The Impact of Forest Fire Management on the Population Structure of Glade Species in the Ozarks

颈蜥（Crotaphytus collaris）生活在奥扎克被称为glades的露头岩石上。森林火灾的扑灭摧毁了许多林中空地，并将周围的森林从开阔的林地变成了茂密的林下植被。到1980年，在斯特格尔山自然区域内或附近没有项圈蜥蜴种群。在1984年至1989年期间，我们将三个种群的项圈蜥蜴转移到这个自然地区恢复的林中空地上。在1993年之前，我们观察到没有动物在林中分散，也没有新的林中殖民地。1994年，密苏里州自然资源部开始在该地区规定焚烧。在火灾管理下，林地间开始发生遗传交换，44个林地被定植，种群规模增加了10倍以上。我们建议：(1)继续记录蜥蜴的活动范围扩大并描述其遗传后果；(2)量化在火灾管理下林间空地灭绝和再定居的数量；(3)测量林间空地种群之间遗传交换的数量；(4)监测种群的遗传健康。我们很少有机会观察到一个物种种群结构的剧烈变化。我们可以。保护生物学非常重视当地种群之间的交流，在这里我们可以直接测试景观层面的管理是否会影响这种交流。保护生物学的另一个基本工具是有效种群大小，它可以用来监测遗传多样性丧失的速度和潜在有害近亲繁殖的积累速度。因为我们知道初始状态（最初的三个易位种群），我们可以以前所未有的精度估计有效大小，并将我们的估计与基于常用近似值的估计进行比较。考虑到有效规模在保护中的重要性，这样的比较早就应该进行了，我们处于一个独特的位置来做这件事。

gThe collared lizard (Crotaphytus collaris) lives on rocky outcrops in the Ozarks called glades. Suppression of forest fires has destroyed many glades and has transformed the surrounding forest from an open woodlands into a forest with a dense understory. By 1980 no populations of collared lizards existed within or nearby the Stegall Mountain Natural Area. Between 1984 and 1989, we translocated three populations of collared lizards onto restored glades in this natural area. All three flourished, but we observed no animal dispersing between glades and no colonization of new glades up to 1993. In 1994 the Missouri Department of Conservation began prescribed burns in this area. Under fire management, genetic interchanges began to occur between glades, 44 glades were colonized, and the population size increased over10-fold. We propose to (1) continue to document the lizards' range expansion and characterize its genetic consequences, (2) quantify the amount of extinction and recolonization on glades under fire management, (3) measure the amount of genetic interchange among glade populations, and (4) monitor the genetic health of the populations. We rarely have the opportunity to observe drastic alterations in a species' population structure. Here we can. Conservation biology places great importance upon interchange among local populations, and here we can directly test whether or not landscape-level management affects such interchanges. Another basic tool of conservation biology is effective population size, which can be used to monitor the rate of loss of genetic diversity and the rate of accumulation of potentially deleterious inbreeding. Because we know the initial state (the original three translocated populations), we can estimate effective sizes with unprecedented accuracy and compare our estimates to those based on the commonly used approximations. Such a comparison is long over due given the importance of effective size in conservation, and we are in a unique position to do it.