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Coffee is an extremely important agricultural commodity, produced in about 80 tropical countries, with an estimated 125 million people depending on it for their livelihoods in Latin America, Africa, and Asia, with an annual production of about nine million tons of green beans. Consisting of at least 125 species, the genus Coffea L. (Rubiaceae, Ixoroideae, Coffeeae) is distributed in Africa, Madagascar, the Comoros Islands, the Mascarene Islands (La Réunion and Mauritius), tropical Asia, and Australia. Two species are economically important for the production of the beverage coffee, C. arabica L. (Arabica coffee) and C. canephora A. Froehner (robusta coffee). Higher beverage quality is associated with C. arabica. Coffea arabica is a self-fertile tetraploid, which has resulted in very low genetic diversity of this significant crop. Coffee genetic resources are being lost at a rapid pace due to varied threats, such as human population pressures, leading to conversion of land to agriculture, deforestation, and land degradation; low coffee prices, leading to abandoning of coffee trees in forests and gardens and shifting of cultivation to other more remunerative crops; and climate change, leading to increased incidence of pests and diseases, higher incidence of drought, and unpredictable rainfall patterns. All these factors threaten livelihoods in many coffee-growing countries.
The economics of coffee production has changed in recent years, with prices on the international market declining and the cost of inputs increasing. At the same time, the demand for specialty coffee is at an all-time high. In order to make coffee production sustainable, attention should be paid to improving the quality of coffee by engaging in sustainable, environmentally friendly cultivation practices, which ultimately can claim higher net returns.
The world’s forest cover is approximately 4 billion hectares (10 billion acres). Of this total, approximately one-half is temperate forests. These range from the subtropics to roughly 65 degrees in latitude. As we move toward the equator, the forests would generally be considered tropical or subtropical, while forest above the 65th latitude might be considered boreal. Only a relatively small fraction of the forests that are temperate are managed in any significant manner. The major types of management can vary from serious forest protection to selective harvesting, with considerations for regeneration. Intensive forestry exists in the form of plantation forestry and is similar to agricultural cropping. Seedlings are planted, and the trees are managed in various ways while growing (e.g. fertilizers, herbicides, thinnings) and then harvested at a mature age. Typically, the cycle of planting and management then begins anew.
Approximately 200 million hectares of forests are managed beyond simply minimal protection and natural regeneration. Recent estimates suggest that over 100 million hectares globally are intensively managed planted forests. The largest representatives of these forests are found in the Northern Hemisphere (e.g., the United States), China, and various countries of Europe, especially the Nordic countries. However, Brazil, Chile, New Zealand, and Australia are important producers while being in the Southern Hemisphere. A high percentage of managed forests are designed to produce industrial wood for construction and for pulp and paper production.
Finally, in some countries like China, planted forests are intended to replace forests destroyed decades and even centuries ago. Many of these planted forests are intended to provide environmental services, including water capture and control, erosion control and soil protection, flood control, and habitat for wild life. Recently, forests are being considered as a vehicle to help control global warming. In addition, afforestation and/or reforestation may help address damages after a disturbance such as a fire. In China, the “green wall” has been established to prevent shoreline erosion in major coastal areas.
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
A qanat, a kind of subterranean and subhorizontal tunnel, is usually excavated in soft sediments and conducts groundwater to the surface at its emerging point. In addition to the tunnel, each qanat contains several to hundreds of vertical wells for removal of dig materials and ventilation of the tunnel. The depth of these wells increases towards the last one, which is the mother well. According to the literature, the qanat was invented around 800 to 1,000 years
Andrew B. Smith
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
The study of the origins and development of traditional food producing societies in Africa requires a close look at the source of wild progenitors and influences upon aboriginal hunting societies. These influences shaped the direction of adaptive strategies, producing grain agriculturalists, forest agriculturalists, and pastoralists across the different biomes of the continent. How, and if, hunters became pastoralist is still a topic widely discussed in East and southern Africa. Are African cattle an indigenous domesticate?
