Data from: Revisiting the pyrodiversity-biodiversity hypothesis: long-term fire regimes and the structure of ant communities in Neotropical savannas

1. The idea that variable fire regimes (pyrodiversity) may increase habitat heterogeneity and, consequently, increase biodiversity at the landscape level is a relatively old one. However, this idea has been recently challenged by studies showing that the biota of fire-prone ecosystems is so resilient to fire that variation in fire regime has little ecological consequences. 2. We evaluated how communities of ants – a dominant faunal group – differ with variation in the frequency and seasonal timing of fire in Brazilian Cerrado (savanna), a global biodiversity hotspot. We compared the number and composition of ant species foraging on the ground and in trees among experimental treatments with three fire frequencies (unburned for 37 years and burned every 2 or 4 years for the past 16 years) and three seasonal timings (early, mid and late dry season) of fire with a biennial frequency. 3. There were no significant differences in ant species richness in trees, and there were no significant differences in the richness of ground-dwelling ants among plots burned at different times of the dry season. However, unburned plots had fewer ground-dwelling ant species than those burned at 2 or 4 year intervals. We detected marked differences in species composition across regimes varying in both the frequency and the timing of fire, which were related to fire-induced changes in vegetation structure. Over 40% of the overall ant species richness recorded in our study site was attributed to differences in species composition among fire treatments. 4. Synthesis and applications. Our study shows that Cerrado ant diversity at the landscape scale is promoted by a diversity of fire regimes, and therefore supports the validity of the pyrodiversity–biodiversity hypothesis for the Cerrado biome. Our findings suggest that the current policy of fire suppression in Cerrado protected areas has a negative effect on overall biodiversity and therefore should be reconsidered.

1. 火多样性（pyrodiversity）可提升生境异质性，进而提高景观尺度生物多样性的观点由来已久。然而近期相关研究对该观点提出了挑战，这些研究指出，易火生态系统中的生物群系对火灾具有极强的恢复力，因此火制度的变异几乎不会产生生态影响。
2. 本研究以全球生物多样性热点区域巴西塞拉多（Cerrado，热带稀树草原）为研究地点，针对优势动物类群——蚂蚁的群落，探究其如何随火烧频率与火烧季节时间的变化产生差异。我们设置了三类火烧频率处理（37年未火烧地块、过去16年每2年火烧一次地块、每4年火烧一次地块），以及三类两年一次火烧的季节时间处理（旱季早期、旱季中期、旱季晚期），并对比了不同处理下地面与树冠觅食蚂蚁的物种数量及物种组成。
3. 树冠蚂蚁的物种丰富度未出现显著差异，且不同旱季火烧时间的地块间，地表蚂蚁的物种丰富度也无显著区别。但未火烧地块的地表蚂蚁物种丰富度显著低于每2年或每4年火烧一次的地块。我们发现，火烧频率与火烧时间均不同的火制度下，蚂蚁物种组成存在显著差异，这一差异与火灾引发的植被结构变化相关。本研究样地记录到的总蚂蚁物种丰富度中，有超过40%可归因于不同火烧处理间的物种组成差异。
4. 总结与应用。本研究表明，多样的火制度可提升巴西塞拉多景观尺度的蚂蚁多样性，因此验证了塞拉多生物群系中火多样性-生物多样性假说的合理性。研究结果提示，当前巴西塞拉多保护区内的火灾抑制政策会对整体生物多样性产生负面影响，因此该政策亟待重新考量。