Optimal rotation age for carbon sequestration and biodiversity conservation in Vietnam

Biodiversity loss is a major problem in terms of loss of genetic and ecosystem services and more specifically via impacts on the livelihoods, food security and health of the poor. This study modeled forest management strategies that balance economic gains and biodiversity conservation benefits in planted tropical forests. A forest-level model was developed that maximized the net present value (NPV) from selling timber and carbon sequestration while maintaining a given level of biodiversity (as per the population density of birds). The model was applied to Eucalyptus urophylla planted forests in Yen Bai Province, Vietnam. It was found that the inclusion of biodiversity conservation in the model induces a longer optimal rotation age compared to the period that maximizes the joint value from timber and carbon sequestration (from 8 to 10.9 years). The average NPV when considering timber values plus carbon sequestration was 13 million Vietnamese Dong (VND) ha^− 1 (765 USD ha^− 1), and timber, carbon sequestration and biodiversity values were 11 million VND (676 USD) ha^− 1. Given this differential, governments in such tropical countries may need to consider additional incentives to forest owners if they are to encourage maximizing biodiversity and its associated benefits. The results also have some implications for implementing the climate control measure of “Reducing Emissions from Deforestation and Forest Degradation-plus (REDD +)” in developing countries, i.e., payment for carbon sequestration and biodiversity benefits in planted forests.     

The economics of carbon sequestration through pest management: application to forested landbases in New Brunswick and Saskatchewan,Canada

This analysis employs a spruce budworm (Choristoneura fumiferana Clem.) decision support system to examine costs and benefits of sequestering (protecting) carbon in forests through pest management. We analyzed 24 alternative spruce budworm protection scenarios for outbreaks on Prince Albert Forest Management Area (PAFMA) in Saskatchewan and Crown License 1 in New Brunswick. Scenarios included two outbreak severities (moderate and severe), three protection frequencies (very aggressive—protecting every year of the outbreak; aggressive—protecting the peak 3 years of outbreak; and semi-aggressive—protecting every second year of outbreak), and four protection program sizes (10,000 ha, 25,000 ha, 100,000 ha, or 150,000 ha). Under a severe outbreak, the largest (150,000 ha), very aggressive protection scenario provided the highest net CO₂ protected at 24.95 million metric tons (Mt) in PAFMA and 29.19 Mt in License 1. This protection scenario also provided the highest net present value at $64.23 M and $91.36 M in PAFMA and License 1, respectively. On the other hand, benefit/cost ratios were maximized under the smallest (10,000 ha) protection size at 11.90 and 15.37 using the aggressive and semi-aggressive protection frequencies in PAFMA and License 1, respectively. Finally, the discounted cost per ton of CO₂ protected was minimized at $0.48 and $0.37 using the smallest aggressive and semi-aggressive protection frequencies in PAFMA and License 1, respectively. The comparable costs and benefits from the moderate outbreak scenarios were similar, but generally less than, the severe outbreak scenarios. These results provide forest managers with important information needed to justify such carbon sequestration programs on economic grounds.     

The Ankasa Forest Conservation Area of Ghana: Ecosystem service values and on-site REDD + opportunity cost

The Ankasa Forest Conservation Area is one of the most important protected areas (PA) in West Africa. This study aimed at estimating the economic values of selected ecosystem services of the PA and the direct on-site REDD + opportunity costs to communities. We found that the PA stocks 32.8 million m³ (627 m³/ha) of standing trees with a stumpage value of about $ 19.1 million (364 $/ha), 64.3 million tCO₂e (1230 tCO₂e/ha) of carbon worth of $379.5 million ($7257/ha), and 6380 tons of nutrients worth of 0.64 million USD. The direct on-site REDD + opportunity cost for conserving the PA until 2042 was about 6.7–24.1 $/tCO₂e (0.22–0.80 $/tCO2e per year) in net present value. From our field observation of the PA, we did not see a buffer zone that separates the PA from the surrounding land uses. Establishing a buffer zone is very important for the sustainability of the PA. Such an effort, however, should take in to account the opportunity costs to the rural communities associated with possible displacement. Thus, the results of the study could be used as important input for designing policies that will reinforce the sustainability of the Ankasa PA and other conservation sites in Ghana.     

