Tree species of the Araucaria Mixed Forest: which, how many and how threatened are they?

ABSTRACT Although the Araucaria Mixed Forest has long been recognized for their woods and ecosystem services, we still lack basic information on what tree species occur there. Habitat loss and overexploitation have led several tree species of this forest into an extinction process. Therefore, it is urgent to compile what are the tree species of this forest type, identify if these species are threatened and which were not assessed for their threat category. We aimed to answer: (1) How many tree species occur in the Araucaria Mixed Forest? 2) How many of these species are under a threat category? (3) Does the number of threatened species per state/province mirror the species richness of the state/province through the Araucaria Mixed Forest distribution? We found 1,213 tree species for the forest type. The states of São Paulo, Minas Gerais and Rio de Janeiro presented the highest species richness. The number of assessed species reflected the total number of species per state/province. Of the species listed, 5.3 % were classified as threatened and 72.8 % have not been assessed. We provided the most comprehensive tree species list to date for the Araucaria Mixed Forest and unveiled the conservation status of its tree flora.

摘要：尽管南洋杉混交林（Araucaria Mixed Forest）长期以来以其木材与生态系统服务价值为人熟知，但目前仍缺乏该林分内分布的树木物种的基础信息。栖息地丧失与过度开发已导致该林型中的多种树木步入灭绝进程。因此，亟需汇编该林型的树木物种名录，明确这些物种是否受威胁，以及哪些物种尚未开展受威胁等级评估。本研究旨在解答以下三个问题：（1）南洋杉混交林内共有多少种树木？（2）其中多少种被列入受威胁物种？（3）沿南洋杉混交林的分布范围，各州市/省份的受威胁物种数量是否与该区域的物种丰富度相匹配？研究结果显示，该林型共记录到1213种树木。圣保罗州、米纳斯吉拉斯州与里约热内卢州的物种丰富度最高。受评估物种的数量与各州市/省份的总物种数相符。在所收录的物种中，5.3%被归类为受威胁物种，72.8%尚未开展受威胁等级评估。本研究提供了迄今为止最全面的南洋杉混交林树木物种名录，并揭示了该林型树木区系的保护现状。