While African agricultural societies have been well-studied by anthropologists, the origins of their domesticates is much more difficult to ascertain than in pastoralist societies, due to the difficulty of finding food crops in the archaeological record, compared with the bones of domesticated animals, particularly in the tropical environments where organic remains disappear very quickly.
Pastoral societies in Africa, however, were a major driving force for later grain production. Wild grasses were harvested by transhumant nomads, and only with shifting climatic conditions that led to increased sedentarization were farming societies developed around the domestication of indigenous grains, such as sorghum and pearl millet.
In the tropical regions of Africa domestication of a number of indigenous plants, such as yams, oil palm, African rice, and others took place. These are unique to Africa, but the process of control and domestication is poorly understood. This is compounded by the introduction of alien domesticates, such as maize, manioc, and bananas, which have become widespread across the biome. On the other hand, African domesticates, like sorghum, migrated to the Indian subcontinent and constitute a major food resource there. The changing food requirements across the developed world are looking at the Ethiopian grain teff, which is gluten-free and nutrient rich, and without the Ethiopian coffee plant Starbucks would not exist.
Stephan Pauleit, Rieke Hansen, Emily Lorance Rall, Teresa Zölch, Erik Andersson, Ana Catarina Luz, Luca Szaraz, Ivan Tosics, and Kati Vierikko
Urban green infrastructure (GI) has been promoted as an approach to respond to major urban environmental and social challenges such as reducing the ecological footprint, improving human health and well-being, and adapting to climate change. Various definitions of GI have been proposed since its emergence more than two decades ago. This article aims to provide an overview of the concept of GI as a strategic planning approach that is based on certain principles.
A variety of green space types exist in urban areas, including remnants of natural areas, farmland on the fringe, designed green spaces, and derelict land where successional vegetation has established itself. These green spaces, and especially components such as trees, can cover significant proportions of urban areas. However, their uneven distribution raises issues of social and environmental justice. Moreover, the diverse range of public, institutional, and private landowners of urban green spaces poses particular challenges to GI planning. Urban GI planning must consider processes of urban change, especially pressures on green spaces from urban sprawl and infill development, while derelict land may offer opportunities for creating new, biodiverse green spaces within densely built areas.
Based on ample evidence from the research literature, it is suggested that urban GI planning can make a major contribution to conserving and enhancing biodiversity, improving environmental quality and reducing the ecological footprint, adapting cities to climate change, and promoting social cohesion. In addition, GI planning may support the shift toward a green economy.
The benefits derived from urban green spaces via the provision of ecosystem services are key to meeting these challenges. The text argues that urban GI planning should build on seven principles to unlock its full potential. Four of these are treated in more detail: green-gray integration, multifunctionality, connectivity, and socially inclusive planning. Considering these principles in concert is what makes GI planning a distinct planning approach. Results from a major European research project indicate that the principles of urban GI planning have been applied to different degrees. In particular, green-gray integration and approaches to socially inclusive planning offer scope for further improvement
In conclusion, urban GI is considered to hold much potential for the transition toward more sustainable and resilient pathways of urban development. While the approach has developed in the context of the Western world, its application to the rapidly developing cities of the Global South should be a priority.
The economics literature has developed various methods to recover the values for environmental commodities. Two such methods related to revealed preference are property value hedonic models and equilibrium sorting models. These strategies employ the actual decisions that households make in the real estate market to indirectly measure household demand for environmental quality. The hedonic method decomposes the equilibrium price of a house based on the house’s structural and neighborhood/environmental characteristics to recover marginal willingness to pay (MWTP). The more recent equilibrium sorting literature estimates environmental values by combining equilibrium housing outcomes with a formal model of the residential choice process. The two predominant frameworks of empirical sorting models that have been adopted in the literature are the vertical pure characteristics model (PCM) and the random utility model (RUM). Along with assumptions on the structure of preferences, a formal model of the choice process on the demand side, and a characterization of the supply side to close the model, these sorting models can predict outcomes that allow for re-equilibration of prices and endogenous attributes following a counterfactual policy change.
