Boreal countries are rich in forest resources, and for their area, they produce a disproportionally large share of the lumber, pulp, and paper bound for the global market. These countries have long-standing strong traditions in forestry education and institutions, as well as in timber-oriented forest management. However, global change, together with evolving societal values and demands, are challenging traditional forest management approaches. In particular, plantation-type management, where wood is harvested with short cutting cycles relative to the natural time span of stand development, has been criticized. Such management practices create landscapes composed of mosaics of young, even-aged, and structurally homogeneous stands, with scarcity of old trees and deadwood. In contrast, natural forest landscapes are characterized by the presence of old large trees, uneven-aged stand structures, abundant deadwood, and high overall structural diversity. The differences between managed and unmanaged forests result from the fundamental differences in the disturbance regimes of managed versus unmanaged forests. Declines in managed forest biodiversity and structural complexity, combined with rapidly changing climatic conditions, pose a risk to forest health, and hence, to the long-term maintenance of biodiversity and provisioning of important ecosystem goods and services. The application of ecosystem management in boreal forestry calls for a transition from plantation-type forestry toward more diversified management inspired by natural forest structure and dynamics.
Elisabet Lindgren and Thomas Elmqvist
Ecosystem services refer to benefits for human societies and well-being obtained from ecosystems. Research on health effects of ecosystem services have until recently mostly focused on beneficial effects on physical and mental health from spending time in nature or having access to urban green space. However, nearly all of the different ecosystem services may have impacts on health, either directly or indirectly. Ecosystem services can be divided into provisioning services that provide food and water; regulating services that provide, for example, clean air, moderate extreme events, and regulate the local climate; supporting services that help maintain biodiversity and infectious disease control; and cultural services.
With a rapidly growing global population, the demand for food and water will increase. Knowledge about ecosystems will provide opportunities for sustainable agriculture production in both terrestrial and marine environments. Diarrheal diseases and associated childhood deaths are strongly linked to poor water quality, sanitation, and hygiene. Even though improvements are being made, nearly 750 million people still lack access to reliable water sources. Ecosystems such as forests, wetlands, and lakes capture, filter, and store water used for drinking, irrigation, and other human purposes. Wetlands also store and treat solid waste and wastewater, and such ecosystem services could become of increasing use for sustainable development.
Ecosystems contribute to local climate regulation and are of importance for climate change mitigation and adaptation. Coastal ecosystems, such as mangrove and coral reefs, act as natural barriers against storm surges and flooding. Flooding is associated with increased risk of deaths, epidemic outbreaks, and negative health impacts from destroyed infrastructure. Vegetation reduces the risk of flooding, also in cities, by increasing permeability and reducing surface runoff following precipitation events.
The urban heat island effect will increase city-center temperatures during heatwaves. The elderly, people with chronic cardiovascular and respiratory diseases, and outdoor workers in cities where temperatures soar during heatwaves are in particular vulnerable to heat. Vegetation and especially trees help in different ways to reduce temperatures by shading and evapotranspiration. Air pollution increases the mortality and morbidity risks during heatwaves. Vegetation has been shown also to contribute to improved air quality by, depending on plant species, filtering out gases and airborne particulates. Greenery also has a noise-reducing effect, thereby decreasing noise-related illnesses and annoyances. Biological control uses the knowledge of ecosystems and biodiversity to help control human and animal diseases.
Natural surroundings and urban parks and gardens have direct beneficial effects on people’s physical and mental health and well-being. Increased physical activities have well-known health benefits. Spending time in natural environments has also been linked to aesthetic benefits, life enrichments, social cohesion, and spiritual experience. Even living close to or with a view of nature has been shown to reduce stress and increase a sense of well-being.
The emergence of environment as a security imperative is something that could have been avoided. Early indications showed that if governments did not pay attention to critical environmental issues, these would move up the security agenda. As far back as the Club of Rome 1972 report, Limits to Growth, variables highlighted for policy makers included world population, industrialization, pollution, food production, and resource depletion, all of which impact how we live on this planet.
