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Projected outcome of the decision to implement ANR in Desa'a (a), high decision-value variables (b), the respective cashflows (c) and important variables (determined by VIP analysis of PLS regression models) (d). The results were produced through MC simulation (10,000 model runs) of ANR performance over 25 years. In the PLS plot, green bars indicate positive correlations of uncertain variables with the outcome variable, while red bars indicate negative correlations. Blue bars indicate variables that did not meet the threshold of the model sensitivity analysis. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
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Forest and Landscape Restoration (FLR) is carried out with the objective of regaining ecological functions and enhancing human well-being through intervention in degrading ecosystems. However, uncertainties and risks related to FLR make it difficult to predict long-term outcomes and inform investment plans. We applied a Stochastic Impact Evaluation...
Contexts in source publication
Context 1
... never exceeding 4000 USD ha 1 . VIP analysis of outcomes revealed 9 variables that the projected returns were sensitive to. The impact of ANR on yields in the surrounding agricultural area, market price of carbon, annual rate of deforestation, and viability of carbon marketing were the 4 most highly ranked variables correlated with ANR outcomes (Fig. 4d). VOI analysis revealed that there were no critical knowledge gaps to be filled (Fig. ...
Context 2
... projected returns were sensitive to. The impact of ANR on yields in the surrounding agricultural area, market price of carbon, annual rate of deforestation, and viability of carbon marketing were the 4 most highly ranked variables correlated with ANR outcomes (Fig. 4d). VOI analysis revealed that there were no critical knowledge gaps to be filled (Fig. ...
Citations
... Hence, future work that assesses risks in greater detail (e.g. 53 ) for oil palm farming, along with enhanced soil C stocks estimated at deeper depths, can improve the understanding and potential of C prices needed to offset opportunity costs under a much wider range of socio-economic and ecological scenarios than those presented in this study. It is important to mention that programs implemented to compensate landowners for avoided C emissions involve costs associated with the setting up and running of payment operations including monitoring and contractual compliance 54 . ...
Secondary tropical forests are at the forefront of deforestation pressures. They store large amounts of carbon, which, if compensated for to avoid net emissions associated with conversion to non-forest uses, may help advance tropical forest conservation. We measured above- and below-ground carbon stocks down to 1 m soil depth across a secondary forest and in oil palm plantations in Malaysia. We calculated net carbon losses when converting secondary forests to oil palm plantations and estimated payments to avoid net emissions arising from land conversion to a 22-year oil palm rotation, based on land opportunity costs per hectare. We explored how estimates would vary between forests by also extracting carbon stock data for primary forest from the literature. When tree and soil carbon was accounted for, payments of US14–40 tCO2–1 for primary forest would equal opportunity costs associated with oil palm plantations per hectare. If detailed assessments of soil carbon were not accounted for, payments to offset opportunity costs would need to be considerably higher for secondary forests (US$28–80 tCO2–1). These results show that assessment of carbon stocks down to 1 m soil depth in tropical forests can substantially influence the estimated value of avoided-emission payments.
... For instance, the overexploitation of the tree for subsistence use should be minimized by introducing alternative livelihood strategies. In the Desa'a forest, various environmentally friendly and non-destructive alternative livelihoods have been suggested, including the gathering of non-timber forest products (e.g., medicinal plants, edible fruits and honey production), poultry farming and home gardening (Tamba et al., 2021;Gidey et al., 2023). Overgrazing of D. ombet habitats can also be reduced by introducing livestock exclosures. ...
... Overgrazing of D. ombet habitats can also be reduced by introducing livestock exclosures. The latter are critical to enhance the conservation of the species as it improves the microclimate of the area, increasing the abundance of viable seeds for regeneration and protecting the emerged small seedlings (Ghazali et al., 2008;Tamba et al., 2021). Moreover, the degradation of Desa'a forest by soil erosion and runoff can be minimized through community-based construction of soil and water conservation structures like in-situ micro basines, deep and shallow trenches and terraces. ...
Dracaena ombet, a flagship tree species in arid ecosystems, holds a significant ecological, economic, and socio-cultural value. However, its persistence is currently under threat from both anthropogenic and natural factors. Consequently, the species has been listed as an endangered tree species on the IUCN Red List, requiring urgent conservation actions for its continued existence. To develop effective conservation actions, it is necessary to have information on the population dynamics of the species. A study was conducted in the lowland and midland agroecological zones (sites) within the Desa'a dry Afromontane forest, northern Ethiopia to analyze the population status of D. ombet and identify its site-specific threats. At each site, abundance, health status, diameter, height and threats of the species were collected using 60 sample plots (20 m × 20 m) distributed over six transects (500 m × 20 m) spaced one km apart. The study showed that the D. ombet population was characterized by low abundance and unstable structure. It was further characterized by a substantial number of unhealthy damaged and dead trees. The low abundance of the species with unstable age structure in the dry Afromontane forests can be attributed to various factors such as stem cutting and debarking, leaf defoliation, overgrazing, soil erosion, and competition from expansive shrubs. Alternative livelihood options for the local inhabitants should be introduced to minimize the overexploitation of D. ombet for subsistence use in the dry Afromontane forests. The impacts of overgrazing and soil erosion on D. ombet and its Desa'a habitats should also be addressed through the introduction of community-based exclosures and in-situ soil and water conservation practices, respectively.
