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C H A P T E R T W O En~vironmenfalIss?ves of National Imp orfance and fle Role of fte National Ecological Observatory ATefwork The committee examined and identified the main environmental challenges facing the nation. This chapter also discusses the importance of developing education programs in environmental science for the generalp?~blic and the ne~ctgeneration of scientists. Ecological and environmental research has traditionally been dominated by projects of single investigators or small groups working on local scales. However, environmental change and its influence on biological processes occur on regional, conti- nental, and global scales. We define a region on the basis of environmental characteristics that influence biology, such as climate and precipitation (subtropical Florida vs. the desert), terrain (the Rocky Mountains vs. the Great Plains), and the presence and absence of extensive watersheds (the Great Lakes region). We use the term continental to describe transconti- nental processes. Although there are a few continentwide environmental monitoring programs Global Energy and Water Cycle Experiments, National Atmospheric Deposition Program/National Trends Network, Moderate-Resolution Imaging Spectroradiometer, and so on those programs rarely link physical environmental changes to biological processes. To adequately study the sources of and seek solutions for environmental problems on this expanded range of scales, 23

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NEON: ADDRESSING THE NATION'S ENVIRONMENTAL CHALLENGES information on physical and geochemical processes should be comple- mented by biological studies. Furthermore, biological studies must be conducted at the appropriate time and spatial scales to ensure that experimental results are applicable to natural systems and processes (Gardner et al. 2001~. After considering the numerous environmental issues that the nation faces, the committee is in general agreement with the conclusions of the NRC report on Grand Challenges in Environmental Sciences (NRC 2001~. In particular, the committee identified six major environmental chal- lenges for which a NEON-like national network of infrastructure would be essential for their solution. The challenges are to develop an increased understanding, via improved observations, focused experimentation and the development and testing of mechanistic theory of the following . . . pressing environmental issues: . Biodiversity, species composition, and ecosystemfunctioning. Decreases in biodiversity and changes in species composition accompany most human uses of the biosphere. The loss of biodiversity can affect eco- system functioning and ecosystem services of value to society. The loss of biodiversity and shifts in ecosystem composition range from local to continental scales, and thus must be studied on their natural scale if their national implications are to be understood. . Ecological aspects of biogeochemical cycle. Humans are dominating natural processes as the major suppliers of the basic elements of life (carbon, nitrogen, phosphorus, and sulfur). The redistribution of those chemical elements, and human-produced toxins, on regional and continental scales may have profound effects on human health and on ecosystem function and stoichiometry, which may result in shifts in biodiversity, toxin accumulation, and concentration through the food chain. . Ecological implications of climate chance. Human-induced climate a warming and variability strongly affect individual species, community structure and ecosystem functioning. Changes in vegetation in turn affect climate through their role in partitioning radiation and precipitation at 24

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Environmental Issues of National Importance and the Role of NEON the land surface. Climate-driven biological impacts are often only discernable at a regional-continental scale. Regional changes in eco- system processes affect global water and carbon cycles. Therefore, a national approach to understanding biological response to climate variability and change is required. . Ecology and evolution of infectious diseases. Exposure to and the dynamics, spread and control of emerging diseases and their effects on humans, crops, livestock, and wildlife require a new level of understand- ing. The majority of emerging infectious diseases in humans either utilize vectors such as mosquitoes or ticks, or are zoonotic diseases that are transmitted from wildlife. That will require knowledge of spatial variations in exposure, of the population dynamics of disease reservoirs, of the effects of pathogens on individual behavior, of the molecular basis of host-parasite interactions, and of the interactions with other pathogens and environmental threats. . . Invasive species. Invasive species affect virtually every ecosystem In the United States, and can cause substantial economic and biological damage. The identification of potentially harmful invasive species, the early detection of new species as invasion begins, and the knowledge base needed to prevent their spread require a comprehensive monitoring and experimental network and a mechanistic understanding of the interplay of invader, ecosystem traits and other factors including climate and land use that determine invasiveness. . Land use and habitat alteration. Deforestation, suburbanization, road construction, agriculture, and other human land-use activities cause changes in ecosystems. Those changes modify water, energy and mate- rial balances and the ability of the biotic community to respond to and recover from stress and disturbance. Actions in one location, such as farming practices in the upper Midwest, can affect areas 1,000 or more miles away because areas are joined by water and nutrient flow in rivers and by atmospheric transport of agrochemicals. Each of these six environmental challenges is a source of effects in human social and economic systems, as wed as in the nation's ecosystems. 25

