No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Impacts of land use and abiotic factors on fruit, seed, and leaf morphology of the desert date Balanites aegyptiaca in Benin: Implications for management
ResearchGate has not been able to resolve any citations for this publication.
Due to their historical interactions with plants, farmers have gained knowledge of natural variations in plant traits that can be useful for the domestication and sustainable management of genetic resources. This study focused on Balanites aegyptiaca (L.) Delile, a neglected and underutilized wild fruit tree species in Benin. The objectives of the study were to assess farmers' (1) perceived phenotypic variations in fruit, seed, leaflet, thorn, and stem bark, (2) desirable and undesirable traits, and (3) on-farm management of the species. Using semi-structured interviews (461) in 14 communities spanning the species distribution area, data were collected on perceived phenotypic variation, criteria of classification, desirable and undesirable traits, and on-farm management practices of the species. Descriptive statistics and principal component analysis were used for the data analysis in R software. Results revealed 10 criteria to differentiate morphological types of the species, the most cited criteria being thorns length (100%), stem bark color (91.1%), leaf shape (70%), fruit size (54.2%), and fruit pulp taste (45.8%). Preferred characteristics were large fruits (50.4%), sweet fruits (42.8%), elongated leaf (70%), yellowish stem bark (88.9%), long thorn (64.5%) and fruiting trees (100%) and depended on age, geographical location, and gender. Interestingly, reasons supporting these preferences reveal potential for multi-traits selection. The most encountered farmer management practices were tree sparing on-farm (18.5%), and protection against grazing (10.2%) and fire (10.4%). However, the extent of these practices does not guarantee sustainable management of the species. Our findings provide interesting insights for further domestication initiatives. However, further research is needed to understand the interrelated relationship between genotypes and environmental factors in shaping the observed morphological variations.
Botanical surveys in all parts of Pakistan are mainly focused on ethnomedicinal uses of plants, and very little attention has been paid to documenting edible wild fruit species (EWFs). Multiple methodologies and tools were used for data collection. In a recent survey 74 EWF species belonging to 29 families were documented, including their medicinal uses for the treatment of various diseases. The most cited (23%) preparation method was raw, fresh parts. The UV and RFC of EWF species ranged from 0.08 to 0.4 and from 0.02 to 0.18, respectively. In terms of specific disease treatments and their consensus, the ICF ranged from 0 to 0.38. Sexual, gastrointestinal, and respiratory disorders had the highest use reports, and 11 species of plants had the highest FL of 100%. On the basis of uses reported by the inhabitants of seven districts of Southern Khyber Pakhtunkhwa Province, the CSI ranged from the lowest 1.3 to the highest 41. It is concluded that the traditional uses of EWF species depend mainly on socio-economic factors rather than climatic conditions or the number of species. However, there is a gradual loss of traditional knowledge among the younger generations. The present survey is the first baseline study about the socio-economic dimension of local communities regarding the use of EWF species for food as well as medicine.
Annona senegalensis Pers is a multipurpose tree species valued for food and medicinal uses in Africa. Although there have been attempts to document the proximate composition of fruits and leaves, little is known about the relative role of soil, climate, and genotype on the nutritional quality. The present study evaluated the variation of the proximate composition of fruits and leaves in populations from Benin and Mozambique. It further assessed the impact of soil, climate and genotype on the proximate composition. Data were collected from four populations genetically different and analyzed using descriptive statistics, analysis of variance (ANOVA), principal component analysis, redundancy analysis (RDA), and variance partitioning. Results revealed significant variation in the proximate composition of fruits and leaves among the studied populations. Ashes and fibers in fruits, and lipids in leaves were 4.8-fold, 2.5- fold, and 1.25-fold higher respectively, in populations from Mozambique. Fruits moisture and lipids content were rather 1.4-fold and 1.10-fold higher in populations from Benin. Moisture and lipids were respectively 6-fold and 1.27-fold higher in fruits than in leaves, while ashes, fibers and proteins were approximately twice higher in the leaves than in the fruits. Genetic groups, climate and soils were found to influence this variation. All three factors explained 74.4% of the variation of nutritional value of fruits and leaves, 31.9% of which was exclusively due to genetic variation, 2.8% to the interaction of climate and soils, 24.1% to the interaction of soil and genetic variation, and 15.5% to the interaction of all three factors. Our study shows that genetic variation and soil properties better than climate, explain the variation of nutritional value of A. senegalensis fruits and leaves and further provides essential information that could be harnessed in the domestication and breeding program of the species for its edible parts.
Published in Bulletin de la Recherche Agronomique du Bénin (BRAB) - ISSN électronique (ISSN : 1840-7099) // 33 (02): 39-55 ---------------------------------------------------------------------------------------------------
La connaissance des usages locaux et de l'importance socio-économique d'une ressource est essentielle pour sa gestion durable. L'étude a porté sur Balanites aegyptiaca, un fruitier sauvage négligé et sous-utilisé au Bénin, et distribué principalement dans la zone phytogéographique soudanienne. L'objectif était de documenter les connaissances locales sur les utilisations de l'espèce ainsi que son importance socio-économique pour les populations locales en lien avec les groupes ethniques, l'âge, le sexe, et le phytodistrict. Les données ont été collectées à travers des entretiens individuels semi-structurés auprès de 461 personnes sélectionnées suivant un échantillonnage aléatoire. Les données collectées portaient sur les usages, l'importance des catégories d'usage (échelle de Likert) et la perception locale sur la dynamique temporelle des peuplements naturels de l'espèce. Au total les 136 usages spécifiques suivants ont été cités : médicinaux (87) ; alimentaires (12) ; cosmétiques (7) ; commerciaux (5) ; artisanaux (4) ; fourrage (2) ; autres catégories (19). Les usages alimentaires (2,38 ± 0,06) et médicinaux (1,80 ± 0,09) ont été les plus cités. La valeur d'usage et l'indice de valeur d'importance ont varié significativement (p ˂ 0.05) entre les groupes socioculturels ou sociolinguistiques, les classes d'âge et les phytodistricts, mais pas entre les sexes. Les adultes et les vieux détiennent plus de connaissances que les jeunes. L'importance socio-économique était plus avérée pour les groupes ethniques du phytodistrict Mékrou-Pendjari Est où la valeur d'usage et l'indice de valeur d'importance étaient les plus élevés. L'espèce a connu une dynamique régressive et les principales causes sont l'agriculture (66,59%) et le pâturage (17,06%). L'étude fournit des informations préliminaires pour la domestication de Balanites aegyptiaca au Bénin.
