Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, 610065 Chengdu, China.
College of Mathematics, Sichuan University, 610065 Chengdu, China.
Sci Total Environ. 2022 Mar 20;813:152665. doi: 10.1016/j.scitotenv.2021.152665. Epub 2021 Dec 27.
Magnoliaceae, a primitive group of angiosperms and distinguished ornamental plants with more than 100 species in China, is one of the most threatened plant family in the wild due to logging, habitat loss, over-collection and climate change. To provide a scientific guide of its conservation for policymakers, we explore the diversity patterns of 114 Magnoliaceae species in China using three diversity indices (species richness, weighted endemism, β-diversity) with a spatial resolution of 10 km by 10 km. Two methods, the top 5% richness algorithm and complementary algorithm, are used to identify diversity hotspots. Conservation gaps are recognized by overlapping the diversity hotspots with Chinese nature reserves. Our results indicate that Magnoliaceae species richness and weighted endemism are high in tropical to subtropical low montane forests in southern China, exceptionally high in southernmost Yunnan and boundary of Guizhou, Guangxi and Hunan. The β-diversity are scattered in southern China, suggesting a different species composition among grid cells. We identify 2524 grids as diversity hotspots for Magnoliaceae species in China, with 24 grids covered by three diversity indices (first-level diversity hotspots), 561 grids covered by two indices (second-level diversity hotspots) simultaneously and 1939 grids (76.8%) covered by only one index (third-level diversity hotspots). The first-level diversity hotspots include over 70% of the critically endangered Magnoliaceae species and are the priority areas for Magnoliaceae conservation. However, only 24% of the diversity hotspots fall in nature reserves and only ten grids are from the first-level diversity hotspots. Zhejiang, Guizhou and Fujian have less than 20% of diversity hotspots covered by nature reserves and need attention in future Magnoliaceae conservation. Using multiple diversity indices and algorithms, our study identifies diversity hotspots and conservation gaps and provides scientific basis for Magnoliaceae conservation in future.
木兰科是被子植物的一个原始类群，具有观赏价值，在中国有超过 100 种，是受威胁最严重的植物科之一，由于伐木、栖息地丧失、过度采集和气候变化，该科许多物种在野外面临灭绝。为了为决策者提供保护的科学指导，我们使用三个多样性指数（物种丰富度、加权特有性、β多样性），以 10km×10km 的空间分辨率，对中国的 114 种木兰科物种的多样性模式进行了探索。使用前 5%丰富度算法和补充算法两种方法来识别多样性热点。通过将多样性热点与中国自然保护区重叠，识别保护空白区。研究结果表明，木兰科物种丰富度和加权特有性在中国南方热带到亚热带低山地森林中较高，在云南最南端、贵州、广西和湖南交界处尤其高。β多样性在华南地区呈分散状，表明网格单元之间的物种组成不同。我们确定中国有 2524 个网格为木兰科物种的多样性热点，其中 24 个网格被三个多样性指数覆盖（一级多样性热点），561 个网格同时被两个指数覆盖（二级多样性热点），1939 个网格（76.8%）只被一个指数覆盖（三级多样性热点）。一级多样性热点包括超过 70%的极危木兰科物种，是木兰科保护的优先地区。然而，只有 24%的多样性热点位于自然保护区内，只有 10 个网格来自一级多样性热点。浙江、贵州和福建的多样性热点被自然保护区覆盖的比例不到 20%，在未来的木兰科保护中需要引起关注。本研究使用多种多样性指数和算法，确定了多样性热点和保护空白区，为未来木兰科保护提供了科学依据。