The term environmental security didn’t come into general use until the 2000s. It had its first substantive framing in 1977, with the Lester Brown Worldwatch Paper 14, “Redefining Security.” Brown argued that the traditional view of national security was based on the “assumption that the principal threat to security comes from other nations.” He went on to argue that future security “may now arise less from the relationship of nation to nation and more from the relationship between man to nature.”
Of the major documents to come out of the Earth Summit in 1992, the Rio Declaration on Environment and Development is probably the first time governments have tried to frame environmental security. Principle 2 says: “States have, in accordance with the Charter of the United Nations and the principles of international law, the sovereign right to exploit their own resources pursuant to their own environmental and developmental policies, and the responsibility to ensure that activities within their jurisdiction or control do not cause damage to the environment of other States or of areas beyond the limits of national.”
In 1994, the UN Development Program defined Human Security into distinct categories, including:
• Economic security (assured and adequate basic incomes).
• Food security (physical and affordable access to food).
• Health security.
• Environmental security (access to safe water, clean air and non-degraded land).
By the time of the World Summit on Sustainable Development, in 2002, water had begun to be identified as a security issue, first at the Rio+5 conference, and as a food security issue at the 1996 FAO Summit. In 2003, UN Secretary General Kofi Annan set up a High-Level Panel on “Threats, Challenges, and Change,” to help the UN prevent and remove threats to peace. It started to lay down new concepts on collective security, identifying six clusters for member states to consider. These included economic and social threats, such as poverty, infectious disease, and environmental degradation.
By 2007, health was being recognized as a part of the environmental security discourse, with World Health Day celebrating “International Health Security (IHS).” In particular, it looked at emerging diseases, economic stability, international crises, humanitarian emergencies, and chemical, radioactive, and biological terror threats. Environmental and climate changes have a growing impact on health. The 2007 Fourth Assessment Report (AR4) of the UN Intergovernmental Panel on Climate Change (IPCC) identified climate security as a key challenge for the 21st century. This was followed up in 2009 by the UCL-Lancet Commission on Managing the Health Effects of Climate Change—linking health and climate change.
In the run-up to Rio+20 and the launch of the Sustainable Development Goals, the issue of the climate-food-water-energy nexus, or rather, inter-linkages, between these issues was highlighted. The dialogue on environmental security has moved from a fringe discussion to being central to our political discourse—this is because of the lack of implementation of previous international agreements.
Enuvie G. Akpokodje
Deltas have played a significant role in the growth of human civilization because of their unique economic and ecological importance. However, deltas are becoming increasingly vulnerable because of the impact of intensive human developmental activities, high population and urban growth, subsidence, climate change, and the associated rise in sea level. The trapping of sediments by dams is another major threat to the long-term stability and sustainability of deltas. The emergence and global acceptance of the concept of sustainable development in the 1980s led to the advent of several multidisciplinary and applied fields of research, including environmental science, environmental geology, and sustainability science. Environmental geology focuses on the application of geologic knowledge and principles to broad-ranging environmental and socioeconomic issues, including the specific problems confronting deltas. The key environmental geologic challenges in deltas (especially urban delta areas) are: increasing exposure and vulnerability to geologic hazards (flooding, cyclones, etc.), rise in sea level, decreasing sediment load supply, contamination of soil and water resources, provision of adequate drinking water, and safe waste disposal. The application of geologic knowledge and principles to these challenges requires consideration of the critical geologic controls, such as the geological history, stratigraphy, depositional environment, and the properties of the alluvial sediments. Until recently, most of the traditional engineered solutions in the management of deltas were designed to keep out water (fighting nature), typically without adequate geological/hydrological input, rather than building with nature. Recent innovative approaches to delta management involve a paradigm shift from the traditional approach to a more integrated, holistic, adaptive, and ecologically based philosophy that incorporates some critical geological and hydrological perspectives, for instance, widening and deepening rivers and flood plains as well as constructing secondary channels (i.e., making more room for water). A key challenge, however, is the establishment of a close and functional communication between environmental geologists and all other stakeholders involved in delta management. In addition, there is growing global consensus regarding the need for international cooperation that cuts across disciplines, sectors, and regions in addressing the challenges facing deltas. Integrating good policy and governance is also essential.