Wild edible fruit plant species (WEFs) are species that are not cultivated or domesticated but are available in their natural habitat, providing a readily available source of food, medicine, and economic value to the local people. In recent times, WEFs have been threatened by over-exploitation, land-use changes, and biodiversity loss. This study aims to (1) identify and document wild edible fruit plant species, (2) investigate the patterns of knowledge, use, and management of WEFs in the Ulu Masen protected area; and (3) assess threats to wild edible fruit plant species and recommend possible management scenarios for their conservation. The study was conducted in six villages of Pantai Ceuremen subdistrict, Southeast Aceh, Indonesia, namely Sikundo, Jambak, Canggai, Lawet, Pulo Tungoh, and Keutambang. The plant materials were randomly collected from the study area, while local knowledge was gathered through a semi-structured survey and in-depth interviews involving 209 respondents that were selected using random sampling. A total of 53 wild edible fruit plants from 30 genera and 21 families were found to be commonly used. Syzygium pycnanthum, Syzygium littorale, Syzygium polyanthum, Garcinia xanthochymus, Baccaurea polyneura, Flacourtia rukam, Sandoricum koetjape, and Baccaurea racemosa were the most important species for local communities in the study area. The WEFs in the study area is influenced by a variety of factors, primarily agricultural expansion, which means that conservation practices need to be improved through the implementation of management strategies, prioritizing species currently used by local communities. Management strategies based on traditional knowledge, such as community-based forest management systems (CBFMS) are being considered for future conservation, and they are also being implemented in other developing countries with similar circumstances.
Spatiotemporally consistent data on global cropland extent is essential for tracking progress towards sustainable food production. In the present study, we present an analysis of global cropland area change for the first two decades of the twenty-first century derived from satellite data time-series. We estimate that, in 2019, the cropland area was 1,244 Mha with a corresponding total annual net primary production (NPP) of 5.5 Pg C year ⁻¹ . From 2003 to 2019, cropland area increased by 9% and cropland NPP by 25%, primarily due to agricultural expansion in Africa and South America. Global cropland expansion accelerated over the past two decades, with a near doubling of the annual expansion rate, most notably in Africa. Half of the new cropland area (49%) replaced natural vegetation and tree cover, indicating a conflict with the sustainability goal of protecting terrestrial ecosystems. From 2003 to 2019, global per-capita cropland area decreased by 10% due to population growth. However, the per-capita annual cropland NPP increased by 3.5% as a result of intensified agricultural land use. The presented global, high-resolution, cropland map time-series supports monitoring of natural land appropriation at the local, national and international levels.
In the Anthropocene, more than three quarters of ice-free land has experienced some form of human-driven habitat modification, with agriculture dominating 40% of the Earth’s surface. This land use change alters the quality, availability, and configuration of habitat resources, affecting the community composition of plants and insects, as well as their interactions with each other. Landscapes dominated by agriculture are known to support a lower abundance and diversity of pollinators and frequently larger populations of key herbivore pests. In turn, insect communities subsidized by agriculture may spill into remaining natural habitats with consequences for wild plants persisting in (semi) natural habitats. Adaptive responses by wild plants may allow them to persist in highly modified landscapes; yet how landscape-mediated variation in insect communities affects wild plant traits related to reproduction and defense remains largely unknown. We synthesize the evidence for plant trait changes across land use gradients and propose potential mechanisms by which landscape-mediated changes in insect communities may be driving these trait changes. Further, we present results from a common garden experiment on three wild Brassica species demonstrating variation in both defensive and reproductive traits along an agricultural land use gradient. Our framework illustrates the potential for plant adaptation under land use change and predicts how defense and reproduction trait expression may shift in low diversity landscapes. We highlight areas of future research into plant population and community effects of land use change.
Background and aims-Geographic patterns of phenotypic variability can inform understanding of the resilience potential of plant species to environmental hazards such as climate change. Such understanding provides support for conservation and domestication efforts. Here, we investigated natural morphological variation of the individuals, fruits, seeds, and leaves of the tropical shrub Annona senegalensis Pers. along a climatic gradient. Methods-Morphological data were collected on shrubs, fruits, seeds, and leaves of 150 shrubs from five populations in the three climatic zones of Benin. Linear mixed effects models were used to test the variability of the morphological traits of the species and also to estimate the variance components in order to tease apart the importance of each source of variation. The most important morphological descriptors discriminating climatic zones were identified using a stepwise discriminant analysis. Redundancy analysis was then used to determine the relationships between discriminant morphological traits and bioclimatic variables. Key results-Morphological traits of A. senegalensis varied greatly both within and among climatic zones. A substantial part (42%) of the among-climatic zones phenotypic variability in the species was attributable to climate, mainly rainfall and temperature. Morphological traits such as big shrubs, big fruits, and high number of seeds per fruit were associated with high mean annual rainfall and low mean temperature of the warmest quarter. Conclusions-The findings suggest an important zonal adaptation of the species to climate variability. The phenotypic diversity pattern that we highlighted can be useful when designing conservation policies for the species. However, quantitative genetics through common garden or reciprocal transplantation experiments related to the species' populations would enable to explore the heritable part of the observed variability to support effective conservation and domestication efforts.
The miracle plant Synsepalum dulcificum is a multipurpose natural sweetener and a promising West African orphan fruit shrub candidate for genetic improvement. Unfortunately, basic knowledge such as phenotypic variation and inheritance estimates required for implementing a breeding program are still lacking. A set of 203 accessions were sampled in two habitats from seven populations spread across the Dahomey Gap (DG) and the Upper Guinea forest (UG) in West Africa. The phenotypic diversity and allometric relationships among functional traits were analysed; the broad-sense heritability was estimated for fruit-traits, and a mini-core collection was developed in the species. Quantitative variation in tree-and fruit-traits was recorded, and multivariate analyses were performed to assess relationships among accessions, whereas heritability was estimated using the coefficient of repeatability. Tree-traits observed in S. dulcificum were more variable than fruit-traits. While habitat-type only affected tree-traits, the provenance population significantly affected both fruit-and tree-traits, with the UG populations outperforming the DG ones. Significant correlations were observed among fruit-traits on one hand, and among tree-traits on the other hand, whereas poor correlations were observed between tree-and fruit-traits. The multivariate analysis grouped accessions in three clusters. Promising individuals for high fruit mass and pulp-dense genotypes' selection were identified within clusters. Repeatability estimates for fruit-traits ranged from 0.015 (edible ratio) to 0.88 (fruit mass). The Core Hunter algorithm enabled the extraction of 41 individuals as robust representatives of the initial set of 203 accessions, and the mapping of this core collection suggested Dahomey Gap as a centre of diversity of the species. These original findings offer opportunities, not only for the genetic improvement of S. dulcificum, but also for targeted ex-situ conservation in the species.
Recent studies show coordinated relationships between plant leaf traits and their capacity to predict ecosystem functions. However, how leaf traits will change within species and whether interspecific trait relationships will shift under future environmental changes both remain unclear. Here, we examine the bivariate correlations between leaf economic traits of 515 species in 210 experiments which mimic climate warming, drought, elevated CO2, and nitrogen deposition. We find divergent directions of changes in trait-pairs between species, and the directions mostly do not follow the interspecific trait relationships. However, the slopes in the logarithmic transformed interspecific trait relationships hold stable under environmental changes, while only their elevations vary. The elevation changes of trait relationship are mainly driven by asymmetrically interspecific responses contrary to the direction of the leaf economic spectrum. These findings suggest robust interspecific trait relationships under global changes, and call for linking within-species responses to interspecific coordination of plant traits. It is unclear whether rapid global change will lead to unexpected trait combinations. In this global meta-analysis on vascular plants, Cui et al. show that, although within-species responses do not always follow the leaf economic spectrum, the slopes of interspecific trait relationships are robust to rapid environmental change.
