119 research outputs found
Poverty and poor education are key determinants of high household food insecurity among populations adjoining forest concessions in the Congo Basin
Background:
The trees and non-timber forest products (NTFPs) of the Congo Basin play a key role in alleviating food insecurity among millions of people around the world. Although many studies have been conducted both nationally and regionally on issues of food insecurity in the Congo Basin, little is known on the effects of timber exploitation on household food insecurity statues of forest dependent communities in this region. This study focused on the determination of the principal indicators of household food security status of populations living around six selected forest concessions in the Congo Basin.
Method:
We randomly surveyed 724 households in thirty-four communities living in six popular forest concessions around the Congo Basin. Food consumption pattern data was collected using a validated food-frequency questionnaire in 2012. Household Food Insecurity Access Prevalence (HFIAP) was assessed using the HFIAP indicator and households were categorized into four levels of household food insecurity status as follows: Food secure (HFIAS = 0); mildly food insecure (HFIAS 1–8); moderately food insecure (HFIAS 9–13); and severely food insecure (HFIAS 14–27).
Results:
The majority of the households interviewed were headed by women (73.1 %, 76.6 %, and 58.6 % for Cameroon, DRC and Gabon respectively), most of them married (84.6 %, 100 %, 57.6 % for Cameroon, DRC and Gabon respectively) with an average age range of 30–49 years. Most of the household members were engaged in farming and/or illegal logging as the main revenue generating activities. Results of global household food insecurity categorized 63.8 % of households in Cameroon as fully food secure and 36 % as food insecure. In the DRC (92.9 %) and Gabon (92.7 %), almost all the survey households were categorized as either moderately or severely food insecure; clearly elucidating the existence of severe insufficiency in the quantity and quality of food meant for human nutrition in these areas. The means of household food insecurity scores for the DRC (17.40 ± 4.15) and Gabon (14.9 ± 5.87) were significantly higher when compared to the average score for Cameroon ((7.55 ± 6.62) at p < 0.0001. This literally means that many of the households especially in DRC and Gabon face enormous difficulties in obtaining an adequate dietary energy supply. Gender (female), educational level (illiterate), and age (young) were positively correlated to food insecurity levels.
Conclusion:
Our results revealed that, despite the potential contribution of the Congo Basin forests, through enhancing access to different forms of quality foods such as bush meat, wild foods, and medicine, not forgetting the provision of agricultural land, local construction material, and income generation resources, the prevalence of food insecurity among the population adjoining forest concessions in the region is severe. This prevalence is alarming around forest concessions of the DRC and Gabon and in one concession of Cameroon. Given that poverty and poor education were positively correlated to household food insecurity, they were considered the paramount determinants of household food insecurity in this region
The contribution of NTFPs gathering: To rural people's livelihoods around two timber concessions in Gabon
NTFP are often presented as bringing a major contribution to rural livelihoods in terms of food and cash, and this particularly for rural communities. Few data are available in Gabon to confirm this common assertion. An annual monitoring of 127 households was conducted in 14 villages around two timber concessions in the south-east and south-west regions of Gabon. Conventional socio‐economic survey tools such as focus group discussions, census and semi-structured interviews of households were used in gathering data during one year. Results reveal that rural people depend on various sources of livelihoods for food and income generation, but overall, the current contributions of vegetal NTFPs are insignificant compared to other activities. Odika (Irvingiagabonensis), atanga sauvage (Dacryodes buettneri), fungus (Termitomyces spp) and “nut” (Coula edulis) represent the main forest products that are commonly harvested