Innovations to the hedonic model have enabled researchers to more aptly value environmental goods in the face of complications such as non-marginal changes (i.e., identification and endogeneity concerns with respect to recovering the entire demand curve), non-stable hedonic equilibria, and household dynamic behavior. Recent advancements in the sorting literature have also allowed these models to accommodate consumer dynamic behavior, labor markets considerations, and imperfect information. These established methods to estimate demand for environmental quality are a crucial input into environmental policymaking. A better understanding of these models, their assumptions, and the potential implications on benefit estimates due to their assumptions would allow regulators to have more confidence in applying these models’ estimates in welfare calculations.
Edward B. Barbier
Since the 2004 Indian Ocean tsunami, there has been strong interest globally in restoring mangrove ecosystems and their potential benefits from protecting coastlines and people from damaging storms. However, the net economic gains from mangrove restoration have been variable; there have been some notable project successes but also some prominent failures. There is also an ongoing debate over whether or not the cost of mangrove restoration is justified by the benefits these ecosystems provide. Although the high costs of mangrove restoration and the risk of failure have led to criticism of such schemes, perhaps the more pertinent concern should be whether the ex post option of restoration is economically beneficial compared to preventing irreversible mangrove conversion to alternative land uses. Case studies on mangrove valuation from Brazil and Thailand illustrate the key issues underlying this concern. Since much recent mangrove restoration has been motivated by the trees’ potential storm-protection benefit, a number of studies have valued mangroves for this purpose. However, mangroves are also valued for other important benefits, such as providing collected products for local coastal communities and serving as nursery and breeding grounds for off-shore fisheries. The implications of these benefits for mangrove restoration can be significant. It is also important to understand the appropriate use of benefit transfer when it is difficult to value restored mangroves, methods to incorporate the potential risk of mangrove restoration failure, and assessment of cost-effective mangrove restoration.
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
Massive population declines and species extinction have characterized the 20th and early 21st centuries. These local and global phenomena do not only involve the loss of particular species, habitats, and ecosystem services; they also result in a general reduction in biotic diversity. Ecological research has long indicated the importance of biodiversity within and across ecosystems. However, capturing the economic value of biodiversity remains a challenge.
Biodiversity is a multidimensional public good; it encompasses the diversity of genes, species, functional groups, habitats, and ecosystems. A large empirical literature in biology and ecology indicates that biodiversity has a stabilizing effect on ecosystems—the higher the biodiversity within a given ecosystem type, the more stable and resilient (well-functioning) is the ecosystem. However, the economic importance of biodiversity goes beyond this stabilizing effect.
The multidimensionality and complexity of the biodiversity concept has led to a multitude of approaches to its economic valuation. While the theoretical and conceptual literature has focused on biodiversity as insurance and pool of options, empirical studies have been much more diverse. Given the public-good nature and complexity of biodiversity, stated preference methods are particularly common. The focus on biodiversity valuation has fostered many important theoretical and methodological developments. Many estimates exist of the willingness to pay for biodiversity conservation in different countries across the world; however, relatively few studies have been conducted in developing countries, despite the considerably higher biodiversity levels there as compared with the better-covered developed countries.
Valuation of biodiversity is a controversial subject and the economic, predominantly anthropocentric approach has been criticized frequently. However, non-anthropocentric accounts of biodiversity value are problematic for their own reasons; an important question is whether biodiversity has intrinsic value and, if yes, whether this can be captured within the economic perspective. Valuation of biodiversity remains a vibrant topic at the intersections of disciplines such as ecology, environmental ethics, and economics.