Key message
Correlations were observed between Balanites aegyptiaca fruit morphology and kernel oil yield and quality, thus suggesting the possibility of selecting trees with smaller fruits and lower pulp/seed ratio for edible oil production.
Abstract
Phenotypic variations in fruit morphology (length, diameter, total fruit weight, anatomical part weight percentages) and kernel chemical traits (gross composition, amino acid content, fatty acid composition of kernel oil) were assessed in a natural population of Balanites aegyptiaca (L.) Del. grown in the South-East of Sudan, with the main aim of highlighting the potential of B. aegyptiaca kernel for edible oil production. Mature fruits were randomly collected from eight trees, representative of eight distinct categories for shape (length/diameter ratio) and size (weight). Significant tree-to-tree differences in fruit morphology and kernel composition have been registered. The smallest fruits were characterised by the highest kernel contribution to the whole fruit weight, while the largest fruits showed the smallest seeds. The highest oleic/linoleic acid ratio in kernel oil fatty acids was found in fruits characterized by the lowest pulp percentage; the maximum oil yield (highest kernel percentage and kernel oil percentage) was associated to the highest levels of polyphenolic antioxidants and the highest radical scavenging activity of kernel tissues. Experimental data suggested the possibility of selecting trees with large fruits and high pulp/seed ratio, suitable for direct consumption as human food, and trees with smaller fruits and lower pulp/seed ratio for oil production.
Information on how biotic factors influence delivery of ecosystem services (ES) in natural systems is important for holistic landscape management. In this study, we assessed the perceived effects of elephants’ presence on ES supply in the Pendjari Biosphere Reserve in West Africa. A total of 112 respondents, including riparian communities and reserve officials, were interviewed. First, we used ranking techniques based on stakeholders’ perceptions to evaluate differences in perceived importance of ES. Second, we assessed the perceived impact of elephants on ES supply from both direction and intensity perspective. Third, we assessed the economic importance of threatened ESs and elephants’ damages related economic losses incurred by households. Twenty-seven ES were enumerated, 13 provisioning ES, 12 cultural ES, and two from the regulating and maintenance ES category. Provisioning ES were perceived as the most important although not significantly different from other categories. PES were also found to be most affected negatively by elephants’ impacts. However, elephants’ presence increased supply of cultural ES. The average cost of the losses due to elephants’ negative impacts ranged from 586.05 per year and per victim household. These results were discussed in relation to management actions necessary to facilitate coexistence between elephant and local populations.
Chaya (Cnidoscolus aconitifolius) (Mill.) I.M. Johnst is a neglected and underutilized crop, cultivated clonally by the Maya from pre-Hispanic times to the present in their home gardens for their own consumption. Like other crops in the early stages of domestication, cultivated chaya co-occurs with its wild relatives, however, the degree of domestication of chaya is unclear. Wild and cultivated chaya exhibit some morphological differences, however, no study has assessed quantitatively the degree of divergence between these varieties. The main objective of this study was to assess the domestication degree of chaya, by measuring morphological divergence in vegetative traits (leaf number, area, toughness, trichome number, as well as plant size, number of branches and trunk width) in wild and cultivated plants. Our results show that cultivated and wild plants had only a minor degree of overlap in the multivariate morphological space. The cultivated variety had more branches and leaves, and their leaves were softer and had fewer trichomes than the wild variety. This divergence is probably reinforced by the fact that desirable traits (number of branches and leaves) are negatively correlated with undesired traits (number of trichomes and toughness). Despite significant divergences between the two varieties, a few cultivated plants fell within phenotypic range of variation for wild plants, which could be due to recent artificial selection.
Balanites aegyptiaca is a drought‐tolerant tree naturally distributed in Africa and has a high potential for biofuel production and livelihood. To understand the plant tolerance to drought stress, B. aegyptiaca plants collected from five provenances were subjected for 4 weeks to drought stress through different regimes of soil volumetric water content (VWC, i.e. 25% control, 15% as moderate and 5% as a severe drought stress) followed by 2‐week recovery. Morpho‐physiological responses as well as the changes in antioxidant defences under water stress and recovery were investigated. Drought stress significantly reduced plant biomass‐related parameters, stomatal conductance, quantum efficiency and increased leaf temperature. Each provenance showed specific patterns of stress response reactions that were detected in a cluster analysis. The large leaf area and a high level of lipid peroxidation in Cairo provenance increased its sensitivity to severe drought. For provenances El‐Kharga and Yemen, the highest tocopherol contents and the highest catalytic activities of ascorbate peroxidase (SOD), catalase (CAT), glutathione reductase (GR) and dehydroascorbate reductase (DHAR) were recorded. These traits contributed to the high drought tolerance of these two provenances in comparison with the other provenances. All plants recovered from stress and showed specifically increased activity of glutathione‐S‐transferase (GST) as a repair mechanism. Results showed that the drought tolerance level in B. aegyptiaca is provenance‐dependent.
Afzelia africana Sm. is a tree species found in different climatic conditions affected by chronic human disturbance. It is known that trees can respond to their environments by changing their morphological traits. Also, as plants store their reserves in fruits, seeds and leaves, long-lasting disturbance may impact morphological traits of fruits, seeds and leaves. Thus, in this study, we evaluated (1) the variation of morphological traits of A. africana according to climatic conditions and human disturbance, and (2) the relationships among morphological traits. Twelve morphological parameters based on fruits, seeds and leaflets were assessed across three climatic zones and compared for individuals in protected and disturbed landscapes. Univariate and multivariate analyses were used to evaluate the effects of climatic factors and disturbance. Highest values for fruit, seed and leaflet traits were observed in humid areas indicating for best performance under optimal conditions. Significant adverse effects of human disturbance were observed for traits in the humid and drier areas. The interaction between climatic conditions and disturbance was significant for most traits suggesting a climate-dependent effect of the disturbance on evaluated traits. Bioclimatic variables were thus identified as potential drivers of traits. Some significant and positive associations were observed among fruit and seed traits. These morphological trait variations are valuable insights to guide sustainable management and conservation of A. africana populations in different climatic zones and habitats types in Benin.
An investigation was carried out on variations in the morphological traits of Tamarindus indica LINN. fruits (length, breadth, mass, and pulp mass) and seeds (number and mass) from the different agroecological zones and land use types of Uganda. Fruits were collected from the two land use types in the three agroecological zones and measured for various morphological traits. The study sites were located between 593 and 1,096 meters above sea level. ANOVA was used to test the differences in morphological traits of fruits and seeds between agroecological zones and land use types. The morphological traits relationship was determined using Pearson Correlation Coefficient (R). There were significant (P≤0.05) variations among the T. indica fruits and seed morphological traits within the agroecological zones and land use types. Lake Victoria Crescent agroecological zone recorded higher fruits morphological traits values. Wild and on-farm land use types were superior in fruits and seed traits, respectively. Many seeds per fruit (17) were recorded in Uganda (Eastern agroecological zone) than those recorded elsewhere. Significant uphill positive linear correlations between all morphological traits (P≤0.05) were observed, with the strongest relationships being between seed mass and seed number (R=0.79), fruit mass and fruit length (R=0.75), pulp mass and fruit mass (R=0.73), and seed mass and fruit mass (R=0.73). However, fruit breadth presented slightly weaker positive linear correlations with all other morphological traits. This is the first quantitative evaluation of T. indica morphological traits variation in Uganda. Dispersion/variation and correlation relationships suggest that all the studied morphological traits can be used for selection of plus trees for tree breeding improvement such as yield per tree. The observed variations are probably attributed to influence of agroecological zones’ factors, environmental factors, climate, land use types, and farming systems, a reflection of T. indica adaptation to different conditions showing high genetic and phenotypic differences to be exploited.
