Semideciduous Forest Research Articles

A Review on Medicinal Properties of Gmelina Arborea (Gambhari Plant)

Abstract: Ayurveda is a science of life practiced in Indian subcontinent from the ancient time. In global prospective, it is complete and holistic system in which a number of drugs have multiple beneficial actions are shown. So that the massive research is required to proof the beneficial effect of drugs. Gmelina arborea, a fast-growing deciduous tree belongs to the family Lamiaceae, and is an important plantation species in many tropical areas around the world. The species is naturally distributed in semi-deciduous forests in India. The tree is also an important medicinal plant in the Indian Systems of Medicine. Gmelina arborea (gambhari) also a drug already mentioned in Ayurveda used for the various purposes in ayurvedic literature. This plant have so many medicinal properties like digestive, cardio tonic, diuretic, laxative and pulmonary and nervine tonic. It improves digestion, memory, helps overcome giddiness and is useful in burning sensation, fever, thirst, heart diseases, nervous disorders and piles. In this review paper we concluded the Medicinal properties of Gmnelia arborea (gambhari) plant.

Evaluation and phenotypic plasticity of taro [Colocasia esculenta (l.) Schott.] genotypes for nutrient and anti-nutrient composition.

The study was carried out to determine the nutritional and anti-nutritional composition of taro genotypes and also determine the phenotypic plasticity of the genotypes in two agro ecological zones in Ghana. The towns and zones were Bunso in the semi deciduous forest (an upland) and Tano Dumasi in the forest savannah transition agro-ecological (a waterlogged area) zone in the Eastern and Ashanti regions respectively.Two (2) freshly harvested corms of each genotype from each location were assessed for their nutritional (moisture, protein, carbohydrate, ash and fat) and anti-nutritional (phytate, oxalate and tannin) composition Data collected were subjected to analysis of variance and AMMI analysis using GenStat 12 edition to assess the effect of genotype, environment and their interaction on the traits studied. Phenotypic plasticity for the genotypes and the traits studied was also calculated. Pearson correlation was also conducted to assess the relationship between the traits studied. There were significant differences among the genotypes for nutrient and anti-nutrient composition except for percentage fat, indicating enough genetic variability among the genotypes, giving room for good selection progress for development of taro varieties. A higher magnitude of the environment over genotype and genotype by environment interaction observed indicates the influence of environment in the expression of the nutritional and anti-nutritional traits. Observed varied phenotypic plasticity among the genotypes for the nutrient and anti-nutrients composition also indicates varied adaptation of the genotypes to the environment. Genotypes BL/SM/115, CE/MAL/32 and CE/IND/16 and hybrids KAO19 × CE/MAL/32 and CE/IND/16×KAO19, CE/IND/16 × BL/SM/10, and CE/IND/16 × BL/SM/115 which recorded high nutrients and low anti-nutrients content and were stable across the environments can be released to farmers for cultivation. They could also be included in breeding programs for the development of enhanced nutritional quality of taro in Ghana.

Does forest fire modify the diametric distribution of lianas? A study case in a semideciduous seasonal forest with Araucaria angustifolia (Bertol.) Kuntze in Brazil

Does forest fire modify the diametric distribution of lianas? A study case in a semideciduous seasonal forest with Araucaria angustifolia (Bertol.) Kuntze in Brazil

Nutrient cycling aspects as possible ecosystem functional indicators of successional stage in Semideciduous seasonal forest, Rio de Janeiro state, Brazil