Scenario analysis of the impacts of forest management and climate change on the European forest sector carbon budget

Analysis of the impacts of forest management and climate change on the European forest sector carbon budget between 1990 and 2050 are presented in this article. Forest inventory based carbon budgeting with large scale scenario modelling was used. Altogether 27 countries and 128.5 million hectare of forests are included in the analysis. Two forest management and climate scenarios were applied. In Business as Usual (BaU) scenario national fellings remained at the 1990 level while in Multifunctional (MultiF) scenario fellings increased 0.5–1% per year until 2020, 4 million hectare afforestation program took place between 1990 and 2020 and forest management paid more attention to current trends towards more nature oriented management. Mean annual temperature increased 2.5 °C and annual precipitation 5–15% between 1990 and 2050 in changing climate scenario. Total amount of carbon in 1990 was 12 869 Tg, of which 94% in tree biomass and forest soil, and 6% in wood products in use. In 1995–2000, when BaU scenario was applied under current climatic conditions, net primary production was 409 Tg C year⁻¹, net ecosystem production 164 Tg C year⁻¹, net biome production 84.5 Tg C year⁻¹, and net sequestration of the whole system 87.4 Tg C year⁻¹ which was equal to 7–8% of carbon emissions from fossil fuel combustion in 1990. Carbon stocks in tree biomass, soil and wood products increased in all applied management and climate scenarios, but slower after 2010–2020 than that before. This was due to ageing of forests and higher carbon densities per unit of forest land. Differences in carbon sequestration were very small between applied management scenarios, implying that forest management should be changed more than in this study if aim is to influence carbon sequestration. Applied climate scenarios increased carbon stocks and net carbon sequestration compared to current climatic conditions.     

Five years of REDD+ governance: The use of market mechanisms as a response to anthropogenic climate change

Forest ecosystems worldwide are increasingly subjected to human intervention, leading commentators to argue that forests should be viewed as anthropogenic ecosystems. REDD+ is an emerging inter-governmental policy instrument aimed at both reducing deforestation and forest degradation and combatting climate change, whereby developed countries pay developing countries to reduce their forest-based emissions. The paper details a five-year research project to evaluate REDD+ quality of governance and develop governance standards for the mechanism. Quality of governance was evaluated in five key international institutional elements: the REDD + related negotiations in the global climate talks; the support and funding agencies UN-REDD, Forest Carbon Partnership Facility (FCPF), Forest Investment Programme (FIP) and the REDD + Partnership. This research was complemented by national level governance assessments and related standards setting initiatives in Nepal and Papua New Guinea. The researchers conclude that REDD+ confronts a number of challenges, notably around resources for capacity building, and benefit sharing. In addition, the lack of provisions for changing behaviour and solving the problem of forest-based emissions in the current safeguards render them inadequate to the task of delivering quality of governance. In the absence of consistent governance standards, REDD + will only partially be successful in combatting climate change in the Anthropocene.     

Nutrient and carbon budgets in forest soils as decision support in sustainable forest management

Knowledge about the nutrient and carbon budgets in forest soils is essential to maintain sustainable production, but also in several environmental issues, such as acidification, eutrophication and climate change. The budgets are strongly influenced by atmospheric deposition as well as forestry. This study demonstrates how budget calculations for nitrogen (N), carbon (C) and base cations (BC) can be used as a basis for policy decisions on a regional level in Sweden.The study was based on existing nutrient and C budget calculations on a regional scale in Sweden. The nutrient budgets have been calculated for each square in a national 5 km × 5 km net by means of mass balances including deposition, harvest losses, leaching, weathering (BC) and fixation (N). Scenarios with different deposition and forestry intensity have been run and illustrated on maps. A simplified C budget has been estimated by multiplying the N accumulation with the C/N ratio in the organic layer, based on the assumption that the C/N ratio in the accumulating organic matter is equal to the ratio in the soil organic matter pool. The budget approaches differ from earlier budget studies since they involve regional high resolution data, combine deposition and forestry scenarios and integrate different environmental aspects.The results indicate that whole-tree harvesting will cause net losses of N and base cations in large parts of Sweden, which means that forestry will not be sustainable unless nutrients are added through compensatory fertilization. To prevent net losses following whole-tree harvesting, compensatory fertilization of base cations would be required in almost the whole country, whereas N fertilization would be needed mainly in the northern half of Sweden. The results further suggest that today's recommendations for N fertilization should be revised in southern Sweden by applying the southwest–northeast gradient of the N budget calculations. The C and N accumulation calculations show that C sequestration in Swedish forest soils is not an effective or sustainable way to decrease the net carbon dioxide emissions. A better way is to apply whole-tree harvesting and use the branches, tops and needles as biofuel replacing fossil fuels. This could reduce the present carbon dioxide emissions from fossil fuels substantially.The study shows that high resolution budget calculations that illuminate different aspects of sustainability in forest ecosystems are important tools for identifying problem areas, investigating different alternatives through scenario analyses and developing new policies. Cooperation with stakeholders increases the probability that the research will be useful.     