Fruit type, an important reproductive trait, is closely related to reproduction strategy, community dynamics and biotic interactions. However, limited research has explored the geographic distribution of fruit type and the underlying abiotic factors influencing this on a large scale. Here we aim to study large-scale distribution patterns of fleshy-fruited plant species and the most important environmental drivers for different growth forms in utilizing the fruit type and distribution data for over 27000 plant species in China. Results indicated that the proportion of fleshy-fruited species was higher in southeast China, and this pattern was consistent between different growth forms. Overall, the proportion of fleshy-fruited species was higher in wet, warm, and stable environments. Notably, mean annual precipitation had the greatest predictive contribution to woody fleshy-fruited species distributions, but mean annual temperature best predicted the herbaceous fleshy-fruited species distributions. We provide the first map of a large-scale distribution of fleshy-fruited plant species for different growth forms in the northern hemisphere and show that these geographic patterns are mainly determined by contrasting climatic gradients. Recognizing that climate factors have different relationships with different growth forms of fleshy-fruited species advances our knowledge about fruit type and environment. This work contributes to predictions of the global distribution of fleshy-fruited species under future climate change scenarios and provides a reference for continued research on the complex interactions between plants, frugivores and the environment.
Some tree improvement programs in Africa use nursery tests to investigate genetic and geographic variation in growth, but do they lead to the same conclusions as field tests? We investigated this question using provenance/progeny tests (12 provenances, 108 families) of Balanites aegyptiaca from semi-arid Niger. The nursery test included treatments for time (12–16 months) and watering regime (reduced and normal). Family variation was significant for shoot diameter (Sdia), height (Sht), dry weight (Swt) and root dry weight (Rwt) in the nursery, and for tree height at 1 and 2 years (Fht-1, Fht-2) but not at 13.5 years (Fht-13.5) in the field. Provenance variation was significant only for root/shoot weight ratio (RSwt) in the nursery. Family mean Fht-1 and Fht-2 were positively correlated with all nursery growth variables except RSwt. Provenance mean Fht-2 was positively correlated with Sht, while provenance mean Fht-13.5 was negatively correlated with Swt and positively correlated with RSwt. Family mean survival at 13.5 years was positively correlated with Swt, Sdia, Fht-1 and Fht-2. Family mean Rwt, RSwt and Fht-2 increased from the more humid western to the drier eastern locations. Most correlations with nursery growth variables were stronger at 16 than at 12 months and in the normal compared with the reduced watering regime. Results suggest that Swt and Sdia may be useful for predicting family survival in the field, and Rwt and RSwt may be useful for investigating geographic variation in growth in the field. We recommend conducting both nursery and long-term field tests.
This literature review aimed to improve knowledge on a threatened species Afzelia africana Sm and Pers (Fabaceae). The species thrives across several regions in Africa, demonstrating it ecological plasticity. To date, many studies on the species, have been conducted mainly to describe the vegetation and species communities or to measure its structure. However, a huge gap of knowledge exists on the species ecology, and this may jeopardize its sustainable management. This review showed the importance of conducting studies that will help to understand disturbances and species adaptation to environmental stress. Therefore, assessment of threats, measurment of functional traits
and demography of Afzelia africana are essential to understand the species life strategies and adapations.
Cette analyse bibliographique visait à améliorer les connaissances sur Afzelia africana Sm et Pers (Fabaceae), une espèce menacée. L’espèce est distribuée à travers plusieurs régions en Afrique, démontrant sa plasticité écologique. À ce jour, plusieurs études sur Afzelia africana ont été conduites principalement pour décrire la végétation et la composition floristique de ses habitats ou de mesurer sa structure. Cependant, un déficit de connaissance existe encore sur l’écologie de l’espèce et ceci peut remettre en cause sa gestion durable. Cette analyse a permis de montrer l’importance de conduire des études qui peuvent aider à mieux comprendre les perturbations et les stratégies
d’adaptation de l’espèce aux stress environnementaux. Ainsi, l’évaluation des perturbations et la mesure des traits fonctionnels et de la démographie de Afzelia Africana, sont essentielles à la compréhension des stratégies de vie et d’adaptation de l’espèce.
We created a new dataset of spatially interpolated monthly climate data for global land areas at a very high spatial resolution (approximately 1 km 2). We included monthly temperature (minimum, maximum and average), precipitation, solar radiation, vapour pressure and wind speed, aggregated across a target temporal range of 1970–2000, using data from between 9000 and 60 000 weather stations. Weather station data were interpolated using thin-plate splines with covariates including elevation, distance to the coast and three satellite-derived covariates: maximum and minimum land surface temperature as well as cloud cover, obtained with the MODIS satellite platform. Interpolation was done for 23 regions of varying size depending on station density. Satellite data improved prediction accuracy for temperature variables 5–15% (0.07–0.17 ∘ C), particularly for areas with a low station density, although prediction error remained high in such regions for all climate variables. Contributions of satellite covariates were mostly negligible for the other variables, although their importance varied by region. In contrast to the common approach to use a single model formulation for the entire world, we constructed the final product by selecting the best performing model for each region and variable. Global cross-validation correlations were ≥ 0.99 for temperature and humidity, 0.86 for precipitation and 0.76 for wind speed. The fact that most of our climate surface estimates were only marginally improved by use of satellite covariates highlights the importance having a dense, high-quality network of climate station data.
This paper describes the technical development and accuracy assessment of the most recent and improved version of the SoilGrids system at 250m resolution (June 2016 update). SoilGrids provides global predictions for standard numeric soil properties (organic carbon, bulk density, Cation Exchange Capacity (CEC), pH, soil texture fractions and coarse fragments) at seven standard depths (0, 5, 15, 30, 60, 100 and 200 cm), in addition to predictions of depth to bedrock and distribution of soil classes based on the World Reference Base (WRB) and USDA classification systems (ca. 280 raster layers in total). Predictions were based on ca. 150,000 soil profiles used for training and a stack of 158 remote sensing-based soil covariates (primarily derived from MODIS land products, SRTM DEM derivatives, climatic images and global landform and lithology maps), which were used to fit an ensemble of machine learning methods—random forest and gradient boosting and/or multinomial logistic regression—as implemented in the R packages ranger, xgboost, nnet and caret. The results of 10–fold cross-validation show that the ensemble models explain between 56% (coarse fragments) and 83% (pH) of variation with an overall average of 61%. Improvements in the relative accuracy considering the amount of variation explained, in comparison to the previous version of SoilGrids at 1 km spatial resolution, range from 60 to 230%. Improvements can be attributed to: (1) the use of machine learning instead of linear regression, (2) to considerable investments in preparing finer resolution covariate layers and (3) to insertion of additional soil profiles. Further development of SoilGrids could include refinement of methods to incorporate input uncertainties and derivation of posterior probability distributions (per pixel), and further automation of spatial modeling so that soil maps can be generated for potentially hundreds of soil variables. Another area of future research is the development of methods for multiscale merging of SoilGrids predictions with local and/or national gridded soil products (e.g. up to 50 m spatial resolution) so that increasingly more accurate, complete and consistent global soil information can be produced. SoilGrids are available under the Open Data Base License.
