Universidade de Pernambuco - Campus Garanhuns, Garanhuns, Pernambuco, Brazil.
Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, Universidade de Pernambuco - Campus Petrolina, Petrolina, Pernambuco, Brazil.
Bull Entomol Res. 2024 Aug;114(4):571-580. doi: 10.1017/S0007485324000567. Epub 2024 Sep 23.
Global warming is exposing many organisms to severe thermal conditions and is having impacts at multiple levels of biological organisation, from individuals to species and beyond. Biotic and abiotic factors can influence organismal thermal tolerance, shaping responses to climate change. In eusocial ants, thermal tolerance can be measured at the colony level (among workers within colonies), the population level (among colonies within species), and the community level (among species). We analysed critical thermal maxima (CT) across these three levels for ants in a semiarid region of northeastern Brazil. We examined the individual and combined effects of phylogeny, body size (BS), and nesting microhabitat on community-level CT and the individual effects of BS on population- and colony-level CT. We sampled 1864 workers from 99 ant colonies across 47 species, for which we characterised CT, nesting microhabitat, BS, and phylogenetic history. Among species, CT ranged from 39.3 to 49.7°C, and community-level differences were best explained by phylogeny and BS. For more than half of the species, CT differed significantly among colonies in a way that was not explained by BS. Notably, there was almost as much variability in CT within colonies as within the entire community. Monomorphic and polymorphic species exhibited similar levels of CT variability within colonies, a pattern not always explained by BS. This vital intra- and inter-colony variability in thermal tolerance is likely allows tropical ant species to better cope with climate change. Our results underscore why ecological research must examine multiple levels of biological organisation.
全球变暖使许多生物暴露在极端热条件下，并对生物组织的多个层次产生影响，从个体到物种，甚至更广泛的范围。生物和非生物因素可以影响生物的热耐受性，从而塑造其对气候变化的响应。在真社会性蚂蚁中，热耐受性可以在群体水平（群体内部的工蚁之间）、种群水平（物种内部的群体之间）和群落水平（物种之间）进行测量。我们分析了巴西东北部半干旱地区蚂蚁在这三个层次上的临界高温极限（CT）。我们检验了系统发育、体型（BS）和筑巢微生境对群落水平 CT 的单独和综合影响，以及 BS 对种群和群体水平 CT 的个体影响。我们从 47 个物种的 99 个蚂蚁群体中采集了 1864 只工蚁样本，对其 CT、筑巢微生境、BS 和系统发育历史进行了描述。在物种间，CT 范围从 39.3°C 到 49.7°C，而群落水平的差异主要由系统发育和 BS 解释。对于超过一半的物种，群体间的 CT 差异显著，而这无法用 BS 来解释。值得注意的是，在群体内 CT 的变异性几乎与整个群落内的变异性相当。单态和多态物种在群体内的 CT 变异性表现出相似的水平，这种模式并不总是由 BS 解释。这种热耐受性的重要的群体内和群体间变异性可能使热带蚂蚁物种更好地应对气候变化。我们的研究结果强调了为什么生态研究必须研究多个层次的生物组织。
