Heterogeneity and assessment uncertainties in forest characteristics and biomass carbon stocks: Important considerations for climate mitigation policies

The management of forests to store carbon and mitigate climate change has received significant international attention during the last decade. Using in situ data from a 2008–2009 forest inventory field campaign in Sri Lanka, this study describes the structural characteristics and carbon stocks of six natural forest types. This paper has a dual scope: i) to highlight the variation in carbon stored in aboveground biomass within and between forest types and ii) to determine the implications of the allometric equations chosen to calculate biomass carbon stocks. This study concerns work related to climate change interventions, such as Reducing Emissions from Deforestation and Forest Degradation (REDD+) and other forest-related, performance-based initiatives that require proper monitoring, reporting, and verification of carbon stocks, sinks and emissions. The results revealed that forests are heterogeneous in terms of tree density and height–diameter relationships, both between and within the six forest types investigated. The mean aboveground carbon stock in the different forest types ranged from 22 to 181 Mg C ha⁻¹, and there were statistically significant differences in the carbon stocks of the six forest types in 7 of 15 cases. The estimated carbon stock depended heavily on the allometric equation used for the calculations, the variables, and its application to the specific life zone. Due to the diversity of forest structures, these results suggest that caution should be taken when applying default values to estimate forest carbon stocks and emission values in reporting and accounting schemes. The results also indicated the need for allometric equations that are context-specific for different forest types. Therefore, new field investigations and measurements are needed to determine these specific allometric equations, as well as the potential variation in forest carbon stocks in tropical natural forests.     

Carbon storage in a bamboo (Bambusa vulgaris) plantation in the degraded tropical forests: Implications for policy development

Tropical forests potentially contribute to global climate change mitigation through carbon sequestration, hence a global carbon pool. In order to mitigate the global climate change impact, the Kyoto protocol developed the clean development mechanism (CDM) which supports carbon credits for plantation activities in developing countries. Unfortunately, none of the CDM forestry projects included bamboo as a carbon reservoir. Although bamboo is an integrating part of tropical forest ecosystems, it was overlooked in the initial negotiating process. The present study, therefore, investigated the carbon storage potential of a common bamboo species, Bambusa vulgaris at Lawachara forest reserve of Bangladesh. Results showed that five-year-old B. vulgaris stand stored in total 77.67 t C ha⁻¹ of which 50.44 t C ha⁻¹ were stored in the above ground biomass (culms, branches and leaves), 2.52 t C ha⁻¹ in the below ground biomass and 24.71 t C ha⁻¹ in the soils. This amount of carbon storage is much more promising than the carbon storage of many other tree species considered in the CDM projects. These findings demonstrate the potential of B. vulgaris to be considered in CDM projects as a plantation species and thereby mitigate climate change impact more efficiently.     

Forest fragmentation reduced carbon storage in a moist tropical forest in Bangladesh: Implications for policy development

Forest fragmentation is continued to be widespread in the tropics resulting in reduced ecosystem services including carbon storage. However, the effect of forest fragmentation is not considered in the current carbon policy. We investigated the effect of forest fragmentation on tree biomass carbon and soil organic carbon (SOC) storage in a moist tropical forest in Bangladesh. Above and below-ground tree biomass carbon were calculated by using widely accepted allometric equations and SOC was measured by sampling soils up to 10 cm depth and analyzing them in a soil laboratory. Results showed that carbon storage in tree biomass was significantly lower in fragmented forests (16.3 ± 1.37 t C ha⁻¹) than in contiguous forests (31.21 ± 2.75 t C ha⁻¹) (p < 0.001). Likewise, a significantly lower SOC was contained in the soils of fragmented forests (17.26 ± 0.83 t C ha⁻¹) than in contiguous forests (21.62 ± 0.78 t C ha⁻¹) (p < 0.001). Thus a total of 36% less carbon retained in tree biomass and soils in fragmented forests than in contiguous forests. Backward multiple linear regression analysis revealed tree density, tree height, tree DBH, height-diameter ratio (H/D) and tree species richness as influential factors of carbon variation in fragmented forests. All these structural parameters except tree species richness were significantly lower in fragmented forests, were positively associated with carbon storage and explained together 69% of the carbon storage variation. These findings suggest that the altered stand structure and tree allometry likely caused reduced carbon storage in fragmented forests and highlight the importance of landscape scale management intervention in the tropics. Here, we provided with the evidence of strong negative impact of forest fragmentation on carbon storage and argue that this effect should be in consideration which is currently overlooked in existing carbon accounting systems for tropical forests.     