One of the frequent questions by users of the mixed model function lmer of the lme4 package has been: How can I get p values for the F and t tests for objects returned by lmer? The lmerTest package extends the 'lmerMod' class of the lme4 package, by overloading the anova and summary functions by providing p values for tests for fixed effects. We have implemented the Satterthwaite's method for approximating degrees of freedom for the t and F tests. We have also implemented the construction of Type I - III ANOVA tables. Furthermore, one may also obtain the summary as well as the anova table using the Kenward-Roger approximation for denominator degrees of freedom (based on the KRmodcomp function from the pbkrtest package). Some other convenient mixed model analysis tools such as a step method, that performs backward elimination of nonsignificant effects - both random and fixed, calculation of population means and multiple comparison tests together with plot facilities are provided by the package as well.
Understanding interactions between forest and the adjacent people is crucial for participative management of forest resources. In order to determine the ecological diversity and the conservation strategies of wild edible fruit tree species (WEFT species) in protected areas, this study was conducted in the Lama Forest Reserve in southern Benin. An inventory of WEFTs species was carried out in 53 plots systematically delimited in the typical dense forest, degraded dense forest, young and old fallows of the Lama Forest Reserve. An ethnobotanical survey was conducted with 136 respondents and the WEFT species habitats were identified using a Simple Correspondence Analysis on the density data. A list of priority species was generated using Compound Ranking System method. The results revealed ten (10) WEFT species, including Dialium guineense, Diospyros mespiliformis, Drypetes floribunda, Mimusops andogensis, Pterocarpus santalinoides in typical dense forest; Pancovia bijuga, Psidium guajava, Lecaniodiscus cupanioides, in degraded dense forest and Ficus capensis, Spondias mombin in fallows. Unlike the other species, the average density of D. guineense, D. mespiliformis, D. floribunda, L. cupanioides and M. andongensis varied significantly (P<0.01) from one vegetation type to another. WEFT species recorded, were mainly used for food and medicinal purposes. The compound ranking system method revealed that P. guajava, S. mombin, F. capensis, P. santalinoides and P. bijuga were top priority species for conservation. More protection effort should be made on the degraded dense forest and fallows to ensure the conservation of these species. Further, priority WEFT species need to be included in plantation programs to reduce pressure from riparian populations.
Vitellaria paradoxa C. F. Gaertn., commonly known as shea tree or Vitellaria, is ranked the most important tree species of the savannah regions in the most African countries due to its ecological and economic importance for livelihoods and national economies. However, the savannah regions are the most vulnerable areas to the global climate change. Moreover, the Vitellaria populations on farmlands are threatened by the dominance of old trees with low or lack of regeneration. In this study both morphological and genetic diversity were assessed using several phenotypic traits and 10 microsatellite markers, respectively, to assess the impact of land use and agro-ecozone types on Vitellaria in Ghana. The land use types were forests and farmlands, and the agro-ecozone types included the Transitional, Guinea, and Sudan savannah zones. The mean values of morphological traits, such as diameter at breast height (DBH) and canopy diameter (CD), were statistically different between forest (DBH = 22.20, CD = 5.37) and farmland (DBH = 39.85 CD = 7.49) populations (P < 0.00001). The Sudan savannah zone with mean petiole length of 4.96 cm showed significant difference from the other zones, likely as a result of adaptation to drier climate conditions. Genetic data analysis was based on 10 microsatellite markers and revealed high genetic diversity of Vitellaria in Ghana: mean expected heterozygosity, He was 0.667, and allelic richness, measured as number of effective alleles Ae, was 4.066. Both farmlands and forests were very diverse indicating lack of negative influence of farmer’s selection on genetic diversity. Fixation index was positive for all populations (mean FIS = 0.136) with farmlands recording relatively higher values than forests in all ecological zone types studied, probably indicating less gene flow in the farmlands. Moderate differentiation (F′ST = 0.113) was comparable to other similar tree species. Both land use and ecological zone types influenced genetic differentiation of Vitellaria at varying levels. The species was spatially structured across three ecozones and following climatic gradient. The forest reserves are used in situ conservation for Vitellaria in Ghana. High diversity observed in the most arid zones provides opportunity to find and use appropriate plant materials for breeding climate change resilient trees.
Investigating crop origins is a priority to understand the evolution of plants under domestication, develop strategies for conservation and valorization of agrobiodiversity and acquire fundamental knowledge for cultivar improvement. The date palm (Phoenix dactylifera L.) belongs to the genus Phoenix, which comprises 14 species morphologically very close, sometimes hardly distinguishable. It has been cultivated for millennia in the Middle East and in North Africa and constitutes the keystone of oasis agriculture. Yet, its origins remain poorly understood as no wild populations are identified. Uncultivated populations have been described but they might represent feral, i.e. formerly cultivated, abandoned forms rather than truly wild populations. In this context, this study based on morphometrics applied to 1625 Phoenix seeds aims to (1) differentiate Phoenix species and (2) depict the domestication syndrome observed in cultivated date palm seeds using other Phoenix species as a “wild” reference. This will help discriminate truly wild from feral forms, thus providing new insights into the evolutionary history of this species. Seed size was evaluated using four parameters: length, width, thickness and dorsal view surface. Seed shape was quantified using outline analyses based on the Elliptic Fourier Transform method. The size and shape of seeds allowed an accurate differentiation of Phoenix species. The cultivated date palm shows distinctive size and shape features, compared to other Phoenix species: seeds are longer and elongated. This morphological shift may be interpreted as a domestication syndrome, resulting from the long-term history of cultivation, selection and human-mediated dispersion. Based on seed attributes, some uncultivated date palms from Oman may be identified as wild. This opens new prospects regarding the possible existence and characterization of relict wild populations and consequently for the understanding of the date palm origins. Finally, we here describe a pipeline for the identification of the domestication syndrome in seeds that could be used in other crops.