Historical development of institutional arrangements for forest monitoring and REDD + MRV in Peru: Discursive-institutionalist perspectives

The goal of reducing emissions from deforestation and forest degradation, and the roles of conservation, sustainable management of forests and enhancement of forest carbon stocks in developing countries (REDD +) under UNFCCC has triggered a new discussion on forest resource assessments in these countries. The international process on measurement, reporting and verification of REDD + outcomes (REDD + MRV) expands the scope of forest inventories to include quantification of forest carbon stocks and their changes for results-based REDD + payments. UNFCCC decisions also specify methods to be used, and actors to be involved. Although forest management in developing countries has clearly been influenced by international processes in the past, exactly how and to what extent REDD + MRV has affected institutional arrangements for forest assessments in developing countries remains unknown. Using as a theoretical framework Discursive-Institutionalism, a concept derived from political science, this paper examines (1) the historical evolution of institutional arrangements for forest inventories in Peru; and (2) how and to what extent their development has been shaped by international processes on forests, and, more recently, specifically by REDD + MRV. The findings show that the international REDD + MRV discussion has expanded the objectives of forest assessments in Peru, inspired the mobilization of new actors and resources, and spawned the development of new protocols for forest assessments. However, the ‘depth’ of these changes is not yet extensive, since the new rules for forest inventories have not yet been formally adopted, and the institutes envisaged to implement forest inventories, including measurement of carbon stocks and their changes, have not been established.     

Life cycle inventories of roundwood production in northern Wisconsin: Inputs into an industrial forest carbon budget

Carbon budgets are developed to understand ecosystem dynamics and are increasingly being used to develop global change policy. Traditionally, forest carbon budgets have focused on the biological carbon cycle; however, it is important to include the industrial forest carbon cycle as well. The overall objective of this study was to quantify the major carbon fluxes associated with the production of Wisconsin's industrial roundwood, by using life cycle inventory (LCI) methodology to produce an industrial forest carbon budget. To achieve this objective we (1) developed carbon LCIs for the harvest process for three major forest ownerships (state, national, and private non-industrial), (2) developed carbon LCIs for a dimensional lumber and two oriented strand board (OSB) mills and (3) completed a scaled version of 1 and 2 to include more Wisconsin forestlands and to incorporate the other major processes within the industrial forest carbon cycle (e.g. primary mill, secondary mill, product use and product disposal processes of the industrial forest carbon cycle). The carbon budgets for the harvesting process of the Chequamegon-Nicolet National Forest (CNNF), the Northern Highland American Legion State Forest (NHAL), and the non-industrial private forests that participated in the managed forest laws of Wisconsin (MFL-NIPF) were 0.10, 0.18 and 0.11 tonnes C ha⁻¹ year⁻¹), respectively. The dimensional lumber and OSB products were both net carbon sources, and released 0.05–0.09 tonnes C/tonnes C processed). More carbon is sequestered than released within the industrial forest carbon cycle of Wisconsin's national (6 g C m⁻² year⁻¹), state (12 g C m⁻² year⁻¹) and non-industrial private forests (7 g C m⁻² year⁻¹). Using published net ecosystem production data we estimate that the net forest carbon cycle budget (sum of the biological and industrial C cycle, [Gower, S.T., 2003. Patterns and mechanisms of the forest carbon cycle. Ann. Rev. Environ. Resour. 28, 169–204]) for the CNNF ranges between −897 and 348 g C m⁻² year⁻¹. Life cycle inventories of wood and paper products should be clear and explicitly state what processes are included, so that results can be used by policy makers and future researchers.     