Semideciduous Seasonal Forest is a phytophysiognomy of Atlantic Forest with high plant richness but low representativeness in few remnants areas in different successional stages. The assessment of the degree of conservation of those areas helps to indicate whether there is a need for taking strategies to favor forest succession. Thus, the aim of this study was to identify litterfall and its nutrient content, accumulated litter biomass on topsoil, leaf litter decomposition, and topsoil (0–10 cm) chemical attributes as possible indicators of successional stages in areas of Seasonally Semideciduous Forest. We collected available information in literature on CAPES Portal and Google Scholar (May/2021 to February/2022) for Pinheiral municipality, State of Rio de Janeiro, Brazil, which were evaluated by multivariate analysis. Accumulated litter biomass, nutrient content (N, P, K) in total litterfall, pH and P availability in topsoil, leaf litter decomposition constant, and half-life time of leaf litter were the most sensitive attributes to indicate the successional stage in the study area, according to Principal Component Analysis. This multivariate analysis indicated that areas in early successional stage were associated with higher values of leaves contribution, half-life of leaf litterfall, contents of Ca and K in total litterfall, whereas areas in middle successional stage were associated with higher values of pH, total organic carbon, exchangeable Ca2+, K+, and Mg+, sum of bases and cation exchange capacity, and lower values of extractable acidity and exchangeable Al3+ in the topsoil. Areas in advanced stages of succession were associated to higher values of total litterfall and its nutrient content (N, K, Mg), accumulated litter biomass, available P in topsoil, and leaf litter decomposition constant. The Cluster multivariate analysis revealed that the areas in advanced successional stage presented high dissimilarity in relation to the areas in early and middle successional stage.

Age matters: variations in parasitoid diversity along a successional gradient in a dry semi-deciduous tropical forest.

Parasitoids are an important group of insects because their species number is among the highest. Multiple studies have addressed the relationships between forest successional age and insect diversity by focusing on herbivorous organisms, but changes in diversity of parasitoids are still poorly known. This work analyses the diversity of parasitoids in tropical forests representing three successional stages. A total of 30 traps were placed, ten in each forest successional stages. We estimated true diversity of Ichneumonidae species and guilds and explored the relationship between their diversity and the abundance of plant species using an Indicator Species Analysis; the relationship between parasitoid species and plant richness and abundance was tested using a Redundancy Analysis. A total of 1522 individuals and 168 morpho-species were captured in four months. Species richness showed no differences; however, parasitoid abundance was higher in young forest, while intermediate forest had the highest true diversity values (1D) with 71.6 effective species. According to insect guilds, richness, abundance, and diversity were similar in the three vegetation successional stages. This finding may be explained based on the intermediate disturbance hypothesis, which postulates that moderate disturbance levels favor the highest diversity. In conclusion, successional age matters, i.e., diversity is the highest in intermediate stages, while the old forests harbors guilds unique to that successional stage, such as parasitoids of melitophagous larvae of bees. Other successional stages were characterized by a single species of parasitoid, belonging to the genera Eiphosoma and Anomalon, which may indicate altered and preserved forests, respectively.

Morpho-anatomical traits and leaf nutrient concentrations vary between plant communities in the Cerrado–Amazonia transition?

Leaves are the most variable plant organ, responding and adapting to the environment in the long and short term. However, the link between leaf functional traits and environmental gradients is challenging, especially in systems of high diversity, such as transitional regions between savannas and tropical forests that are considered unstable. Here we evaluate anatomical and morphological traits and nutrient concentrations for the most representative woody species of four vegetation types (i.e., semideciduous forest, cerradão, typical cerrado, and cerrado rupestre) in the Amazonia–Cerrado transition to explore how vegetation will respond to changes in the environment. We found that closed-canopy species invested in traits related to rapid resource acquisition (e.g., higher leaf water content, larger stomata size, and higher maximum opening of the stomatal pore), while open-canopy species optimized traits related to resource conservation and protection from physical damage (e.g., higher leaf thickness, smallest maximum stomatal pore opening and smaller size of stomata). Our study shows that functional traits play an important role in adapting to environmental gradients and help explain the performance of trees in the Amazonia–Cerrado transition, opening the door to a more accurate prediction of plant community responses over time.

