Forest Management under Fire Risk when Forest Carbon Sequestration Has Value

In this paper, we develop a multiple forest use model to determine the optimal harvest date for a forest stand producing both timber and carbon benefits under a risk of fire. The preferences of the representative non-industrial private forest (NIPF) owner are modeled though an expected utility specification. We introduce saving as a decision of the forest owner at any time. The problems of forest management and saving decisions are solved simultaneously using a stochastic dynamic programming method. A numerical programming method is used to characterize the optimal forest and saving policies. We apply this framework to model the behavior of a representative NIPF owner located in the Southwest of France. The empirical application indicates that a higher risk of fire will decrease the optimal rotation period, while higher carbon prices will increase the optimal harvesting age. We show that increasing the risk of fire leads to a reduction in rotation duration. On the contrary, a higher carbon price makes carbon sequestration more profitable, thereby leading to increasing the rotation duration. We then show how the carbon price/risk of fire frontier is affected by risk aversion

Forest Management under Fire Risk when Forest Carbon Sequestration Has Value

In this paper, we develop a multiple forest use model to determine the optimal harvest date for a forest stand producing both timber and carbon benefits under a risk of fire. The preferences of the representative non-industrial private forest (NIPF) owner are modeled though an expected utility specification. We introduce saving as a decision of the forest owner at any time. The problems of forest management and saving decisions are solved simultaneously using a stochastic dynamic programming method. A numerical programming method is used to characterize the optimal forest and saving policies. We apply this framework to model the behavior of a representative NIPF owner located in the Southwest of France. The empirical application indicates that a higher risk of fire will decrease the optimal rotation period, while higher carbon prices will increase the optimal harvesting age. We show that increasing the risk of fire leads to a reduction in rotation duration. On the contrary, a higher carbon price makes carbon sequestration more profitable, thereby leading to increasing the rotation duration. We then show how the carbon price/risk of fire frontier is affected by risk aversion

Household Energy Choices and Fuelwood Consumption: An Econometric Approach to the French Data

In an international context of soaring oil prices and growing awareness of the need to combat global warming, wood would appear to be becoming increasingly competitive and desirable for our environment. France is the leading consumer of fuelwood in the EU, mainly for home consumption and for heating, although the share of wood in primary energy consumption is still very low (4%). It is therefore important to understand how domestic consumer fuelwood demand is determined. We propose an econometric analysis of fuelwood consumption by modeling the choice made by consumers of the type of use of wood for heating, and the possible combination between one energy used as a main source of heating and another used as a back-up. Our estimations show that this choice is mainly determined by income. Wood is chosen as the main energy source by the poorest households. Consumption is price sensitive in the case of main use of wood (price elasticity of -0.4), but price elasticity is lower in the case of back-up use, and varies according to the type of energy used as the main source (electricity, gas, fuel oil)

Household Energy Choices and Fuelwood Consumption: An Econometric Approach to the French Data

In an international context of soaring oil prices and growing awareness of the need to combat global warming, wood would appear to be becoming increasingly competitive and desirable for our environment. France is the leading consumer of fuelwood in the EU, mainly for home consumption and for heating, although the share of wood in primary energy consumption is still very low (4%). It is therefore important to understand how domestic consumer fuelwood demand is determined. We propose an econometric analysis of fuelwood consumption by modeling the choice made by consumers of the type of use of wood for heating, and the possible combination between one energy used as a main source of heating and another used as a back-up. Our estimations show that this choice is mainly determined by income. Wood is chosen as the main energy source by the poorest households. Consumption is price sensitive in the case of main use of wood (price elasticity of -0.4), but price elasticity is lower in the case of back-up use, and varies according to the type of energy used as the main source (electricity, gas, fuel oil)

A methodological way of evaluating innovative cropping systems integrating risk beliefs and risk preferences

