Forest fragmentation effects on patch occupancy and population viability of herbaceous plant species

• Published in: The New phytologist Vol. 166; no. 3; pp. 723 - 736
• Main Authors: Honnay, Olivier, Jacquemyn, Hans, Bossuyt, Beatrijs, Hermy, Martin
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science 01.06.2005; Blackwell Science Ltd; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biodiversity; Biological and medical sciences; Biological Evolution; Conservation biology; Demography; Ecosystem; edge effects; Extinct species; extinction debt; Forest conservation; Forest ecology; Forest habitats; Forest regeneration; forests; Fundamental and applied biological sciences. Psychology; genetic differentiation; genetic diversity; genetic drift; Habitat fragmentation; herbaceous plants; inbreeding; literature reviews; metapopulation; Metapopulation ecology; patch turnover; plant breeding; plant communities; plant ecology; plant fertility; plant genetics; Plants; pollen limitation; Species; species diversity; Synecology; Tansley Reviews; Terrestrial ecosystems; Trees - physiology; Forests; Vegetals; patch turnover; extinction debt; Genetic diversity; Review; Fragmentation; Species diversity; edge effects; metapopulation; pollen limitation; genetic differentiation; Population dynamics; Species richness
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2005.01352.x

Habitat fragmentation is one of the major threats to species diversity. In this review, we discuss how the genetic and demographic structure of fragmented populations of herbaceous forest plant species is affected by increased genetic drift and inbreeding, reduced mate availability, altered interactions with pollinators, and changed environmental conditions through edge effects. Reported changes in population genetic and demographic structure of fragmented plant populations have, however, not resulted in large-scale extinction of forest plants. The main reason for this is very likely the long-term persistence of small and isolated forest plant populations due to prolonged clonal growth and long generation times. Consequently, the persistence of small forest plant populations in a changing landscape may have resulted in an extinction debt, that is, in a distribution of forest plant species reflecting the historical landscape configuration rather than the present one. In some cases, fragmentation appears to affect ecosystem integrity rather than short-term population viability due to the opposition of different fragmentation-induced ecological effects. We finally discuss extinction and colonization dynamics of forest plant species at the regional scale and suggest that the use of the metapopulation concept, both because of its heuristic power and conservation applications, may be fruitful.