The impact of carbon trade on the management of short-rotation forest plantations

We extended the Hartman model to examine the optimal rotation, taking into consideration the economic benefits of wood and the dynamics of three carbon pools (aboveground biomass, dead organic matter, and harvested forest products). Chinese fir (Cunninghamia lanceolata) stands in Southern China were taken for a numerical example to analyze the effects of carbon price on the optimal management of short-rotation plantations. The results show that, with the current price of carbon, introducing the effects of harvesting on different carbon pools into the decision model would increase the optimal rotation age on poor (SI = 10) and medium (SI = 17) sites by one year, while it does not have any impact on the optimal rotation for good sites (SI = 21). Irrespective of site condition, the optimal rotation age is not sensitive to carbon price and interest rate. An increase in interest rate by 1% would reduce the optimal rotation age by one year. In conclusion, forest carbon trade could effectively enhance land owners' income from short-rotation forest plantations. However, it does not lead to any significant increase in forest carbon sink.     

Prospects and challenges of tenure and forest governance reform in the context of REDD + initiatives in Nepal

This paper argues that the Reducing Emission from Deforestation and Forest Degradation (REDD +) initiatives in Nepal have not adequately understood and considered institutional and political issues around forest tenure and governance challenges. The paper is developed based on reviews of polices, assessments of project activities, interviews with key informants, and observation of ongoing REDD + related public discussions. We found that the REDD + initiatives so far appear to have prioritized technical issues such as carbon assessment, reference scenario, and measurement, reporting and verification of emissions. However, a major policy challenge in Nepal is the substantial deforestation and degradation going on, which leads to substantial challenges of leakage and threatens Nepal's National REDD + policy ambition. The key drivers of deforestation and degradation in Nepal are still poorly identified, analyzed and understood. Inadequate focus of Nepal's present REDD + readiness on the core issues of contested forest tenure and frail governance entails that an unrealistic policy and institutional measures would be developed in addressing these issues of deforestation and degradation. Consequently, it would seriously undermine the prospect of achieving emission reduction — the very goal of REDD +. It is suggested that a robust analysis, collective understanding and broadly agreed policy measures for curbing deforestation must be at the core of REDD + readiness process.     

Changing stock of biomass carbon in a boreal forest over 93 years

The growing stock more than doubled from 1.6 to 3.4 million m³ between 1912 and 2005 in forests on an area of 387 km² in southern Finland. The stock expansion continued for 93 years noting interim results, which were available for 1959, 1982, 1994 and 1999. Forested area in the region hardly changed. Carbon sequestration was mainly a result of a long-term recovery from forest degradation, a legacy of land use in the 18th and 19th centuries. Tree demography responded to management change especially of mature stands: Average tree size and stocking density of stands increased. On average the expanding biomass stock sequestered 18 tons C annually per km² (18 g C per m²). In comparison, the emissions of fossil carbon in the region were estimated at 12 tons C per km² (12 g C per m²) on average. However, fossil CO₂ emissions exceeded biomass sequestration in recent decades. The powerful and persistent expansion of the carbon stock was an unintended co-benefit of forestry, which was motivated by the intention to improve timber yield. On the more negative side the change in management introduced clear-cuts, and a loss of diverse elements of the pre-industrial biota.     

What does it take to institute REDD +? An analysis of the Kilosa REDD + pilot,Tanzania

Reduced emissions from deforestation and forest degradation (REDD +) has been seen as an important element in future climate policies. This paper analyzes the establishment of a REDD + pilot project in Kilosa district, Tanzania. It documents changes in organizations and institutions for land management undertaken to enable villagers to produce and sell stored carbon. Moreover, it evaluates the legitimacy both of the process of introducing REDD + and the outcomes in the form of new governance structures. We find that establishing tradable carbon is demanding. In fact, no carbon has yet been sold. We observe that while the Kilosa REDD + pilot managed to engage local communities to a rather unusual extent, the case also showed that introducing REDD + ‘on the ground’ faces several challenges regarding legitimacy.     

An enterprise-level economic analysis of losses and financial assistance for eastern Ontario maple syrup producers from the 1998 ice storm

This paper reports estimates of the costs of damage from the ice storm of 1998 for two producer size categories of maple syrup operation (1000 and 3000 tap) and three damage levels (light, moderate and severe) for eastern Ontario. These size categories represent approximately 500 and 1500 trees in production, respectively, given the general practice in the region of installing two taps per tree. Damage categories were defined on the basis of the proportion of average crown loss inflicted by the storm. Partial budget capital budgeting and stochastic simulation were used to generate interval estimates of damages. Sensitivity analysis was used to explore the robustness of the estimated damages. Estimated losses for 1000-tap operators with light, moderate and severe damage were $5385, $13 821 and $28 721, respectively. Losses for 3000-tap operators with light, moderate and severe damage were $14 160, $37 399 and $75 630, respectively. Average government financial assistance was found to be within 5–30% of the estimated losses.     

