Page 20 - 《广西植物》2022年第3期
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3 6 4                                 广  西  植  物                                         42 卷
       climate change and human activities. Hereꎬ we aim to simulate the changes in the geographical distribution pattern of
       A. multinervis since the last interglacial (LIG) and to explore how climatic factors restrict the potential suitable areasꎬ to
       provide a reliable scientific basis for habitat protection and cultivation of A. multinervis and its surrounding wildlife. In
       this studyꎬ based on optimized MaxEnt model and ArcGIS softwareꎬ we simulated the potential suitable areas of A.

       multinervis and its spatial change pattern. The importance of environmental factors that constrains current geographical
       distribution was evaluated by percent contribution(PC)ꎬ permutation importance(PI) and Jackknife test. The results
       were as follows: (1) The prediction accuracy of the optimized MaxEnt model was extremely highꎬ as indicated by the
       value of the area under the receiver operator characteristic curve over 0.97. The potential suitable areas of A. multinervis
       for the present distribution were mainly distributed in the Yangtze River basin at the junction of Guizhouꎬ Sichuan and
       Chongqingꎬ of which the best suitable area was around Chishui River basin in Guizhou. The key environmental factors
       affecting the potential distribution of A. multinervis were mean diurnal range (bio2)ꎬ annual precipitation (bio12)ꎬ
       seasonality of precipitation (bio15) and range of annual temperature (bio7). (2) The potential middle ̄high suitable
                                           4   2                                 4  2
       area of A. multinervis in current was 2.692 6×10 km ꎬ in last interglacial (LIG) was 2.277 3×10 km ꎬ in the mid ̄
                              4   2                              4  2                      4   2
       Holocene (MH) was 2.831×10 km ꎬ in four future scenarios were 2.159 6×10 km (2050s RCP2.6)ꎬ 2.605 1×10 km
                              4  2                       4  2
       (2050s RCP8.5)ꎬ 2.330 4×10 km (2070s RCP2.6)ꎬ 2.460 4×10 km (2070s RCP8.5)ꎬ respectively. (3) Under the
       four future discharge scenariosꎬ the newly increased area of A. multinervis was concentrated in Sichuan and Guizhouꎬ
       while it was concentrated in Chongqing in the mid ̄Holocene. All the above results indicate that the distribution range of
       A. multinervis is narrow and the potential suitable area is very smallꎬ and the unique topographic advantage of Chishui
       River Basin may be the main refuge place of A. multinervis.
       Key words: Altingia multinervisꎬ MaxEnt modelꎬ potential suitable areaꎬ environmental factorsꎬ refuge


       近年来ꎬ全球气候变化和人类活动对环境、生                          et al.ꎬ 2018)ꎮ
   物圈和生物多样性的影响日益显著ꎬ主要表现在                                 全球气候变暖是 21 世纪生物多样性保护的重
   降水的次数、强度和频率极不稳定ꎬ以及热浪、干                            大挑战 之 一ꎬ 而 生 态 位 模 型 ( environmental niche

   旱、雷暴、洪水和飓风等极端事件的频发( D′Amato                       modelsꎬENMs)对气候变化下物种适宜潜在分布的
   et al.ꎬ 2020)ꎮ 其中ꎬ极端气候事件强度和频率的                    变化性预测ꎬ已成为多个领域研究的热点( Li et
   增加ꎬ将 直 接 对 植 物 分 布 产 生 较 大 的 负 面 影 响              al.ꎬ 2020)ꎮ 生态位模型在生态、进化和生物地理
   (Mga et al.ꎬ2021)ꎮ 由于气候变化的复杂性和不                   学中被广泛应用ꎬ因其能够对物种进行连续性预
   可预测性ꎬ以及地理位置的特殊性ꎬ植物对气候变                            测和 潜 在 适 宜 分 布 范 围 的 变 化 描 述 ( Galante et
   化的适应就显得尤为重要( Ceccarelli & Grandoꎬ                 al.ꎬ 2017ꎻMariano et al.ꎬ 2019)ꎮ 目前常用生态位
   2020)ꎮ 为应对气候变化ꎬ特别是在气候环境恶劣                         模型主要有:最大熵模型(MaxEnt) ( Sobek ̄Swant et
   的情况下ꎬ微避难所就极有可能是支持当地物种                             al.ꎬ 2012)、规则集遗传算法模型( GARP) ( Zhang
   生存的栖息地(Mclaughlin et al.ꎬ 2017)ꎮ 目前ꎬ虽             et al.ꎬ 2020)、 CLIMEX 模 型 ( Szyniszewska et al.ꎬ
   然对一些物种的灭绝机制已有新的进展ꎬ但仍未                             2020)等ꎮ 其中ꎬMaxEnt 模型是最常用的小生境建
   知哪些气候因子变化引起了物种灭绝ꎬ以及有多                             模工具之一( Feng et al.ꎬ 2019)ꎬ是由于该模型对
   少物种会面临灭绝风险( Roman ̄Palacios & Wiensꎬ               极少的样本数量(n≥5)就能较好地模拟出物种的
   2020)ꎮ 在气候和人为土地利用变化的双重作用                          适生 范 围ꎬ 且 成 本 低、 操 作 简 单、 运 行 时 间 短

   下ꎬ植物生存和繁衍所需的栖息地类型大幅减少ꎬ                            (Pearson et al.ꎬ 2007)ꎮ 因此ꎬMaxEnt 模型常被国
   并呈 现 碎 片 化 ( Sales et al.ꎬ 2020ꎻ Karl et al.ꎬ     内外研究者应用于珍惜濒危动植物保护( Farashi
   2020)ꎮ 而减缓气候变化和人类活动对原始森林                          & Shariatiꎬ 2017ꎻ Han et al.ꎬ 2019 )、 物 种 入 侵
   生态系统的干扰ꎬ有益于物种间进行自然更新、基                            (Kariyawasam et al.ꎬ 2020ꎻ 陈剑等ꎬ2021)、作物种

   因交流和空间迁移等过程( Matteo et al.ꎬ 2020)ꎮ                植区划 ( Zhang et al.ꎬ 2016)、 病 虫 害 防 治 ( Li et
   因此ꎬ在气候变化的背景下保护生物多样性ꎬ需要                            al.ꎬ 2019)等领域ꎮ
   制定出保护濒危物种切实可行的保护策略( Suggitt                           赤水 蕈 树 ( Altingia multinervis) 是 金 缕 梅 科
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