Concomitant effects of multiple disturbances (logging, fire, biological invasion) on native tree abundances into West Africa's semi-deciduous forests

West African semi-deciduous forests face multiple disturbances directly linked to human activities. A major unknown is the concomitant effects that these disturbances might have on forest communities. We (i) studied the long-term (>30 years) response of 17,038 trees from 207 semi-deciduous forest species to the three disturbances (fire, logging and biological invasion) in a 100-ha experimental set-up, (ii) examined the links between species-specific responses and functional traits related to resource acquisition and to defense strategies, and (iii) listed species vulnerable to local disturbances, in relation to their global vulnerabilities. Our results show that all three disturbances have long-lasting negative impacts on the current abundance of species. The most sensitive species to disturbance are those with a conservative resource strategy and which invest little in defensive strategies. We found that species that are locally vulnerable to fire are also globally highly threatened species. In the context of West Africa's almost extinct forests, we propose (i) the conservation of the last remaining deciduous forests in West Africa, knowing that opening them to logging simultaneously increases the risk of fire, (ii) the use of native species in reforestation programs to limit the risk of biological invasions, and (iii) the implementation of fire control strategies in conservation and forest restoration policies.

Updated distribution of an alien frog species, Lithobates catesbeianus (Shaw, 1802), in Ecuador: new records of Bullfrog in the semideciduous lowland forest of western Ecuador

We report the occurrence of Lithobates catesbeianus (Shaw, 1802), Bullfrog, in a protected semidecidu-ous forest in the city of Guayaquil, Guayas, Ecuador and in a nearby wildlife management center. Bosqueira Pro-tected Forest is an isolated spot of diversity surrounded by urbanization, quarries, and highways. We found a juvenile Bullfrog in a water canal on the edge of the protected forest, near a private housing complex, and several tadpoles in an artificial pond in a wildlife management center located near the reserve. This is the first sighting of the invasive L. catesbeianus in a native ecosystem in Guayaquil. We also report the this species from, three other provinces of Ecuador, based on observations in iNaturalist. These records reinforce the ability of L. catesbeianus to adapt easily to varied environmental conditions and to disturbed areas. The invasion of L. catesbeianus towards semideciduous forest represents a new threat to biodiversity, particularly the endemic fauna, due to predation or competition. In future studies, it will be important to fully evaluate the Bullfrog diet and population status to esti-mate its impact on remnant forests of Guayaquil.

Foraging ecology of the bird Eupsittula canicularis (Psittaciformes: Psittacidae) in a modified Mexican landscape

Introduction: Seasonal phenological variations in tropical forests cause changes in food resource availability. Animals use foraging strategies to follow the food supply in these settings. The Orange-fronted Parakeet (Eupsittula canicularis) mainly inhabits the tropical dry forest of the Mexican Pacific to Northwest Costa Rica, although little is known about its diet and foraging strategies. Objective: To assess spatial variability in food resource abundance, diet, and foraging behavior of the Orange-fronted Parakeet in a modified landscape in Oaxaca Coast, Mexico. Methods: 30 phenology transects (200 × 6 m) were established during the dry season (February-June 2019) to measure food resource availability in primary deciduous, semi-deciduous, and secondary forests. The Orange-fronted Parakeets diet was determined by focal foraging observations, and dietary niche breadth and resource selection were considered to determine feeding strategies. Results: Orange-fronted Parakeets fed on fruits (42.3 %), seeds (29.3 %), and flowers (28.4 %) of 13 plant species and presented a broad dietary niche breadth with a higher frequency of foraging in primary forest. The Orange-fronted Parakeets select resources and adapt their foraging strategies based on food resource availability in each habitat. Conclusions: The study findings highlights the need to maintain the complete forest structure in a modified landscape to ensure food resources availability for Orange-fronted Parakeets during the breeding season.

