Beyond Timber: forest management models for transforming conflict into cooperation

This Brief is based on a report prepared for the CGIAR Research Program on Forests, Trees and Agroforestry aiming at documenting outcomes achieved by the Program’s research activities.The competing needs of different groups who depend upon the Congo Basin rainforest can be met if innovative, new research-based models for multiple-use forest management are employed.The models, together with accompanying policy guidance, have been endorsed by the region’s forest administration body COMIFAC and offer the potential to alleviate both the conflict between groups and the pressures on the landscape, allowing livelihoods and forest to flourish. Underpinned by groundbreaking, multi-disciplinary, international research, the models embody combined insights into local people’s needs, the ecologica

Guide methodologique des etudes ecologique et genetique sur la disponibilite de quelques especes a usage-multiples dans et autour des concessions forestieres dans le bassin du Congo

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Safeguarding villagers’ access to foods from timber trees: Insights for policy from an inhabited logging concession in Gabon

This study assessed the abundance of and access to tree species (Ozigo, Dacryodes buettneri; and Abam, Gambeya lacourtiana) that yield edible fruits to villagers and timber to the logging industry in and around a logging concession in Gabon. Participatory mapping combining GPS coordinates and interviews was carried out with 5 female and 5 male collectors in each of two villages within or adjacent to the logging concession. Precommercial and harvestable (>70 cm dbh) Ozigo and Abam trees, as well as their stumps, were also quantified on 20 five ha plots in the 2012 cutting area of the concession and on 21 five ha plots on 10 km transects from each village. Distances to 59 Abam and 75 Ozigo from which fruits were collected ranged from 0.7 to 4.46 Km from the village centres. Most collections were by mixed groups made up of men, women and children (54%) at an average of 1.21 ± 0.09 km; or by men and women (18%) at 2.21 ± 0.15 km; or women and children (14%) at 4.03 ± 0.22 km from the village. Almost 28% of all of the collection trees were inside the logging concession boundaries but outside the village agricultural zone, 43% were inside the village agricultural zone, and 29% were outside the logging concession. Only 33% of Ozigo collection trees had reached commercial size while 75% of Abam trees had. No stumps were found on any sample plots, probably reflecting the ban on felling Ozigo which was in effect at the time; and the relatively low commercial value of Abam. Densities of precommercial Ozigo trees in the cutting area were more than double their densities around the villages (236.0 ± 20.3100 ha−1and 96.6 ± 17.2100 ha−1, respectively), while densities of harvestable Ozigo trees were 7 times higher in the cutting area than around villages (120 ± 20.2100 ha−1and 17.1 ± 3.4100 ha−1respectively). This probably reflects past and current anthropogenic pressures around the villages, including logging and land clearance for agricultural fields. Densities of precommercial Abam were almost four times higher around the village (22.3 ± 5.6 and 6.0 ± 2.9) than on the cutting area. Villagers did not record a decline in availability of or access to these fruits over the past 5 years, suggesting little or no immediate conflict between timber production and access to fruits from these trees

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

Foliar trait contrasts between African forest and savanna trees: Genetic versus environmental effects

Journal ArticleVariations in leaf mass per unit area (Ma) and foliar concentrations of N, P, C, K, Mg and Ca were determined for 365 trees growing in 23 plots along a West African precipitation gradient ranging from 0.29 to 1.62m a-1. Contrary to previous studies, no marked increase in Ma with declining precipitation was observed, but savanna tree foliar [N] tended to be higher at the drier sites (mass basis). Generally, Ma was slightly higher and [N] slightly lower for forest vs savanna trees with most of this difference attributable to differences in soil chemistry. No systematic variations in [P], [Mg] and [Ca] with precipitation or between trees of forest vs savanna stands were observed. We did, however, find a marked increase in foliar [K] of savanna trees as precipitation declined, with savanna trees also having a significantly lower [K] than those of nearby forest. These differences were not related to differences in soil nutrient status and were accompanied by systematic changes in [C] of opposite sign. We suggest an important but as yet unidentified role for K in the adaption of savanna species to periods of limited water availability; with foliar [K] being also an important factor differentiating tree species adapted to forest vs savanna soils within the 'zone of transition' of Western Africa.Natural Environment Research Council TROBIT Consortium projectRoyal Society - University Research Fellowshi

Beyond timber: balancing demands for tree resources between concessionaires and villagers

