Gallery Forest Research Articles

Study of the natural habitats of the great grasscutter (Tryonomys swinderianus TEMINK, 1827) with a view to its conservation in situ at Sangarédi, Boké prefecture

The Sangarédi area, located in the prefecture of Boké, has vegetation essentially composed of tree and shrub savannah, the natural biotope of the great grasscutter. Today, this vegetation is under serious threat from human activity, with mining companies exploiting large areas, thereby destroying the environment. This state of affairs has contributed to a reduction in the habitat of this animal, which is highly prized by the local population. The aim of the study was to contribute to the identification, location and characterisation of the habitats of the great grasscutter in Lower Guinea, with a view to its conservation in situ. A questionnaire was drawn up and applied to a sample of 260 individuals in 3 selected localities in the Sangarédi sub-prefecture. The results of this study revealed forest galleries and fallow land in which the great grasscutter is found. 54 sites were identified. The existence of the cane rat was confirmed in five (5) habitat types. In situ conservation of natural habitats is one of the safest alternatives for preserving the grasscutter.

Common Hippopotamus, Hippopotamus Amphibian (Linnaeus, 1758) in the Kouoptamo Subdivision-Cameroon

The Kouoptamo subdivision is one of the localities of the Noun Division that adjoins the Noun River. It served as a study area because of the presence of hippopotamus. This study carried out from January to July 2017, aimed to contribute to the sustainable management of wildlife by improving the observation of hippopotamuses (Hippopotamus amphibius) along the Noun River in the Kouoptamo subdivision. The data were obtained by administering a semi-structured survey form to fishermen, farmers, and local authorities. The results show that the average number of hippopotamuses observed along the River Noun in Kouoptamo is 10. On average, Mefuh records a very abundant potential with 13 individuals. This is followed by Buea and Mangouhnoun (7), Upstream of the dam (5), Makoumahou (4), and Downstream of the dam (3). According to habitat types, megaherbivores are highest in herbaceous savannah (6), followed by forest gallery (5), and finally shrub savannah (3). The months of observation are January and April with the greatest potential (20) and (15), followed by February and June (9) respectively, then March, May, and July (7) respectively. These pachyderms are most frequently observed in the afternoon between 2 p.m. and 6 p.m. (7), followed by the morning between 5 a.m. and 10 a.m. (6), then at midday between 11 a.m. and 1 p.m. (5) and finally at night between 7 p.m. and 4 a.m. (4). Very few studies have been carried out on hippopotamuses in Cameroon, so aspects of their biology and ecology remain unknown; precise estimates of population size and evolutionary trends are still incomplete. However, according to the CBD, knowledge of these resources is essential for better management.

Taxonomic diversity of terrestrial vertebrates in west-central Mexico: Conservation from a multi-taxa perspective.

Multi-taxa approaches are increasingly used because they describe complementary aspects of ecosystem dynamics from a community ecology perspective. In west-central Mexico, the complex biogeography and topography have created an environment where temperate and tropical forests converge, resulting in great biological diversity. Within this region, the Sierra de Quila Natural Protected Area (SQPA) offers an important example for understanding ecological community dynamics. We analyze the taxonomic diversity of terrestrial vertebrates in the SQPA by incorporating taxonomic levels associated with species. We evaluated the taxonomic diversity with i) an average taxonomic distinctiveness analysis (alpha diversity) and ii) an analysis of taxonomic dissimilarity and partitioning of turnover and differences in richness components (beta diversity). Tropical forests boast the highest taxonomic diversity of amphibians, reptiles, and birds, while temperate gallery forests exhibit lower values. Our results showed that terrestrial vertebrate alpha and beta diversity patterns respond mainly to contrasting vegetation types (tropical vs. temperate). Regarding beta diversity, the multi-vegetation type analysis showed the highest values for reptiles, followed by amphibians, birds, and mammals. Turnover had the highest contribution to beta diversity, while differences in richness were relevant for amphibians and reptiles, which could be related to their low mobility and sensitivity to environmental conditions. Despite the local scale, the SQPA presented high beta diversity, reflecting historical ecological processes in taxonomic composition derived from contrasting environments and constraints imposed on species. Evaluating taxonomic structure from a multi-taxa perspective is essential for conservation efforts because it allows the spatial recognition of biological assemblages as a first step for local interventions.