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NEON: ADDRESSING THE NATION'S ENVIRONMENTAL CHALLENGES Environmental sustainability and livability depend heavily on natural resource use and other human behaviors. The environment is "the critical infrastructure without which neither an economy nor a society can survive" (NRC 2002~. For that reason, the committee believes that social-science and economic issues related to the six challenges are also appropriate subjects of research for the NEON observatories to support. Although NEON's major emphasis wiD be research on the nature and pace of biological change, the causes and consequences of this change are tightly linked to human systems, and this linkage should not be ignored in the overall NEON research portfolio. The nation faces another great challenge: the necessity to communi- cate scientific understanding of the environment to its citizens and policy-makers. NSF, in its NEON proposal, has recognized that scientists represent only a portion of the user community for NEON, and it envisions students and teachers from kindergarten through postgraduate levels wiD use NEON information for educational activities and NEON facilities for research. The American public will also use NEON to get up-to-date information about environmental issues. The committee therefore supports a major educational and outreach role for NEON. The six environmental challenges and the educational challenge have several common features that dictate that they be addressed through a nationwide network of sites. They are all regional, continental, or global in extent; for instance, invasive species and emerging diseases are of concern precisely because they spread across large portions of the nation and have substantial effects on human health, agriculture, natural resources, recreation, forestry, and other economically important endeavors. Second, the problems are multicausal and embedded in biologically and physically complex, large-scale systems; for instance, climate variability and change modify the structure and functioning of ecosystems, and changes in ecosystem structure, such as conversion from forest to pasture, can affect climate by changing the evapotranspiration rate of water. Third, addressing the biological aspects of the environ- mental challenges requires information on abundances and dynamics of many interdependent species. In the past, collection of such information 26

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Environmental Issues of National Importance and the Role of NEON was a painstaking process that could be accomplished only by highly trained scientists. Finally, to successfully address the environmental challenges would require comparative analysis of ecosystems conducted in the context of long-term, time series observations of key ecological processes and properties; and multiscale research on and monitoring of the propagation of variability across local, regional, and continental scales. The evolution of instrumentation from molecular probes to high-resolution satellite images and sophisticated software for their analysis now allows characterization and documentation of biological changes in a more structured manner and over a broad range of time and spatial scales than was previously possible. Technological advances now facilitate the development of national biological networks for large-scale research, such as that described in the NEON proposal. WeD-controlled multifactor experiments that are replicated across a region or the nation and detailed broad-scale observational studies are essential if we are to address the grand environmental challenges faced by the nation. Experiments can control for the confounding effects of variables and thus promote a clear understanding of cause-effect relations. Experimentation should be complemented by long-term observations and some large-scale long-term monitoring that would demonstrate trends and provide signals for environmental changes. Just as a nuclear accelerator allows physicists to address fundamental questions that could never be answered observationally, a "climate accelerator" might allow environmental scientists to determine some of the potential changes in ecosystems in response to climate change without having to wait for 50 ~ 1 0 or 100 years of observation. Climate accelerator is a term that the com- mittee uses to describe a large chamber with controlled environmental conditions. Environmental condition in the chamber can be manipu- lated to imitate and accelerate climate change hence its name. Such manipulations might provide insights on an ecosystem's resilience to ranid climate chance. Similarlv. a "nitrogen-deposition accelerator" 1 0 ~ ' would allow researchers to accelerate nitrogen deposition in controlled conditions. A series of nitrogen-deposition accelerators could be con- structed in an array of terrestrial, freshwater, estuarine, and marine 27