Extensive areas of the Congo Basin forest are allocated to timber concessionaires. These forests also harbour and support village populations, including indigenous Baka people, who depend on forest foods obtained directly from trees (fruits, oils and caterpillars). Most food-producing tree species are harvested by concessionaires for timber. We documented the availability and abundance of three food tree species around four villages and in two neighboring timber concessions in Cameroon. Data was used to determine the importance of timber concessions as sources of food for local people to provide a foundation for governance arrangements that consider local needs for foods from timber trees. Discussions with concessionaires revealed that some of them have voluntarily refrained from extracting timber species of interest to villagers for their nontimber products. This is either to avoid conflict with villagers, or because regulations have been promulgated to safeguard these resources. The interplay between internal village dynamics, regulations and their implementation by forest guards, and the actions of timber concessions create a complex arena for addressing rights to forest resources. This paper provides information on the accessibility and availability of multiple use timber species as a foundation for negotiations and governance arrangements between concessionaires and local communities

Resistance of African tropical forests to an extreme climate anomaly.

The responses of tropical forests to environmental change are critical uncertainties in predicting the future impacts of climate change. The positive phase of the 2015-2016 El Niño Southern Oscillation resulted in unprecedented heat and low precipitation in the tropics with substantial impacts on the global carbon cycle. The role of African tropical forests is uncertain as their responses to short-term drought and temperature anomalies have yet to be determined using on-the-ground measurements. African tropical forests may be particularly sensitive because they exist in relatively dry conditions compared with Amazonian or Asian forests, or they may be more resistant because of an abundance of drought-adapted species. Here, we report responses of structurally intact old-growth lowland tropical forests inventoried within the African Tropical Rainforest Observatory Network (AfriTRON). We use 100 long-term inventory plots from six countries each measured at least twice prior to and once following the 2015-2016 El Niño event. These plots experienced the highest temperatures and driest conditions on record. The record temperature did not significantly reduce carbon gains from tree growth or significantly increase carbon losses from tree mortality, but the record drought did significantly decrease net carbon uptake. Overall, the long-term biomass increase of these forests was reduced due to the El Niño event, but these plots remained a live biomass carbon sink (0.51 ± 0.40 Mg C ha-1 y-1) despite extreme environmental conditions. Our analyses, while limited to African tropical forests, suggest they may be more resistant to climatic extremes than Amazonian and Asian forests

Height-diameter allometry of tropical forest trees

Copyright © 2011 European Geosciences Union. This is the published version available at http://www.biogeosciences.net/8/1081/2011/bg-8-1081-2011.html doi:10.5194/bg-8-1081-2011Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical countries. Utilising this database, our objectives were: 1. to determine if H:D relationships differ by geographic region and forest type (wet to dry forests, including zones of tension where forest and savanna overlap). 2. to ascertain if the H:D relationship is modulated by climate and/or forest structural characteristics (e.g. stand-level basal area, A). 3. to develop H:D allometric equations and evaluate biases to reduce error in future local-to-global estimates of tropical forest biomass. Annual precipitation coefficient of variation (PV), dry season length (SD), and mean annual air temperature (TA) emerged as key drivers of variation in H:D relationships at the pantropical and region scales. Vegetation structure also played a role with trees in forests of a high A being, on average, taller at any given D. After the effects of environment and forest structure are taken into account, two main regional groups can be identified. Forests in Asia, Africa and the Guyana Shield all have, on average, similar H:D relationships, but with trees in the forests of much of the Amazon Basin and tropical Australia typically being shorter at any given D than their counterparts elsewhere. The region-environment-structure model with the lowest Akaike's information criterion and lowest deviation estimated stand-level H across all plots to within amedian −2.7 to 0.9% of the true value. Some of the plot-to-plot variability in H:D relationships not accounted for by this model could be attributed to variations in soil physical conditions. Other things being equal, trees tend to be more slender in the absence of soil physical constraints, especially at smaller D. Pantropical and continental-level models provided less robust estimates of H, especially when the roles of climate and stand structure in modulating H:D allometry were not simultaneously taken into account

High aboveground carbon stock of African tropical montane forests

Tropical forests store 40–50 per cent of terrestrial vegetation carbon1. However, spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests2. Owing to climatic and soil changes with increasing elevation3, AGC stocks are lower in tropical montane forests compared with lowland forests2. Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC stock of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1–164.2), which is comparable to lowland forests in the African Tropical Rainforest Observation Network4 and about 70 per cent and 32 per cent higher than averages from plot networks in montane2,5,6 and lowland7 forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the Intergovernmental Panel on Climate Change default values for these forests in Africa8. We find that the low stem density and high abundance of large trees of African lowland forests4 is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million hectares of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help to guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse9,10 and carbon-rich ecosystems