Achilleas Vassilopoulos and Phoebe Koundouri
Water accounts for more than 70% of Earth’s surface, making marine ecosystems the largest and most important ecosystems of the planet. However, the fact that a large part of these ecosystems and their potential contribution to humans remains unexplored has rendered them unattractive for valuation exercises. On the contrary, coastal zones, , being the interface between the land, the sea, and human activities competing for space and resources, have been extensively studied with the objective of marine ecosystem services valuation. Examples of marine and coastal ecosystems are open oceans, coral reefs, deep seas, hydrothermal vents, abyssal plains, wetlands, rocky and sandy shores, mangroves, kelp forests, estuaries, salt marshes, and mudflats. Although there are arguments that no classification can capture the ways in which ecosystems contribute to human well-being and support human life, very often policymakers have to decide upon alternative uses of such natural environments. Should a given wetland be preserved or converted to agricultural land? Should a mangrove be designated within the protected areas system or be used for shrimp farming? To answer these questions, one needs first to establish the philosophical basis of value within the ecosystems framework. To this end, two vastly different approaches have been proposed. On the one hand, the nonutilitarian (biocentric) approach relies on the notion of intrinsic value attached to the mere existence of a natural resource, independent of whether humans derive utility from its use (if any) or preservation. Albeit useful in philosophical terms, this approach is still far from providing unambiguous and generally accepted inputs to the tangible problem of ecosystem valuation. The utilitarian (anthropocentric) perspective, on the other hand, assumes that natural environments have value to the extent that humans derive utility from placing such value. According to the total economic value (TEV) approach, this value can be divided into “use” and “nonuse.” Use values involve some interaction with the resource, either directly or indirectly, while nonuse values are derived simply from the knowledge that natural resources and aspects of the natural environment are maintained. Existence and altruistic values fall within this latter category.
Not surprisingly, economists have long revealed a strong preference for the utilitarian approach. As a result, the valuation of marine ecosystems requires that we understand the ecosystem services they deliver and then attach a value to the services. But what tools are available to economists when valuing marine ecosystems? For the most part, ecosystem services are not traded in formal markets and thus actual prices are usually not available. Valuation techniques essentially seek different ways to estimate measures like Willingness To Pay (WTP), Willingness To Accept (WTA), or expenditures and costs. The techniques used for the valuation of ecosystem services can be divided into three main families: market-based, revealed preference, and stated preference. Finally, value-transfer methods are also used when estimates of value are available in similar contexts. All these methods have advantages and disadvantages, with different methods being suitable for different situations. Hence, extra caution is required during the design and implementation of valuation attempts.
Amy W. Ando and Noelwah R. Netusil
Green stormwater infrastructure (GSI), a decentralized approach for managing stormwater that uses natural systems or engineered systems mimicking the natural environment, is being adopted by cities around the world to manage stormwater runoff. The primary benefits of such systems include reduced flooding and improved water quality. GSI projects, such as green roofs, urban tree planting, rain gardens and bioswales, rain barrels, and green streets may also generate cobenefits such as aesthetic improvement, reduced net CO2 emissions, reduced air pollution, and habitat improvement. GSI adoption has been fueled by the promise of environmental benefits along with evidence that GSI is a cost-effective stormwater management strategy, and methods have been developed by economists to quantify those benefits to support GSI planning and policy efforts. A body of multidisciplinary research has quantified significant net benefits from GSI, with particularly robust evidence regarding green roofs, urban trees, and green streets. While many GSI projects generate positive benefits through ecosystem service provision, those benefits can vary with details of the location and the type and scale of GSI installation. Previous work reveals several pitfalls in estimating the benefits of GSI that scientists should avoid, such as double counting values, counting transfer payments as benefits, and using values for benefits like avoided carbon emissions that are biased. Important gaps remain in current knowledge regarding the benefits of GSI, including benefit estimates for some types of GSI elements and outcomes, understanding how GSI benefits last over time, and the distribution of GSI benefits among different groups in urban areas.
