The Value of Forests to World Food Security

We assembled information on the contribution and value of forests to world food security. An assessment was made of the role of forests and non-timber products in the food system of developing countries. We estimated that upwards of 300 million people annually earn part or all of their livelihood and food from forests. A total of about $90 billion in non-timber products are harvested each year. Forests also help to protect land, water, and biological resources, and they play an important role in maintaining the productivity of agricultural and environmental systems.     

End-of-Life Infrastructure Economics for "Clean Vehicles" in the United States

Rising fuel prices and concern over emissions are prompting automakers and legislators to introduce and evaluate "clean vehicles" throughout the United States. Hybrid electric vehicles (HEVs) are now on the roads, electric vehicles (EVs) have been test marketed, and niche vehicles such as high-fuel-economy microcars are being considered for introduction. As these vehicles proliferate and mature, they will eventually reach their end of life (EOL). In the United States, an extensive recycling infrastructure exists for conventional, internal combustion engine (ICE) vehicles. Its primary constituents are the disassembler and the shredder. These industries, as well as battery recyclers, are expected to play integral roles in the EOL processing of clean vehicles.
A model of the automobile-recycling infrastructure and goal programming techniques are used to assess the materials streams and process profitabilities for several different clean vehicles. Two-seat EVs with lead-acid or NiMH batteries are compared with two- and four-seat HEVs and microcars. Changes to the nonferrous content in the vehicle bodies are explored and compared for the effect on processing profit-ability. Despite limitations associated with the linearity of goal programming techniques, application of this tool can still provide informative first-order results. Results indicate that although these clean vehicles may not garner the same profit levels as conventional ICE vehicles, they are profitable to process if there are markets for parts and if there are sufficient quantities of nonferrous materials.     

Impact of Firm-Based Environmental Standards on Subsidiaries and Their Suppliers: Evidence from Motorola-Penang

How successful are multinational corporations in extending their firm-based environmental standards to their subsidiaries and those subsidiaries' local suppliers in their global production networks in developing countries? We address this question through an in-depth case study of how Motorola, a prominent multinational electronics firm with an extensive global production network, is using a set of firm-based standards to meet several new stringent European Union environmental directives. The case study demonstrates that these firm-based standards appear to be enabling a major subsidiary and its suppliers in one developing economy to reduce the environmental intensities of their production activities. This finding suggests that the firm-based environmental standards of multinationals with extensive global production networks might contribute to a leveling up of environmental standards in subsidiaries and their local suppliers, rather than a "race to the bottom", thus reinforcing the technique or intensity effects associated with open trade, investment, and technology policies.     

Using Input-Output Analysis to Measure the Environmental Pressure of Consumption at Different Spatial Levels

Input-output modeling is a useful tool for tracing environmental impacts of consumption. Because it includes impacts originating from production layers of infinite order (capturing the entire economy), input-output modeling is highly relevant for studies operating in a life-cycle context. In this article we show how the input-output approach can be used to enumerate the problem of sustainable consumption. Based on a literature survey including research done by the authors we present measures of the emissions of carbon dioxide at different spatial levels: nation, city, and household. Further, we take more environmental effects into account and introduce the concept of environmental efficiency by combining input-output modeling and data envelopment analysis. Finally, we discuss the policy relevance of the different measures. The article demonstrates that input-output modeling has a wide range of life-cycle oriented applications when combined with other data sources such as detailed trade statistics, foreign input-output and environmental statistics, and household expenditure data.     

Small trees,big problems: Comparative leaf function under extreme edaphic stress

Premise of the Study

The pygmy forest, a plant community of severely stunted conifers and ericaceous angiosperms, occurs on patches of highly acidic, nutrient‐poor soils along the coast of Northern California, USA. This system is an excellent opportunity to study the effect of severe nutrient deficiency on leaf physiology in a naturally‐occurring ecosystem. In this study, we seek to understand the physiological mechanisms stunting the plants' growth and their implications for whole plant function.

Methods

We measured 14 traits pertaining to leaf photosynthetic function or physical structure on seven species. Samples were taken from the pygmy forest community and from conspecifics growing on higher‐nutrient soils, where trees may grow over 30 m tall.

Key Results

Pygmy plants of most species maintained similar area‐based photosynthetic and stomatal conductance rates to conspecific controls, but had lower specific leaf area (leaf area divided by dry weight), lower percent nitrogen, and less leaf area relative to xylem growth. Sequoia sempervirens, a species rare in the pygmy forest, had a categorically different response from the more common plants and had remarkably low photosynthetic rates.

Conclusions

Pygmy plants were not stunted by low photosynthetic rates on a leaf‐area basis; instead, several species had restricted whole‐plant photosynthesis due to low leaf area production. Pygmy plants of all species showed signs of greater carbon investment in their leaves and higher production of nonphotosynthetic leaf tissue, further contributing to slow growth rates.     

