Puig-Gironès Roger, Santos Xavier, Bros Vicenç
Departament de Ciències Ambientals, Universitat de Girona, C. Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain; Equip de Biologia de la Conservació, Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals & Institut de la Recerca de la Biodiversitat (IRBIO), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Catalonia, Spain.
CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, R. Padre Armando Quintas s/n, 4485-661 Vairão, Portugal.
Sci Total Environ. 2023 Jun 10;876:162677. doi: 10.1016/j.scitotenv.2023.162677. Epub 2023 Mar 7.
In fire-prone regions, fire is a major natural disturbance which shapes ecosystem function and community composition. Fire has a direct and dramatic effect on soil fauna and, especially, on non-mobile species such as land snails. The factors that make the Mediterranean Basin a fire-prone region may also lead to the appearance after fires of certain functional traits related to ecological and physiological characteristics. Knowledge of how community structure and function change along the post-fire succession will be useful for understanding the processes that drive biodiversity patterns in burnt areas and for implementing appropriate biodiversity management strategies. Here, we examine long-interval taxonomic and functional changes occurred in a snail community four and 18 years after a fire in the Sant Llorenç del Munt i l'Obac Natural Park (NE Spain). Our field-based study demonstrates that the land snail assemblage responds both taxonomically and functionally to fire and that there was a clear replacement of dominant species from the first to the second sampling period. Variation in community composition between different post-fire ages can be attributed to snail species traits and successional changes in post-fire habitat conditions. At taxonomic level, there was great variation in snail species turnover between both periods, being the development of the understorey vegetation structure the main driver of this variation. The replacement of functional traits between times since fire suggests that xerophilic and mesophilic preferences play an important role after fire and are largely determined by the complexity of post-fire microhabitats. Our analysis indicates that immediately after a fire there is a time-window of opportunity that attracts species specializing in early successional habitats, which thereafter are replaced due to the changing conditions resulting from succession. Consequently, knowing the functional traits of species is important for determining the impacts of disturbances on the taxonomic and functional communities.
在火灾频发地区，火灾是塑造生态系统功能和群落组成的主要自然干扰因素。火灾对土壤动物群，尤其是对诸如陆地蜗牛等不移动物种具有直接且显著的影响。使地中海盆地成为火灾频发地区的因素，也可能导致火灾后出现某些与生态和生理特征相关的功能性状。了解群落结构和功能如何随火灾后的演替而变化，将有助于理解驱动火烧地区生物多样性模式的过程，并有助于实施适当的生物多样性管理策略。在此，我们研究了圣洛伦索德尔蒙特伊洛巴克自然公园（西班牙东北部）一场火灾发生四年和十八年后蜗牛群落发生的长期分类学和功能变化。我们基于实地的研究表明，陆地蜗牛群落无论在分类学上还是功能上都对火灾做出了响应，并且从第一个采样期到第二个采样期，优势物种发生了明显更替。不同火灾后时期之间群落组成的变化可归因于蜗牛物种的性状以及火灾后栖息地条件的演替变化。在分类学层面，两个时期之间蜗牛物种更替存在很大差异，林下植被结构的发展是这种变化的主要驱动因素。火灾后不同时间功能性状的更替表明，嗜旱和嗜中偏好性状在火灾后发挥重要作用，并且在很大程度上由火灾后微生境的复杂性决定。我们的分析表明，火灾后立即存在一个机会窗口，吸引了专门适应早期演替栖息地的物种，这些物种随后由于演替导致的条件变化而被取代。因此，了解物种的功能性状对于确定干扰对分类学和功能群落的影响很重要。
