Biological Sciences Department, Bindura University of Science Education, Private Bag, 1020, Bindura, Zimbabwe.
Biological Sciences Department, Sewanee: The University of the South, 735 University Avenue, Sewanee, TN, 37383, USA.
Environ Monit Assess. 2020 May 16;192(6):372. doi: 10.1007/s10661-020-08342-x.
It is important to understand how species distributions will shift under climate change. While much focus has been on species tracking temperature changes in the northern hemisphere, changing precipitation patterns in tropical regions have received less attention. The aim of the study was to estimate the current distribution of wet and dry miombo woodlands of sub-Saharan Africa and to predict their distributions under different climate change scenarios. A maximum entropy method (Maxent) was used to estimate the distributions and for projections. Occurrence records of dominant tree species in each woodland were used for modeling, together with altitude, soil characteristics, and climate variables as the environmental variables. Modeling was done under all four representative concentration pathways (RCPs) and three general circulation models. Three dominant tree species were used in models of dry miombo while seven were used for wet miombo. Models estimated dry miombo to cover almost the entire known distribution of miombo woodlands while wet miombo were estimated to predominate in parts of Angola, southern Democratic Republic of Congo, Malawi, Tanzania, Zambia, and Zimbabwe. Future climate scenarios predict a drier climate in sub-Saharan Africa, and as a result, the range of dry miombo will expand. Dry miombo were predicted to expand by up to 17.3% in 2050 and 22.7% in 2070. In contrast, wet miombo were predicted to contract by up to - 28.6% in 2050 and - 41.6% in 2070. A warming climate is conducive for the proliferation of dry miombo tree species but unfavorable for wet miombo tree species.
了解物种分布在气候变化下如何变化非常重要。虽然人们对北半球物种跟踪温度变化给予了很多关注，但热带地区降水模式的变化却没有得到太多关注。本研究的目的是估计撒哈拉以南非洲湿润和干燥米邦古林地的当前分布，并预测它们在不同气候变化情景下的分布。最大熵方法（Maxent）用于估计分布和预测。每个林地优势树种的出现记录用于建模，同时使用海拔、土壤特征和气候变量作为环境变量。在所有四个代表性浓度途径（RCP）和三个通用环流模型下进行建模。在干燥米邦古模型中使用了三种主要树种，而在湿润米邦古模型中使用了七种。模型估计干燥米邦古将覆盖几乎整个米邦古林地的已知分布，而湿润米邦古则估计在安哥拉、刚果民主共和国南部、马拉维、坦桑尼亚、赞比亚和津巴布韦的部分地区占主导地位。未来气候情景预测撒哈拉以南非洲的气候将更加干燥，因此干燥米邦古的范围将扩大。到 2050 年和 2070 年，干燥米邦古的范围预计将分别扩大 17.3%和 22.7%。相比之下，到 2050 年和 2070 年，湿润米邦古的范围预计将分别收缩 28.6%和 41.6%。气候变暖有利于干燥米邦古树种的繁殖，但不利于湿润米邦古树种的繁殖。
