De Meester Nele, Dos Santos Giovanni A P, Rigaux Annelien, Valdes Yirina, Derycke Sofie, Moens Tom
Marine Biology Unit, Department of Biology, Ghent University, Gent, Belgium; Center for Molecular Phylogeny and Evolution, Ghent University, Gent, Belgium.
Departmento de Zoologia, CCB, Federal University of Pernambuco, UFPE, Recife-PE, Brasil.
PLoS One. 2015 Jul 6;10(7):e0131625. doi: 10.1371/journal.pone.0131625. eCollection 2015.
In addition to an increase in mean temperature, climate change models predict decreasing amplitudes of daily temperature fluctuations. In temperate regions, where daily and seasonal fluctuations are prominent, such decreases in daily temperature fluctuations can have a pronounced effect on the fitness of species and on the outcome of species interactions. In this study, the effect of a temperature regime with daily fluctuations versus a constant temperature on the fitness and interspecific interactions of three cryptic species of the marine nematode species complex of Litoditis marina (Pm I, Pm III and Pm IV) were investigated. In a lab experiment, different combinations of species (monospecific treatment: Pm I and Pm IV and Pm III alone; two-species treatment: Pm I + Pm IV; three-species treatment: Pm I + Pm IV + Pm III) were subjected to two different temperature regimes: one constant and one fluctuating temperature. Our results showed that fluctuating temperature had minor or no effects on the population fitness of the three species in monocultures. In contrast, interspecific interactions clearly influenced the fitness of all three species, both positively and negatively. Temperature regime did have a substantial effect on the interactions between the species. In the two-species treatment, temperature regime altered the interaction from a sort of mutualism to commensalism. In addition, the strength of the interspecific interactions changed depending on the temperature regime in the three-species treatment. This experiment confirms that interactions between the species can change depending on the abiotic environment; these results show that it is important to incorporate the effect of fluctuations on interspecific interactions to predict the effect of climate change on biodiversity.
除了平均温度升高外，气候变化模型预测每日温度波动的幅度会减小。在日波动和季节波动都很显著的温带地区，每日温度波动的这种减小可能会对物种的适应性以及物种间相互作用的结果产生显著影响。在本研究中，研究了具有每日波动的温度模式与恒温对海洋线虫物种复合体Litoditis marina的三种隐性物种（Pm I、Pm III和Pm IV）的适应性和种间相互作用的影响。在一项实验室实验中，将不同的物种组合（单物种处理：单独的Pm I、Pm IV和Pm III；双物种处理：Pm I + Pm IV；三物种处理：Pm I + Pm IV + Pm III）置于两种不同的温度模式下：一种是恒温，另一种是波动温度。我们的结果表明，波动温度对单培养中这三种物种的种群适应性影响较小或没有影响。相比之下，种间相互作用明显对所有三种物种的适应性产生了积极和消极的影响。温度模式确实对物种之间的相互作用有重大影响。在双物种处理中，温度模式将相互作用从一种互利共生关系改变为偏利共生关系。此外，在三物种处理中，种间相互作用的强度随温度模式而变化。该实验证实物种之间的相互作用会根据非生物环境而改变；这些结果表明，纳入波动对种间相互作用的影响对于预测气候变化对生物多样性的影响很重要。
