The natural habitats of many species have become fragmented into small" islands,"
principally by human activities. In this paper we discuss the long-term genetic and
evolutionary consequences of fragmentation as inferred from studies on populations that
have undergone natural habitat fragmentation in the Ozark Mountains. The Ozarks are the
highest land formation found in the midwestern United States. Because of the absence of
major geographical barriers around the Ozarks, plants and animals from diverse parts of the …

Habitat fragmentation is one of the most serious threats to plant biodiversity at the within-
population level. Growing attention on the genetic effects of habitat fragmentation is reflected
in the 2008 publication of several review papers. In general, fragmentation showed a
negative effect on the genetic variability of plant populations. However, for forest trees the
genetic signal of fragmentation seems less clear. Here I discuss the development of less
explored issues that can help to clarify some unresolved questions about tree responses to …