Data from: Repeated habitat disturbances by fire decrease local effective population size

Effective population size is a fundamental parameter in population genetics, and factors that alter effective population size will shape the genetic characteristics of populations. Habitat disturbance may have a large effect on genetic characteristics of populations by influencing immigration and gene flow, particularly in fragmented habitats. We used the Florida Sand Skink (Plestiodon reynoldsi) to investigate the effect of fire-based habitat disturbances on the effective population size in the highly threatened, severely fragmented, and fire dependent Florida scrub habitat. We screened seven microsatellite loci in 604 individuals collected from 12 locations at Archbold Biological Station. Archbold Biological Station has an active fire management plan and detailed records of fires dating to 1967. Our objective was to determine how the timing, number, and intervals between fires affect effective population size, focusing on multiple fires in the same location. Effective population size was higher in areas that had not been burned for more than ten years and decreased with number of fires and shorter time between fires. A similar pattern was observed in abundance: increasing abundance with time-since-fire and decreasing abundance with number of fires. The ratio of effective population size to census size was higher at sites with more recent fires and tended to decrease with time-since-last-fire. These results suggest that habitat disturbances, such as fire, may have a large effect in the genetic characteristics of local populations and that Florida Sand Skinks are well adapted to the natural fire dynamics required to maintain Florida scrub.有效种群大小（effective population size）是种群遗传学中的核心基础参数，任何能够改变有效种群大小的因素，均可塑造种群的遗传特征。生境干扰可通过影响种群迁入与基因流，对种群的遗传特征产生显著影响，在破碎化生境中这一效应尤为突出。本研究以佛罗里达沙石龙子（Plestiodon reynoldsi）为研究对象，在受严重威胁、高度破碎化且依赖火生态的佛罗里达灌丛生境中，探究基于火的生境干扰对有效种群大小的影响。我们对从阿奇博尔德生物站（Archbold Biological Station）12个采样点采集的604个个体的7个微卫星位点进行了分型筛选。阿奇博尔德生物站拥有现行的火管理计划，并保存有自1967年起的详细火灾记录。本研究旨在明确火灾的发生时序、频次与间隔时长如何影响有效种群大小，重点关注同一地点的多次火灾事件。研究结果显示，近十年未发生火烧的区域有效种群大小更高；而火灾频次越高、火烧间隔越短，有效种群大小则越低。种群丰度也呈现出相似的变化模式：丰度随距上次火烧的时间增长而升高，随火灾频次增加而降低。有效种群大小与普查种群大小的比值，在近期发生过火烧的样地中更高，且整体呈现出随距上次火烧时间延长而下降的趋势。上述结果表明，火灾这类生境干扰可对局域种群的遗传特征产生显著影响，同时也说明佛罗里达沙石龙子已很好地适应了维持佛罗里达灌丛生态系统所需的自然火动态过程。