Balanites aegyptiaca (L.) Delile is a species of tropical flora for which the variety aegyptiaca is adapted to Sahelian climate. The species is among those chosen for the restoration of Sahelian ecosystems in the context of the pan-African reforestation project, the Great Green Wall for the Sahara and Sahel Initiative (GGW). This study redefines the distribution range and its ecology and studies its uses in the Ferlo region in the north of Senegal using surveys carried out among the local population. The eco-geographical study shows that the species occupies several Sahel-Saharan regions of Africa and the Middle East. With broad ecological amplitude, it is very resistant to drought and relatively indifferent to the type of soil. Results of the ethno-botanical survey show that local people in the Ferlo region have a wealth of knowledge and expertise on B. aegyptiaca. These surveys also revealed the extent to which local populations rely on the tree for food, fodder, construction and medicine. The fruit and wood are the most highly prized parts of the tree, with the greatest use of the fruit in people’s diets. In medicinal terms, B. aegyptiaca is used to treat several affections. Marketing the fruits could be of socio-economic interest for local people, and in particular, for women. This study is particularly opportune since B. aegyptiaca var. aegyptiaca is currently being planted in large numbers within the Great Green Wall for the Sahara and the Sahel Initiative (GGW). It also provides information that could help in better management of this natural resource, adapted both to the hostile Sahelian climate and of great use to Mankind. © 2014 FAC UNIV SCIENCES AGRONOMIQUES GEMBLOUX. All rights reserved.
Women’s Traditional Knowledge, Use Value, and the Contribution of Tamarind (
Tamarindus indica
L.) to Rural Households’ Cash Income in Benin. This study examined differences in knowledge, use values, and contribution of tamarind (Tamarindus indica) to women’s cash income during the dry season, focusing on seven tribal groups in Benin. Data were gathered using semistructured individual interviews and monitoring, and were analyzed using quantitative ethnobotanical methods. Principal component analysis was applied to describe the use value and use forms of tamarind according to different tribes. Tamarind was found to play an important role in local communities’ livelihoods. Overall, 26 different uses were mentioned for tamarind products. Most commonly, the fruit (pulp) was used to make beverages, as a laxative and purgative, and it seems to be the only plant part sold commercially. Bark was frequently used as a medicine to treat wounds, and leaves were used to make porridge and as an antibiotic. Medicinal, cultural, and material use categories were correlated best with the Fulani, whereas commerce was most correlated with Gourma tribes (PCA analysis). There were significant differences for tamarind utilization among the tribal groups, with overall ethnobotanical use values (EUVT) ranging from 10 to 14, and contribution to cash income ranging from 8.8% to 56.4%. In view of its domestication potential, it is crucial that traditional tribal knowledge of tamarind be preserved and integrated into management policies. Further development and research needs for utilization and conservation are improvement of commercialization, organization of market channels, and extent of genetic diversity within and among populations.
Balanites aegyptiaca (L.) Delile. is one of the priority indigenous fruit trees for rural communities in the West African Sahel. As part of a
participatory tree domestication program in Niger, phenotypic variation in fruit and seed morphology was assessed in four
natural populations in eastern Niger. Measured variables were weight of the fruit, seed coat and kernel; length and width
of the fruit and seed (25 trees per population, 30 fruits per tree). Derived variables were the tree’s coefficient of variation
(CVs) for each measured variable, and two sets of factor scores from principal components analysis of tree means and CVs.
ANOVA indicated significant variation in all measured variables due to trees nested in populations. ANOVA and simple linear
regression indicated significant geographic variation in some variables: the drier parts of the sample region tended to have
heavier fruits and kernels, longer/narrower seeds, and lower within-tree variability in fruit and seed width. Length and width
were strongly correlated between fruits and seeds, fruit weight was moderately correlated with seed dimensions, and CVs of
fruit weight and width were moderately correlated with the CV of seed width. Some hypotheses for the geographic variation
are presented, and some practical implications of the correlations for tree domestication programs are discussed.
Keywords
Balanites aegyptiaca
-Domestication-Fruit and seed morphology-Selection
Folk Classification, Perception, and Preferences of Baobab Products in West Africa: Consequences for Species Conservation
and Improvement.The present study is a component of a baobab (Adansonia digitata L.) domestication research program being undertaken in Benin, Burkina Faso, Ghana, and Senegal. Surveys conducted on a total
of 129 women and 281 men of different ages included questions on perceptions and human/cultural meaning of morphological variation,
use forms, preferences (desirable/undesirable traits), and links between traits. Local people in the four countries use 21
criteria to differentiate baobab individuals in situ. According to them, the easier the bark harvesting, the tastier the pulp and leaves; the slimier the pulp, the less tasty
it is; the more closely longitudinally marked the fruit capsules, the tastier the pulp. This study shows that farmers are
able to use preferred combinations of traits as a guide in collecting germplasm from trees. This can allow the selection of
trees that would be candidates for propagation, and planning for a domestication program based on the indigenous knowledge.
In this article, we present FactoMineR an R package dedicated to multivariate data analysis. The main features of this package is the possibility to take into account different types of variables (quantitative or categorical), different types of structure on the data (a partition on the variables, a hierarchy on the variables, a partition on the individuals) and finally supplementary information (supplementary individuals and variables). Moreover, the dimensions issued from the different exploratory data analyses can be automatically described by quantitative and/or categorical variables. Numerous graphics are also available with various options. Finally, a graphical user interface is implemented within the Rcmdr environment in order to propose an user friendly package.
Domestication Syndrome in Caimito (
Chrysophyllum cainito
L.): Fruit and Seed Characteristics: The process of domestication is understudied and poorly known for many tropical fruit tree crops. The star apple or caimito tree (Chrysophyllum cainito L., Sapotaceae) is cultivated throughout the New World tropics for its edible fruits. We studied this species in central Panama, where it grows wild in tropical moist forests and is also commonly cultivated in backyard gardens. Using fruits collected over two harvest seasons, we tested the hypothesis that cultivated individuals of C. cainito show distinctive fruit and seed characteristics associated with domestication relative to wild types. We found that cultivated fruits were significantly and substantially larger and allocated more to pulp and less to exocarp than wild fruits. The pulp of cultivated fruits was less acidic; also, the pulp had lower concentrations of phenolics and higher concentrations of sugar. The seeds were larger and more numerous and were less defended with phenolics in cultivated than in wild fruits. Discriminant Analysis showed that, among the many significant differences, fruit size and sugar concentration drove the great majority of the variance distinguishing wild from cultivated classes. Variance of pulp phenolics among individuals was significantly higher among wild trees than among cultivated trees, while variance of fruit mass and seed number was significantly higher among cultivated trees. Most traits showed strong correlations between years. Overall, we found a clear signature of a domestication syndrome in the fruits of cultivated caimito in Panama.
Baobab (Adansonia digitata) is a multi-purpose tree used daily by rural African communities. The present study aimed at investigating the level of morphometric and genetic variation and spatial genetic structure within and between threatened baobab populations from the three climatic zones of Benin.
A total of 137 individuals from six populations were analysed using morphometric data as well as molecular marker data generated using the AFLP technique.