Analysing foregone costs of communities and carbon benefits in small scale community based forestry practice in Nepal

Reducing emissions from deforestation and forest degradation, conservation and sustainable management of forests and enhancement of forest carbon (REDD+) are considered to be important cost effective approaches for global climate change mitigation; therefore, such practices are evolving as the REDD+ payment mechanism in developing countries. Using six years (2006–2012) data, this paper analyses trade-offs between carbon stock gains and the costs incurred by communities in generating additional carbon in 105 REDD+ pilot community forests in Nepal. It estimates foregone benefits for communities engaged in increasing carbon stocks in various dominant vegetation types. At recent carbon and commodity prices, communities receive on average US$ 0.47/ha/year of carbon benefits with the additional cost of US$ 67.30/ha/year. One dollar’s worth of community cost resulted 0.23 Mg of carbon sequestration. Therefore, carbon payment alone may not be an attractive incentive within small-scale community forestry and should link with payments for ecosystem services. Moreover, the study found highest community sacrificed benefits in Shorea mixed broadleaf forests and lowest in Schima-Castanopsis forests, while carbon benefits were highest in Pine forests followed by Schima-Castanopsis forests and lowest in Rhododendron-Quercus forests. This indicates that costs and benefits may vary by vegetation type. A policy should consider payment for other environmental services, carbon gains, co-benefits and trade off while designing the REDD+ mechanism in community based forest land use practice with equitable community outcomes. The learning from this study will help in the formulation of an appropriate REDD+ policy for community forestry.     

Carbon mitigation potential of the French forest sector under threat of combined physical and market impacts due to climate change

Objectives(1) To quantify the contribution of the French forest-wood product chain in terms of carbon sequestration and substitution when accounting for both the physical impacts (shifts in tree growth and mortality rates) and the market impacts (increased demand of harvested wood products (HWP)) of climate change (cc) and the subsequent forest managers adaptations; (2) To assess the uncertainty of the impacts on the above carbon balance and on forest allocation; and (3) To assess the role of managers’ expectations toward these future, uncertain but highly anticipated, impacts.MethodologyWe used a bio-economic model of the French Forest Sector (FFSM++) that is able to consider and integrate: (a) the effects of climate change over forest dynamics; (b) forest investment decisions (among groups of species) according to expected profitability; and (c) market effects in terms of regionalised supply, consumption and trade of HWP, depending on the forest resource stocks and international prices. By including both forest dynamics and forest products, we can evaluate the carbon balance taking the following elements into consideration: (a) carbon sequestered in live and dead biomass in the forest; (b) carbon sequestered in HWP; (c) carbon substituted when wood is used in place of fossil fuels or more energy-intensive materials; and (d) carbon released by forest operations.ResultsWhen the model is run at constant conditions for the next century, the average carbon potential of French forests is 66.2–125.3 Mt CO₂ y⁻¹, depending on whether we consider only inventoried wood resources, HWP pools and direct energy substitution, or if we also account for the carbon stored in tree branches and roots and if we consider the more indirect, but also largely more subjective, material substitution. These values correspond to 18.3% and 34.7%, respectively, of the French 2010 emissions (361 Mt CO₂). However, when we consider both the probable increment of coniferous mortality and changes in forest growth, plus the rise in HWP demand worldwide, the average sequestration rate of the French forest decreases by 6.6–5.8% to 61.8–118.0 Mt CO₂ y⁻¹. Running partial scenarios, we can assess the relative interplay of these two factors, where the price factor increases the HWP stock while decreasing the forest stocks (where the latter effect prevails), while the physical impact of climate change reduces both, but to a lesser extent. Considering short-sighted forest managers, whose behaviour is based uniquely on the observed conditions at the time decisions are made, we obtain a limited effect of the overall carbon balance but a relatively large impact on the area allocation of broadleaved vs. coniferous species.     