北京植物园不同功能型植物叶经济谱

通过对北京植物园不同功能型植物的叶片光合参数、叶绿素荧光参数、叶面积、叶干质量以及叶氮含量等性状参数进行测定,分析了不同功能型植物的叶经济谱.结果表明: 生活型中草本植物、生活史中一年生植物、光合型中C4植物靠近叶经济谱中快速投资-收益型物种的一端,而生活型中乔木和灌木、生活史中多年生植物、光合型中C3植物位于缓慢投资-收益型物种的一端,表明不同功能型植物通过叶片性状间的权衡采取不同的环境适应策略,验证了不同功能型植物叶经济谱的存在.不同功能型植物叶片性状具有明显差异,其中不同生活型间的叶片比叶面积(SLA)、叶氮含量(N_mass)、最大净光合速率(A_mass)、光合氮利用效率(PNUE)均表现出草本植物>藤本植物>灌木>乔木;不同生活史间一年生植物的SLA、N_mass、A_mass、PNUE均显著高于多年生植物;不同光合型间植物的A_mass、PNUE、PSⅡ实际光化学效率(Φ_PSⅡ)均表现出C4>C3.N_mass、A_mass、SLA两两之间呈显著正相关,而PSⅡ有效光化学量子产量(F_v′/F_m′)与SLA呈显著负相关;PNUE与SLA呈显著正相关.     

Biomass and lipid enhancement in Ankistrodesmus sp. cultured with reused and minimal nutrients media

Microalgae are a promising feedstock for biofuel production. Lipid content in microalgae could be enhanced under nutrient depletion. This work investigated the effect of the nutrient on lipid accumulation in Ankistrodesmus sp. culture. Batch cultures were carried out using fresh BG11 medium, and after the harvest, the medium was reused for the next culture; this method was repeated two times. The maximum lipid productivity of 29.75 mg L^?1 day^?1 was obtained from the culture with the second reuse medium. In continuous cultures, Ankistrodesmus sp. was cultured in both fresh and modified BG11 mediums. The modified BG11 medium was adjusted to resemble the content of the first reuse medium. As a comparison between batch and continuous cultures, it was proven that the productivity in the continuous culture was better than in the batch, where the achievable maximum biomass and lipid were 188.30 and 38.32 mg L^?1 day^?1. The maximum lipid content of 34.22% was obtained from the continuous culture at a dilution rate of 0.08 day^?1, whereas the maximum saturated and unsaturated fatty acid productivities of 79.96 and 104.54 mg L^?1 day^?1 were obtained at a dilution rate of 0.16 day^?1.     

Market Failure and the Environmental Policies of Firms: Economic Rationales for "Beyond Compliance" Behavior

This paper is an inquiry into the circumstances under which the voluntary provision of environmental public goods might be sensible from a firm's point of view. If environmental externalities were the only departure from the economic assumptions of perfect competition, and if no firms had preferential access to superior (low-cost) stocks of natural resources, firms that volunteered to internalize costs could not survive. But because externalities coexist with other departures from the competitive paradigm, such as asymmetric information and oligopoly competition, firms may find it in their shareholders' interests to provide environmental public goods to a greater degree than required by law. A number of firms, especially in Europe and North America, assert that they are pursuing "beyond-compliance" environmental policies. From the perspective of a firm's shareholders, it makes sense to pursue such policies if they increase the firm's expected value or if they appropriately manage business risk.
This paper discusses economically rational explanations for such policies. It analyzes the ways in which a firm's chances of financial success in pursuing any one of them are influenced by the firm's market position and organizational capabilities and by the basic structure of the industry in which it competes.     

Intangibility in intertemporal choice

Since the advent of the discounted utility (DU) model, economists have thought about intertemporal choice in very specific terms. DU assumes that people make explicit trade-offs between costs and benefits occurring at different points in time. While this explicit trade-off perspective is simple and tractable, and has stimulated productive research, it does not provide a very realistic representation of a wide range of the most important intertemporal trade-offs that people face in daily life. If one considers the most important and commonly discussed examples of intertemporal choices, a striking pattern emerges: in almost all cases, early outcomes tend to be concrete (e.g. purchasing this latte), but later outcomes tend to be much less tangible (e.g. the unknown item that could have been purchased later with the money spent on this latte). We propose that people rely on anticipatory emotions as a proxy for intangible outcomes when trade-offs are implicit. This paper reviews neuroeconomic evidence that has begun to elucidate the role of anticipatory emotions in decisions involving intangible outcomes. Although most progress has been made in the domain of spending and saving, we discuss how the existing neuroeconomic research could be extended to other domains where trade-offs are ill defined.