Five primer pairs resulted in a total of 217 scored bands with 78.34 % of them being polymorphic. A two-level AMOVA of 137 individuals from six baobab populations revealed 82.37 % of the total variation within populations and 17.63 % among populations (P < 0.001). Analysis of population structure with allele-frequency based F-statistics revealed a global F(ST) of 0.127 +/- 0.072 (P < 0.001). The mean gene diversity within populations (H(S)) and the average gene diversity between populations (D(ST)) were estimated at 0.309 +/- 0.000 and 0.045 +/- 0.072, respectively. Baobabs in the Sudanian and Sudan-Guinean zones of Benin were short and produced the highest yields of pulp, seeds and kernels, in contrast to the ones in the Guinean zone, which were tall and produced only a small number of fruits with a low pulp, seed and kernel productivity. A statistically significant correlation with the observed patterns of genetic diversity was observed for three morphological characteristics: height of the trees, number of branches and thickness of the capsules.
The results indicate some degree of physical isolation of the populations collected in the different climatic zones and suggest a substantial amount of genetic structuring between the analysed populations of baobab. Sampling options of the natural populations are suggested for in or ex situ conservation.
Balanites aegyptiaca is a key agroforestry tree species widely distributed across the African drylands, and with a high socioeconomic potential for rural communities. Previous research studies have revealed the importance of this multipurpose fruit tree species from an ecological perspective, however, there is still little documentation of the current state of knowledge and research perspectives required for setting further sustainable management policies for the species. Here, we conducted a global systematic review covering the last three decades (1989-2021), to understand the patterns and insights from publications on various aspects related to both the conservation ecology and the domestication of B. aegyptiaca. Published materials were identified using four online search engines including Science Direct, Google Scholar, African Journals Online and Scopus. A total of 4538 publications were initially identified, of which 346 publications were finally retained, on the basis of broad cross-disciplinary perspectives. These 346 publications covered 24 African countries and the five African sub-regions. The majority of the publications was recorded in both West Africa (n = 170) and East Africa (n = 106), while the North Africa (n = 34), Central Africa (n = 21) and Southern Africa (n = 15) had the lowest number of publications on B. aegyptiaca along its distribution range in Africa. About 70% of the studies un-dertaken in West Africa were from Nigeria, Senegal and Burkina Faso. In-depth analyses of these publications showed critical research gaps on B. aegyptiaca, in terms of its distributional ecology, socioeconomic importance, reproductive biology, ecophysiological performance, genetic diversity and propagation initiatives. This review provides crucial information that would guide the development of research agenda and sustainable strategies for conservation and domestication of the desert date in Africa.
Wild oil plants (WOP) are species used for food, cosmetics, nutraceutical, and medicine. In Benin, their importance is still poorly documented. This study investigated the diversity of WOPs and identified priority species for valorization in Benin. Literature synthesis was used to gather data on a list of WOP species. This was completed by ethnobotanical surveys involving users (traditional healers, farmers, fishers, traders, and resource persons), actors in the three biogeographical zones of Benin (Guineo-Congolian, Sudano-Guinean, and Sudanian zones). In addition, field visits to the species habitats were conducted with the help of local populations to assess the true presence of species mentioned during the survey and their availability. Data were collected on the identity of informants, WOPs used or known, ethnobotanical, nutritional and economic values, valorization level, their national distribution and threat status. Data were analyzed using the Chi-square test and Principal Component Analysis (PCA). Findings showed that oils extracted from these WOP seeds serve for medicinal (49.25%), food (29.85%), cosmetic (17.91%), and fuel (2.99%) purposes, and neither gender nor the main occupation defined knowledge of WOP diversity. A total of 36 WOPs belonging to 25 botanical families were identified. The top five priority species to be valorized across the country were: Balanites aegyptiaca (L.) Delile, Ricinodendron heudelotii (Bail.) Pierre, Lophira lanceolata Tiegh. ex Keay, Sesamum indicum L., and Cleome gynandra L. These species were identified as important resources for alleviating poverty and food insecurity in the communities and as potential candidates for the development of the oilseed sector in Benin. Further studies are needed to document the indigenous knowledge associated with those species, existing processing techniques, and exploitable capital to ensure their sustainable management.
The domestication of plants, an evolutionary process of importance worldwide, has been widely studied in annual species but very little in perennial species, especially fruit trees. Most studies of domestication have focused on the comparison of morphological characteristics between wild and cultivated populations and on patterns of evolution of phenotypic characteristics that are under selection, known as the domestication syndrome. The objective of this research was to investigate the domestication status of populations of Huaya India (Melicoccus oliviformis, Sapindaceae) in the Yucatan Peninsula using ethnobotanical and morphological evidence. The species is cultivated in both rural and urban communities in this area, and wild populations of Huaya India are found surrounding these sites. We gathered ethnobotanical data by conducting semi-structured interviews and through participatory observation. For each fruit, sugar content and morphological characteristics were measured in situ. The results show the Huaya India presents minimal differences between wild and cultivated fruits in characteristics that are often associated with domestication (weight, length, fruit diameter, exocarp thickness, and sugar content). We attribute these results to the unconscious management to which this species has been and continues to be subjected by the inhabitants of the Maya communities, but further study is needed to determine the extent to which the observed differences reflect genetic differences due to human selection, environmental effects, or a combination of the two.
Rain-water penetration of the soil beneath a number of dry grassland communities was examined a few hours after a light shower in Kenya Masailand. It was found that for the particular communities studied, the type of soil present and the amount of rainfall, the depth of rain-water penetration is approximately equal to the height of the plant plus the normal penetration of the shower into the bare soil. The sectional area of the wet soil mass beneath each vegetation clump is also approximately equal to the sectional area of the clump showing above ground plus an area corresponding to the amount which would have fallen there had there been no plant cover. It is considered that in the overgrazed dry grassland parts of Kenya Masailand, stem-flow and rain-water penetration around trees of B. aegyptiaca may now be playing a part in changing the character of the local vegetation. It is also suggested that leaf catchment-stemflow systems may be involved in the maintenance of grassland vegetation patterns noted in other regions by other workers.
Methodology extending nonparamet-ric goodness-of-fit tests to discrete null distribu-tions has existed for several decades. However, modern statistical software has generally failed to provide this methodology to users. We offer a revision of R's ks.test() function and a new cvm.test() function that fill this need in the R language for two of the most popular nonpara-metric goodness-of-fit tests. This paper describes these contributions and provides examples of their usage. Particular attention is given to vari-ous numerical issues that arise in their implemen-tation.
Recent interest in the role of ecology in species formation has led to renewed discussion of the stages in the process of speciation. Although attempts to classify the stages in the process of species formation date back at least as far as Alfred Russel Wallace, one of the most intense debates on the subject occurred among botanists during the mid‐20th Century. The present review outlines the progression of the historical debate about stages in the evolution of species, which was instigated by the genecological classification scheme of Göte Turesson in the 1920s, championed in the mid‐century by Jens Clausen, and then brought under harsh scrutiny by many in the 1960s and 1970s. At the heart of the controversy is the question of whether speciation occurs rapidly on a local scale or gradually through the formation of geographically widespread ecotypes that evolve as precursors to species. A corollary to this debate is the question of whether speciation is reversible and, if so, how does it become irreversible? A third wave of interest in stages in the process of speciation is currently underway, thus making a modern historical narrative of the debate important. Both contemporary and past evolutionary biologists have argued that viewing speciation as being composed of stages can free researchers from concerns over species definitions and focus attention on the mechanisms involved in the process. How speciation becomes irreversible and whether ecogeographically isolated ecotypes are integral to this process remain as important unresolved issues. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106, 241–257.