by rural people, primarily for subsistence purposes while the surplus is sold. Although some efforts were made to promote the NTFP sector in the country, the results of this study suggest that: (1) the main components of the decree No.137/PR/MEFP of February 4, 2009, that prohibited the logging of five multiple use tree species over a period of 25 years should be reconsidered for revision; (2) the State authorities and partners should promote projects aiming at increasing the knowledge of the NTFP sector. These projects should contribute to the census of NTFP (for food, medicine and services), characterize their uses, the market chains of target products, and the development potential of NTFP. Such projects may help Gabon and other Congo Basin countries to fix norms/standards for a sustainable natural resource management and for enhancing their contribution to the national economy. This will be particularly relevant in the light of dwindling oil revenues and the need to diversify and promote other revenue sources in the country. (Résumé d'auteur
Derivation of diameter measurements for buttressed trees, an example from Gabon
Many tropical tree species have buttresses at the standard breast height (1.3 m above ground) of diameter measurement, with a presumable role in improving nutrient acquisition or tree anchorage in the ground (Newbery et al. 2009, Richter 1984). Measuring the diameter using standard dendrometrical tools such as callipers or graduated tapes, which require that the cross-section of the trunk has a convex shape, is then impossible (Nogueira et al. 2006). The recommended method in this case is to measure the diameter above the buttress (DAB), thus possibly leading to biased estimates of the basal area (West 2009), of tree above-ground biomass (Dean & Roxburgh 2006, Dean et al. 2003) and of tree growth (Metcalf et al. 2009). As an alternative, one can measure the basal area at breast height of buttressed trees, using a method that can deal with the irregular non-convex shape of the cross-section of the stem such as the Picus calliper, photogrammetry or 3D laser scanning (Badia et al. 2003, Dean 2003, Newbery et al. 2009).</jats:p
Evaluation of the contribution of NTFPs gathering: to rural people’s livelihoods around two timber concessions in Gabon
NTFP are often presented as bringing a major contribution to rural livelihoods in terms of food and cash, and this particularly for rural communities. Few data are available in Gabon to confirm this common assertion. An annual monitoring of 127 households was conducted in 14 villages around two timber concessions in the south-east and south-west regions of Gabon. Conventional socio‐economic survey tools such as focus group discussions, census and semi-structured interviews of households were used in gathering data during one year. Results reveal that rural people depend on various sources of livelihoods for food and income generation, but overall, the current contributions of vegetal NTFPs are insignificant compared to other activities. Odika (Irvingiagabonensis), atanga sauvage (Dacryodes buettneri), fungus (Termitomyces spp) and “nut” (Coula edulis) represent the main forest products that are commonly harvested by rural people, primarily for subsistence purposes while the surplus is sold. Although some efforts were made to promote the NTFP sector in the country, the results of this study suggest that: (1) the main components of the decree No.137/PR/MEFP of February 4, 2009, that prohibited the logging of five multiple use tree species over a period of 25 years should be reconsidered for revision; (2) the State authorities and partners should promote projects aiming at increasing the knowledge of the NTFP sector. These projects should contribute to the census of NTFP (for food, medicine and services), characterize their uses, the market chains of target products, and the development potential of NTFP. Such projects may help Gabon and other Congo Basin countries to fix norms/standards for a sustainable natural resource management and for enhancing their contribution to the national economy. This will be particularly relevant in the light of dwindling oil revenues and the need to diversify and promote other revenue sources in the country
Trees for Food and Timber: are community interests in conflict with those of timber concessions in the Congo Basin?