Generic and Specific Models for Volume Estimation in Forest and Savanna Phytophysiognomies in Brazilian Cerrado.

The Cerrado has high plant and vertebrate diversity and is an important biome for conserving species and provisioning ecosystem services. Volume equations in this biome are scarce because of their size and physiognomic diversity. This study was conducted to develop specific volumetric models for the phytophysiognomies Gallery Forest, Dry Forest, Forest Savannah, and Savannah Woodland, a generic model and a model for Cerrado forest formation. Twelve 10 m × 10 m (100 m²) (National Forest Inventory) plots were used for each phytophysiognomy at different sites (regions) of the Federal District (FD) where trees had a diameter at breast height (DBH; 1.30 m) ≥5 cm in forest formations and a diameter at base height (Db; 0.30 m) ≥5 cm in savanna formations. Their diameters and heights were measured, they were cut and cubed, and the volume of each tree was obtained according to the Smalian methodology. Linear and nonlinear models were adjusted. Criteria for the selection of models were determined using correlation coefficients, the standard error of the estimates, and a graphical analysis of the residues. They were later validated by the chi-square test. The resultant models indicated that fit by specific phytophysiognomy was ideal; however, the generic and forest formation models exhibited similar performance to specific models and could be used in extensive areas of the Cerrado, where they represent a high potential for generalization. To further increase our understanding, similar research is recommended for the development of specific and generic models of the total volume in Cerrado areas.

Functional traits mediate ant community assembly in a West African savannah-forest mosaic (Côte d'Ivoire)

African forest-savannah mosaics are complex landscapes holding mixtures of woody grasslands (savannah) and different forest systems (gallery forests and forest islands). In these landscapes, ants are highly diverse and perform essential ecosystem services, however, the assembly of ant communities in African forest-savannah mosaics is poorly understood. Here we showed the diversity and species overlap of ant communities in three habitats of the West African savannah and quantified the contribution of thermal tolerances and trophic ecology to community assembly. We investigated ant diversity in the West African Comoé National Park (Côte d'Ivoire) at 16 sites of three habitat types within a forest-savannah mosaic: continuous gallery forest, isolated forest islands and savannah. Across all sites, we collected a total of 91 species from 35 genera from three strata: trees, leaf litter, and soil. Additionally, we assessed differences in functional traits (trophic groups and thermal tolerance) between habitat types and strata. Though species richness was similar in all three habitats, there was a clear separation in species assemblages and functional traits between the two forest habitats and the savannah. Species assemblage shifts were primarily due to species turnover between savannah and forest habitats. In addition, the turnover in species assemblages from forests to savannah habitats was associated with a change in the thermal tolerance of species and in the proportion of trophobionts and predators. Forest and savannah habitats support distinct ant communities with different functional traits and contribute additively to the landscape-scale diversity of the West African ant fauna. Land-use and park management should focus on conserving both savannah and forest sites in tropical protected areas such as the Comoé National Park.

Diversity of tree flora in the forest galleries of four ponds in the Comoé National Park (north-east Ivory Coast)

The riparian forest galleries of the ponds in the Comoé National Park (CNP) constitute microhabitats colonised by a specific plant and animal community. These plant formations are of great research interest. These initiatives could lead to efficient management of these biomes in the short, medium and long term. This study is part of an effort to make the most of plant resources in forest galleries. The aim of this study is to assess the diversity of riparian species in the ponds of the CNP. The information was collected using the surface survey method combined with the roving inventory method. The inventory identified 78 species divided into 63 genera and 30 families. The buffalo pond forest gallery has the highest species richness, with 39 species in 33 genera and 19 families. The study also showed that for trees with DBH ≥10 cm, the species Diospyros mespiliformis (25.89%), Mitragyna inermis (17.11%), Khaya senegalensis (12.27%), Piliostigma thonningii (11.65 %), Cola gigantean (11.16 %), Vitellaria paradoxa (10.90 %) and Zanthoxylum zanthoxyloides (10.84%)) are the most abundant in riparian pond formations. The Fabaceae and Rubiaceae families are the most represented in terms of number of species, demonstrating that the flora of the forest galleries in Comoé National Park is of major ecological interest.

