Despite the progression of land degradation and deforestation leading to vegetation fragmentation, most of the population in Mali are still strongly dependent on trees. The current study aimed at exploring how woody species diversity, density and regeneration varies with land use types (farmland, fallow and forest). The study also puts a particular focus on abundance, regeneration and distribution of Parkia biglobosa, a high value tree crop. Data were gathered through systematic vegetation surveys in 48 quadrat plots of 50 × 50 m distributed in three land use types. Ninety one woody species belonging to 72 genera and 30 families were recorded. Land use affected woody species regeneration, density and diversity and the structure of P. biglobosa. The highest mean number of species per plot was recorded in fallow (11.1 ± 1.5) and forest (10.8 ± 0.7) compared with farmland (6.9 ± 1.0). The most abundant regeneration individuals were recorded in the fallow (1998 ± 333 ha−1), followed by forest (1532 ± 167 ha−1) and farmland (897 ± 264 ha−1). For trees, the mean density of 99 ± 26 ind. ha−1 recorded in farmland is similar to fallow (156 ± 46 ha−1) but lower than forest (559 ± 133 ha−1). The lower Shannon’s diversity index H′ was also observed in the farmland (1.3 ± 0.1) compared with fallows (1.7 ± 0.2) and forests (1.9 ± 0.1). Spatial distribution of regeneration individuals for each species obtained from Morisita’s index showed aggregated patterns for most of the species while Canonical Correspondance Analysis showed more common species between fallow and forest. P. biglobosa trees growing in farmland had the greatest value (57.6 ± 7.0 cm) for collar diameter compared to that of forest (33.7 ± 4.6 cm) and fallow (31.2 ± 4.7 cm).
Tag: farmlands
Grevillea grown on farmland: Timber business environment and value chain (part 2)
Grevillea robusta was introduced in Kenya as a shade tree for coffee and tea cash crops. It was adopted by coffee planters from the very early days of the industry in Kenya and by 1910 the Forest Department had started planting it in mixed stands with cypress (Cupressus lusitanica). In the 1940s, it was widely recommended as a timber tree for planting at altitudes below 2,000 metres, while cypress was recommended for higher altitudes (Graham 1945:133). The species is currently well accepted and established around the East African highlands having been naturalized locally in the last 100 years. In these densely populated zones, it is an important source of fuel wood and income from sale of construction timber. The wood is appreciated for fuelwood because it dries quickly- the trees are usually heavily pruned for fuel and construction of small farm buildings. The pale pinkish brown timber has a beautiful, well-marked silver grain, making it desirable for furniture and cabinet work. The species is popular with farmers because it provides viable products, it is easy to propagate and can grow in low-fertility soils.
Grevillea grown on farmland: Timber business environment and its value chains
Grevillea robusta was introduced in Kenya as a shade tree for coffee and tea cash crops. It was adopted by coffee planters from the very early days of the industry in Kenya and by 1910 the Forest Department had started planting it in mixed stands with cypress (Cupressus lusitanica). In the 1940s, it was widely recommended as a timber tree for planting at altitudes below 2,000 metres, while cypress was recommended for higher altitudes (Graham 1945:133). The species is currently well accepted and established around the East African highlands having been naturalized locally in the last 100 years. In these densely populated zones, it is an important source of fuel wood and income from sale of construction timber. The wood is appreciated for fuelwood because it dries quickly- the trees are usually heavily pruned for fuel and construction of small farm buildings. The pale pinkish brown timber has a beautiful, well-marked silver grain, making it desirable for furniture and cabinet work. The species is popular with farmers because it provides viable products, it is easy to propagate and can grow in low-fertility soils.
Sex ratio of dioecious Allanblackia stuhlmannii (Engl.) Engl. in Tanzanian Usambara forests and farmlands
Dioecious Allanblackia stuhlmannii, in East Usambara Mountains becomes a farmland tree when farmers leave the species after clearing the forests. This study examined the process of continuous thinning on sex ratio. Density in natural forest was estimated to be 34–74 mature trees per hectare with an average male:female ratio among reproducing trees observed to be 1:0.59. Density in farmland was 0.5–20 trees per hectare with male:female ratio ranging from 1:0.48 on recent farmland to 1:2 on old farmland. Our results suggest that the reduction of Allanblackia trees in new clearings was not sex biased; however, subsequent cutting targeted mainly males leaving farmland to be populated predominantly with females. Initial sex segregation of A. stuhlmannii is not known, but a 10-year old gene bank of related Allanblackia parviflora in Ghana suggests an even segregation. Allanblackia is gender stable albeit there are few observations of plants changing from male to female during the first year’s flowering and occasional fruit production in males. Average diameter at breast height for first flowering of 44 males was 13.3 cm and that of 17 females 16.3 cm. Decline in Allanblackia trees in farmland from 2011 to 2016 was estimated at about 13% (range from 0 to 23% in monitoring plots) and most of these were male trees.