Much of the Congo Basin is managed for timber from dozens of species. More than 60% also produce non-timber products, including foods. For five multiple use tree species in Cameroon, Democratic Republic of Congo (DRC) and Gabon (Entandrophragma cylindricum, Baillonella toxisperma, Erythrophleum suaveloens, Dacryodes buettneri and Gambeya lacourtiana), we studied gathering and consumption by communities, edible caterpillars hosted, the densities of trees around villages and in concessions and the impacts of timber harvesting . We also studied the consumption of forest foods and the nutritional values of fruits and seeds of various tree species. Villagers walked up to six km during day trips to collect fruits or caterpillars, gathering from concessions if the village was within or near it. When foods were gathered from trees smaller than the cutting diameter (which varied by country and species), there was no conflict with timber harvesting. However, the volume of edible caterpillars hosted increased with diameter and harvestable trees were the most productive. Caterpillars, tree fruits and seeds provide fats, vitamins and minerals that complement agricultural foods. Densities of B. toxisperma, valued for its edible oil, were higher around villages than in concessions. The proportion of commercial trees harvested for timber varied from less than 3% to more than 50%, depending on the species. Different species had different geneflow distances, meaning viable regeneration could be expected with residual adults at different maximum distances. E. cylindricum had more effective dispersal than E. suaveolens. The production of timber and nontimber products can be sustained from the same concessions, for different stakeholders, with appropriate practices and arrangements
Invasive potential of the Peruvian pepper tree (Schinus molle) in South Africa
Thesis (PhD (Conservation Ecology and Entomology))--University of Stellenbosch, 2009.ENGLISH ABSTRACT: Natural and semi-natural ecosystems and human communities worldwide are under siege
from a growing number of destructive invasive alien species. Alien species are those
whose presence in an area is due to intentional or accidental introduction as a result of
human activities. Some alien species become invasive, and some cause tremendous
destruction to the ecosystem and their stability, but we do not yet understand fully the
many factors that determine the levels of invasiveness in alien species. However,
management of alien plants requires a detailed understanding of the factors that make
them invasive in their new habitat. The aim of this study was to explore in detail the
processes and potential for invasion of Schinus molle (Peruvian pepper tree) into semiarid
savanna in South Africa and to examine the potential for this species to invade
further in these ecosystems, and in other South African biomes.
In this thesis I explored the patterns and processes of invasion of S. molle in semiarid
savanna using small-scale experiments to investigate physical and ecological barriers
to invasion that prevent or accelerate the invasion of this species. I examined factors such
as pollination; seed production; seed dispersal; seed predation and viability, all known to
contribute to invasiveness. I highlighted the critical role of microsite conditions
(temperature, humidity, water availability) in facilitating S. molle seedling establishment
in semi-arid savanna and demonstrated that microsite type characteristics need to be
considered for management and monitoring of the species in South Africa. I
demonstrated the ability of S. molle to out-compete indigenous woody plants for light and
other resources and also showed that disturbance of natural ecosystems was not a
prerequisite for invasion, although human activities such as tree planting have played a
major role in disseminating this species in South Africa.
Predicting the future distribution of invasive species is very important for the
management and conservation of natural ecosystems, and for the development of policy.
For this reason, I also assessed the present and potential future spatial distribution of S.
molle in South Africa by using bioclimatic models and a simulation-based spread model.
I produced accurate profiles of environmental conditions (both biophysical and those related to human activities) that characterize the planted and naturalized ranges of this
species in South Africa, by linking species determinants, potential habitat suitability and
likely spread dynamics under different scenarios of management and climate change. All
those components provided insights on the dynamics of invasions by fleshy-fruited
woody alien plants in general, and on S. molle invasions in South Africa in particular. I
developed a conceptual model that described S. molle population dynamics leading to an
understanding of the processes leading to the invasive spread of this species in South
Africa. This work also emphasized the need for policy review concerning the invasive
status of S. molle in South Africa, and recommendations are made for future research.AFRIKAANSE OPSOMMING: Die natuurlike and half-natuurlike ekosisteme sowel as menslike gemeenskappe
wereldwyd word bedreig deur ‘n groeiende hoeveelheid indringerplantspesies.
Indringerplantspesies (daardie spesies wie se teenwoordigheid toegeskryf kan word aan
opsetlike of toevallige inbringing deur menslike toedoen) is ‘n bedreiging nie net vanweë
die massiewe verwoesting van die ekosisteme en ekosisteemstabilitiet nie, maar ook
omdat ons nog nie ten volle verstaan hoe hulle van skaars in hul natuurlike omgewing tot
dominant in hul nuwe habitat gaan nie. Bestuur van indringer plante vereis ’n begrip van
biologise en ekologiese faktore wat lei tot hulle indringing in die nuwe habitat. Die
primêre doel van hierdie studie was om in detail uit te vind wat die prosessesse en
potensiaal is vir die indringing van S. molle (die Peruviaanse peper boom) in droë
savanna en om indringingspatrone in droë savanna met huidige en potensieële
toekomstige patrone in ander Suid-Afrikaanse biome te vergelyk.