Russian environmental history is a new field of inquiry, with the first archivally based monographs appearing only in the last years of the 20th century. Despite the field’s youth, scholars studying the topic have developed two distinct and contrasting approaches to its central question: How should the relationship between Russian culture and the natural world be characterized? Implicit in this question are two others: Is the Russian attitude toward the non-human world more sensitive than that which prevails in the West; and if so, is the Russian environment healthier or more stable than that of the United States and Western Europe? In other words, does Russia, because of its traditional suspicion of individualism and consumerism, have something to teach the West? Or, on the contrary, has the Russian historical tendency toward authoritarianism and collectivism facilitated predatory policies that have degraded the environment? Because environmentalism as a political movement and environmental history as an academic subject both emerged during the Cold War, at a time when the Western social, political, and economic system vied with the Soviet approach for support around the world, the comparative (and competitive) aspect of Russian environmental history has always been an important factor, although sometimes an implicit one. Accordingly, the existing scholarly works about Russian environmental history generally fall into one of two camps: one very critical of the Russian environmental record and the seeming disregard of the Russian government for environmental damage, and a somewhat newer group of works that draw attention to the fundamentally different concerns that motivate Russian environmental policies. The first group emphasizes Russian environmental catastrophes such as the desiccated Aral Sea, the eroded Virgin Lands, and the public health epidemics related to the severely polluted air of Soviet industrial cities. The environmental crises that the first group cites are, most often, problems once prevalent in the West, but successfully ameliorated by the environmental legislation of the late 1960s and early 1970s. The second group, in contrast, highlights Russian environmental policies that do not have strict Western analogues, suggesting that a thorough comparison of the Russian and Western environmental records requires, first of all, a careful examination of what constitutes environmental responsibility.
The Mississippi River, the longest in North America, is really two rivers geophysically. The volume is less, the slope steeper, the velocity greater, and the channel straighter in its upper portion than in its lower portion. Below the mouth of the Ohio River, the Mississippi meanders through a continental depression that it has slowly filled with sediment over many millennia. Some limnologists and hydrologists consider the transitional middle portion of the Mississippi, where the waters of its two greatest tributaries, the Missouri and Ohio rivers, join it, to comprise a third river, in terms of its behavioral patterns and stream and floodplain ecologies.
The Mississippi River humans have known, with its two or three distinct sections, is a relatively recent formation. The lower Mississippi only settled into its current formation following the last ice age and the dissipation of water released by receding glaciers. Much of the current river delta is newer still, having taken shape over the last three to five hundred years.
Within the lower section of the Mississippi are two subsections, the meander zone and the delta. Below Cape Girardeau, Missouri, the river passes through Crowley’s Ridge and enters the wide and flat alluvial plain. Here the river meanders in great loops, often doubling back on itself, forming cut offs that, if abandoned by the river, forming lakes. Until modern times, most of the plain, approximately 35,000 square miles, comprised a vast and rich—rich in terms of biomass production—ecological wetland sustained by annual Mississippi River floods that brought not just water, but fertile sediment—topsoil—gathered from across much of the continent. People thrived in the Mississippi River meander zone. Some of the most sophisticated indigenous cultures of North America emerged here. Between Natchez, Mississippi, and Baton Rouge, Louisiana, at Old River Control, the Mississippi begins to fork into distributary channels, the largest of which is the Atchafalaya River. The Mississippi River delta begins here, formed of river sediment accrued upon the continental shelf. In the delta the land is wetter, the ground water table is shallower. Closer to the sea, the water becomes brackish and patterns of river sediment distribution are shaped by ocean tides and waves. The delta is frequently buffeted by hurricanes.
