Land Use / Land Cover Change And Impact On Carbon Stocks In The Atacora Chain Of Mountains, A Biodiversity Hotspot In Benin (West Africa)

Mountain areas are fragile ecosystems that play important roles in people’s livelihoods and maintenance of the global ecosystem through the provision of many ecosystem services. Land use/cover (LULC) change is considered one of the major threats to mountain areas due to its effects on ecosystem services including carbon stocks. In this study we assessed LULC change between 1987 and 2015 and its impact on aboveground carbon stocks in the Atacora Chain of Mountains (ACM) in Benin, West Africa. Supervised classification was performed to delineate LULC classes on three dates (1987, 2001 and 2015), and forest measurements carried out in the land cover classes, to estimate the aboveground biomass and the subsequent carbon stocks. Seven land cover classes were delineated: gallery forests, woodlands, savanna, water, settlements, bare lands and farm lands. LULC changes were characterized by three transitions: 1) the change of man-made land cover into savanna, 2) the change of natural vegetation into man-made land cover and 3) the degradation of gallery forests and woodland into less wooded vegetation. The aboveground carbon stock in gallery forests, woodland and tree savanna were significantly greater than in shrub savanna. During the 28 years of assessment, LULC change in gallery forests, woodland and savanna caused an estimated overall aboveground carbon release of 17.10% in the ACM. From the aboveground carbon quantity in the ACM, it appeared that this ecosystem is a potential carbon reservoir. Because the aboveground carbon stock in shrub savanna is significantly lower as compared to gallery forests, woodland and tree savanna and the rates of degradation from gallery forests and woodland to savanna are high, 53.62% and 59.99% respectively in 28 years, LULC change may undermine the ACM ability to store carbon and contribute to climate change mitigation. There is a need to investigate the drivers of this degradation for actions to preserve the natural vegetation in the ACM. Keywords: Atacora Chain of Mountains; Land use/land cover (LULC); Benin; West Africa; Carbon stock DOI: 10.7176/JEES/10-6-13 Publication date:June 30th 202

Maladies et plantes vasculaires du Karité (Vitellaria paradoxa Gaertn) au Bénin

La présente étude vise à évaluer les maladies et les plantes vasculaires du karité (Vitellaria paradoxa C. F. Gaertn) dans les savanes Soudanienne (SS) et Nord guinéenne (SNG) du Bénin. Pour ce faire, quarante sites au total ont été prospectés au cours du mois de juillet 2018. Sur chaque site, l’incidence et la sévérité des symptômes de maladies, la densité et la distribution des plantes vasculaires ont été étudiées. Des échantillons de feuilles malades, des plantes vasculaires du karité ont été prélevés pour lʼidentification au laboratoire. Lasiodiplodia theobromae, Colletotrichum gloeosporioides, Pestalotiopsis sp, Xanthomonas sp ont été les agents pathogènes identifiés. Les valeurs d’incidence étaient élevées dans la SS (59,6% L. theobromae, et de 42,2% Xanthomonas sp) et dans la SNG (67,5% Pestalotiopsis sp et de 55% L. theobromae). Les valeurs de sévérité étaient élevées dans la SS (39% L. theobromae et de 30,6% Xanthomonas sp) et dans la SNG (54,7% Pestalotiopsis sp et 43% L. theobromae). Les données collectées sur la densité des plantes vasculaires ont montré une Orchidiaceae holo-épiphyte (Calyptrochilum christyanum), une Moraceae hémi-épiphyte (Ficus thonningii), une Renonculaceae (Alafia barteri) et deux Loranthaceae (Tapinanthus dodoneifolius, Tapinanthus globiferus). T. dodoneifolius et T. globiferus sont plus répandus avec des taux d’infestation moyens respectifs de 68,67% et de 66,58% et des densités moyennes par plant respectives de 5,64 touffes et de 2,52 touffes. Ainsi, les efforts d’amélioration de la production de karité doivent prendre en compte les stratégies de lutte contre ces agents pathogènes et plantes vasculaires.   The present study aims to assess diseases and vascular plants of the shea-butter tree (Vitellaria paradoxa C. F. Gaertn) in Sudan Savanna (SS) and Northern Guinea Savanna (NGS) of Benin. Thus, forty (40) sites in total were surveyed in July 2018. On each site, incidence and severity of the disease symptoms, and density and distribution of vascular plants of the shea-butter tree were studied. Samples of diseased leaves and vascular plants of the sheabutter tree were collected for laboratory identification. The pathogens Lasiodiplodia theobromae, Colletotrichum gloeosporioides, Pestalotiopsis sp) and Xanthomonas sp were identified. The incidence values were high in SS (59.6% L. theobromae and 42.2% Xanthomonas sp) and in NGS (67.5% Pestalotiopsis sp and 55% L. theobromae). The severity values were high in SS (39% L. theobromae and 30.6% Xanthomonas sp) and in NGS (54.7% Pestalotiopsis sp and 43% L. theobromae). Data collected on the density of vascular plants of the shea-butter tree showed one holo-epiphytic Orchidiaceae (Calyptrochilum christyanum), one Moraceae (Ficus thonningii), one Renonculaceae (Alafia barteri) and two Loranthaceae (Tapinanthus dodoneifolius, Tapinanthus globiferus). T. dodoneifolius and T. globiferus were more widespread with respectively infestation rate of 68.67% and 66.58%, and respectively average densities per shea plant of 5.64 tufts and 2.52 tufts. Thus, efforts to improve shea-butter production must take into account strategies for disease pathogens and vacular plants control in the sheabutter parklands in Benin

Data from: Recurrent fruit harvesting reduces seedling density but increases the frequency of clonal reproduction in a tropical tree