Species Richness, Abundance, and Vertical Distribution of Epiphytic Bromeliads in Primary Forest and Disturbed Forest.

Epiphytes represent a key component in tropical forests. They are affected by anthropogenic and natural disturbances suffered by forests, since they depend on their hosts and the microclimatic conditions they generate. We analyzed differences in abundance, species richness, and vertical distributions of epiphytic bromeliads in primary and disturbed forests. We found a higher abundance (5316 individuals) and species richness (8 species) of bromeliads in disturbed forest than in primary forest (1360 individuals and 4 species, respectively). Most bromeliads (97%) were found on Taxodium mucronatum, a dominant tree with rough bark in the disturbed forest (gallery forest). Bromeliads were more abundant in the middle of the tree and diminished towards the trunk base and the upper crown. Tillandsia baileyi was the most abundant bromeliad, and the size categories of this species differentially colonize trees in gallery forest according to Johansson zones; seedlings of T. baileyi abundantly colonize the upper canopy, and juveniles colonize the middle canopy or secondary branches. Gallery forest represents an important reservoir for epiphytic bromeliads. Hence, it is important to extend this kind of study to wetland sites to understand the role they play as a habitat for epiphytes, as well as the dynamics and ecological processes that occur in such habitats.

Thermal and morphometric correlates of the extremely low rate of energy use in a wild frugivorous primate, the Mayotte lemur

Primates spend on average half as much energy as other placental mammals while expressing a wide range of lifestyles. However, little is known about how primates adapt their rate of energy use in the context of natural environmental variations. Using doubly labelled water, behavioral and accelerometric methods, we measured the total energy expenditure (TEE) and body composition of a population of Eulemur fulvus (N = 12) living in an agroforest in Mayotte. We show that the TEE of this medium-sized cathemeral primate is one of the lowest recorded to date in eutherians. Regression models show that individual variation in the rate of energy use is predicted by fat-free mass, body size, thigh thickness and maximum temperature. TEE is positively correlated with increasing temperature, suggesting that thermoregulation is an important component of the energy budget of this frugivorous species. Mass-specific TEE is only 10% lower than that of a closely related species previously studied in a gallery forest, consistent with the assertion that TEE varies within narrow physiological limits. As lemur communities include many species with unique thermoregulatory adaptations, circadian and/or seasonal temperature variations may have constituted a major selective pressure on the evolution of lemur metabolic strategies.

Contribution of Landsat Multispectral Images to the Land Cover Dynamics of the Toéghin-Bangré Watershed for the Period 1998 to 2022 in Burkina Faso

Remote sensing plays an important role in the continuous observation of the earth's surface. It produces large databases that can be used to map and monitor natural resources. To this end, land-use maps are genuine planning and decision-making tools for natural resource management. The aim of this study is to use remote sensing products to show the dynamics of land use, to understand these dynamics and their impact on water resources in general and on hydrology in particular. Specifically, it is a question of identifying the similarities and differences that have occurred, and finally evaluating the rate of change. The methodology adopted is the use of the likelihood algorithm to produce three thematic classifications for the years 1998, 2010 and 2022. Overall accuracy is determined from the confusion matrix, which ranges from 80% to 91%. Supervised classification yielded seven occupancy classes: water bodies, cultivated areas, gallery forests, habitats/outcrops, grassy savannahs, wooded savannahs and bare ground. Quantification of change from 1998 to 2022, assessed by the rate of change (Tc), shows a progressive trend estimated at 31.82% (habitats/outcrops) and 43.40% (grassy savannah), and a regressive trend estimated at -17.92% (cultivated areas); -95.15% (gallery forests); -51.93% (water bodies) and -78.36% (bare ground). At the end of our study, diachronic analysis enabled us to quantify changes between the years 1998-2010, 2010-2022 and overall 1998-2022 with good precision.

