随着许多地区昆虫种群的减少,保护生物学家越来越多的任务是确定威胁昆虫物种的因素,并制定有效的保护策略。全球保护关注的一类昆虫是萤火虫(鞘翅目:Lampyridae)。尽管大多数物种缺乏萤火虫种群的定量数据,轶事报道表明,近几十年来,一些萤火虫的数量有所下降。研究人员假设北美萤火虫种群受到栖息地丧失的威胁最大,农药使用,和光污染,但是,这些因素在塑造萤火虫种群中的重要性尚未在广泛的空间尺度上得到严格的研究。使用来自公民科学计划FireflyWatch的超过24,000项调查(涵盖2008-16)的数据,我们训练了机器学习模型来评估多种因素对生物发光萤火虫种群的相对重要性:农药,晚上的人造灯光,土地覆盖,土壤/地形,短期天气,长期气候。我们的分析表明,萤火虫的丰度是由土壤条件之间复杂的相互作用驱动的(例如,砂成分百分比),气候/天气(例如,生长度日),和土地覆盖特征(例如,农业和不透水覆盖物的百分比)。鉴于气候和天气条件对萤火虫的丰度有重大影响,萤火虫种群很有可能会受到气候变化的影响,随着一些地区质量越来越高,支持更大的萤火虫种群,和其他人可能完全失去人口。总的来说,我们的结果支持与威胁萤火虫种群的因素有关的假设,尤其是栖息地的丧失,并表明气候变化可能构成比以前评估中认识到的更大的威胁。因此,北美萤火虫种群的未来保护将取决于1)通过萤火虫观察等程序对种群进行持续和持续的监测,2)努力减轻气候变化的影响,和3)昆虫友好的保护做法。
As insect populations decline in many regions, conservation biologists are increasingly tasked with identifying factors that threaten insect species and developing effective strategies for their conservation. One insect group of global conservation concern are
fireflies (Coleoptera: Lampyridae). Although quantitative data on firefly populations are lacking for most species, anecdotal reports suggest that some firefly populations have declined in recent decades. Researchers have hypothesized that North American firefly populations are most threatened by habitat loss, pesticide use, and light pollution, but the importance of these factors in shaping firefly populations has not been rigorously examined at broad spatial scales. Using data from >24,000 surveys (spanning 2008-16) from the citizen science program Firefly Watch, we trained machine learning models to evaluate the relative importance of a variety of factors on bioluminescent firefly populations: pesticides, artificial lights at night, land cover, soil/topography, short-term weather, and long-term climate. Our analyses revealed that firefly abundance was driven by complex interactions among soil conditions (e.g., percent sand composition), climate/weather (e.g., growing degree days), and land cover characteristics (e.g., percent agriculture and impervious cover). Given the significant impact that climactic and weather conditions have on firefly abundance, there is a strong likelihood that firefly populations will be influenced by climate change, with some regions becoming higher quality and supporting larger firefly populations, and others potentially losing populations altogether. Collectively, our results support hypotheses related to factors threatening firefly populations, especially habitat loss, and suggest that climate change may pose a greater threat than appreciated in previous assessments. Thus, future conservation of North American firefly populations will depend upon 1) consistent and continued monitoring of populations via programs like Firefly Watch, 2) efforts to mitigate the impacts of climate change, and 3) insect-friendly conservation practices.