Over the last century and a half people have transformed the lower Mississippi River, principally through the construction of levees and drainage canals that have effectively disconnected the river from the floodplain. The intention has been to dry the land adjacent to the river, to make it useful for agriculture and urban development. However, an unintended effect of flood control and wetland drainage has been to interfere with the flood-pulse process that sustained the lower valley ecology, and with the process of sediment distribution that built the delta and much of the Louisiana coastline. The seriousness of the delta’s deterioration has become especially apparent since Hurricane Katrina, and has moved conservation groups to action. They are pushing politicians and engineers to reconsider their approach to Mississippi River management.
Juha Merilä and Ary A. Hoffmann
Changing climatic conditions have both direct and indirect influences on abiotic and biotic processes and represent a potent source of novel selection pressures for adaptive evolution. In addition, climate change can impact evolution by altering patterns of hybridization, changing population size, and altering patterns of gene flow in landscapes. Given that scientific evidence for rapid evolutionary adaptation to spatial variation in abiotic and biotic environmental conditions—analogous to that seen in changes brought by climate change—is ubiquitous, ongoing climate change is expected to have large and widespread evolutionary impacts on wild populations. However, phenotypic plasticity, migration, and various kinds of genetic and ecological constraints can preclude organisms from evolving much in response to climate change, and generalizations about the rate and magnitude of expected responses are difficult to make for a number of reasons.
First, the study of microevolutionary responses to climate change is a young field of investigation. While interest in evolutionary impacts of climate change goes back to early macroevolutionary (paleontological) studies focused on prehistoric climate changes, microevolutionary studies started only in the late 1980s. The discipline gained real momentum in the 2000s after the concept of climate change became of interest to the general public and funding organizations. As such, no general conclusions have yet emerged. Second, the complexity of biotic changes triggered by novel climatic conditions renders predictions about patterns and strength of natural selection difficult. Third, predictions are complicated also because the expression of genetic variability in traits of ecological importance varies with environmental conditions, affecting expected responses to climate-mediated selection.
There are now several examples where organisms have evolved in response to selection pressures associated with climate change, including changes in the timing of life history events and in the ability to tolerate abiotic and biotic stresses arising from climate change. However, there are also many examples where expected selection responses have not been detected. This may be partly explainable by methodological difficulties involved with detecting genetic changes, but also by various processes constraining evolution.
There are concerns that the rates of environmental changes are too fast to allow many, especially large and long-lived, organisms to maintain adaptedness. Theoretical studies suggest that maximal sustainable rates of evolutionary change are on the order of 0.1 haldanes (i.e., phenotypic standard deviations per generation) or less, whereas the rates expected under current climate change projections will often require faster adaptation. Hence, widespread maladaptation and extinctions are expected. These concerns are compounded by the expectation that the amount of genetic variation harbored by populations and available for selection will be reduced by habitat destruction and fragmentation caused by human activities, although in some cases this may be countered by hybridization. Rates of adaptation will also depend on patterns of gene flow and the steepness of climatic gradients. Theoretical studies also suggest that phenotypic plasticity (i.e., nongenetic phenotypic changes) can affect evolutionary genetic changes, but relevant empirical evidence is still scarce. While all of these factors point to a high level of uncertainty around evolutionary changes, it is nevertheless important to consider evolutionary resilience in enhancing the ability of organisms to adapt to climate change.
Fisheries science emerged in the mid-19th century, when scientists volunteered to conduct conservation-related investigations of commercially important aquatic species for the governments of North Atlantic nations. Scientists also promoted oyster culture and fish hatcheries to sustain the aquatic harvests. Fisheries science fully professionalized with specialized graduate training in the 1920s.