Shifting patterns of oil palm driven deforestation in Indonesia and implications for zero-deforestation commitments

Oil palm plantations in Indonesia have been linked to substantial deforestation in the 1990s and 2000s, though recent studies suggest that new plantations are increasingly developed on non-forest land. Without nationwide data to establish recent baseline trends, the impact of commitments to eliminate deforestation from palm oil supply chains could therefore be overestimated. We examine the area and proportion of plantations replacing forests across Sumatra, Kalimantan, and Papua up to 2015, and map biophysically suitable areas for future deforestation-free expansion. We created new maps of oil palm plantations for the years 1995, 2000, 2005, 2010 and 2015, and examined land cover replaced in each period. Nationwide, oil palm plantation expansion occurred at an average rate of 450,000 ha yr⁻¹, and resulted in an average of 117,000 ha yr⁻¹ of deforestation, during 1995–2015. Our analysis of the most recent five-year period (2010–2015) shows that the rate of deforestation due to new plantations has remained relatively stable since 2005, despite large increases in the extent of plantations. As a result, the proportion of plantations replacing forests decreased from 54% during 1995–2000, to 18% during 2010–2015. In addition, we estimate there are 30.2 million hectares of non-forest land nationwide which meet biophysical suitability criteria for oil palm cultivation. Our findings suggest that recent zero-deforestation commitments may not have a large impact on deforestation in Sumatra, where plantations have increasingly expanded onto non-forest land over the past twenty years, and which hosts large potentially suitable areas for future deforestation-free expansion. On the other hand, these pledges could have more influence in Kalimantan, where oil palm driven deforestation increased over our study period, and in Papua, a new frontier of expansion with substantial remaining forest cover.     

Interventions to better manage the carbon stocks in Australian Melaleuca forests

Forests and woodlands dominated by tree species of the genus Melaleuca cover around 7,556,000 ha in Australia and predominantly occur as wetland ecosystems. In this Viewpoint, we use published secondary data to estimate that there is likely to be between 158 tC/ha and 286 tC/ha stored in Melaleuca forests. These estimates are at least five times greater than the previous estimate made by the Australian Government (about 27.8 tC/ha). There are 2.1 million ha of protected Melaleuca forest which likely stock between 328 M tC and 601 M tC; equivalent to between 2.7% and 5.0% of total carbon storage of all Australian native forests. These estimates are significant because it appears that carbon stocks in Melaleuca forests are currently dramatically under-estimated in Australia's national greenhouse gas emissions inventory reported under the United Nations Framework Convention on Climate Change (UNFCCC). Whilst the precision of the estimates is limited by the availability of rigorous primary data, we also argue that the estimates are indicative and meaningful, and this synopsis highlights the fact that this forest type should be considered a significant carbon store nationally and globally.     

The potential and cost of increasing forest carbon sequestration in Sweden

This paper examines the potential and the cost of promoting forest carbon sequestration through a tax/subsidy to land owners for reducing/increasing carbon storage in their forests. We use a partial equilibrium model based on intertemporal optimization to estimate the impacts of carbon price (the tax/subsidy rate) on timber harvest volume and price in different time periods and on the change of forest carbon stock over time. The results show that a higher carbon price would lead to higher forest carbon stocks. The tax/subsidy induced annual net carbon sequestration is declining over time. The net carbon sequestration during 2015–2050 would increase by 30.2 to 218.3 million tonnes of CO₂, when carbon price increases from 170 SEK to 1428 SEK per tonne of CO₂. The associated cost, in terms of reduced total benefits of timber and other non-timber goods, ranges from 80 SEK to 105.8 SEK per tonne of CO₂. The change in carbon sequestration (as compared with the baseline case) beyond 2050 is small when carbon price is 680 SEK per tonne of CO₂ or lower. With a carbon price of 1428 SEK per tonne of CO₂, carbon sequestration will increase by 70 million tonnes of CO₂ from the baseline level during 2050-2070, and by 64 million tonnes during 2070–2170.     