VEGETATION COVER DYNAMICS OF THE ECOLOGICAL CORRIDORS OF MAYO-KEBBI WEST IN CHAD FROM 2009 TO 2019

This study highlights the application of remote sensing and Geographic Information Systems (GIS) in monitoring vegetation formations in the Mayo-Kebbi West province. The general objective of this study is to contribute to better management and conservation of vegetation formations in the Lere-Binder wildlife reserves, Sena-Oura National Park, and the Yamba Berte forest formation. The spatio-temporal evolution of vegetation was analyzed using Sentinel imagery from 2009 and 2019. The results and matrix analyses showed that 42.86% of the land cover units (grassland, shrubland to woodland, and flood zone) experienced a regression of 7.6 ha per year, while 57.14% (water bodies, fields, gallery forest, and open forest) showed progression. It is noteworthy that the main factors driving vegetation degradation are agriculture, livestock farming, logging, charcoal production, and gold mining.

Epiphytic Dynamics of the Adaptations to the Changes of Habitats in Taï National Park

Anthropogenic pressures in the eastern zone of the Taï National Park have led to the fragmentation of plant formations. The forests in the eastern part of the park have suffered significant degradation of plant cover and a significant loss of biodiversity. Therefore, this study makes it possible to contribute to monitoring the dynamics of reconstitution of the plant cover based on the ecological characteristics and the distribution of epiphytes present in the Djapadji management sector. Floristic inventories were carried out. In the plots, all trees with a DBH ≥ 5 cm were counted and recorded for the study of the structure of plant formations, all species carrying an epiphyte were recorded and the epiphyte was identified. The analysis of the data presents a flora composed of 26 epiphytes distributed in 18 genera and 9 families, mainly present in mountain forests. The diversity of epiphytic plants is highest in mountain forests, followed by hydromorphic, secondary and gallery forests. Strict epiphytes and Hemiepiphytes are more present in the most preserved habitats, while accidental epiphytes are observed in reconstitution biotopes. The distribution of epiphytic plants allows us to affirm that the formerly anthropized forests of the Djapadji sector present a good dynamic of reconstitution.

A potentially endangered new species of the genus Rowlandius (Arachnida: Schizomida: Hubbardiidae) from Northeastern Brazil

A new species of schizomid, Rowlandius ufpi sp. nov., is described based on individuals collected in gallery and riverine forests in a Cerrado-Caatinga ecotone in northeastern Brazil. Rowlandius ufpi sp. nov. is the sixth species of the genus found in Brazil and raises to 62 the number of described species of genus Rowlandius. This is also the first epigean species of Rowlandius inhabiting a Brazilian dry forest leaf litter. Males of Rowlandius ufpi sp. nov. can be easily distinguished from other conspecifics by the presence of three depressions in the dorsal region of the flagellum, with the posteromedian depression located in the posterior third part of the dorsal surface. The females of Rowlandius ufpi sp. nov. are recognized by the sub-square shaped spermathecae with short median lobes.

Detection of two alphaviruses: Middelburg virus and Sindbis virus from enzootic amplification cycles in southwestern Uganda.

Our knowledge of alphavirus genetic diversity is mainly based on viruses isolated from anthropophilic mosquito species, humans, and livestock during outbreaks. Studies on alphaviruses from sylvatic amplification cycles in sub-Saharan Africa have been conducted less often than from epizootic environments. To gain insight into alphavirus diversity in enzootic transmission cycles, we collected over 23,000 mosquitoes in lowland rainforest and savannah gallery forest in southwestern Uganda and tested them for alphavirus infections. We detected Sindbis virus (SINV) in a Culex Culex sp. mosquito and Middelburg virus (MIDV) in Eretmapodites intermedius and Mansonia africana. MIDV is a mosquito-borne alphavirus that causes febrile illness in sheep, goats, and horses and was previously not known to occur in Uganda. SINV, also a mosquito-borne alphavirus, causes mild infections in humans. Full genomes of SINV and MIDV were sequenced, showing a nucleotide identity of 99% to related strains. Both isolates replicated to high titres in a wide variety of vertebrate cells. Our data suggest endemic circulation of SINV and MIDV in Uganda.

