Estación Experimental Agropecuaria Catamarca, Instituto Nacional de Tecnología Agropecuaria (INTA), Sumalao, Valle Viejo, Catamarca, Argentina.
INIBIOMA, CONICET - Universidad Nacional del Comahue, Bariloche, Argentina.
PLoS One. 2018 Jun 28;13(6):e0199811. doi: 10.1371/journal.pone.0199811. eCollection 2018.
Plant species disjunctions have attracted the interest of ecologists for decades. We investigated Trichloris crinita, a native C4 perennial grass with disjunct distribution between subtropical regions of North and South America, testing the hypothesis that the species has a similar realized climatic niche in both subcontinents. The climatic niche of T. crinita in North and South America was characterized and compared using presence records and five uncorrelated bioclimatic variables selected according to their ecological importance for the species. We used reciprocal modeling to make geographic projections of the realized niche within each subcontinent. Niche overlap between T. crinita distributions in North and South America was intermediate for the individual climatic variables and the multivariate space. In all cases the test of equivalence between climates inhabited by T. crinita indicated that the realized niche of the species differ significantly between subcontinents. Also, the similarity test showed that in the majority of cases the realized niche in both subcontinents was significantly different than that expected by chance. T. crinita occupied a greater diversity of environments in South than in North America, while in the latter its distribution was displaced to drier and warmer environments. The modeled geographic distribution using the actual occurrences of the species in North America did not accurately predict the distribution in South America, and vice versa. Together, these results led us to reject the hypothesis of similar niche of T. crinita in both subcontinents. This information may be useful to manage restoration efforts by presenting the suitable areas and climates for the species, and suggesting that translocation of individuals between subcontinents could only be recommended with caution because introduced genotypes can be potentially maladaptive, and could colonize sites actually not occupied by the species within each subcontinent.
植物物种间断分布引起了生态学家数十年的兴趣。我们研究了 Trichloris crinita，这是一种原产于 C4 的多年生草本植物，分布于北美洲和南美洲的亚热带地区之间，检验了该物种在两个大陆具有相似实现气候位的假设。使用存在记录和根据对物种生态重要性选择的五个不相关生物气候变量，我们描述和比较了北美和南美的 T. crinita 的气候位。我们使用相互递归模型对每个大陆内实现的生态位进行地理投影。对于单个气候变量和多变量空间，T. crinita 在北美的分布与南美的分布之间的生态位重叠处于中等水平。在所有情况下，对 T. crinita 栖息的气候进行等效性检验表明，该物种在两个大陆的实现生态位之间存在显著差异。此外，相似性检验表明，在大多数情况下，两个大陆的实现生态位与随机预期显著不同。T. crinita 在南美的环境多样性大于北美的环境多样性，而在北美的分布则转移到更干燥和温暖的环境。使用北美实际发生的物种进行的地理分布模型并不能准确预测南美的分布，反之亦然。总之，这些结果使我们拒绝了 T. crinita 在两个大陆具有相似生态位的假设。这些信息可能有助于管理恢复工作，提供适合物种的地区和气候，并表明在两个大陆之间迁移个体只能谨慎推荐，因为引入的基因型可能潜在地不适宜，并可能在每个大陆内的物种实际未占据的地点殖民化。