New records of the azure gallinule Porphyrio flavirostris (Gmelin, 1789) (Gruiformes: Rallidae) for the state of Paraná

Although it has a wide distribution in the country, the Azure Gallinule (Porphyrio flavirostris) has become rare in the southern region, due to the drainage of wetlands, implementation of hydroelectric reservoirs and the reduction of surrounding forests. Through the inventory carried out in the municipality of Capanema, field trips in Francisco Alves and Foz do Iguaçu in humid areas with a predominance of seasonal semideciduous forest, individuals of P. flavirostris were registered in October 2019, December 2020 and January 2021 on the floating vegetation. This work communicates new records of the species in the state of Paraná and makes a brief contribution about its conservation status.

Breeding Success of Primary and Secondary Burrow-Nesting Birds on Stream Banks in Central Brazil

Underground burrow nests of three bird species: Amazonian Motmot Momotus momota, Rufous-tailed Jacamar Galbula ruficauda and Swallow Tanager Tersina viridis were monitored for eight years on stream banks, in a Seasonal Semideciduous Forest, to enable determining whether, or not, being a burrow excavator bird is associated with nest predation, and how important the role played by nest dimensions in this nesting system is. Predation was the main cause of nest failures, although there was no significant difference in nest predation between secondary (SCN) and primary (PCN) cavity (burrow)-nesting species. Offspring predation rate was the only one recording significant result; the lowest offspring predation rate was associated with PCN species — Amazonian Motmot but, again, there was no significant difference between PCN and SCN species. On the other hand, SCN species — Swallow Tanager has compensated offspring losses due to its increased fecundity, which enabled two broods per breeding season. No nest parameter has influenced predation rates, although our data suggested the need of further investigating the length of the nest access tunnel.

Response of soil microbial biomass and enzyme activity in coffee-based agroforestry systems in a high-altitude tropical climate region of Brazil

Soil microbial communities are key indicators of changes in soil quality caused by cropping systems. Although there are studies that prove that coffee agroforestry systems increase or maintain soil organic matter levels, the effect of microbial biomass and enzymatic activity in tropical regions, especially in places with high altitude and mild temperatures, is still poorly understood. Thus, the present study aimed to evaluate the influence of two agroforestry systems (AFS-G: coffee intercropped with Grevillea robusta, AFS-C: coffee intercropped with Toona ciliata) and Coffea arabica monoculture on soil microbial biomass and activity and on the arylsulfatase and β-glucosidase enzyme activities, taking a native forest (Semi-deciduous tropical forest, with a predominance of the genera Parapiptadenia and Anadenanthera) as the control system. This study was performed in Oxisol soil areas located in the municipality of Barra do Choça, Bahia, Brazil. Litter (L, F and H layers) and soil topsoil (0–10 cm depth) samples were collected. Both were collected with four repetitions (four composite samples) in each system, litter with a 0.0625 m2 template and soil using a Dutch auger. The carbon microbial biomass, microbial activity (CO₂ released), arylsulfatase and β-glucosidase enzyme activities, organic carbon (SOC) and total nitrogen were also analyzed in the soil samples. The coffee with Grevillea robusta agroforestry system (AFS-G) did not reduce SOC compared to native forest, but the coffee with cedar agroforestry system had SOC losses at a rate of 0.56 Mg ha−1 year−1. The AFS-C cultivation system presented more MB-C (468.43 µg g−1) when compared to the other coffee systems. The AFS-G maintained the microbial activity levels and β-glucosidase and arylsulfatase enzyme activities in relation to the native forest. Coffee agroforestry systems (both AFS-G and AFS-C) in a tropical high-altitude climate region in Brazil are more favorable to maintain microorganisms and their activity in the soil, and therefore should be encouraged in order to more sustainably manage coffee growing.

