Potential tree species extinction, colonization and recruitment in Afromontane forest relicts

Tree species regeneration determines future forest structure and composition, but is often severely hampered in small forest relicts. To study succession, long-term field observations or simulation models are used but data, knowledge or resources to run such models are often scarce in tropical areas. We propose and implement a species accounting equation, which includes the co-occurring events extinction, colonization and recruitment and which can be solved by using data from a single inventory. We solved this species accounting equation for the 12 remaining Afromontane cloud forest relicts in Taita Hills, Kenya by comparing the tree species present among the seedling, sapling and mature tree layer in 82 plots. A simultaneous ordination of the seedling, sapling and mature tree layer data revealed that potential species extinctions, colonizations and recruitments may induce future species shifts. On landscape level, the potential extinction debt amounted to 9% (7 species) of the regional species pool. On forest relict level, the smallest relicts harbored an important proportion of the tree species diversity in the regeneration layer. The average potential recruitment credit, defined as species only present as seedling or sapling, was 3 and 6 species for large and small forest relicts, while the average potential extinction debt was 12 and 4 species, respectively. In total, both large and small relicts are expected to lose approximately 20% of their current local tree species pool. The species accounting equations provide a time and resource effective tool and give an improved understanding of the conservation status and possible future succession dynamics of forest relicts, which can be particularly useful in a context of participatory monitoring

Field guide of the woody plant species of Taita Hills, Kenya

This field guide represents a comprehensive treatment of the 184 woody plant species occurring in the Afromontane cloud forests of Taita Hills, Kenya. The first part contains an introduction to the Taita Hills and Eastern Arc Mountains, a list with endemic plant species, the multiple benefits the forests provide, additional references and a manual to use this guide. The second part contains identification keys that allow the reader to find the correct scientific name based on easy observable leaf characters rather than on more complex flower structure. The third part contains species fact sheets. These sheets are arranged alphabetically by their scientific names and include local vernacular names, diagnostic characteristics, (traditional) uses, photographs and illustrations. The last part contains a glossary of botanical terms and a species index.nrpages: 272status: publishe