Structure of ant assemblages and effect of environmental conditions in gallery forests with different conservation status in the Humid Chaco ecoregion of Argentina

Structure of ant assemblages and effect of environmental conditions in gallery forests with different conservation status in the Humid Chaco ecoregion of Argentina

Effects of climate variability and/or land use dynamics on the hydrological balance of the Cavally river catchment at Toulepleu, West Africa

Abstract The study focuses on assessing the individual and combined impacts of climate variability and land use change on hydrological responses. The results indicate that the basin, urban area, cropland, degraded forest, and open forest shows an increasing trend, while gallery forest show a decreasing trend over the period 1992–2015. Climatic variability is marked by two climatic periods (a wet one from 1980 to 1996 and a dry one from 1997 to 2016) with a 35% decrease in rainfall. Regardless of the state of the landcover used, the simulated mean annual runoff decreases by 67.92% between the wet and dry climate periods. Changes in land use between 1992 and 2015 reduce mean annual runoff by 4.71%. Analysis of the joint effect of climatic and LU variation shows a 68.96% reduction in runoff. In this catchment, the joint impact has a clearly greater effect on runoff than the climatic impact, which is greater than that of human activities. There is a need for policymakers to prioritise sustainable land use practices and integrated water resource management strategies in the area to mitigate the combined effects of climate variability and anthropogenic activities, ensuring the long-term resilience of the ecosystem and water availability for local communities.

Strengthening Forest Landscape Restoration through Understanding Land Use Dynamics: Case Study of Tchamba Prefecture (Togo)

Land use and land cover (LULC) change remains a major concern in many countries. To examine how land is used for increased actions on forest landscape restoration (FLR) issues, this study analyses LULC changes from 1991 to 2022 and predict future patterns for the years 2050 in Tchamba Prefecture, Togo, using remote sensing and the Cellular Automata-Markov modelling technique. Results show that dense forests and gallery forests (18.85%), open forest/woodland (20.17%), and tree and shrub savannah (50.04%) were the predominant classes of the landscape in 1991. However, by 2022, most tree and shrub savannah had been converted to mosaic crop/fallow land (52.27%), open forest/woodland (19.32%), and plantation (7.09%). Thus, between 1991 and 2022, forest area decreased from 89.87% to 48.96%; a 45.52% reduction in coverage. Predictions are that open forest/woodland, tree and shrub savannah will decline, while mosaic crop/fallow land will increase (51.66%). However, slight increases were recorded in plantation (9.43%) and a slight balance in dense forests/gallery forests (16.17%). Consequently, forest area will slightly change between 2022 (48.96%) and 2050 (47.41%). These changes in LULC are associated to socio-economic pressures and political instability in the 1990s. So, the return to stability, the promotion of community forests as a key restoration model, and the valorisation of agroforestry species allows for the stabilisation of dense forests/gallery forests areas and an increase in plantation. Thus, it is therefore for all stakeholders involved in restoration processes to consider this information when planning FLR activities.

Increasing fire severity alters the species composition and decreases richness of seeds potentially dispersed by small mammals

AbstractSeed dispersal is a key process that influences the recruitment of plant species, yielding profound consequences on vegetation structure. This process can be affected by environmental disturbances, such as fires, leading to varied impacts on the agents involved, both dispersers and plants. We investigated the potential role of small mammals (rodents and marsupials) as seed dispersers in a Neotropical savanna (Brazilian Cerrado). We also evaluated the impact of fire severity on the seed dispersal services provided by these animals in gallery forests, 3 years after a major fire event. We live‐trapped small mammals in 14 sites, 7 of which were located in forests classified in three categories of fire severity (“unburned”, “low severity”, or “moderate severity”). We captured 13 mammal species, finding a total of 11,688 seeds in their feces (collected inside traps or handling bags). These seeds encompassed 28 plant species from at least 8 families. A multivariate analysis (NMDS) revealed differences among small mammal species in terms of potentially dispersed plants, with seeds of 18 plant species being consumed by no more than one small mammal species. An increase in fire severity affected the composition of plant species potentially dispersed, changed the relative role of forest small mammals as seed dispersers, and decreased observed richness of defecated seeds. We conclude that high‐severity wildfires affect highly relevant ecological processes, such as seed dispersal by animals. These effects could impact the recruitment dynamics of plant species and, consequently, the vegetation recovery and plant community composition in fire‐affected areas.Abstract in Portuguese is available with online material.

