Sapling biomass allometry and carbon content in five afforestation species on marginal farmland in semi-arid Benin

Climate Change Sensitivity of Multi-Species Afforestation in Semi-Arid Benin

“…The region has been significantly affected by land degradation driven by deforestation and soil nutrient mining, which threatens the sustainability of forest and farming systems [18,46,47]. To combat land degradation, national and local projects to intensify forest cover, reclaim degraded lands and mitigate the effects of climate change (e.g., the project "10 Million Trees, 10 Million Souls"; http://news.acotonou.com/h/61311.html) through the planation of commercially important food (e.g., M. oleifera) and biofuel (e.g., J. curcas) tree crops have been carried out in the region [26,48].…”

“…Seedlings were planted in monospecific plots at the experimental site in July 2014 after 2.5-4 months, and were monitored over 15 months [18,20,26]. These local species were selected based on the fast growth rate of their shoots and roots in response to water and nutrient supply, as well as their socio-economic importance and increasing recent efforts to expand their plantation acreage in West Africa [18,26]. Each plot contained Sustainability 2018, 10,1931 5 of 23 48 seedlings with a 2 m × 1 m spacing, resulting in an initial stand density of 5000 trees ha −1 , which was used in the simulations.…”

“…Tree morphological properties and biomass were measured at the beginning and end of the 2014 and 2015 rainy seasons (i.e., 5, 11, and 15 MaP) on two to six saplings randomly selected per experimental plot [20,26]. After measuring the height (H, m) and stem diameter (D, cm), the selected trees were felled for total biomass determination, and that of the different tree fractions.…”

“…Our study may be the first to test explicitly this generic approach to assess climate change risks for newly established dryland afforestation sites. The datasets stem from a site in a semi-arid zone of West Africa, where tree-based land restoration is high on the agenda and existing information is not sufficient to assess the robustness of afforestation option for a range of tree species [18,20,26].…”

“…The aim of our research was to assess the climate sensitivity of two afforestation species-Jatropha curcas L. and Moringa oleifera Lam.-in the early stages of their development (i.e., the first two years of growth), decisive for the future growth [42] and also when plants are most sensitive to changes in water availability [43][44][45]. The two species have been subjects of silvicultural trials on degraded cropland in northern Benin [18,20,26]. The specific objectives were to (i) compare different indicators calculated from climate records to identify those with the greatest predictive power for the first two years of tree growth; (ii) quantify the climate-growth relationships of tree growth over the first two years, and (iii) test possible adaptation strategies to reduce the sensitivity of saplings to extreme climate events.…”