Farmers and their groves: Will cost inefficiency lead to land use change?

Increased forest areas and climate change mitigation are policy goals enhanced by expanding private forest ownership. This study shows transfer of land from farms owning forested acreage associated with low quality land and high production costs achieves such goals. Calculated cost efficiency scores show a large gap between the most and least efficient farms, and farms with forests are less cost efficient. Land reforestation through subsidy programs could replace income from agricultural production. We illustrate that farms from the applied FADN panel could reforest 45,000 hectares, binding about 0.5 mln tons of carbon annually without limiting food or feed supply.     

Methodology to calculate the carbon footprint of household land use in the urban planning stage

The growing concerns of climate change require implementing measures to quantify, to monitor and to minimize greenhouse gas (GHG) emissions. Nonetheless, most of the measures available are not easy to define or execute because they rely on current emissions and have a corrective character. To address this issue, a methodology to characterize GHG emissions that allows implementing preventive measures is proposed in this paper. The methodology is related to household urban planning procedures and considers urban infrastructures to characterize GHG emissions and to execute preventive measures based on sustainability design criteria. The methodology has been tested by applying it to a set of medium-sized municipalities with average GHG emissions from 6,822.32 kgCO_2eq/year to 5,913.79 kgCO_2eq/year for every residential unit. The results indicate that the greatest pollutant source is transport, especially in the issuance of street network design, followed by gas and electricity consumption. The average undevelopable land area required for the complete GHG emissions capture amounts to 3.42 m² of undevelopable land for every m² of urbanizable land and 9.02 m² of undevelopable land for every m² of built land.     

Assessing the efficiency of switchgrass different cultural practices for pellet production

Switchgrass is a perennial crop producing high amounts of biomass for good quality pellet production. The objective of this study is to examine the efficiency of different cultural practices of switchgrass for pellet production under field conditions for four different N-fertilization (0, 80, 160 and 240 kg ha⁻¹) and two different irrigation levels (0 and 250 mm), in two soils in central Greece with rather different moisture status over the period 2009–2012. Moreover, comparison between three harvest methods (two different types of bales and silage) was made. The results derived from this study revealed that the bale at 22 kg is the harvesting practice with the highest costs while there was reduction of efficiency scores when nitrogen levels increased. At both environments the efficiency scores followed the same trend, confirming that low levels of nitrogen fertilization enhance the economic competitiveness of switchgrass production. Palamas site is the area where switchgrass for pellet production had positive income ranging from 400 to 1600 € ha⁻¹, while Velestino site had always negative. Therefore, places like Velestino with non-aquic soil should be avoided for switchgrass. These data suggest that growing switchgrass for solid biofuel production as energy crop is a worthwhile decision only in areas with a moderately shallow groundwater table (aquic soil) or maybe in high precipitation regions.     

Wood biomass use for energy in Europe under different assumptions of coal,gas and CO2 emission prices and market conditions

This study examines the effects of different coal, natural gas and carbon emission prices and market situations on the use of wood for electricity and heat production in the European Union. The analysis is carried out using the global forest sector model EFI-GTM expanded to cover electricity and heat production from wood, coal, natural gas, wind and solar energy. Analysis shows that with low coal and gas prices, use of wood for energy will be limited to low cost logging residues. With high coal, and especially natural gas prices, industrial wood also comes to be used for energy. At a carbon price of 100 €/tCO₂, some 32 Mm³ of industrial wood, in addition to 224 Mm³ of logging residues, are projected to be used for electricity and heat in the EU region (including Norway and Switzerland) in 2030. The relatively low quantity of industrial wood used by the energy sector despite the collapse of the use of coal is explained by the fact that under high CO₂ prices, other energy forms like natural gas, solar and wind energy become more and more competitive. However, the amount of industrial wood used for energy may substantially increase with subsidies for using wood for electricity and heat, even with relatively low carbon prices. With a high coal and gas price and a carbon price of 100 €/t, a subsidy of 30 €/MWh to the wood based and coal with wood co-firing electricity production will have a significant impact on the European wood based sector. Depending on the development of the market demand for forest industry products, such a subsidy may cause a 10–12.5% reduction in forest products production, a 6–9% increase in harvest level, about 30–60% increase in the pulpwood prices, and a 6–9 fold increase of wood imports in the EU, compared to the respective case without a subsidy in 2030.     