Butterfly Assemblages Differ among Vegetation Types in Southern Amazonia

Environmental heterogeneity is considered an important factor supporting the evolution and maintenance of biodiversity. At small scales, such heterogeneity is thought to promote species co-existence through an increase in niche opportunities. Amazonia, the largest and most biodiverse rainforest in the world, presents a large number of vegetation types within its territory. Here, we tested the hypothesis that butterfly assemblages differ among five vegetation types at a small scale (less than 1 km2) in a region of Southern Amazonia. The vegetation types studied were forest gap, terra firme, igapó, semi-deciduous forest, and bamboo forest. The richest and most abundant community was in forest gap; igapó was the least rich, but held the second most abundant community and the only one with nine indicator species instead of two or three. Assemblage composition differed among all vegetation types, with the exception of forest gap and bamboo forest. Different light levels, temperatures, humidity, and host plant availability among vegetation types are likely relevant factors influencing these butterfly assemblages. The results suggest that the presence of various vegetation types in the region promotes the coexistence of butterfly species, and that specific threats to each vegetation type should be addressed to conserve the region’s biodiversity.

Qualitative mutant traits within the indigenous chicken population in selected ecological zones of Ghana

A study was carried out to find out the various mutant traits present in the indigenous chicken population and their influence on egg production in the three ecological zones of Ghana. Four hundred and five (405) households were purposively selected across the Guinea Savannah, Semi-deciduous Rain Forest and Coastal Savannah ecological zones. Structured questionnaire and on-site interviews were used to obtain information from the local chicken keepers. The individual birds were phenotypically observed for the presence of the following genes; frizzle, naked neck, silkiness, polydactyl, ptilopody, crest feathered and flightless. Data on flightless chickens were not available except their gene frequencies since the respondents do not keep them for economic purposes. The data collected were organised and analysed such that phenotypic groups were considered as treatments and ecological zones as blocks. The frequency of the genes responsible for mutant traits were obtained from a count of the proportion of recessive in the sample using the Hardy Weinberg rule. The calculated gene frequencies for the mutant traits observed within the local chicken population ranged from 0.01 to 0.05 which differed significantly (p<0.05) from the expected Mendelian values of 0.75. Average clutch size per year, number of eggs set and chicks hatched per natural incubation were not significantly different (p>0.05) among the three ecological zones. The percentage hatchability for Guinea savannah and Coastal savannah were relatively higher compared to Semi-deciduous rain forest. In terms of phenotypes, polydactyl birds were significantly better (p<0.05) in average eggs per clutch per bird, number of eggs set for natural incubation and number of chicks hatched. Despite the low frequencies of these mutant birds, they had a higher potential for egg laying compared to their recessive counterparts.

Assessing plant diversity change in logged and unlogged dense semi-deciduous production forest of eastern Cameroon

This study was carried out in the dense semi-deciduous production forest of East Cameroon. The objective of this work of this study was to provide comparative floristic knowledge that can serve as a basis for the planning and sustainable management of ligneous plant resources in Communal Forests before and after logging. Sampling was done in unlogged and logged forest. Data collection was carried out using the linear transects subdivided into 10 plots of 25 m × 20 m (500 m2) with an equidistance of 225 m for the inventory of all trees with dbh ≥10 cm installed measured at 1.3 m above ground level. Nested quadrats 5 m × 5 m, oriented south-west and north-east were set up in each plot for the counting and identification of all individuals with a diameter less than 10 cm. The analysis of inventory data showed that the floristic composition was higher in the unlogged forest. The individuals were more evenly distributed in the logged (Pielou's equitability index = 0.83) than in the unlogged forest. The study of the functional spectra showed that the flora of the two forest types was dominated by Guinean-Congolese species (67.57% in the unlogged forest and 63.07% in the logged forest) and Phanerophytes, particularly Mesophanerophytes. The dominance of sarcochorous species reveals that the main mode of dissemination in this forest is zoochory, particularly endozoochory. The presence of pleochroic species in the logged forest reveals the importance of dissemination by water in the environment. The plants surveyed were divided into five plant assemblages (three for logged forest and two for unlogged forest) based on ecological parameters. The findings of this study suggest that forest management which combines assisted natural regeneration with the natural process of secondary succession facilitates the reconstitution of the vegetation cover and, by extension, the conservation of biodiversity in post-logging forest concessions.