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NEON: ADDRESSING THE NATION'S ENVIRONMENTAL CHALLENGES habitats to determine the multiple effects of anthropogenic increases in nitrogen deposition from the atmosphere or from groundwater or rivers. A climate accelerator or a nitrogen-deposition accelerator would require major investments in facilities and infrastructure. This chapter outlines briefly the nature of the six ecological and environmental challenges and how a national network of biological infrastructure like NEON would contribute to addressing them. The six challenges are presented in alphabetical order, and the committee feels that addressing any of them would advance environmental science. The contribution of a network of biological infrastructure to education and how they complement each other are also discussed. BIODIVERSITY, SPECIES COMPOSITION, AND ECOSYSTEM FUNCTIONING Biodiversity (or biological diversity) refers to the number of species and the extent of genetic variability in those species in a given site. Species composition refers to the array of species and their relative abun- dance in a community in a given site. Human actions are having major effects on both biological diversity and the species composition of ecosystems (NRC 1997~. For example, modern forestry practices often involve replacing the diverse trees that had inhabited a recently harvested site with one strain of one species. That has been done repeatedly in the Pacific Northwest, where Douglas fir was planted, and in the Southeast where loblolly pine are planted after forest harvest. Similarly, intensive grazing often leads to the local loss of grassland plant species, as does the deliberate planting of various pasture species. Atmospheric deposition of nitrogen that originated in agricultural fertilizer or high-temperature combustion of fossil fuels also leads to reduced plant diversity and to shifts in plant community composition. Fire suppression, habitat frag- mentation and destruction, overexploitation of natural resources, species extinctions, and many other human actions also cause large changes in ecosystem biodiversity and composition. 28

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Environmental Issues of National Importance and the Role of NEON Research has shown that such changes in diversity and composition may affect the stabilipr, productivity, carbon storage, invasibili~, and disease incidence of ecosystems and the nature and value of services that they provide to societr (e.g., Nacem et al. 1996, Tilman et al. 1996, 2001, Hector et al. 1999, Loreau et al. 2001~. The longest-term biodiversipr study is an experiment begun in 1994 at Cedar Creek Long Term Ecological Research (LTER) site in Minnesota and still running. That endeavor has determined the effects of manipulated plant bio- diversi~ and composition on ecosystem productivity, nutrient dynamics, and disease dynamics (Tilman et al. 2001~. It has been shown that the loss of plant diversity in those prairie grasslands led to decreased produc- tiv~pr (Figure 2-1), decreased retention of the limiting resource, decreased 1 .4 1 .2 ~ 1.0 N a,, 0.8 (a 0.6 Is 0.4 0.2 0.0 _~ ~~~ j998 ~ If.+ ~ ... '-1 I................ ...... 1 9.9.? ! 0 2 4 6 8 10 12 14 16 Species number FIGURE 2-1 Relationship between' total biomass arid species diversity of ar' , . 7, 7 7 A_ 7 A_ 7 ~ By- . 7~7 . 7 7- . exper~mer~talpra~r~e-grasslar'~ art cedar Preen, ant ~r~rzesota. Claret overstay (r~z~mber of speciesJ ar~dilar~t composition' were controlled ir' this experiment. SOURCE: Tilmar' et al. 2001. 29

