Patterns of niche filling and expansion across the invaded ranges of an Australian lizard

Studies of realized niche shifts in alien species typically ignore the potential effects of intraspecific niche variation and different invaded-range environments on niche lability. We incorporate our detailed knowledge of the native-range source populations and global introduction history of the delicate skink Lampropholis delicata to examine intraspecific variation in realized niche expansion and unfilling, and investigate how alternative niche modelling approaches are affected by that variation. We analyzed the realized niche dynamics of L. delicata using an ordination method, ecological niche models (ENMs), and occurrence records from 1) Australia (native range), 2) New Zealand, 3) Hawaii, 4) the two distinct native-range clades that were the sources for the New Zealand and Hawaii introductions, and 5) the species’ global range (including Lord Howe Island, Australia). We found a gradient of realized niche change across the invaded ranges of L. delicata: niche stasis on Lord Howe Isl...针对外来物种实现生态位偏移（realized niche shift）的相关研究，通常忽略了种内生态位变异（intraspecific niche variation）以及不同入侵范围环境对生态位易变性（niche lability）的潜在影响。本研究依托对玲珑石龙子（Lampropholis delicata）原生范围源种群的详尽认知与全球引种历史，旨在探究实现生态位扩张与生态位空缺（realized niche expansion and unfilling）的种内变异，并分析该类变异对不同生态位建模方法的影响。我们采用排序方法（ordination method）、生态位模型（ENMs）以及以下5类物种出现记录，对玲珑石龙子的实现生态位动态开展了分析：1) 澳大利亚（原生分布范围）、2) 新西兰、3) 夏威夷、4) 作为新西兰与夏威夷引种来源的两个独立原生支系（native-range clades），以及5) 该物种的全球分布范围（包含澳大利亚豪勋爵岛（Lord Howe Island））。研究发现，玲珑石龙子入侵范围内的实现生态位变化呈现梯度特征：豪勋爵岛的生态位保守……