Climate change-induced ecosystem disturbance: a review on sclerophyllous and semi-deciduous forests in Tunisia.

According to the sixth assessment report of the Intergovernmental Panel on Climate Change (IPCC), global climate change is now unequivocal. Tunisia, like many other countries, has been affected by climate changes, including rising temperatures, intense heatwaves, and altered precipitation regimes. Tunisia's mean annual temperatures has risen about +1.4 °C in the twentieth century, with the most rapid warming taking place since the 1970s. Drought represents a primary contributing factor to tree decline and dieback. Long-term drought can result in reduced growth and health of trees, thereby increasing their susceptibility to insect pests and pathogens. Reported increases in tree mortality point toward accelerating global forest vulnerability under hotter temperatures and longer, more intense droughts. In order to assess the effect of these climate changes on the current state of forest ecosystems in Tunisia and their evolution, an investigative study was required. Here, we review the current state of knowledge on the effects of climate change on sclerophyllous and semi-deciduous forest ecosystems in Tunisia. Natural disturbance during recent years, as well as the adaptability and resilience of some forest species to climate change, were surveyed. The Standardized Precipitation Evapotranspiration Index (SPEI) is a multi-scalar drought index based on climate data that has been used to analyse drought variability. The SPEI time scale analysis showed a negative trend over the 1955-2021 period in Tunisian forest regions. In 2021, Tunisia lost 280 km2 of tree cover to fires, which is equivalent to 26% of the total lost area between 2008 and 2021. Changing climate conditions have also affected phenological parameters, with an advance in the start of the green season (SOS) of 9.4 days, a delay at the end of the green season (EOS) of 5 days, with a consequent extended duration of the green season (LOS) by an average of 14.2 days. All of these alarming findings invite us to seek adaptation strategies for forest ecosystems. Adapting forests to climate change is therefore a challenge for scientists as well as policymakers and managers.

Accelerated Soil Erosion and Sedimentation Associated with Agricultural Activity in Crater-Lake Catchments of Western Uganda

Intensifying agricultural activity associated with rapid population growth in rural western Uganda exerts immense pressure on natural resources, threatening not only soil fertility in the uplands but also water quality of the region’s many small crater lakes. To assess the relative risk of excess sediment and nutrient loading to individual lakes due to (inter) rill erosion within the catchments, we used the revised universal soil loss equation (RUSLE) and sediment delivery distributed model (SEDD) to estimate soil loss and sedimentation in 75 crater-lake catchments with diverse types and intensities of land use, including 17 catchments situated partly or entirely in national parks. We found that variation in potential soil loss (Ap) among all studied catchments was strongly related to differences in mean slope within each catchment. We also found substantial seasonal variation in vegetation cover, and thus, estimated actual soil loss (Am), on both cultivated land and protected savanna grassland, whereas the vegetation cover of protected semi-deciduous tropical forest was seasonally stable. Lacking detailed field data to validate model output, we used the ratio between estimated actual soil loss (Am) and potential soil loss (Ap) to evaluate the relative influences of land-use intensity and type, as well as the impact of protective measures. Our results showed that due to their characteristically steep slopes (21% on average), all crater catchments were highly susceptible to soil loss, and because most of them were small (203 ha on average), a large portion of the eroded material was transported to and deposited in the lakes. Given the strong dependence of the local population on these crater lakes as source of water and fish protein, and on the surrounding land for crop production, increased effort by environmental planners and managers is required to safeguard or restore the long-term availability of these natural resources. Avoiding bare soil conditions by restoring natural vegetation or employing agricultural techniques that provide high vegetation cover throughout the year are likely to result in considerable improvements.