National REDD + reference levels deduced from the global deforestation curve

This article proposes an approach to one of the most prominent problems for the establishment of a REDD + regime — namely reference level determination. We have developed a standardised approach for the consideration of national circumstances in REDD + reference levels, which applies the global curve of forest cover development as the benchmark for accounting of avoided deforestation. The approach draws on the identification and empirical quantification of a global deforestation curve which was created by applying the forest transition concept (Köthke et al., 2013). By the underlying regression model the most relevant national circumstances were identified as the average of 140 countries. These national circumstances represent the development stages of the individual countries, from which their future forest cover development in the global average can be determined.By applying national data for estimating the corresponding average development the article identifies national reference levels for 86 REDD + target countries which are still in their deforestation phase. It is estimated by how much actual deforestation in each country deviates from the mean deforestation curve; the period considered is 2005–2010. This is the first time a uniform global deforestation pattern was used to determine the consideration of national circumstances in REDD + reference levels. The quantitative results provided here may be an important basis for further policy discussions about reference level determination.     

Climate-sensitive modelling of site-productivity relationships for Norway spruce (Picea abies (L.) Karst.) and common beech (Fagus sylvatica L.)

The aim of the presented research project is to fit a site index model capable for predicting changes in site-productivity in a changing climate. A generalized additive model is used to predict site index as a function of soil and climate variables. The climate parameter values are estimated using the regional climate model WETTREG, based on global climate simulations with the global circulation model ECHAM5/MPI-OM for the reference period from 1961 to 1990. The climate values are further regionalized on a 200 m × 200 m grid. The generalized additive model quantifies the partial linear and non-linear effects of the predictor variables on site index. The model is parameterized for Norway spruce (Picea abies (L.) Karst.) and common beech (Fagus sylvatica L.) in Lower Saxony, Germany. Two case studies investigate the model's ability to generate information in order to support forest management planning decisions under a changing climate. One example analyzes the possible shift in site index of spruce along a precipitation gradient under the International Panel on Climate Change (IPCC) emission scenario A1B in the period from 2041 to 2050. The other case study shows possible future changes in site index of beech along a temperature gradient.     

The role of government in operationalising markets for REDD + in Indonesia

The global climate initiative Reducing Emissions from Deforestation and Forest Degradation (REDD +) initially included carbon markets as one potential policy mechanism to finance a range of forestry projects in developing countries. Indonesia was an early leader on REDD +, and set up the regulatory frameworks and monitoring systems to support demonstration projects that could trade credits in voluntary carbon markets. This article applies a neoliberal governmentality framework to evaluate the development of REDD + market institutions in Indonesia during the Readiness period between 2008 and 2013. It critiques the role of the state in this process, and how the authority of public agencies shapes the actions of private subjects. The case of Indonesia indicates a pivotal role for government agencies at multiple levels in integrating the operation of REDD + market activities within a supportive regime of forest and land management. Critical to this process was legislation to trade in forest carbon and obtain project licenses, devolved land-use planning and forest management that could support commercial activities, and robust MRV surveillance systems to oversee on-ground activities. Despite these efforts, projects were often subject to an uncertain and highly contested forest management regime, undermining attempts to demonstrate the viability of operationalising market mechanisms at the local scale.     

