Tree regeneration and future dynamics of the laurel forest on Tenerife, Canary Islands

Abstract

We studied two sites in the laurel forest of Tenerifeto predict future changes in canopy composition. We used twoprojection methods: Horn’s ‘Markovian Projection’, whichutilizes information on juveniles in the vicinity of canopytrees, and a ‘Stand Projection’, which ignores such informa-tion. We performed these projections both including and ex-cluding a-sexual regeneration. Although all of our projectionspredict a change in species composition, inclusion of a-sexualreproduction decreased the magnitude of successional change.The persistence of Prunus lusitanica and Ilex canariensisappears to be highly dependent on a-sexual regeneration.Both the Markov- and stand projections predict a slightconvergence in species composition between the two siteswhen only sexual regeneration is considered, and also a higherdominance of the shade-tolerant species Laurus azorica. Whena-sexual regeneration is also considered, some divergence isshown, with less projected change in the stand projection thanin the Markov projection. In spite of some differences betweenthe models, general patterns such as an increase of shade-tolerant species (Laurus azorica and Prunus lusitanica) and adecrease of shade-intolerant species (Erica arborea, Ericascoparia and Myrica faya) are consistent.