Aim Woody vegetation patterns in African savannas north of the equator are closely connected to human presence, but the distinctions between natural and anthropogenic landscapes have not been clear to many observers. Criteria for identifying savanna landscapes on a continuum of intensity of anthropic impact are explored.
Methods A key savanna tree species, Vitellaria paradoxa (Sapotaceae), was used as model for evaluating anthropic impact. Fruits harvested from tree populations across the species range were analysed for variation in traits valued by indigenous peoples. A simple selection index was used to scale tree populations from a hypothetical wild state to a hypothetical domesticated state. Index values were compared with trait values along climate zone gradients and evaluated in the context of indigenous savanna management practices and historical species distribution reports.
Results Trait values such as fruit size and shape, pulp sweetness, and kernel fat content show a significant influence of temperature and rainfall. At the same time, the mean values of groups of traits vary perpendicular to the general climatic zone gradient. Selection index values between Vitellaria populations vary up to sixfold, with highest values in central Burkina Faso. Comparison of present day Vitellaria distribution with historical range limits show range expansion by human migration.
Main conclusions The prevalence of major economic tree species in the savannas of Africa north of the equator is a strong indicator of human involvement in tree dispersal. This conclusion is supported by paleobotanical evidence and by recent Vitellaria range expansion as a result of human migration. The presence of high mean values of several Vitellaria fruit traits in central Burkina Faso suggests that selection for desired characteristics has occurred. The impact of indigenous savanna peoples on woody species composition and spatial distribution is probably much greater than usually thought and is the result of a deliberate strategy of altering the landscape to provide needed human resources.
There may have been 4–5 million people in Amazonia at the time of European contact. These people cultivated or managed at
least 138 plant species in 1492. Many of these crop genetic resources were human artifacts that required human intervention
for their maintenance, i.e., they were in an advanced state of domestication. Consequently, there was a relationship between
the decline of Amazonian Amerindian populations and the loss of their crop genetic heritage after contact. This relationship
was influenced by the crop’s degree of domestication, its life history, the degree of landscape domestication where it was
grown, the number of human societies that used it, and its importance to these societies. Amazonian crop genetic erosion probably
reflects an order of magnitude loss and the losses continue today.
A Amazônia poderia ter tido de 4 a 5 milhÕes de habitantes quando os Europeus chegaram. Estes povos cultivaram ou manejaram
pelo menos 138 espécies vegetais em 1492. Muitos destes recursos genéticos eram artefatos humanos que requeriam a intervenção
humana para sua manutenção, ou seja, estavam num estado avançado de domesticação. Conseqiientemente, existiu uma relaçao entre
o declínio das populaçÕes indigenas da Amazônia e a perda de seus recursos genéticos apòs o contato. Esta relaç00E3o foi influenciada
pelo grau de domesticação do cultivo, sua história de vida, o grau de domesticação da paisagem em que foi cultivada, o número
de sociedades indigenas que o utilizou, e sua importância a estas sociedades. A erosão dos recursos genéticos indigenas da
Amazônia provavelmente reflete uma perda de um ordern de magnitude e as perdas continuam hoje.
Two types of selection operate (and complement each other) in plants under domestication: (a) conscious or intentional selection applied by the growers for traits of interest to them; (b) unconscious or automatic selection brought about by the fact that the plants concerned were taken from their original wild habitats and placed in new (and usually very different) human-made or human-managed environments. The shift in the ecology led automatically to drastic changes in selection pressures. Numerous adaptations vital for survival in the wild environments lost their fitness under the new sets of conditions. New traits were automatically selected, resulting in the build-up of characteristic “domestication syndromes,” each fitting the specific agricultural environment provided by the farmer.
The present paper assesses the evolutionary consequences of the introduction of the wild plants into several sets of contrasting farming situations. These include: (a) the type of maintenance applied, whether seed planting or vegetative propagation; (b) the plant organs for which the crop has been grown, whether they are reproductive parts or vegetative parts; (c) the impact of the system of tilling, sowing, and reaping on the evolution of grain crops; (d) the impact of the horticultural environment on fruit crops.
In west Africa, the alarming rate of land use intensification and the assumed deterioration of parkland species calls for assessments of locally valued non-timber forest product (NTFP) yielding populations. This study focused on the baobab tree, Adansonia digitata Linn., in Cinzana, Mali. Here by conducting biological inventories in different land use types and interviews we addressed the following central questions. (1) How does the harvesting of baobab NTFPs in different land use types (fallow, cropland, and village (habitation) areas) affect the viability of its population? (2) By which ways do humans, other than by harvesting, affect the viability of the population? The viability of a population is, in this study, treated as a characteristic that is determined by the mature population size and its regeneration potential (recruit population). Baobab products in Cinzana are used on a regular basis and valued in a cultural context, like in many parts of west Africa. For the local society, the sustained viability of the baobab populations is therefore essential. Fruit harvesting has an impact on dispersal and establishment, while leaf harvesting causes mutilation that reduces the number of fruits on each tree. Mutilation was more severe in cropland than in fallows, and cropland individuals were most prone to damages from plowing and livestock. The baobab populations were, however, more dense and comprised more recruits, in cropland and village areas compared to fallows, and seedlings were in fact not found in fallow. These differences are explained by management practices related to the land use type. In addition to the differences in baobab density and population structure between cropland and fallows, the weak correlation between density of recruits and mature individuals testifies to the importance of the specific ecological role that humans play in baobab dispersal and establishment. Clearly, harvesting is not the only way by which humans influence the viability of baobab populations. Some practices are beneficial, either intentional (e.g. seedling protection, transplanting) or unintentional (e.g. dispersal of seeds in garbage), while others are detrimental (e.g. livestock browsing, plowing). At present local management practices contribute to sustain the viability of the species. The results point to the fact that the baobab population is not declining but in need of management that secures the maintenance of a genetically diverse population.
Balanites aegyptiaca (L.) is an important tree in the semi-arid ecosystem with beneficial attributes. However, very little information is available in its reproductive biology. In order to better control the reproduction system of B. aegyptiaca, three experimental approaches are used: floral morpholgy, fluorochromatic procedure and hand pollination. The floral morphology shows that B. aegyptiaca flowers are hermaphrodite and gathered in several types of inflorescence (clusters, fascicles or glomerules). They blossomed asynchronically and nectar is exuded by the flowers. Top ovary holds five anatropous ovules. The second approach consisting in fluorochromatic procedure reveals a pollen with 3 apertures and a viability rate of 92%. This viability decrease down to 50% after a storage at -5°C for 7 days. Finally, the hand pollination proves that B. aegyptiaca is a partially auto-compatible plant and the main vectors of pollination are Halictidae (Hymenopterae) and Dipterae.
Morphological variability of Balanites aegyptiaca (L.) Del. in the region of Ouaddaï in Chad
- Abdoulaye
Principaux facteurs environnementaux du Burkina Faso
- Dipama