Pervasive and persistent effects of ant invasion and fragmentation on native ant assemblages
Pervasive and persistent effects of ant invasion and fragmentation on native ant assemblages
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DOI：
10.1002/ecy.3257
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发表时间：
2021-01-12
期刊：
影响因子：
4.8
通讯作者：
Suarez, Andrew, V
中科院分区：
文献类型：
--
作者：
Achury, Rafael;Holway, David A.;Suarez, Andrew, V
生物入侵是全球变化的主要原因，但其长期影响仍然难以预测。入侵物种可以在很长一段时间内保持丰富，或者表现出种群崩溃，使本土社区得以恢复。非本地物种的丰度和影响也可能与随时间变化的生境特征密切相关。我们调查了栖息地破碎化和入侵的阿根廷蚂蚁（Linepithema humile）的长期影响，重新调查蚂蚁在40灌丛栖息地片段在南部沿海加州，最初采样21年前。在景观尺度上，片段面积，而不是片段年龄或阿根廷蚂蚁的平均丰度，继续解释本地蚂蚁物种丰富度的变化，两个样本年之间的物种面积关系没有不同的斜率或截距。在局部范围内，在过去的21年里，我们发现入侵的总面积增加了（+36.7%，估计为占陷阱的比例），阿根廷蚂蚁的相对丰度增加了（+121.95%，估计为陷阱中工人的平均数量）。与1996年相比，2017年阿根廷蚂蚁平均丰度也从城市边缘向内增加。更大程度的渗透到片段可能会减少本地蚂蚁的丰富性，消除避难所的本地蚂蚁的片段，不包含足够的内部面积。在一个片段，我们在过去的21年中采样了8次，阿根廷蚂蚁的平均丰度随着时间的推移而增加，而本地地面觅食蚂蚁的多样性从14种下降到4种。值得注意的是，本地物种的预测是特别敏感的入侵和栖息地丧失的综合影响，没有检测到在我们最近的采样，包括军蚁属Neivamyrmex的任何网站。相反，两个引进的蚂蚁物种（Brachymyrmex patagonicus和Pheidole flavens），在1996年未被发现，现在常见的和广泛的在我们的网站。我们的研究结果表明，在行为和数量上占主导地位的入侵物种可以保持高密度和抑制本地的多样性，延长时间。
Biological invasions are a leading cause of global change, yet their long-term effects remain hard to predict. Invasive species can remain abundant for long periods of time, or exhibit population crashes that allow native communities to recover. The abundance and impact of nonnative species may also be closely tied to temporally variable habitat characteristics. We investigated the long-term effects of habitat fragmentation and invasion by the Argentine ant (Linepithema humile) by resurveying ants in 40 scrub habitat fragments in coastal southern California that were originally sampled 21 yr ago. At a landscape scale, fragment area, but not fragment age or Argentine ant mean abundance, continued to explain variation in native ant species richness; the species-area relationship between the two sample years did not differ in terms of slope or intercept. At local scales, over the last 21 yr we detected increases in the overall area invaded (+36.7%, estimated as the proportion of occupied traps) and the relative abundance of the Argentine ant (+121.95%, estimated as mean number of workers in pitfall traps). Argentine ant mean abundance also increased inward from urban edges in 2017 compared to 1996. The greater level of penetration into fragments likely reduced native ant richness by eliminating refugia for native ants in fragments that did not contain sufficient interior area. At one fragment where we sampled eight times over the last 21 yr, Argentine ant mean abundance increased over time while the diversity of native ground-foraging ants declined from 14 to 4 species. Notably, native species predicted to be particularly sensitive to the combined effect of invasion and habitat loss were not detected at any sites in our recent sampling, including the army ant genus Neivamyrmex. Conversely, two introduced ant species (Brachymyrmex patagonicus and Pheidole flavens) that were undetected in 1996 are now common and widespread at our sites. Our results indicate that behaviorally and numerically dominant invasive species can maintain high densities and suppress native diversity for extended periods.