In hierdie tesis ondersoek ek die patrone en prosesse wat verband hou met die
indringing van S. molle in droë savanna deur gebruik te maak van kleinskaalse
eksperimente om fisiese en ekologise hindenisse te ondersoek wat indringing van S. molle
in Suid-Afrika voorkom of versnel. Dit sluit faktore in wat bekend is om by te dra tot
indringing van plant spesies, soos bestuiwing, saadproduksie, saadpredasie en
kiemkragtigheid. Ek het die kritieke rol beklemtoon van mikroomgewingskondisies
(temperatuur, humiditeit, waterbeskikbaarheid) in die fasilitering van S. molle
saailingvestiging in droë savanna en het gedemonstreer dat die tipe
mikroomgewingskarakteristieke in ag geneem moet word by betuur en monitering van
die verspreiding van S. molle in Suid-Afrika. Ek het die vermoë van S. molle om
inheemse plante te uitkompeteer gedemonstreer, en het gewys dat versteuring van
natuurlike ekosisteme nie ’n voorvereiste vir S. molle indringing was nie, hoewel
menslike aktiwiteite soos boomaanplantings ’n groot rol speel deur by te dra tot
indringing van hierdie spesie in Suid-Afrika. Voorspelling van toekomstige verspreiding van indringerspesies is baie belangrik
vir die bestuur en bewaring van natuurlike ekosisteme, sowel as vir ontwikkeling van
wetgewing. Daarom is die huidige en potensiele toekomstige ruimtelike verspreiding van
S. molle in Suid-Afrika bereken deur inkorporering van bioklimaatsmodelle en simulering
gebasseer op ’n verspreidingsmodel. Ek het derhalwe akkurate profiele van
omgewingstoestande (beide fisiese en daardie wat verband hou met menslike aktiwiteite)
wat die aangeplante en natuurlike omvang van die spesie in Suid-Afrika kenmerk
geproduseer deur spesiedeterminante, potensieële geskiktheid van habitatte en moontlike
verspeidingsdinamika onder verskillende bestuursscenarios en kimaatsverandering te
koppel. Al hierdie komponente verskaf insig in die dinamika van die indringing van
houtagtige plante met vlesige vrugte oor die algemeen en S. molle in besonder in Suid-
Afrika. Hierdie werk beklemtoon ook die behoefte vir hersiening van beleidsrigtings wat
betrekking het op die indringerstatus van S. molle in Suid-Afrika en maak aanbevelings vir toekomstige navorsing
Invasive potential of the Peruvian pepper tree (Schinus molle) in South Africa
Thesis (PhD (Conservation Ecology and Entomology))--University of Stellenbosch, 2009.ENGLISH ABSTRACT: Natural and semi-natural ecosystems and human communities worldwide are under siege
from a growing number of destructive invasive alien species. Alien species are those
whose presence in an area is due to intentional or accidental introduction as a result of
human activities. Some alien species become invasive, and some cause tremendous
destruction to the ecosystem and their stability, but we do not yet understand fully the
many factors that determine the levels of invasiveness in alien species. However,
management of alien plants requires a detailed understanding of the factors that make
them invasive in their new habitat. The aim of this study was to explore in detail the
processes and potential for invasion of Schinus molle (Peruvian pepper tree) into semiarid
savanna in South Africa and to examine the potential for this species to invade
further in these ecosystems, and in other South African biomes.
