Rodrigues P M S, Silva J O, Eisenlohr P V, Schaefer C E G R
Departamento Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, BR.
Departamento de Biologia Geral, Universidade Estadual de Montes Claros, Montes Claros, MG, BR.
Braz J Biol. 2015 Aug;75(3):679-84. doi: 10.1590/1519-6984.20913. Epub 2015 Aug 25.
The aim of this study was to evaluate the ecological niche models (ENMs) for three specialist trees (Anadenanthera colubrina, Aspidosperma pyrifolium and Myracrodruon urundeuva) in seasonally dry tropical forests (SDTFs) in Brazil, considering present and future pessimist scenarios (2080) of climate change. These three species exhibit typical deciduousness and are widely distributed by SDTF in South America, being important in studies of the historical and evolutionary processes experienced by this ecosystem. The modeling of the potential geographic distribution of species was done by the method of maximum entropy (Maxent).We verified a general expansion of suitable areas for occurrence of the three species in future (c.a., 18%), although there was reduction of areas with high environmental suitability in Caatinga region. Precipitation of wettest quarter and temperature seasonality were the predictor variables that most contributed to our models. Climatic changes can provide more severe and longer dry season with increasing temperature and tree mortality in tropics. On this scenario, areas currently occupied by rainforest and savannas could become more suitable for occurrence of the SDTF specialist trees, whereas regions occupied by Caatinga could not support the future level of unsustainable (e.g., aridity). Long-term multidisciplinary studies are necessary to make reliable predictions of the plant's adaptation strategies and responses to climate changes in dry forest at community level. Based on the high deforestation rate, endemism and threat, public policies to minimize the effects of climate change on the biodiversity found within SDTFs must be undertaken rapidly.
本研究的目的是评估巴西季节性干旱热带森林（SDTFs）中三种特有树木（南美山蚂蝗、梨叶白坚木和乌伦杜瓦）的生态位模型（ENMs），同时考虑当前和未来悲观情景（2080年）下的气候变化。这三个物种表现出典型的落叶性，在南美洲的SDTFs中广泛分布，对该生态系统经历的历史和进化过程研究具有重要意义。通过最大熵（Maxent）方法对物种潜在地理分布进行建模。我们发现，尽管卡廷加地区环境适宜性高的区域有所减少，但未来这三个物种适宜出现的区域总体上有所扩大（约18%）。最湿润季度的降水量和温度季节性是对我们模型贡献最大的预测变量。气候变化会导致热带地区旱季更加严重和漫长，树木死亡率上升。在这种情况下，目前被雨林和稀树草原占据的区域可能更适合SDTF特有树木的出现，而卡廷加地区则无法维持未来不可持续的水平（如干旱）。有必要进行长期多学科研究，以便在群落水平上对干旱森林中植物的适应策略和对气候变化的反应做出可靠预测。基于高森林砍伐率、特有性和威胁，必须迅速制定公共政策，以尽量减少气候变化对SDTFs中生物多样性的影响。
