Taxonomic revision reveals potential impacts of Black Summer megafires on a cryptic species

Context: Sound taxonomy is the cornerstone of biodiversity conservation. Without a fundamental understanding of species delimitations, as well as their distributions and ecological requirements, our ability to conserve them is drastically impeded. Cryptic species – two or more distinct species currently classified as a single species – present a significant challenge to biodiversity conservation. How do we assess the conservation status and address potential drivers of extinction if we are unaware of a species' existence? Here, we present a case where the reclassification of a species formerly considered widespread and secure – the sugar glider (Petaurus breviceps) – has dramatically increased our understanding of the potential impacts of the catastrophic 2019–20 Australian megafires to this species. Methods: We modelled and mapped the distribution of the former and reclassified sugar glider (Petaurus breviceps). We then compared the proportional overlap of fire severity classes between the former and reclassified distribution, and intersect habitat suitability and fire severity to help identify areas of important habitat following the 2019–20 fires. Key Results: Taxonomic revision means that the distribution of this iconic species appears to have been reduced to 8% of its formerly accepted range. Whereas the 2019–20 Australian megafires overlapped with 8% of the formerly accepted range, they overlapped with 33% of the proposed range of the redefined Petaurus breviceps. Conclusions: Our study serves as a sombre example of the substantial risk of underestimating impacts of mega-disturbance on cryptic species, and hence the urgent need for cataloguing Earth's biodiversity in the age of megafire.

研究背景：声音分类学（Sound taxonomy）是生物多样性保护的基石。若未能从根本上厘清物种界定、分布范围及其生态需求，我们开展物种保护的能力将受到严重掣肘。隐存种（cryptic species）——即当前被归为同一物种的两个或多个独立物种——对生物多样性保护构成重大挑战。倘若我们尚未知晓某一物种的存在，又该如何评估其保护现状、探究其潜在灭绝驱动因素？本研究针对曾被视为分布广泛且种群安全的蜜袋鼯（Petaurus breviceps）开展重新分类，这一工作极大加深了我们对2019-2020年澳大利亚灾难性巨型野火对该物种潜在影响的认知。
研究方法：我们对原分类体系及重新分类后的蜜袋鼯（Petaurus breviceps）的分布范围进行建模与制图。随后对比原分布范围与重新分类后分布范围的火灾严重性等级比例重叠情况，并叠加栖息地适宜性与火灾严重性图层，以识别2019-2020年巨型野火后具备重要保护价值的栖息地区域。
主要结果：分类学修订表明，这一标志性物种的分布范围仅为其原认定分布范围的8%。2019-2020年澳大利亚灾难性巨型野火曾覆盖原认定分布范围的8%，却覆盖了重新定义后的蜜袋鼯（Petaurus breviceps）拟议分布范围的33%。
研究结论：本研究作为极具警示意义的案例，揭示了人们极有可能低估大型扰动事件对隐存种造成的影响，故而在巨型野火频发的时代，对地球生物多样性进行全面编目已刻不容缓。