Herbivory may promote a non-native plant invasion at low but not high latitudes
Herbivory may promote a non-native plant invasion at low but not high latitudes
复制标题
草食性可能会促进低纬度地区非本地植物的入侵，但不会促进高纬度地区的非本地植物入侵
DOI：
10.1093/aob/mcz121
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发表时间：
2019-10-09
期刊：
影响因子：
4.2
通讯作者：
Ding, Jianqing
中科院分区：
文献类型：
--
作者：
Lu, Xinmin;He, Minyan;Ding, Jianqing
背景和目的对本地物种来说，生物相互作用的强度，如草食性，预计会随着纬度的增加而降低。这在多大程度上适用于入侵物种，以及这种变化对本地物种和入侵物种之间的竞争有什么影响，这些都还没有被研究清楚。在此基础上，对中国不同纬度地区入侵植物互花蓟马（Alternanthera philoxeroides）的食草性影响及其与本土同属植物互花蓟马（a.s essilis）的竞争进行了研究。方法通过跨越10个纬度的普通园林试验，考察草食动物对绿叶橐吾和无梗橐吾的影响，以及它们之间的竞争随纬度的变化。此外，在北纬21度~ 36.8度范围内进行了野外调查，考察了黄花蓟马的入侵是否因草食的变化而随纬度变化。实验结果表明，在无草食动物竞争条件下，无尾草的盖度显著高于绿草，而在低纬度地区，两者盖度基本相当。而在中纬度地区，绿叶茅的平均盖度始终高于无梗叶茅。在高纬度地区，第二年只出现了无梗蚜。草食动物丰度随纬度的变化而降低，在中纬度，无梗密蝽比无梗密蝽更早出现。在野外调查中，绿草与无梗草的覆盖面积之比随纬度呈驼峰状。结论草食性只会通过改变竞争结果而有利于黄花蓟马在低纬度地区的入侵，而其他因素如早熟在高纬度地区对黄花蓟马的入侵也有重要影响。这些结果表明，促进植物入侵的关键因素可能随着纬度的变化而变化，突出了在生物地理框架内梳理多种因素在植物入侵中的作用的重要性。
Background and Aims The strengths of biotic interactions such as herbivory are expected to decrease with increasing latitude for native species. To what extent this applies to invasive species and what the consequences of this variation are for competition among native and invasive species remain unexplored. Here, herbivore impacts on the invasive plant Alternanthera philoxeroides and its competition with the native congener A. sessilis were estimated across latitudes in China.Methods An common garden experiment spanning ten latitudinal degrees was conducted to test how herbivore impacts on A. philoxeroides and A. sessilis, and competition between them change with latitude. In addition, a field survey was conducted from 21 degrees N to 36.8 degrees N to test whether A. philoxeroides invasiveness changes with latitude in nature as a result of variations in herbivory.Key Results In the experiment, A. sessilis cover was significantly higher than A. philoxeroides cover when they competed in the absence of herbivores, but otherwise their cover was comparable at low latitude. However, A. philoxeroides cover was always higher on average than A. sessilis cover at middle latitude. At high latitude, only A. sessilis emerged in the second year. Herbivore abundance decreased with latitude and A. philoxeroides emerged earlier than A. sessilis at middle latitude. In the field survey, the ratio of A. philoxeroides to A. sessilis cover was hump shaped with latitude.Conclusion These results indicate that herbivory may promote A. philoxeroides invasion only at low latitude by altering the outcome of competition in favour of the invader and point to the importance of other factors, such as earlier emergence, in A. philoxeroides invasion at higher latitudes. These results suggest that the key factors promoting plant invasions might change with latitude, highlighting the importance of teasing apart the roles of multiple factors in plant invasions within a biogeographic framework.