作 者 ：蒋霞, 倪健
期 刊 ：植物生态学报 2005年 29卷 1期 页码：98-107
关键词：西北干旱区；荒漠植物种；地理分布；气候；可能潜在分布区；
Keywords:Arid lands, Northwestern China, Climate, Desert plant species, Geographical range, Potential distribution range,
摘 要 ：选择面积广阔、地理位置特殊、气候干旱、地形地貌多样、生态系统脆弱以及人类活动长期干扰，而且目前面临着西部大开发和环境保护双重矛盾的西北干旱区作为研究区域，通过收集西北干旱区多种优势种和常见种的地理分布资料，选取10 种分布范围相对明确、资料相对齐备的荒漠植物种：短叶假木贼（Anabasis brevifolia）、木蓼（Atraphaxis frutescens）、沙拐枣（Calligonum mongolicum）、膜果麻黄（Ephedra przewalskii）、裸果木（Gymnocarpos przewalskii）、梭梭柴（Haloxylon ammodendron）、白梭梭（Haloxylon persicum）、尖叶盐爪爪（Kalidium cuspidatum）、松叶猪毛菜（Salsola laricifolia）和合头草（Sympegma regelii），定量分析其地理分布与气候因子的关系，并据此估测其潜在中心分布区和潜在最大分布范围，与实际分布范围进行比较。结果表明，10种荒漠植物的Holdridge生物温度、降水量和可能蒸散率的平均值、标准差、最大值和最小值比较准确地反映了我国荒漠地区的典型气候特征，说明植物种分布与气候的定量对应关系较好。其可能潜在分布的估测中，中心分布估测图与植物种的实际分布范围有较好的对应性，而在最大可能分布的估测图中，与实际有一定误差及存在一些不合理的地方，但种与种之间有差异。究其原因，首先在于目前所拥有的植物种分布和气象资料的限制，而且植物种的实际分布范围受到人为活动的影响较大，所以无法完全把握植物种与气候的准确定量关系；其次，气候极值所预测的只是植物种分布的最大可能性，而不能表现出植物种现实分布的主要地区，气候均值与标准差所反映的中心分布区，其准确性更可靠；再者，模拟预测仅考虑了植物种与大气候的关系，而没有考虑决定植物分布的其它环境因素，如土壤、基质、地形等地理因素。
Abstract:We choose the arid land of northwestern China as our study area because of its extensive area, specific geographical location, dry climate, varied topography, vulnerable ecosystems and long-term human disturbance, as well as the existence of current conflicts between economic development and environmental protection. Based on the literature, we choose ten desert species with clear and relatively accurate geographical distribution ranges to model their distributions: Anabasis brevifolia, Atraphaxis frutescens, Calligonum mongolicum, Ephedra przewalskii, Gymnocarpos przewalskii, Haloxylon ammodendron, Haloxylon persicum, Kalidium cuspidatum, Salsola laricifolia, and Sympegma regelii. The quantitative relationship between each species distribution range and climatic factors was analyzed. The central and maximum potential distribution ranges of the 10 species were estimated and compared to their actual geographical distributions. Results showed that the mean value, standard deviation, maximum and minimum Holdridge‘s annual biotemperature, annual precipitation and potential evapotranspiration ratio of the 10 desert species reflected typical characteristics of desert climates and were in good agreement. The calculated central distribution ranges were in good agreement with a species‘actual distribution range, but there were differences among a species‘s maximum potential distribution and actual distribution due to three major factors: 1) The uncertainties associated with a species current distribution and lack of accurate climate data restricted the accuracy of the species-climate relationships and human impacts have altered the actual distributions of these desert species; 2) The maximum potential distribution area was estimated using the maximum and minimum climate values of species, which is less accurate than the potential central distribution range estimated by the mean climate and standard deviation; and, 3) The estimated potential range was calculated based on species-climate relationships only. Other environmental factors, such as soil, geology and topography, which also influence species distributions, were not considered.