In this thesis I explored the patterns and processes of invasion of S. molle in semiarid
savanna using small-scale experiments to investigate physical and ecological barriers
to invasion that prevent or accelerate the invasion of this species. I examined factors such
as pollination; seed production; seed dispersal; seed predation and viability, all known to
contribute to invasiveness. I highlighted the critical role of microsite conditions
(temperature, humidity, water availability) in facilitating S. molle seedling establishment
in semi-arid savanna and demonstrated that microsite type characteristics need to be
considered for management and monitoring of the species in South Africa. I
demonstrated the ability of S. molle to out-compete indigenous woody plants for light and
other resources and also showed that disturbance of natural ecosystems was not a
prerequisite for invasion, although human activities such as tree planting have played a
major role in disseminating this species in South Africa.
Predicting the future distribution of invasive species is very important for the
management and conservation of natural ecosystems, and for the development of policy.
For this reason, I also assessed the present and potential future spatial distribution of S.
molle in South Africa by using bioclimatic models and a simulation-based spread model.
I produced accurate profiles of environmental conditions (both biophysical and those related to human activities) that characterize the planted and naturalized ranges of this
species in South Africa, by linking species determinants, potential habitat suitability and
likely spread dynamics under different scenarios of management and climate change. All
those components provided insights on the dynamics of invasions by fleshy-fruited
woody alien plants in general, and on S. molle invasions in South Africa in particular. I
developed a conceptual model that described S. molle population dynamics leading to an
understanding of the processes leading to the invasive spread of this species in South
Africa. This work also emphasized the need for policy review concerning the invasive
status of S. molle in South Africa, and recommendations are made for future research.AFRIKAANSE OPSOMMING: Die natuurlike and half-natuurlike ekosisteme sowel as menslike gemeenskappe
wereldwyd word bedreig deur ‘n groeiende hoeveelheid indringerplantspesies.
Indringerplantspesies (daardie spesies wie se teenwoordigheid toegeskryf kan word aan
opsetlike of toevallige inbringing deur menslike toedoen) is ‘n bedreiging nie net vanweë
die massiewe verwoesting van die ekosisteme en ekosisteemstabilitiet nie, maar ook
omdat ons nog nie ten volle verstaan hoe hulle van skaars in hul natuurlike omgewing tot
dominant in hul nuwe habitat gaan nie. Bestuur van indringer plante vereis ’n begrip van
biologise en ekologiese faktore wat lei tot hulle indringing in die nuwe habitat. Die
primêre doel van hierdie studie was om in detail uit te vind wat die prosessesse en
potensiaal is vir die indringing van S. molle (die Peruviaanse peper boom) in droë
savanna en om indringingspatrone in droë savanna met huidige en potensieële
toekomstige patrone in ander Suid-Afrikaanse biome te vergelyk.
In hierdie tesis ondersoek ek die patrone en prosesse wat verband hou met die
indringing van S. molle in droë savanna deur gebruik te maak van kleinskaalse
eksperimente om fisiese en ekologise hindenisse te ondersoek wat indringing van S. molle
in Suid-Afrika voorkom of versnel. Dit sluit faktore in wat bekend is om by te dra tot
indringing van plant spesies, soos bestuiwing, saadproduksie, saadpredasie en
kiemkragtigheid. Ek het die kritieke rol beklemtoon van mikroomgewingskondisies
(temperatuur, humiditeit, waterbeskikbaarheid) in die fasilitering van S. molle
saailingvestiging in droë savanna en het gedemonstreer dat die tipe
mikroomgewingskarakteristieke in ag geneem moet word by betuur en monitering van
die verspreiding van S. molle in Suid-Afrika. Ek het die vermoë van S. molle om
inheemse plante te uitkompeteer gedemonstreer, en het gewys dat versteuring van
natuurlike ekosisteme nie ’n voorvereiste vir S. molle indringing was nie, hoewel
menslike aktiwiteite soos boomaanplantings ’n groot rol speel deur by te dra tot
indringing van hierdie spesie in Suid-Afrika. Voorspelling van toekomstige verspreiding van indringerspesies is baie belangrik