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NEON: ADDRESSING THE NATION'S ENVIRONMENTAL CHALLENGES removal and storage of atmospheric carbon dioxide, increased incidence of species-specific fungal diseases of leaves, and decreased insect diversity (Tilman et al. 1996, 2001, Mitchell et al. 2002, Haddad et al. 2001~. A similar experiment was performed in European grasslands and was replicated in eight nations of the European Union, from Ireland and Sweden to Portugal and Greece (Hector et al. 1999~. Those two field experiments have generated numerous questions and controversies in ecology because it is not known whether the experi- mental results observed would apply to other grasslands, let alone to other terrestrial, lake, or coastal ecosystems. That raises a central issue: How wed can results from one or two studies be generalized and applied to other localities and other ecosystem types? How can results be scaled up from one site to a continent? For example, in the Minnesota study, ecosystems planted to 16 prairie grassland plant species removed and stored 2.7 times as much carbon dioxide as did ecosystem planted to a single species. Does that imply that managed forests that are planted to many tree species would remove and store more carbon? Might the number of fish species in a fishery influence its productivity and stability? Might the biodiversity of any type of ecosystem influence the flow and quality of goods and ecosystem services that it provides to society? Answers to such fundamental questions require a continental-scale, coordinated research program. The same experiments that showed that biodiversity affected various ecosystem processes also showed that the species composition of eco- systems was as important as biodiversity. Management practices including grazing timing and intensity, the identity of grazing species, fire frequency, logging frequency and methods, reforestation or revegeta- tion methods, and nutrient loading rates all affect both the biodiversity and the species compositions of terrestrial and aquatic ecosystems. Biodiversity and species composition, in turn, determine the flow, quality, and economic value of the goods and services that the ecosystems produce. To seek solutions to declines in ecosystem services due to diseases, species invasion, altered biogeochemical cycles, climate change, and land use, we need to know how these phenomena affect species composition 30

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Environmental Issues of National Importance and the Role of NEON and biodiversity. Few sites across the nation have regular inventories of species abundances, and most such inventories are limited to a few types of species (such as tree species or bird species); this leaves the vast majority of their biodiversity unidentified and not quantified. Such data should be collected in a variety of sites that span the major natural and managed terrestrial, freshwater, and coastal ecosystem types of the nation. Biodiversity surveys should be closely tied to experimental studies of the effects of biodiversity and species composition on ecosystem function and . . r provision or services. ECOLOGICAL ASPECTS OF BIOGEOCHEMICAL CYCLES Alteration of biogeochemical cycles on regional, to continental, and global scales is a hallmark of human activity. We fix nitrogen from the atmosphere for agriculture or as a byproduct of combustion. We return carbon stored in fossil fuels to the atmosphere. We mine, smelt, trans- port, use and discard rare elements in support of an industrialized society. We create and release large quantities of pesticides, herbicides, fungicides and other persistent organic pollutants. Products and byproducts of our various actions escape to the atmosphere and hydrosphere and are transported over long distances, establishing connections between centers of human activity and "remote" regions. Humans are inadvertently conducting a global experiment by modify- ing biogeochemical cycles through mining, combustion of fossil fuels, large-scare conversion and use of global landscapes, and modification and use of such critical elements as agricultural fertilizers. Many anthropo- genic toxicants, such as mercury and polychlorinated biphenyls, are fit transported from their sources to distant and dispersed areas through the atmosphere. The basic elements of life and important toxins are being distributed at regional and continental scales, and may be deposited as 'toxic snow' in remote and seemingly pristine sites as alpine and northern lakes (Schindler 1999~. Emissions of carbon, nitrogen, and sulfur have altered their availability to land and water biota and created shifts in biodiversity and ecosystem function. Heavy metals and organic com- 0 1 ' 31

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NEON: ADDRESSING THE NATION'S ENVIRONMENTAL CHALLENGES pounds are transmitted to soils and waterways and are often accumulated and concentrated through food chains. Common characteristics of such alterations from preindustrial conditions include an increase in cycling rate through the atmosphere and biosphere, increases in the atmospheric reservoir, and enhanced bioavailability. For example, it is estimated that humans have more than doubled the rate at which reactive forms of nitrogen are created from the relatively inert N2 in the atmosphere. The production of nitrogen fertilizers with the Haber-Bosch process, high-temperature combustion of fossil fuels, and an increase in the cultivation of legumes are the primary causes of the doubling of terrestrial nitrogen inputs. Similarly, human activity now dominates global phosphorus and carbon cycling, land use, marine fisheries, and much of the hydrologic cycle (Vitousek et al. 1997, Carpenter et al. 1999, Postel 1999~. Although increased cycling of carbon, nitrogen, sulfur, and phos- phorus increases primary productivity, it also causes loss of biodiversity, changes in dominant species in ecosystems; production of byproducts, such as aluminum, other heavy metals, and tropospheric ozone, and other harmful conditions. For example, algal biomass decomposition that results from increased primary production in aquatic systems can overwhelm oxygen supplies, leading to eutrophic and anoxic conditions. All those adverse effects are caused by the transport of locally produced compounds, wastes, and byproducts through the regional atmosphere and waterways to adjacent or distant areas of deposition and response. Therefore,understandingbiogeochemistryon regional, continental, and global scales is at the heart of addressing the social and environmental problems resulting from changes in the distribution and concentration of elements. For example, carbon dynamics and sequestra- tion in landscapes are the subjects of one of the most socially relevant biogeochemical studies that need to be addressed on a continental scale. Current estimates of carbon storage in the ecosystems of North America depend on the method used to derive. The development of the eddy covariance method for measuring net carbon balances over short periods has revolutionized ecosystem bio- 32