Mapping properties to monitor forests: Landholder response to a large environmental registration program in the Brazilian Amazon

Across the tropics, development banks and conservation donors are investing millions in property mapping and registration projects to improve accountability for deforestation. An evaluation of the effectiveness and accuracy of existing environmental registries is crucial to assure the success of future efforts. This study presents an evaluation of deforestation and registration behavior in response to one of the largest of these property registration programs to date — the Rural Environmental Registry (CAR) in the Amazonian state of Pará. From late 2007 to 2013, approximately 100,000 properties covering 30 million hectares of self-declared claims were entered in this digital registry. We used fixed effects regression models and property level data to assess how registration influenced deforestation on different sizes of properties. Registration had little impact on deforestation behavior, with the exception of a significant reduction on “smallholder” properties in the size range of 100–300 ha. We link this reduction to interacting incentives from forest protection and land regularization policies and suggest that desire to strengthen land claims motivates these landholders’ response to the environmental registry. We also present evidence that some landholders may be registering incomplete or inaccurate parcels into the self-declared system to strategically benefit from policy incentives. Our results for smallholder properties indicate that environmental registries may have potential to facilitate reductions in deforestation if combined with a favorable combination of incentives. However, in places where land tenure is still being negotiated, the utility of environmental registries for forest policy enforcement and research may be limited without ongoing investment to resolve uncertainty around land claims.     

Compensating for past deforestation: Assessing the legal forest surplus and deficit of the state of Pará, eastern Amazonia

Up to 80% of each private rural property in the Brazilian Amazon is protected by law through the Legal Reserve (LR) mechanism of the federal Forest Code, underlining the conservation importance of forests on private lands in one of the world̿s most important biomes. However, our understanding of the discrepancies in levels of forest protection on private lands as obligated by the law versus what occurs in practice remains very poor. We assessed patterns of forest cover and legal compliance with the Forest Code in the 1.25 Mkm² Brazilian state of Pará, which has the highest deforestation rate in the Amazon. We evaluate the LR deficit and surplus patterns for different sized properties and across 144 municipalities, and found that the total LR surplus (12.6 Mha) was more than five times the total area of deficit (2.3 Mha). Yet, from the total surplus, only 11% can be legally deforested while the remaining 89% is already protected by law but can be used (sold or rented) to compensate for areas that are under deficit. Medium and large-scale properties make up most of the total LR deficit area, while agrarian reform settlements had comparatively large amounts of both compensation-only surplus and deforestable surplus. Most of the municipalities (77%) in the state could compensate their total deficit with surplus areas of LR in the same municipality, while the remainder can be compensate their deficit in one or more neighbouring municipalities, indicating compensation can always take place close to the source of the deficit. Maximising the environmental benefits of achieving Forest Code compliance requires measures that go beyond the existing legal framework, including interventions to avoid further deforestation in places where it is still legal, compensate in close proximity to areas with legal reserve deficit and promote local restoration on degraded lands.     

Estimating the opportunity costs of reducing carbon dioxide emissions via avoided deforestation,using integrated assessment modelling