New record of Vitex orinocensis Kunth (Lamiaceae) for the state of Cear&amp;aacute;, Brazil: insights on its conservation

We report the first record of Vitex orinocensis Kunth (Lamiaceae) from Cear&amp;aacute; state, northeastern Brazil. This species was collected in an upland Semideciduous Seasonal Forest. This occurrence adds new information about the flora of Cear&amp;aacute; and expands the geographic range of this species in Brazil, which is important for its conservation. We provide taxonomic information, distribution map, implications for its conservation status, photographs, and a identification key for the Vitex Tour. ex L. species from Cear&amp;aacute;.

On-Farm Experimentation with Improved Maize Seed and Soil Amendments in Southern Ghana: Productivity Effects in Small Holder Farms

Maize production in Ghana is limited by several factors including inadequate use of improved varieties and poor soil fertility management. To contribute to addressing these challenges in maize production, two on-farm experiments were conducted each in the semi deciduous forest and coastal savannah agroecological zones (AEZs) of Ghana during the major and minor cropping seasons of 2017. The study adopted a 3 × 4 factorial arranged in an RCBD with four replications in the major season. The factors were three maize varieties (Omankwa, Obatanpa, and Ahomatea) and four soil amendments (goat manure at 5 t·ha−1; inorganic fertilizer (N-P2O5-K2O at 95-37.5–37.5 kg·ha−1); 50% goat manure (2.5 t·ha−1) + 50% inorganic fertilizer (N-P2O5-K2O at 47.5–18.75–18.75 kg·ha−1); and the control (no soil amendment)).To evaluate the residual implications of these soil amendments in the minor season, each plot used in the major season was further divided into two except for the control plot, resulting in a split plot design with factorial of 3 maize varieties × 7 soil amendments. The results revealed a significant interaction between maize variety and soil amendment in both seasons with the use of sole inorganic fertilizer resulting in significantly higher ( p &lt; 0.05 ) grain yields for all varieties in both AEZs in the major cropping season. In the minor season, the combined treatment of 50% goat manure + 50% inorganic fertilizer resulted in higher grain yields for all the varieties in both AEZs with improved maize (Omankwa and Obatanpa) having significantly higher ( p &lt; 0.05 ) grain yields (33–40%) than the landrace (Ahomatea). The significantly lower ( p &lt; 0.05 ) performance of maize varieties on the residual plots in both AEZs suggests that there were minimal residual effects from the major season. Thus, in continuously cropped fields, the use of inorganic fertilizer + goat manure is required in addition to improved seeds for sustainable maize production.

Life after fire - Long-term responses of 20 timber species in semi-deciduous forests of West Africa

Understanding the response of commercial timber species to fire is fundamental to designing sustainable forest management strategies in West Africa. In this area of high deforestation for agriculture, semi-deciduous tropical forests have been reduced to a trickle in 50 years and are now subject not only to logging but also to increasingly frequent fires. This paper aims to study the long-term (37 years) demographic and growth responses of 20 timber species after a spatially heterogeneous fire in a West African semi-deciduous forest. We (i) inventoried, in 2020, 100 hectares of plots already established before the 1983 fire, (ii) built demographic and growth models, in a Bayesian framework, to estimate the vulnerability to fire of each species and (iii) linked this vulnerability to functional traits: wood density (WD) and bark thickness (BT). Our results show that most species have lower current abundances but higher growths in burnt areas than in fire-preserved areas. We identified three categories of vulnerability to fire: 1 non-vulnerable species, 16 species with vulnerable demography, and 3 highly vulnerable species. Species with high wood density or thin bark show higher demographic vulnerability to fire. Our results show that fire management is a top priority in West African semi-deciduous forests to maintain long-term populations of timber species and ultimately the forest industry. The differences in vulnerability observed, and the strong predictive power of the functional traits studied, should make it possible to (i) better define harvesting rates and adapt them to fire risk and (ii) better select commercial species to be promoted for reforestation or natural (assisted) regeneration.