Charles Darwin’s 1881 publication of The Formation of Vegetable Mould Through the Action of Worms sparked some of the most interesting research ideas on the utilization of earthworms. The evolution of their uses can be traced from ancient times, when earthworms were revered as soil organisms that could predict weather patterns, up to the first decades of the 21st century, when earthworms are considered one of the most versatile creatures for recycling organic wastes, a protein source in feedstock formulations, an active ingredient in pharmaceuticals, dynamic organisms in bioremediation, and the main organisms that drive the production of potent organic soil amendment. Vermiculture is the art, science, and industry of raising earthworms for any of the above-mentioned purposes. Vermicomposting is the art, science, and industry of the utilization of certain species of earthworms (out of more than 9,000) to manage organic wastes to produce soil amendments called vermicomposts. Research has demonstrated that many vermicomposts can accelerate germination, increase growth, and enhance yield of plants in the greenhouse, even at low substation rates in plant growth media. When utilized as a supplemental organic amendment in the field, vermicomposts can increase the growth and yield of crops. A number of reports have demonstrated the ability of the vermicomposts to suppress pests and diseases. These suppressions have been attributed to the rich microbial population and the diversity of microorganisms of vermicompost, which is contributed by the mesophilic process itself, allowing microorganism to multiply in orders of magnitude, unlike the traditional thermophilic composting process. The presence of other plant growth regulators, such as plan growth hormones and humic acids, also have major contributions to the positive effects of vermicomposts on plant growth and yield. Aqueous extracts from vermicompost, referred to commonly as “tea,” have been reported to produce positive responses of plant growth and yield, and suppression properties have been explored. More currently, vermicomposts have been used in alternative soil-less plant production techniques such as hydroponics. When used at very low rates in hydroponics and with much-reduced nutrients from inorganic sources, vermicompost tea application can produce plant yields equivalent to those raised in full inorganic fertilizers.
Maite M. Aldaya, M. Ramón Llamas, and Arjen Y. Hoekstra
The water footprint concept broadens the scope of traditional national and corporate water accounting as it has been previously known. It highlights the ways in which water consuming and polluting activities relate to the structure of the global economy, opening a window of opportunity to increase transparency and improve water management along whole-production and supply chains. This concept adds a new dimension to integrated water resources management in a globalized world.
The water footprint is a relatively recent indicator. Created in 2002, it aims to quantify the effect of consumption and trade on the use of water resources. Specifically, the water footprint is an indicator of freshwater use that considers both direct and indirect water use of a consumer or producer. For instance, the water footprint of a product refers to the volume of freshwater used to produce the product, tracing the origin of raw material and ingredients along their respective supply chains. This novel indirect component of water use in supply chains is, in many cases, the greatest share of water use, for example, in the food and beverage sector and the apparel industry. Water footprint assessment shows the full water balance, with water consumption and pollution components specified geographically and temporally and with water consumption specified by type of source (e.g., rainwater, groundwater, or surface water). It introduces three components:
1. The blue water footprint refers to the consumption of blue water resources (i.e., surface and groundwater including natural freshwater lakes, manmade reservoirs, rivers, and aquifers) along the supply chain of a product, versus the traditional and restricted water withdrawal measure.
2. The green water footprint refers to consumption through transpiration or evaporation of green water resources (i.e., soilwater originating from rainwater). Green water maintains natural vegetation (e.g., forests, meadows, scrubland, tundra) and rain-fed agriculture, yet plays an important role in most irrigated agriculture as well. Importantly, this kind of water is not quantified in most traditional agricultural water use analyses.
3. The grey water footprint refers to pollution and is defined as the volume of freshwater that is required to assimilate the load of pollutants given natural concentrations for naturally occurring substances and existing ambient water-quality standards.
The water footprint concept has been incorporated into public policies and international standards. In 2011, the Water Footprint Network adopted the Water Footprint Assessment Manual, which provides a standardized method and guidelines. In 2014, the International Organization for Standardization adopted a life cycle-based ISO 14046 standard for the water footprint; it offers guidelines to integrate water footprint analysis in life-cycle assessment for products. In practice, water footprint assessment generally results in increased awareness of critical elements in a supply chain, such as hotspots that deserve most attention, and what can be done to improve water management in those hotspots.