Estimates show that, in recent years, deforestation and forest degradation accounted for about 17% of global greenhouse gas emissions. The implementation of REDD (Reducing Emissions from Deforestation and Forest Degradation in Developing Countries) is suggested to provide substantial emission reductions at low costs, although cost estimates show large uncertainty. Cost estimates can differ, as they depend on the approach chosen, for example: giving an economic stimulus to entire countries, taking landowners as actors in a REDD framework, or starting from protecting carbon-rich areas. This last approach was chosen for this analysis. Proper calculation of the economic cost requires an integrated modelling approach involving biophysical impact calculations and their associated economic effects. To date, only a few global modelling studies have applied such an approach. In modelling REDD measures, the actual implementation of REDD can take many forms, with implications for the results. This study assumes that non-Annex I countries will protect carbon-rich areas against deforestation, and therefore will refrain from using these areas as agricultural land. The opportunity costs of reducing deforestation within the framework of REDD were assessed using an integrated economic and land-use modelling approach comprising the global economic LEITAP model and the biophysical IMAGE model. One of the main methodological challenges is the representation of land use and the possibility to convert woodlands land into agricultural land. We endogenised the availability of agricultural land by introducing a flexible land supply curve, and represented the implementation of REDD policies as a reduction in the maximum amount of unmanaged land that potentially would be available for conversion to agriculture, in various regions in the world. In a series of model experiments, carbon-rich areas in non-Annex I countries were protected from deforestation. In each consecutive scenario the protected area was increased, starting off with the most carbon rich lands, worldwide systematically working down to areas with less carbon storage. The associated opportunity costs, expressed in terms of GDP reduction, were calculated with the economic LEITAP model. The resulting net reduction in carbon dioxide emissions from land-use change was calculated with the IMAGE model. From the sequence of experiments, marginal cost curves were constructed, relating carbon dioxide emission reductions to the opportunity costs. The results showed that globally a maximum of around 2.5 Gt carbon dioxide emissions could be avoided, annually. However, regional differences in opportunity costs are large and were found to range from about 0 to 3.2 USD per tonne carbon dioxide in Africa, 2 to 9 USD in South America and Central America, and 20 to 60 USD in Southeast Asia. These results are comparable to other studies that have calculated these costs, in terms of both opportunity costs and the regional distribution of emissions reduction.     

The financial benefits of forest certification: Case studies of acacia growers and a furniture company in Central Vietnam

The demand for forest products is growing and plantation forests are supplying an increasing proportion of wood to industry. There are also increasing market requirements to demonstrate the sustainability of timber supply. Vietnam has some 3.9 M ha of plantation forests, 44% of which is on short-rotations managed by smallholders. More than 80 percent of the harvested volume from the plantation forests is used for woodchip production to serve domestic and international markets. The Vietnam Government has goals to increase the domestic supply of suitable wood for furniture production to international markets by increasing the supply of larger logs grown in plantations and the supply of certified wood to industry. However, it is not clear that these objectives will necessarily benefit growers and processors. This study compared financial returns from certified and non-certified forest products for: (1) growers with 10-year rotation acacia plantations; and (2) a furniture processing business (battens for chair and table) in Quang Tri Province, Central Vietnam. The data were collected from smallholder tree growers and a sawmilling company, triangulated with and supplemented by formal and informal interviews with other stakeholders. Currently, much of the cost of certification is met by external aid donors. Results showed that net returns from both certified and non-certified timber products are positive for both actors and are higher from certified timber production than non-certified timber production. When the full costs of certification are included, the benefits to growers of certification are much reduced and potentially negative unless the fixed costs can be spread over a large group of growers. A minimum of group with 3000 ha may be required to make certification cost effective. In recent years, the price difference between the certified and non-certified logs is narrowing and this may discourage farmers from attaining certification. For the sawmiller, the benefit of certified timber production is greater. It would be in their interests to increase prices paid to growers for certified logs. Government policy measures to support certification should include consideration of who bears the cost, support for aggregation of smallholder growers and improved communication in timber supply chains.     

