin, and Hebei, as well as in northern Henan, and southeastern Inner Mongolia. The total suitable distribution area for Amur corktree is 11.71 million km2, accounting for 12.27% of the total area of the country, and among this area, the highly suitable area was 189400 km2, accounting for 1.97% of the total area of the country. These highly suitable areas were situated in the eastern part of Heilongjiang Province, most parts of Jilin Province, the southeastern part of Liaoning Province, and most areas of Beijing. 2） Standard deviation of seasonal variation in temperature （ 35.7% ）, annual precipitation （ 28% ）, slope （6.5%）, mean annual temperature （6.7%）, and organic carbon content （5.8%） were the five main environmental factors influencing the distribution of the Amur corktree, and the total rate of contribution was 82.7%. A seasonal variation in temperature standard deviation in the range of 14000--16000, an average annual rainfall in the range of 600--800 mm, slope in the range of 20--8°, average annual temperature in the range of 1--7 ℃, and a soil organic carbon content in the range of 25--65 g/kg are the most suitable ranges for Amur corktree distribution. The distribution of wild Amur corktree in China is much less than its potential distribution. Shandong, Shanxi, and Henan Provinces and Inner Mongolia are available regions for Amur corktree distribution where they are not currently widely distributed. The analysis of the key factors influencing the distribution and growth of Amur corktree showed that the higher the standard deviation of seasonal variation in temperature （ 14000-16000）, the higher the degree for Amur corktree growth; an average annual precipitation of 700 mm was the most suitable precipitation for Amur corktree growth, which suggested that Amur corktree has a moderate requirement for water; a slope of 2-8 ° was the most suitable, which showed that the Amur corktrees are usually distributed on a gentle slope ; and an average annual temperature of 4 ℃ and soil organic carbon content of 50 g/kg were also the most suitable variables for Amur corktree growth.