... The largest part of the forest area is located in the highlands of Tigray with extensions into Afar's lowland. The overall altitude ranges from around 900 m in the lowlands up to 3000 m a.s.l. in the highlands (Tamba et al., 2021). The forest acts as a buffer zone between the hot lowlands of Afar and the cooler highlands of Tigray (Hishe et al., 2021). ...
... The forest inhabits around 90 different tree and shrub species but used to be dominated by Juniperus procera and Olea europaea subsp. Cuspidata, which are characteristic species for dry Afromontane forests (Tamba et al., 2021). However, the forest is constantly under tremendous anthropogenic as well as climate induced pressure, which results in degradation and a changing species composition. ...
... For instance, the overexploitation of the species for generating income should be reduced by introducing alternative livelihood sources. In the Desa'a forest, various environmentally friendly alternative livelihoods have been suggested, including the collection of non-timber forest products (e.g., medicinal plants and honey), poultry farming and home gardening (Tamba et al., 2021;Gidey et al., 2023). Overgrazing in the species habitats can also be reduced through introducing livestock exclosures. ...
... Overgrazing in the species habitats can also be reduced through introducing livestock exclosures. This is important to enhance the conservation of the species as it improves the microclimate of the area, increasing the abundance of viable seeds and protecting the emerged seedlings (Ghazali et al., 2008;Tamba et al., 2021;Gidey et al., 2023). ...
... The largest part of the forest area is located in the highlands of Tigray with extensions into Afar's lowland. The overall altitude ranges from around 900 m in the lowlands up to 3000 m a.s.l. in the highlands (Tamba et al., 2021). The forest acts as a buffer zone between the hot lowlands of Afar and the cooler highlands of Tigray (Hishe et al., 2021). ...
... The forest inhabits around 90 different tree and shrub species but used to be dominated by Juniperus procera and Olea europaea subsp. Cuspidata, which are characteristic species for dry Afromontane forests (Tamba et al., 2021). However, the forest is constantly under tremendous anthropogenic as well as climate induced pressure, which results in degradation and a changing species composition. ...
... The ability of experts to provide useful estimates that actually express the state of knowledge on particular variables can be enhanced through a process known as 'calibration training'. From range estimates for all model input variables, the net benefits of particular intervention options can then be computed through probabilistic simulations (Tamba et al., 2021). Content courtesy of Springer Nature, terms of use apply. ...
Many farmers hesitate to adopt new management strategies with actual or perceived risks and uncertainties. Especially in ornamental plant production, farmers often stick to current production strategies to avoid the risk of economically harmful plant losses, even though they may recognize the need to optimize farm management. This work focused on the economically important and little-researched production system of ornamental heather (Calluna vulgaris) to help farmers find appropriate measures to sustainably improve resource use, plant quality, and profitability despite existing risks. Probabilistic cost-benefit analysis was applied to simulate alternative disease monitoring strategies. The outcomes for more intensive visual monitoring, as well as sensor-based monitoring using hyperspectral imaging were simulated. Based on the results of the probabilistic cost-benefit analysis, the expected utility of the alternative strategies was assessed as a function of the farmer's level of risk aversion. The analysis of expected utility indicated that heather production is generally risky. Concerning the alternative strategies, more intensive visual monitoring provides the highest utility for farmers for almost all levels of risk aversion compared to all other strategies. Results of the probabilistic cost-benefit analysis indicated that more intensive visual monitoring increases net benefits in 68% of the simulated cases. The application of sensor-based monitoring leads to negative economic outcomes in 85% of the simulated cases. This research approach is widely applicable to predict the impacts of new management strategies in precision agriculture. The methodology can be used to provide farmers in other data-scarce production systems with concrete recommendations that account for uncertainties and risks.
Supplementary information:
The online version contains supplementary material available at 10.1007/s11119-022-09909-z.
Assisted Natural Regeneration (ANR) is a set of restoration strategies and interventions primarily based on natural regeneration, aimed at accelerating succession and providing multiple benefits in degraded ecosystems and landscapes. These strategies have the potential to significantly contribute to global Forest and Landscape Restoration efforts. However, ANR faces challenges due to limited recognition, support, and formal integration into relevant sectors and restoration policies, particularly in tropical regions. The dearth of evidence-based syntheses further compounds these challenges. To address this gap, a bibliometric analysis of selected scientific publications on ANR (n = 208) from 1987 to 2023 was conducted, using Web of Science and Google Scholar databases. A systematic review was undertaken, using a subset of original research articles (n = 44), to synthesize published data on interventions, contexts, costs, and benefits of ANR and to identify major knowledge gaps. Analysis of bibliometric metadata revealed an increasing annual output of ANR publications in over 80 journals, encompassing various document types and authors from over 40 countries. Despite ANR's formal emergence in the Philippines, Brazil has taken the lead in both its research and implementation, and international collaboration in ANR research has grown. While ANR research focused mostly on ecosystem services and ecological outcomes, social aspects have been poorly studied. Diverse ANR interventions align not only with ecological restoration but also with integrated land management, biodiversity conservation, forest and landscape restoration, and forest management. The cost-effectiveness of ANR implementation, especially in restoration for carbon storage, exhibited considerable variability when compared to active tree planting, and varied with intervention types, time, land use history, and long-term costs. This synthesis provides critical insights and evidence to enhance the effective integration of ANR into restoration and reforestation programs and policies.