Studies on the ecological impacts of non-timber forest products (NTFP) harvest reveal that plants are often more resilient to fruit and seed harvest than to bark and root harvest. Several studies indicate that sustainable fruit harvesting limits can be set very high (>80% fruit harvesting intensity). For species with clonal and sexual reproduction, understanding how fruit harvest affects clonal reproduction can shed light on the genetic risks and sustainability of NTFP harvest. We studied 18 populations of a gallery forest tree, Pentadesma butyracea (Clusiaceae), to test the impact of fruits harvest, climate and habitat size (gallery forest width) on the frequency of sexual or clonal recruitment in Benin, West Africa. We sampled populations in two ecological regions (Sudanian and Sudano-Guinean) and in each region, we selected sites with low, moderate and high fruit harvesting intensities. These populations were selected in gallery forests with varying width to sample the natural variation in P. butyracea habitat size. Heavily harvested populations produced significantly less seedlings but had the highest density and proportion of clonal offspring. Our study suggests that for plant species with dual reproductive strategy (via seeds and clonal), fruit harvesting and associated disturbances that come with it can lead to an increase in the proportion of clonal offspring. This raises the issue that excessive fruit harvest by increasing the proportion of clonal offspring to the detriment of seed originated offspring may lead to a reduction in genetic diversity with consequence on harvested species capability to withstand environmental stochasticity

Response of a tropical tree to non-timber forest products harvest and reduction in habitat size.

Non-timber forest products (NTFPs) are widely harvested by local people for their livelihood. Harvest often takes place in human disturbed ecosystems. However, our understanding of NTFPs harvesting impacts in fragmented habitats is limited. We assessed the impacts of fruit harvest, and reduction in habitat size on the population structures of Pentadesma butyracea Sabine (Clusiaceae) across two contrasting ecological regions (dry vs. moist) in Benin. In each region, we selected three populations for each of the three fruit harvesting intensities (low, medium and high). Harvesting intensities were estimated as the proportion of fruits harvested per population. Pentadesma butyracea is found in gallery forests along rivers and streams. We used the width of gallery forests as a measure of habitat size. We found negative effects of fruit harvest on seedling and adult density but no significant effect on population size class distribution in both ecological regions. The lack of significant effect of fruit harvest on population structure may be explained by the ability of P. butyracea to compensate for the negative effect of fruit harvesting by increasing clonal reproduction. Our results suggest that using tree density and population structure to assess the ecological impacts of harvesting clonal plants should be done with caution

Data 1: Seedling and adult Density and Basal Area for Pentadesma

Data 1: Population density and basal area data for 18 Pentadesma butyraceae populations in Benin, West Africa This data set includes for each plot in each of the 18 populations of Pentadesma butyraceae in Benin, seedling, clonal and adult densities, and population level fruit harvesting intensity and gallery forest width

Diversité des Espèces de Faunes Chassées et Impact sur la Biodiversité Animale (Nord-Ouest du Bénin)

Hunting is an important activity for communities close to wildlife reserves, despite its negative impacts on wildlife. For one and a half day, daily monitoring was conducted alongside the hunters during 203 hunting parties in the study area. This paper focuses on identifying the species hunted, to analyze the different sampling sites, and to evaluate the pressure on the fauna. The use of Generalized Linear Models realized in the software R 3.4.1 allowed the treatment of the data of the collected species. A total of 2712 game animals, belonging to 09 orders of animals and 34 species, were identified among the samples. The most severed species were small-sized species such as Lepus crawashayi (31.12%), Francolinus bicalcaratus (29.09%), and Thryonomys swinderianus (10.88%). Most game is slaughtered in the fields (53.28%), fallows (29.17%) and on rocky outcrops (3.32%), and some are taken from the protected savannah (1.29%). The samples are non-selective, resulting in damage to wildlife biodiversity. This pressure is also manifested by the presence of endangered species in the IUCN Red List samples, such as the vulnerable Ourebie (Ourebia ourebia) (VU) and Denham’s Bustard (Neotis denhami), another critically endangered species (CR). The harvested species are small resilient species that are resistant to hunting pressure for the moment. As the population increases, this hunt will no longer be sustainable.La chasse est une activité importante pour les communautés proches des réserves de faunes malgré ses impacts négatifs sur les espèces sauvages. Durant un an et demi, un suivi quotidien a été mené aux côtés des chasseurs pendant 203 parties de chasse dans la zone d’étude. L’objectif de cette étude était de recenser les espèces chassées, d’analyser les différents lieux des prélèvements et d’évaluer la pression subie par la faune. L’utilisation des Modèles Linéaires Généralisés réalisés avec le logiciel R 3.4.1 ont permis le traitement des données des espèces prélevées. Au total, 2712 gibiers appartenant à 09 ordres d’animaux et 34 espèces ont été recensés parmi les prélèvements. Les espèces les plus abattues étaient des espèces de petites tailles comme Lepus crawashayi (31,12 %), Francolinus bicalcaratus (29,09 %) et Thryonomysswinderianus (10,88 %). La plupart des gibierssont abattus dans les champs (53,28%) et les jachères (29,17%) et sur les affleurements rocheux (3,32%) et quelques-uns sont prélevés à l’intérieur de la savane protégée (1,29%). Les prélèvements sont non sélectifs, d’où des atteintes à la biodiversité faunique. Cette pression se manifeste aussi par la présence des espèces menacées dans les prélèvements , inscrites sur la liste rouge de l’UICN, comme l’Ourebie (Ourebia ourebia) , une espèce vulnérable (VU) et l’Outarde de Denham (Neotis denhami), une autre espèce en danger critique (CR). Les espèces prélevées sont des espèces résilientes de petites tailles qui résistent à la pression de la chasse pour le moment, mais, avec l’augmentation de la population, cette chasse ne sera plus soutenable