Chozas Sergio, Chefaoui Rosa M, Correia Otília, Bonal Raúl, Hortal Joaquín
cE3c, Centro de Ecologia, Evolução e Alterações Ambientais, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Edifício C2, Piso 5, 1749-016 Lisboa, Portugal.
Departamento de Biogeografía y Cambio Global, Museo Nacional de Ciencias Naturales (MNCN-CSIC), C/José Gutiérrez Abascal 2, 28006 Madrid, Spain.
Ann Bot. 2017 May 1;119(7):1157-1167. doi: 10.1093/aob/mcx004.
The geographical distributions of species are constrained by their ecological requirements. The aim of this work was to analyse the effects of environmental conditions, historical events and biogeographical constraints on the diversification of the three species of the western Mediterranean shrub genus Stauracanthus , which have a parapatric distribution in the Iberian Peninsula.
Ecological niche factor analysis and generalized linear models were used to measure the response of all Stauracanthus species to the environmental gradients and map their potential distributions in the Iberian Peninsula. The bioclimatic niche overlap between the three species was determined by using Schoener's index. The genetic differentiation of the Iberian and northern African populations of Stauracanthus species was characterized with GenalEx. The effects on genetic distances of the most important environmental drivers were assessed through Mantel tests and non-metric multidimensional scaling.
The three Stauracanthus species show remarkably similar responses to climatic conditions. This supports the idea that all members of this recently diversified clade retain common adaptations to climate and consequently high levels of climatic niche overlap. This contrasts with the diverse edaphic requirements of Stauracanthus species. The populations of the S. genistoides-spectabilis clade grow on Miocene and Pliocene fine-textured sedimentary soils, whereas S. boivinii , the more genetically distant species, occurs on older and more coarse-textured sedimentary substrates. These patterns of diversification are largely consistent with a stochastic process of geographical range expansion and fragmentation coupled with niche evolution in the context of spatially complex environmental fluctuations.
: The combined analysis of the distribution, realized environmental niche and phylogeographical relationships of parapatric species proposed in this work allows integration of the biogeographical, ecological and evolutionary processes driving the evolution of species adaptations and how they determine their current geographical ranges.
物种的地理分布受其生态需求的限制。本研究的目的是分析环境条件、历史事件和生物地理限制对西地中海灌木属刺棘花（Stauracanthus）三种物种多样化的影响，这三种物种在伊比利亚半岛呈邻域分布。
利用生态位因子分析和广义线性模型来衡量所有刺棘花物种对环境梯度的响应，并绘制它们在伊比利亚半岛的潜在分布。通过Schoener指数确定三种物种之间的生物气候生态位重叠。用GenalEx对刺棘花物种的伊比利亚和北非种群的遗传分化进行表征。通过Mantel检验和非度量多维标度分析评估最重要环境驱动因素对遗传距离的影响。
刺棘花的三种物种对气候条件表现出非常相似的响应。这支持了这样一种观点，即这个最近分化的分支的所有成员都保留了对气候的共同适应性，因此气候生态位重叠程度很高。这与刺棘花物种不同的土壤需求形成对比。刺棘花属（S. genistoides-spectabilis）分支的种群生长在中新世和上新世质地细腻的沉积土壤上，而遗传距离较远的博伊文刺棘花（S. boivinii）则生长在更古老、质地更粗糙的沉积基质上。这些多样化模式在很大程度上与地理范围扩张和碎片化的随机过程以及在空间复杂环境波动背景下的生态位进化相一致。
本研究中对邻域分布物种的分布、实际环境生态位和系统发育地理关系的综合分析，能够整合驱动物种适应性进化的生物地理、生态和进化过程，以及它们如何决定物种当前的地理范围。