In the paper, we propose a methodological way of leading an economical assessment of innovative cropping systems (ICSs). The originality lies in the integration of the crop management flexibility and the farmers’ risk perception and risk preferences. Two conventional cropping systems have been studied (continuous irrigated maize and wheat/sunflower rotation). For each of them, an innovative long rotation has been co-designed by farmers to reach various objectives, notably reduce the pressure on natural resources. The methodological protocol is tested thought a sample of 23 specialized cash crop farmers of Southwestern France is surveyed: subjective probabilities linked to climatic risk perceived are assessed and farmers’ risk aversion is elicited through experimental lotteries. Without risk consideration, the adoption of ICSs should be discouraged, given the 2010-2011 crop price situation (mean gross margin loss of about 15 %). Accounting for the farmers’ risk perception and risk aversion, and using a risk criteria analysis the results are more mitigated. An adoption premium, computed for each farmer, shows that although all farmers are almost equally risk averse, the levels of adoption premiums are heterogeneous, due to different individual risk perceptions. Finally the paper proposes a method to account for risk preferences and subjective beliefs that raise heterogeneity in the attitude towards innovative cropping systems

Economic Analysis of Summer Fallow Management to Reduce Take-All and N-Leaching in a Wheat Crop Rotation

This paper addresses the question of summer cover crop adoption by farmers in presence of a risk of yield loss due to take-all disease and climate variability. To analyse the public incentives needed to encourage farmers to adopt summer cover crops as a means of reducing N leaching, we combine outputs from an economic, an epidemiological and an agronomic model. The economic model is a simple model of choice under uncertainty. The farmer is assumed to choose among a range of summer fallow managements and input uses on the basis of the expected utility criterion (HARA assumption) in presence of both climate and take all risks. The epidemiological model proposed by Ennaïfar et al. (2007) is used to determine the impact of take all on yields and N-uptake. The crop-soil model (STICS) is used to\ud compute yield developments and N-leaching under various management options and climatic conditions. These models are calibrated to match the conditions prevailing in Grignon, located in the main wheatgrowing\ud area in France. Eight management systems are examined: 4 summer fallow managements: 'wheat volunteers' (WV), 'bare soil' (BS), 'early mustard' (EM), 'late mustard' (LM), and 2 input intensities. We show that the optimal systems are BS (WV) when the take-all risk is (not) taken into account by agents. We then compute the minimum payment to each system such that it emerges in the optimum. We thus derive the required amounts of transfer needed to trigger catch crop adoption. The results of the Monte Carlo sensitivity analysis show that the ranking of management systems is robust over a wide range of input parameters

Long Lasting Persistence of Bacillus thuringiensis Subsp. israelensis (Bti) in Mosquito Natural Habitats

Background: The detrimental effects of chemical insecticides on the environment and human health have lead to the call for biological alternatives. Today, one of the most promising solutions is the use of spray formulations based on Bacillus thuringiensis subsp. israelensis (Bti) in insect control programs. As a result, the amounts of Bti spread in the environment are expected to increase worldwide, whilst the common belief that commercial Bti is easily cleared from the ecosystem has not yet been clearly established. Methodology/Main Findings: In this study, we aimed to determine the nature and origin of the high toxicity toward mosquito larvae found in decaying leaf litter collected in several natural mosquito breeding sites in the Rhône-Alpes region. From the toxic fraction of the leaf litter, we isolated B. cereus-like bacteria that were further characterized as B. thuringiensis subsp. israelensis using PCR amplification of specific toxin genes. Immunological analysis of these Bti strains showed that they belong to the H14 group. We finally used amplified length polymorphism (AFLP) markers to show that the strains isolated from the leaf litter were closely related to those present in the commercial insecticide used for field application, and differed from natural worldwide genotypes. Conclusions/Significance: Our results raise the issue of the persistence, potential proliferation and environmental accumulation of human-spread Bti in natural mosquito habitats. Such Bti environmental persistence may lengthen th