Data from: Ant community and habitat limit colony establishment by the fire ant, Solenopis invicta

Hypotheses of community assembly include limitation through habitat physical attributes, as well as competition among species. Such hypotheses must be resolved through experimental tests.
Previous experiments have shown that: (i) fire ants of the monogyne social form occur mostly in highly disturbed habitat where they do not compete with mature colonies of co-occurring ants; (ii) in native pine forests of northern Florida, habitat disturbance favours fire ants while simultaneously reducing native ants; (iii) fire ants thrive in these disturbances but do not persist as these become less disturbed over time; and finally, (iv) newly mated, dispersing/colony-founding fire ant queens settle preferentially in such disturbed sites.
We now show that by choosing disturbed sites, newly mated, monogyne fire ant queens greatly increase their chances of successful colony establishment. Experimental plots were created in the native ground cover of a north Florida pine forest with all combinations of tilling, shading or reduction of the native ant community.
Newly mated fire ant queens, incipient colonies and small colonies were planted in these plots. Only five of 980 (0·5%) newly mated queen nests survived after 120 days, and only five of 400 incipient colonies (1·3%) survived after 30 days. All survivors were in plots with tilling and/or native ant reduction. Extrapolation indicated that 0·04% of newly mated queens and 0·1% of incipient colonies were likely to have survived at 1 year.
In contrast, planting small colonies resulted in much higher rates of survival – in plots with native ant reduction, fire ants increased on baits throughout the year but decreased in unreduced control plots. Fifteen months after planting 108 colonies, 21 mounds (19%) were found in the ant-reduced plots, but <2% of 108 colonies survived in the control plots.
Taken together, these results show that by landing in disturbed habitat with its reduced native ant population, newly mated fire ants queens increase their chances of successful colony establishment. In contrast to much of the previous literature, our results suggest that ant community assembly proceeds primarily by queen habitat choice and secondarily by filtering and competition.

群落构建假说涵盖基于栖息地物理属性的种群限制机制，以及物种间的种间竞争作用，此类假说需通过实验研究予以验证。
过往相关实验已证实：（i）单蚁后社会型（monogyne social form）红火蚁主要分布于高度受干扰的生境，在此类生境中它们不会与同域共存蚂蚁的成熟蚁群产生竞争；（ii）在佛罗里达州北部的原生松林中，栖息地干扰对红火蚁种群有利，同时会抑制本地蚂蚁群落；（iii）红火蚁可在这类干扰生境中繁盛，但随着干扰程度随时间降低，其种群无法持续存在；最后（iv）刚完成交配、处于扩散/建群阶段的红火蚁蚁后会优先选择此类受干扰位点定居。
本研究证实，通过选择受干扰生境，单蚁后社会型红火蚁蚁后可显著提升其成功建群的概率。研究人员在佛罗里达北部松林的原生地表植被中设置实验样地，涵盖翻耕、遮阴及本地蚂蚁群落去除的全部组合处理。
将刚交配完成的红火蚁蚁后、初建蚁群及小型蚁群接种至上述样地。120天后，980个刚交配蚁后的巢穴中仅5个（0.5%）存活；30天后，400个初建蚁群中仅5个（1.3%）存活。所有存活个体均位于施加了翻耕和/或本地蚂蚁群落去除处理的样地中。外推分析显示，在一年周期后，仅0.04%的刚交配蚁后及0.1%的初建蚁群有望存活。
与之相对，接种小型蚁群的存活率显著更高——在施加本地蚂蚁群落去除处理的样地中，红火蚁在诱饵诱捕中的种群数量全年持续上升，但在未做处理的对照组样地中种群数量下降。在接种108个小型蚁群15个月后，蚂蚁去除处理样地中共发现21个蚁丘（占比19%），而对照组中存活的蚁群占比不足2%。
综合上述结果可知，刚交配的红火蚁蚁后选择本地蚂蚁种群被抑制的受干扰生境定居，能够大幅提升其成功建群的概率。与过往多数研究结论不同，本研究结果提示，蚂蚁群落构建主要通过蚁后的栖息地选择实现，其次才是环境过滤与种间竞争作用。