Padalia Hitendra, Srivastava Vivek, Kushwaha S P S
Forestry and Ecology Department, Indian Institute of Remote Sensing, ISRO, Dehradun, 248001, India,
Environ Monit Assess. 2015 Apr;187(4):210. doi: 10.1007/s10661-015-4415-8. Epub 2015 Mar 26.
Invasive species and climate change are considered as the most serious global environmental threats. In this study, we investigated the influence of projected global climate change on the potential distribution of one of the world's most successful invader weed, bushmint (Hyptis suaveolens (L.) Poit.). We used spatial data on 20 environmental variables at a grid resolution of 5 km, and 564 presence records of bushmint from its native and introduced range. The climatic profiles of the native and invaded sites were analyzed in a multi-variate space in order to examine the differences in the position of climatic niches. Maximum Entropy (MaxEnt) model was used to predict the potential distribution of bushmint using presence records from entire range (invaded and native) along with 14 eco-physiologically relevant predictor variables. Subsequently, the trained MaxEnt model was fed with Hadley Centre Coupled Model (HadCM3) climate projections to predict potential distribution of bushmint by the year 2050 under A2a and B2a emission scenarios. MaxEnt predictions were very accurate with an Area Under Curve (AUC) value of 0.95. The results of Principal Component Analysis (PCA) indicated that climatic niche of bushmint on the invaded sites is not entirely similar to its climatic niche in the native range. A vast area spread between 34 ° 02' north and 28 ° 18' south latitudes in tropics was predicted climatically suitable for bushmint. West and middle Africa, tropical southeast Asia, and northern Australia were predicted at high invasion risk. Study indicates enlargement, retreat, or shift across bushmint's invasion range under the influence of climate change. Globally, bushmint's potential distribution might shrink in future with more shrinkage for A2a scenario than B2a. The study outcome has immense potential for undertaking effective preventive/control measures and long-term management strategies for regions/countries, which are at higher risk of bushmint's invasion.
入侵物种和气候变化被视为最严重的全球环境威胁。在本研究中，我们调查了预计的全球气候变化对世界上最成功的入侵杂草之一——灌木薄荷（Hyptis suaveolens (L.) Poit.）潜在分布的影响。我们使用了网格分辨率为5千米的20个环境变量的空间数据，以及来自其原生和引入范围的564条灌木薄荷存在记录。在多变量空间中分析了原生和入侵地点的气候概况，以检验气候生态位位置的差异。利用来自整个范围（入侵和原生）的存在记录以及14个生态生理相关预测变量，使用最大熵（MaxEnt）模型预测灌木薄荷的潜在分布。随后，将训练好的MaxEnt模型输入哈德利中心耦合模型（HadCM3）气候预测数据，以预测在A2a和B2a排放情景下到2050年灌木薄荷的潜在分布。MaxEnt预测非常准确，曲线下面积（AUC）值为0.95。主成分分析（PCA）结果表明，入侵地点的灌木薄荷气候生态位与原生范围内的气候生态位并不完全相似。预测热带地区北纬34°02′至南纬28°18′之间的大片区域气候适合灌木薄荷生长。预计西非和中非、热带东南亚以及澳大利亚北部的入侵风险较高。研究表明，在气候变化的影响下，灌木薄荷的入侵范围会扩大、退缩或转移。在全球范围内，灌木薄荷的潜在分布未来可能会缩小，A2a情景下的缩小幅度比B2a情景更大。该研究结果对于面临灌木薄荷入侵高风险的地区/国家采取有效的预防/控制措施和长期管理策略具有巨大潜力。
