Studies that provide support for the conservation of transitions between biogeographic regions should be encouraged, given the ecological and evolutionary specificities of these environments. Investigations on evolutionary history may, for example, influence the prioritization of areas for biological conservation, as they enable a better understanding of the processes that shape communities in space and time. We used the occurrence data of tree species available for 87 sites of the Cerrado-Amazon Transition from the NeoTropTree database, together with 73 environmental variables, and investigated the phylogenetic structure (overdispersed, clustered, or randomly distributed communities) and diversity in this region. We evaluated the relationship between phylogenetic metrics and environmental variables using generalized least squares models. Our results demonstrated a predominant pattern of phylogenetic overdispersion, as well as high phylogenetic diversity. Phylogenetic metrics were strongly influenced by bioclimatic variables. Our study demonstrates that the Cerrado-Amazon Transition plays a fundamental role in the conservation of the regional flora both in terms of phylogenetic structure and diversity, but the protected areas in this region harbor only a restricted portion of this high diversity. These results not only confirm that transitional environments are areas of high biological diversity, but, unprecedentedly, this observation occurs from phylogenetic analyses of communities and to a biogeographic region so widely distributed and highly impacted by anthropogenic actions. Such findings point to the urgent need to take varied dimensions of biodiversity in establishing new areas of environmental protection in transition zones into account.

考虑到这些环境在生态和进化上的特殊性，应鼓励为保护生物地理区域之间的过渡提供支持的研究。例如，对进化史的研究可能会影响对生物保护区的优先次序，因为它们可以更好地理解塑造时空社区的过程。我们使用NeoTropTree的87个Cerrado-Amazon过渡站点可用的树种发生数据数据库，以及73个环境变量，并调查了该区域的系统发育结构（过度分散，聚集或随机分布的群落）和多样性。我们使用广义最小二乘模型评估了系统发育指标与环境变量之间的关系。我们的结果证明了系统发育过度分散的主要模式，以及高度的系统发育多样性。系统发育指标受到生物气候变量的强烈影响。我们的研究表明，就系统发育结构和多样性而言，塞拉多－亚马逊过渡带在保护区域植物群中起着根本性的作用，但该地区的保护区仅占这种高度多样性的一小部分。这些结果不仅证实过渡环境是高度生物多样性的区域，而且这种观察从未发生过，从社区的系统发育分析到如此广泛分布并受到人为行动强烈影响的生物地理区域。这些发现表明，迫切需要在建立过渡区新的环境保护领域时考虑到生物多样性的不同方面。