Water footprint assessment, including the estimation of virtual water trade, applied in different countries and contexts, is producing new data and bringing larger perspectives that, in many cases, lead to a better understanding of the drivers behind water scarcity.
Fidel Ribera Urenda
The importance of groundwater has been made particularly evident in the last decades by the growing use of this part of the water cycle in many human activities. Nowadays, vertical wells are the most common, effective, and controlled systems to obtain water from aquifers. These have replaced other techniques, like drains and spring catchments, and are the only way to obtain water from deep groundwater bodies.
One negative hydrodynamic effect of well abstraction is the generation of an inverted, conically shaped depression around the well that grows as water is pumped, and can negatively affect water quantity and quality in the aquifer and related water masses. If the abstraction rate is growing in a specific well or, more commonly, if there is an uncontrolled increase of the number of active wells in the area, these effects could have a strong impact on the aquifer’s long term groundwater reserves (overexploitation) and, in some specific contexts, the water quality. Major examples of these last processes can be observed in most coastal-touristic areas in arid or semiarid climates around the world, where intensive water exploitation is abundant in aquifers hydraulically connected with the sea. In most of these areas, an excessive abstraction rate causes sea-water to penetrate the inland part of the aquifer (marine intrusion). Another typical example of undesirable groundwater management can be found in many intensive agricultural production areas. An increase in the concentration of nitrogen solute ions in groundwater and soils is associated with excessive fertilizer input. In these farming areas, the spatial distances between wells, their designs and final execution, and the abstraction rates are critical in the generation of more or less penetrative depressions cones that ultimately control the quality of abstracted water.
To prevent these negative effects, several aquifer management methodologies can be used. One common method is to set specific abstraction rules for a discrete number of aquifer management sectors, according to the hydrogeological characteristics of the aquifer (flow and chemical parameters) and its relationship with other water masses. These management plans are usually controlled by national water agencies with support from, or coordination with, private user water communities.
Transboundary or international aquifers need more complex management strategies than national aquifers. These demand a multidisciplinary approach including legal, political, economic, and environmental actions and, of course, a precise (quantitative) hydrogeological understanding of current and future abstraction effects.
What Is Public and What Is Private in Water Provision: Insights from Progressive Era Cities in the US Northeast
Gwynneth C. Malin
During the colonial period and into the mid-19th century, residents of US Northeast cities drew water for domestic uses from local ponds, rivers, and ground water sources. In these early urban settlements, procuring water was a daily activity and one linked to economic class. Water provision was often a blend of public and private efforts—if residents wanted a well or a sewer built in their neighborhood, they had to help pay for it. During the 19th and early 20th centuries, city officials in the US Northeast made the gradual transition from relying on private water companies to implementing the public management of water supply. As quickening urbanization and growing immigrant populations rendered local and privately managed water sources undersupplied, elected officials began to search for new sources of water.
Each city’s history is unique, but common themes include an increase in water pollution, the need to tap new water supplies further from city centers, disease prevention, fire extinction, and financial corruption, within both private water companies and municipal efforts to supply water. While most cities of the US Northeast transitioned to municipal operation of water supply during the 19th century, this shift was not without its challenges and complexity. Funding shortages often prevented change, but crises, such as fire, drought, and infectious disease outbreaks forced the hands of municipal officials. Philadelphia was first to transition to public water management in 1801, followed by New York in 1842, and Boston in 1848. In the late 19th century, New York experienced municipal delay, countered later by Progressive-era political forces that ultimately assured permanent public water management. The story of the emerging publicity of water management during this historical period sheds light on a larger narrative about the changing role of the state during the Gilded Age and the Progressive Era. It was during the 19th and early 20th centuries that the public management of water triumphed over private in the cities of the US Northeast.