The impact of forest management plans on trees and carbon: Modeling a decade of harvesting data in Cameroon

By 2010, about 25% (180 million ha) of The International Tropical Timber Organization (ITTO) producer countries’ permanent forest estate was being managed using an approved forest management plan (FMP). While the existence of a FMP is often used as evidence of sustainable forest management (SFM), State officials mandated to monitor and verify FMPs’ implementation often lack the technical knowledge and political incentives to assess the changes that have been introduced, notably in terms of harvested volumes and species. Among tropical timber producers, Cameroon is considered to be exemplary for its progressive forest regulatory framework. Here we aim to estimate for the first time in sub-Saharan Africa the causal impact of the implementation of FMPs on harvested volumes, species and carbon stocks. We do so by using a 12-year (1998–2009) unbalanced longitudinal data set of a detailed, official harvesting inventory of 81 concessions in Cameroon. Results provide evidence to the theoretical expectations that for many years many practitioners have had on the implementation of SFM, i.e. that FMPs show a substantial opportunity to reduce carbon emissions from forest while presenting logging companies with acceptable financial trade-offs. We explore the technical and political reasons for our findings and conclude that these analyses are important for countries that are underwriting carbon-related schemes in which they propose to reduce their emissions through the effective implementation of SFM. We also demonstrate that producer countries do record useful information that, when effectively used, can help them to inform their policies and improve their sustainable development strategies.     

An interactive land use transition agent-based model (ILUTABM): Endogenizing human-environment interactions in the Western Missisquoi Watershed

Forest Transition Theory (FTT) suggests that reforestation may follow deforestation as a result of and interplay between changing social, economic and ecological conditions. We develop a simplistic but empirically data driven land use transition agent-based modeling platform, interactive land use transition agent-based model (ILUTABM), that is able to reproduce the observed land use patterns and link the forest transition to parcel-level heuristic-based land use decisions and ecosystem service (ES). The ILUTABM endogenously links landowners’ land use decisions with ecosystem services (ES) provided by the lands by treating both lands and landowners as interacting agents. The ILUTABM simulates both the land use changes resulting from farmers’ decision behaviors as well as the recursive effects of changing land uses on farmers’ decision behaviors. The ILUTABM is calibrated and validated at 30 m × 30 m spatial resolution using National Land Cover Data (NLCD) 1992, 2001 and 2006 across the western Missisquoi watershed, which is located in the north-eastern US with an estimated area of 283 square kilometers and 312 farmers farming on 16% of the total Missisquoi watershed area. This study hypothesizes that farmers’ land use decisions are made primarily based on their summed expected utilities and that impacts of exogenous socio-economic factors, such as natural disasters, public policies and institutional/social reforms, on farmers’ expected utilities can significantly influence the land use transitions between agricultural and forested lands. Monte Carlo experiments under six various socio-economic conditions combined with different ES valuation schemes are used to assess the sensitivities of the ILUTABM. Goodness-of-fit measures confirm that the ILUTABM is able to reproduce 62% of the observed land use transitions. However, the spatial patterns of the observed land used transitions are more clustered than the simulated counterparts. We find that, when farmers value food provisioning Ecosystem Services (ES) more than other ES (e.g., soil and water regulation), deforestation is observed. However, when farmers value less food provisioning than other ES or they value food provisioning and other ES equally, the forest transition is observed. The ILUTABM advances the Forest Transition Theory (FTT) framework by endogenizing the interactions of socio-ecological feedbacks and socio-economic factors in a generalizable model that can be calibrated with empirical data.     

Policy options towards deforestation reduction in Cameroon: An analysis based on a systematic approach

This study advances measures that can combat deforestation in Cameroon. It also looks at possible carbon dioxide (CO₂) emission reductions and the effects on gross domestic product (GDP) and employment based on selected baseline scenarios based on reductions in deforestation. A systematic approach of analyzing the drivers, agents, socio-economic context, political context, spatial context of deforestation and specific and general deforestation reduction policies is used. The final step of the approach is to verify the repercussions of deforestation reduction on CO₂ emissions, employment and GDP. Monitoring population growth and arable production through intensification of production is promising. The general policies that this study postulates are enforcement, legal adherence, specification of tasks and quotas, collaboration, forest licensing and monitoring. More specific policies could be within the reduction of emissions from deforestation and forest degradation mechanism (REDD+) as well as diversification of livelihoods, mechanization, use of fertilizers and intensive cattle farming inter alia. Reductions in deforestation will reduce atmospheric CO₂, employment in the forestry sector and the share of forestry's contribution to GDP.