Forest degradation and invasive species synergistically impact Mimusops andongensis (Sapotaceae) in Lama Forest Reserve, Benin

Harvesting of Non-Timber Forest Products (NTFPs) can threaten target species, especially those with limited distribution and density. Exploited species also face threats from habitat fragmentation, fire, and invasive species. We assessed the impact of human disturbances and invasive species on the population of a key multipurpose NTFP species, Mimusops andongensis, in Lama Forest reserve (Benin). The densities of adult trees and regenerative stems decreased with increasing degradation. Mimusops andongensis contributed less to total tree density with increasing human disturbance. There were significantly fewer M. andongensis recruits with increasing cover of invasive Chromolaena odorata. Smaller diameter individuals predominated in non-degraded and moderately degraded sites while in degraded sites, the structure showed a negative exponential trend with the density of small diameter individuals being less than two trees/ha. Larger individuals were also rare in degraded sites. The low density of both mature trees and seedlings in degraded sites may undermine the long-term viability of M. andongensis, despite existing protection against NTFP harvesting and other anthropogenic pressures. Management should emphasize facilitating recruitment subsidies and limiting the presence of C. odorata

Latitudinal distribution, co-occurring tree species and structural diversity of the threatened palm Borassus aethiopum (Arecaceae) in Benin, West Africa

Background and aims – Borassus aethiopum Mart. is a wild palm species with high subsistence importance in West Africa. Extensive agriculture and overharvesting of its stem and fruits for multiple uses have caused a decrease of its natural populations in its native range. For conservation purposes, the distribution, abundance and structural diversity of the species were investigated across ten phytodistricts in three biogeographical zones in Benin. Two hypotheses were tested (i) tree floristic composition of B. aethiopum natural habitat changes with phytodistricts and (ii) structural diversity of B. aethiopum changes with phytodistricts, both as potential adaptation strategies to changing ecological conditions. Methods – Geographical coordinates of the species occurrence were recorded. Abundance was assessed in 852 one-ha plots. Structural diversity was studied using structural indices on data from ecological inventories and neighbourhood survey in 70 one-ha plots. Key results – The two hypotheses proved true. B. aethiopum was found in all phytodistricts but with strong variations in abundance. Overall, floristic composition of its natural habitats showed dissimilarities among phytodistricts. Three main vegetation types sheltered B. aethiopum : mixed grass and shrub savannas, savanna woodlands and woodlands, all of which were found in gallery forest landscapes. The density of B. aethiopum was lower in grass savannas but larger, shorter and distant individuals were found there than in savanna woodlands and woodlands. In the latter vegetation types, its density was high with thin, tall and closely spaced individuals. B. aethiopum tolerates mingling with several other tree species but increased mingling tends to lead to positive differentiation in diameter and height. Conclusions – Borassus aethiopum is a sun-demanding species and establishes successful populations in various ecological conditions. It could be mixed with other tree species in tree plantations and modern agroforestry systems as long as water requirements are met. However, it would be preferable that the species is associated with shade tolerant or medium sun-demanding species

Data from: Forest degradation and invasive species synergistically impact Mimusops andongensis (Sapotaceae) in Lama Forest Reserve, Benin

Harvesting of Non-Timber Forest Products (NTFPs) can threaten target species, especially those with limited distribution and density. Exploited species also face threats from habitat fragmentation, fire, and invasive species. We assessed the impact of human disturbances and invasive species on the population of a key multipurpose NTFP species, Mimusops andongensis, in Lama Forest reserve (Benin). The densities of adult trees and regenerative stems decreased with increasing degradation. Mimusops andongensis contributed less to total tree density with increasing human disturbance. There were significantly fewer M. andongensis recruits with increasing cover of invasive Chromolaena odorata. Smaller diameter individuals predominated in non-degraded and moderately degraded sites while in degraded sites, the structure showed a negative exponential trend with the density of small diameter individuals being less than two trees/ha. Larger individuals were also rare in degraded sites. The low density of both mature trees and seedlings in degraded sites may undermine the long-term viability of M. andongensis, despite existing protection against NTFP harvesting and other anthropogenic pressures. Management should emphasize facilitating recruitment subsidies and limiting the presence of C. odorata

Latitudinal distribution, co-occurring tree species and structural diversity of the threatened palm Borassus aethiopum (Arecaceae) in Benin, West Africa

Background and aims – Borassus aethiopum Mart. is a wild palm species with high subsistence importance in West Africa. Extensive agriculture and overharvesting of its stem and fruits for multiple uses have caused a decrease of its natural populations in its native range. For conservation purposes, the distribution, abundance and structural diversity of the species were investigated across ten phytodistricts in three biogeographical zones in Benin. Two hypotheses were tested (i) tree floristic composition of B. aethiopum natural habitat changes with phytodistricts and (ii) structural diversity of B. aethiopum changes with phytodistricts, both as potential adaptation strategies to changing ecological conditions. Methods – Geographical coordinates of the species occurrence were recorded. Abundance was assessed in 852 one-ha plots. Structural diversity was studied using structural indices on data from ecological inventories and neighbourhood survey in 70 one-ha plots. Key results – The two hypotheses proved true. B. aethiopum was found in all phytodistricts but with strong variations in abundance. Overall, floristic composition of its natural habitats showed dissimilarities among phytodistricts. Three main vegetation types sheltered B. aethiopum : mixed grass and shrub savannas, savanna woodlands and woodlands, all of which were found in gallery forest landscapes. The density of B. aethiopum was lower in grass savannas but larger, shorter and distant individuals were found there than in savanna woodlands and woodlands. In the latter vegetation types, its density was high with thin, tall and closely spaced individuals. B. aethiopum tolerates mingling with several other tree species but increased mingling tends to lead to positive differentiation in diameter and height. Conclusions – Borassus aethiopum is a sun-demanding species and establishes successful populations in various ecological conditions. It could be mixed with other tree species in tree plantations and modern agroforestry systems as long as water requirements are met. However, it would be preferable that the species is associated with shade tolerant or medium sun-demanding species

Data_Impact of Forest Degradation and Invasive species on Mimusops andongensis in Lama Forest Reserve in Benin

Data on trees occurrence, dbh and height, data on regeneration occurence, diameter and height, and data on Chromolaena odorata cove