vir die bestuur en bewaring van natuurlike ekosisteme, sowel as vir ontwikkeling van
wetgewing. Daarom is die huidige en potensiele toekomstige ruimtelike verspreiding van
S. molle in Suid-Afrika bereken deur inkorporering van bioklimaatsmodelle en simulering
gebasseer op ’n verspreidingsmodel. Ek het derhalwe akkurate profiele van
omgewingstoestande (beide fisiese en daardie wat verband hou met menslike aktiwiteite)
wat die aangeplante en natuurlike omvang van die spesie in Suid-Afrika kenmerk
geproduseer deur spesiedeterminante, potensieële geskiktheid van habitatte en moontlike
verspeidingsdinamika onder verskillende bestuursscenarios en kimaatsverandering te
koppel. Al hierdie komponente verskaf insig in die dinamika van die indringing van
houtagtige plante met vlesige vrugte oor die algemeen en S. molle in besonder in Suid-
Afrika. Hierdie werk beklemtoon ook die behoefte vir hersiening van beleidsrigtings wat
betrekking het op die indringerstatus van S. molle in Suid-Afrika en maak aanbevelings vir toekomstige navorsing
Performance of seedlings of the invasive alien tree Schinus molle L. under indigenous and alien host trees in semi-arid savanna
We assessed the importance of host trees in influencing invasion patterns of the alien tree Schinus molle L. (Anacardiaceae) in semi-arid savanna in South Africa. Recruitment of S. molle is dependent on trees in its invaded habitat, particularly
Acacia tortilis Hayne. Another leguminous tree, the invasive alien mesquite (Prosopis sp.), has become common in the area recently, but S. molle rarely recruits under
canopies of this species. Understanding of the association between these species is needed to predict invasion dynamics in the region. We conducted experiments to test whether: (i) seedling survival of S. molle is better beneath A. tortilis than beneath mesquite canopies; (ii) growth rates of S. molle seedlings are higher beneath A. tortilis than beneath mesquite. Results showed that growth and survival of S. molle
did not differ significantly beneath the native A. tortilis and the alien Prosopis species. This suggests that microsites
provided by canopies of mesquite are as good for S. molle establishment as those provided by the native acacia. Other factors, such as the failure of propagules to arrive beneath
mesquite trees, must be sought to explain the lack of recruitment beneath mesquite.Centre of Excellence for Invasion Biolog
Recommended from our members
COVID-19, systemic crisis, and possible implications for the wild meat trade in sub-Saharan Africa
Wild animals play an integral and complex role in the economies and ecologies of many countries across the globe, including those of West and Central Africa, the focus of this policy perspective. The trade in wild meat, and its role in diets, have been brought into focus as a consequence of discussions over the origins of COVID-19. As a result, there have been calls for the closure of China’s “wet markets”; greater scrutiny of the wildlife trade in general; and a spotlight has been placed on the potential risks posed by growing human populations and shrinking natural habitats for animal to human transmission of zoonotic diseases. However, to date there has been little attention given to what the consequences of the COVID-19 economic shock may be for the wildlife trade; the people who rely on it for their livelihoods; and the wildlife that is exploited. In this policy perspective, we argue that the links between the COVID-19 pandemic, rural livelihoods and wildlife are likely to be more complex, more nuanced, and more far-reaching, than is represented in the literature to date. We develop a causal model that tracks the likely implications for the wild meat trade of the systemic crisis triggered by COVID-19. We focus on the resulting economic shockwave, as manifested in the collapse in global demand for commodities such as oil, and international tourism services, and what this may mean for local African economies and livelihoods. We trace the shockwave through to the consequences for the use of, and demand for, wild meats as households respond to these changes. We suggest that understanding and predicting the complex dynamics of wild meat use requires increased collaboration between environmental and resource economics and the ecological and conservation sciences
- …