The earliest stage, involving inventory science, trawling surveys, and natural history studies continued to dominate into the 1930s within the European colonial diaspora. Meanwhile, scientists in Scandinavian countries, Britain, Germany, the United States, and Japan began developing quantitative fisheries science after 1900, incorporating hydrography, age-determination studies, and population dynamics. Norwegian biologist Johan Hjort’s 1914 finding, that the size of a large “year class” of juvenile fish is unrelated to the size of the spawning population, created the central foundation and conundrum of later fisheries science. By the 1920s, fisheries scientists in Europe and America were striving to develop a theory of fishing. They attempted to develop predictive models that incorporated statistical and quantitative analysis of past fishing success, as well as quantitative values reflecting a species’ population demographics, as a basis for predicting future catches and managing fisheries for sustainability. This research was supported by international scientific organizations such as the International Council for the Exploration of the Sea (ICES), the International Pacific Halibut Commission (IPHC), and the United Nations’ Food and Agriculture Organization (FAO).
Both nationally and internationally, political entanglement was an inevitable feature of fisheries science. Beyond substituting their science for fishers’ traditional and practical knowledge, many postwar fisheries scientists also brought progressive ideals into fisheries management, advocating fishing for a maximum sustainable yield. This in turn made it possible for governments, economists, and even scientists, to use this nebulous target to project preferred social, political, and economic outcomes, while altogether discarding any practical conservation measures to rein in globalized postwar industrialized fishing. These ideals were also exported to nascent postwar fisheries science programs in developing Pacific and Indian Ocean nations and in Eastern Europe and Turkey.
The vision of mid-century triumphalist science, that industrial fisheries could be scientifically managed like any other industrial enterprise, was thwarted by commercial fish stock collapses, beginning slowly in the 1950s and accelerating after 1970, including the massive northern cod crisis of the early 1990s. In the 1980s scientists, aided by more powerful computers, attempted multi-species models to understand the different impacts of a fishery on various species. Daniel Pauly led the way with multi-species models for tropical fisheries, where the need for such was most urgent, and pioneered the global database FishBase, using fishing data collected by the FAO and national bodies. In Canada the cod crisis inspired Ransom Myers to use large databases for fisheries analysis to show the role of overfishing in causing that crisis. After 1980 population ecologists also demonstrated the importance of life history data for understanding fish species’ responses to fishery-induced population and environmental change.
With fishing continuing to shrink many global commercial stocks, scientists have demonstrated how different measures can manage fisheries for species with different life-history profiles. Aside from the need for effective scientific monitoring, the biggest ongoing challenges remain having politicians, governments, fisheries industry members, and other stakeholders commit to scientifically recommended long-term conservation measures.
David E. Clay, Sharon A. Clay, Thomas DeSutter, and Cheryl Reese
Since the discovery that food security could be improved by pushing seeds into the soil and later harvesting a desirable crop, agriculture and agronomy have gone through cycles of discovery, implementation, and innovation. Discoveries have produced predicted and unpredicted impacts on the production and consumption of locally produced foods. Changes in technology, such as the development of the self-cleaning steel plow in the 18th century, provided a critical tool needed to cultivate and seed annual crops in the Great Plains of North America. However, plowing the Great Plains would not have been possible without the domestication of plants and animals and the discovery of the yoke and harness. Associated with plowing the prairies were extensive soil nutrient mining, a rapid loss of soil carbon, and increased wind and water erosion. More recently, the development of genetically modified organisms (GMOs) and no-tillage planters has contributed to increased adoption of conservation tillage, which is less damaging to the soil. In the future, the ultimate impact of climate change on agronomic practices in the North American Great Plains is unknown. However, projected increasing temperatures and decreased rainfall in the southern Great Plains (SGP) will likely reduce agricultural productivity. Different results are likely in the northern Great Plains (NGP) where higher temperatures can lead to increased agricultural intensification, the conversion of grassland to cropland, increased wildlife fragmentation, and increased soil erosion. Precision farming, conservation, cover crops, and the creation of plants better designed to their local environment can help mitigate these effects. However, changing practices require that farmers and their advisers understand the limitations of the soils, plants, and environment, and their production systems. Failure to implement appropriate management practices can result in a rapid decline in soil productivity, diminished water quality, and reduced wildlife habitat.