Growth and carbon stocks of a spruce forest chronosequence in central Europe

Human induced changes in global environmental conditions are expected to influence or, as it is hypothesised in this study, have already influenced the biomass and growth of forest ecosystems. In this study, we reconstruct the history of tree growth and quantify the standing biomass along a chronosequence of six Norway spruce stands (Picea abies [L.] Karst; 16–142 years old) on acid soils in a mountainous region with high nitrogen deposition. The inventories of the study sites, as well as the historical stem growth of the sample trees were compared with common yield tables, representing growing conditions before 1960, to find out if and when significant changes in growth of trees had occurred. The growth at tree level (0.003–0.030 m³ yr⁻¹) was about 150–350% higher than predicted by the yield tables, independent of tree age. Because of low stand densities due to early thinning, the increase of stem growth at stand level (90% higher than yield table predictions) and the stand volume (35% higher than yield table predictions) were not as high as the increase of growth at tree level. Total biomass at stand level (including stems, branches, twigs, needles and roots) ranged between 35 and 180 t C ha⁻¹. Net primary productivity varied between 6 and 13 t C ha⁻¹ yr⁻¹. Intensive tree thinning activities probably stimulated growth of remaining trees, but the observed growth rates were beyond what would be expected from these activities exclusively. Thus it is assumed that the fertilisation effects of increased nitrogen deposition and CO₂ concentration, and improved climatic conditions due to ongoing climate change, have contributed to the observed changes in stem growth and that the thinning activities were synergetic with changing environmental conditions. The implications for carbon sinks as accountable under the Kyoto Protocol are probably small, because changes in environmental conditions are not accountable under the Kyoto Protocol and most of the observed changes in growth took place before 1990, the baseline for the Kyoto Protocol. Additionally, it is assumed that impacts on the carbon balance of forest stands due to changes in the thinning regime after 1990, which would be accountable according to article 3.4 of the Kyoto Protocol, are very small without any synergetic changes in environmental conditions.     

Governing the design of national REDD +: An analysis of the power of agency

This paper investigates how three aspects of governance systems, namely the policy context, the influence of key agents and their discursive practices, are affecting national-level processes of policy design aimed at REDD +, reducing emissions from deforestation and forest degradation in developing countries; and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks in developing countries. We conducted analysis in six REDD + countries (Brazil, Cameroon, Indonesia, Nepal, Papua New Guinea and Vietnam). The paper combines three methods: policy analysis, media-based discourse analysis and policy network analysis. The paper shows that policies both within and outside the forestry sector that support deforestation and forest degradation create path dependencies and entrenched interests that hamper policy change. In addition, most dominant policy coalitions do not challenge business-as-usual trajectories, reinforcing existing policy and political structures. No minority policy coalitions are directly tackling the root causes of deforestation and forest degradation, that is, the politico-economic conditions driving them. Instead they focus on environmental justice issues, such as calls for increased participation of indigenous people in decision-making. Only in two of the six countries are these transformational change coalitions vocal enough to be heard, yet to exercise their agency effectively and to support more substantial reforms, these coalitions would need the participation of more influential policy actors, particularly state agencies that have the authority to make binding decisions about policy. Furthermore, discourses supporting transformational change would need to be reflected in institutional practices and policy decisions.     

Inhibition of hepatitis C virus replication by chalepin and pseudane IX isolated from Ruta angustifolia leaves

Hepatitis C virus (HCV) infection is highly prevalent among global populations, with an estimated number of infected patients being 170 million. Approximately 70–80% of patients acutely infected with HCV will progress to chronic liver disease, such as liver cirrhosis and hepatocellular carcinoma, which is a substantial cause of morbidity and mortality worldwide. New therapies for HCV infection have been developed, however, the therapeutic efficacies still need to be improved. Medicinal plants are promising sources for antivirals against HCV. A variety of plants have been tested and proven to be beneficial as antiviral drug candidates against HCV. In this study, we examined extracts, their subfractions and isolated compounds of Ruta angustifolia leaves for antiviral activities against HCV in cell culture. We isolated six compounds, chalepin, scopoletin, γ-fagarine, arborinine, kokusaginine and pseudane IX. Among them, chalepin and pseudane IX showed strong anti-HCV activities with 50% inhibitory concentration (IC₅₀) of 1.7 ± 0.5 and 1.4 ± 0.2 μg/ml, respectively, without apparent cytotoxicity. Their anti-HCV activities were stronger than that of ribavirin (2.8 ± 0.4 μg/ml), which has been widely used for the treatment of HCV infection. Mode-of-action analyses revealed that chalepin and pseudane IX inhibited HCV at the post-entry step and decreased the levels of HCV RNA replication and viral protein synthesis. We also observed that arborinine, kokusaginine and γ-fagarine possessed moderate levels of anti-HCV activities with IC₅₀ values being 6.4 ± 0.7, 6.4 ± 1.6 and 20.4 ± 0.4 μg/ml, respectively, whereas scopoletin did not exert significant anti-HCV activities at 30 μg/ml.