Assessment of the CO2 sequestration and emission potential of the Kari classified forest, Burkina Faso

ABSTRACT The aim of this study was to assess changes in the CO2 sequestration and emission capacities of the Kari classified forest. To this end, a study of land use dynamics was carried out using Landsat images from 2000, 2010 and 2019. To assess wood potential and CO2 emissions, a forest inventory was carried out by sampling. The data on vegetation dynamics and wood potential show that more than 90% of the vegetation in this forest has remained stable from 2000 to 2019. However, significant degradation of the vegetation has been recorded in shrub savannahs, tree savannahs and gallery forests. The assessment of wood potential indicates that the forest is stable, balanced and in full recovery. The forest constitutes a carbon dioxide reservoir, with approximately 2.35 MtCO2eq sequestered in 2019. The assessment also reveals that the degradation of the vegetation has led to significant CO2 emissions. Between 2000 and 2010, the study area emitted an average of 94,566 tCO2eq, i.e., an average annual emission of 9,456.6 tCO2eq. The results of this study confirm that the conservation actions carried out by the various stakeholders are making an effective contribution to protecting nature and the services it provides.

Environmental changes in the Eastern Arctic during the Early Gelasian Age: Palynological Data from Lake El'gygytgyn

The 2.373-2.510 Ma BP (isotopic stages 92-99; Early Gelasian Age) interval of the palynological record from Lake El'gygytgyn, northern Chukotka, includes 9 pollen zones characterizing interglacial, interstadial, and glacial plant communities. The boundaries of pollen zones and isotope stages in some cases do not correspond, indicating that the age model developed for the El'gygytgyn core requires revision. Between 2.373 and 2.510 Ma, the warmest climate occurred during MIS93, when larch forests, which included dark coniferous species, spread across the region. Alnus hirsuta (Spach) Turcz. ex Rupr., Chosenia arbutifolia (Pall.) A. K. Skvortsov, and Populus suaveolens Fish. dominated the gallery forests of the river valleys. The development of grass-shrub tundra and larch forest-tundra is associated with periods of climatic cooling, with the coolest conditions occurring at the beginning of MIS97. The consistent presence of Larix pollen throughout the Early Gelasian indicates that even in harsher climatic conditions, larch forest-tundra persisted in the areas of the Anadyr Plateau and Lake El'gygytgyn.

Assessment of Edaphic conditions in the Mozogo-Gokoro National Park (Sudano-Sahelian zone of Cameroon)

Vegetation health and vitality are generally dependent on soil quality. This concept particularly integrates the capacity of soils to ensure suitable conditions for plant growth. Soil physico-chemical analyses were used to make this qualitative assessment in Mozogo-Gokoro National Park. Litter and composite soil samples were collected at different depths from 0 to 150 cm in three collection units (CUs) established in the park vegetation. The results showed that throughout the park, soils have physico-chemical characteristics favourable to plant productivity, particularly in the surface horizons of the CUs, which correspond to dense to clear dry forests and gallery forests. It was particularly observed that there was an abundance of litter, good soil aggregate stability extending to depth, organic matter richness, and medium-to-high cation exchange capacities. Richness in available phosphorus, near-neutral pH water throughout the profile, textures conducive to water percolation and rooting, and absence of salt toxicity were seen as other fertility traits. However, the potential acidity and high C/N ratios confirm the fragility of these soils. These soil characteristics may also be moderately nuanced in the most savannah CU, exhibiting qualitative changes in soil samples from surface to depth. These physico-chemical attributes contrast significantly with those of natural ecosystems with degraded pedological types in the Sudano-Sahelian region, indicating a conservation of resilience in interaction with the vegetation.