Wim De Vries, Enzai Du, Klaus Butterbach Bahl, Lena Schulte Uebbing, and Frank Dentener
Human activities have rapidly accelerated global nitrogen (N) cycling since the late 19th century. This acceleration has manifold impacts on ecosystem N and carbon (C) cycles, and thus on emissions of the greenhouse gases nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4), which contribute to climate change.
First, elevated N use in agriculture leads to increased direct N2O emissions. Second, it leads to emissions of ammonia (NH3), nitric oxide (NO), and nitrogen dioxide (NO2) and leaching of nitrate (NO3−), which cause indirect N2O emissions from soils and waterbodies. Third, N use in agriculture may also cause changes in CO2 exchange (emission or uptake) in agricultural soils due to N fertilization (direct effect) and in non-agricultural soils due to atmospheric NHx (NH3+NH4) deposition (indirect effect). Fourth, NOx (NO+NO2) emissions from combustion processes and from fertilized soils lead to elevated NOy (NOx+ other oxidized N) deposition, further affecting CO2 exchange. As most (semi-) natural terrestrial ecosystems and aquatic ecosystems are N limited, human-induced atmospheric N deposition usually increases net primary production (NPP) and thus stimulates C sequestration. NOx emissions, however, also induce tropospheric ozone (O3) formation, and elevated O3 concentrations can lead to a reduction of NPP and plant C sequestration. The impacts of human N fixation on soil CH4 exchange are insignificant compared to the impacts on N2O and CO2 exchange (emissions or uptake). Ignoring shorter lived components and related feedbacks, the net impact of human N fixation on climate thus mainly depends on the magnitude of the cooling effect of CO2 uptake as compared to the magnitude of the warming effect of (direct and indirect) N2O emissions.
The estimated impact of human N fixation on N2O emission is 8.0 (7.0–9.0) Tg N2O-N yr−1, which is equal 1.02 (0.89–1.15) Pg CO2-C equivalents (eq) yr−1. The estimated CO2 uptake due to N inputs to terrestrial, freshwater, and marine ecosystems equals −0.75 (−0.56 to −0.97) Pg CO2-C eq yr−1. At present, the impact of human N fixation on increased CO2 sequestration thus largely (on average near 75%) compensates the stimulating effect on N2O emissions. In the long term, however, effects on ecosystem CO2 sequestration are likely to diminish due to growth limitations by other nutrients such as phosphorus. Furthermore, N-induced O3 exposure reduces CO2 uptake, causing a net C loss at 0.14 (0.07–0.21) Pg CO2-C eq yr−1. Consequently, human N fixation causes an overall increase in net greenhouse gas emissions from global ecosystems, which is estimated at 0.41 (−0.01–0.80) Pg CO2-C eq yr−1. Even when considering all uncertainties, it is likely that human N inputs lead to a net increase in global greenhouse gas emissions.
These estimates are based on most recent science and modeling approaches with respect to: (i) N inputs to various ecosystems, including NH3 and NOx emission estimates and related atmospheric N (NH3 and NOx) deposition and O3 exposure; (ii) N2O emissions in response to N inputs; and (iii) carbon exchange in responses to N inputs (C–N response) and O3 exposure (C–O3 response), focusing on the global scale. Apart from presenting the current knowledge, this article also gives an overview of changes in the estimates of those fluxes and C–N response factors over time, including debates on C–N responses in literature, the uncertainties in the various estimates, and the potential for improving them.