Greater sexual reproduction contributes to differences in demography of invasive plants and their noninvasive relatives
Greater sexual reproduction contributes to differences in demography of invasive plants and their noninvasive relatives
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DOI：
10.1890/12-1310.1
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发表时间：
2013-05-01
期刊：
影响因子：
4.8
通讯作者：
Knight, Tiffany M.
中科院分区：
文献类型：
--
作者：
Burns, Jean H.;Pardini, Eleanor A.;Knight, Tiffany M.
了解造成入侵的人口统计过程将提高我们对入侵过程的机械性理解，并提高预防和控制工作的效率。然而，以前还没有对入侵物种和非入侵物种的人口学进行现场比较。我们比较了美国密苏里州圣路易斯市引进的17种植物的原位人口学，以对比入侵物种的人口统计模式与它们在广泛的被子植物样本中入侵程度较低的近亲的人口统计模式。利用标本馆的记录来估计传播速率，我们发现先验归类为入侵物种的物种在景观中的最大传播速率高于非入侵引入物种的最大传播速率，这表明专家分类是入侵速率的准确反映。在17个物种中，入侵物种的预计种群增长并不显著大于非入侵引入物种。然而，在五个近亲的分类对中，四个入侵物种的预计种群增长率高于它们的非入侵近亲。一项生命表反应实验表明，一些入侵物种相对于它们的非入侵亲缘物种预测的种群增长率较高，主要是有性繁殖的结果。入侵物种较大的有性繁殖与入侵者的生活史策略更依赖于繁殖力而不是生存是一致的，也与繁殖压力在入侵中的巨大作用相一致。有性繁殖是侵袭性的一个关键的人口统计学相关因素，这表明影响有性繁殖的局部过程，如敌人逃跑，可能具有普遍的重要性。然而，预测的人口增长与地貌中的扩散速度之间的弱相关性表明，区域过程，如扩散，在决定入侵速度方面可能同样重要。
An understanding of the demographic processes contributing to invasions would improve our mechanistic understanding of the invasion process and improve the efficiency of prevention and control efforts. However, field comparisons of the demography of invasive and noninvasive species have not previously been conducted. We compared the in situ demography of 17 introduced plant species in St. Louis, Missouri, USA, to contrast the demographic patterns of invasive species with their less invasive relatives across a broad sample of angiosperms. Using herbarium records to estimate spread rates, we found higher maximum spread rates in the landscape for species classified a priori as invasive than for noninvasive introduced species, suggesting that expert classifications are an accurate reflection of invasion rate. Across 17 species, projected population growth was not significantly greater in invasive than in noninvasive introduced species. Among five taxonomic pairs of close relatives, however, four of the invasive species had higher projected population growth rates compared with their noninvasive relative. A Life Table Response Experiment suggested that the greater projected population growth rate of some invasive species relative to their noninvasive relatives was primarily a result of sexual reproduction. The greater sexual reproduction of invasive species is consistent with invaders having a life history strategy more reliant on fecundity than survival and is consistent with a large role of propagule pressure in invasion. Sexual reproduction is a key demographic correlate of invasiveness, suggesting that local processes influencing sexual reproduction, such as enemy escape, might be of general importance. However, the weak correlation of projected population growth with spread rates in the landscape suggests that regional processes, such as dispersal, may be equally important in determining invasion rate.