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Environmental Issues of National Importance and the Role of NEON geochemical studies. Eddy covariance provides a new window into ecosystem function that increases our understanding of the processes and controls that determine element balances. Over the last decade, tremen- dous advances have been made in the reliability and standardization of the basic measurement system and in the understanding of the physical and mathematical constraints on the interpretation of the signal received. Those developments make the technology well poised for much wider application. Currently, the United States sponsors, through the activity of a number of different agencies, a network of eddy covariance towers designed to measure net carbon balances over different ecosystems. The current system lacks both adequate replication and spatial coherence because of the mixed sources of funding and the lack of a national vision. The congruence of national need, developing technology, and a nascent scientific network means that large gains in our measurement and understanding of carbon fluxes over native and modified ecosystems can be realized immediately through a national network of net carbon balance observatories. Such a network would benefit from the ability to plan, a priori, the optimal number, placement, and operation of a large number of replicate measurement systems. The existing AmeriFlux network (see Plate 1) provides the best current basis for making such estimates, but the network is inadequate with respect to spatial coverage, stratification by vegetation type and land use and management practices, and consistency of the sensors. For example, existing eddy covariance systems tend to be in secondary forests or other relatively stable systems that are undergoing relatively rapid carbon accumulation. Placements are beginning to expand into experimentaDy-modified or more recently disturbed areas, but such systems are still underrepresented. A set of eddy covariance towers could be deployed to compare directly the effects of different land-use patterns, water-availability regimes, or pollution-deposition rates on gross and net carbon exchange. Continuous collection of flux data from such sites provides the basic information needed to test fundamental physiological hypotheses on land-use, water, and pollutant effects and would lead to the development of better models. 33

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NEON: ADDRESSING THE NATION'S ENVIRONMENTAL CHALLENGES prevalence and severity over the last 25 years. Emerging infectious diseases are those whose incidences have increased within the last 2 decades or threaten to increase in the near future. The categorization as an emerg- ing infectious disease may be due to the recognition of the spread of a new agent, to the recognition of an infection that has been present in the population but has gone undetected, or to the recognition that an established disease has an infectious origin. Diseases have been emerging at an increasing rate in wildlife and plants for the past few decades with devastating consequences for biodiversity conservation and human population welfare (Daszak et al. 2000; Anderson and Morales 1994~. For example, chronic wasting disease in deer herds is estimated to have cost Wisconsin $10 minion and Colorado $19 million in 2002 alone () because of reduction of spending by non- resident deer hunters. Diseases of trees in forest, diseases of animals that are valued by tourists, and diseases of plants that change the aesthetic value of ecosystems represent an enormous cost to the nation's primary productivity and tourism. Wildlife also act as a reservoir and can be an important source of transmission of infectious diseases to humans (IOM 2002~. Indeed, 61% of ah human pathogens are capable of natural transmission between animals and humans (WHO 1959) and are thus classified as zoonotic (Taylor et al. 2001~. Because most zoonotic infections in humans are usually acquired from the environment and most emerging disease outbreaks are related to ecological disruptions, the study of zoonotic epidemiology requires fundamental ecological knowledge. Although vaccination for and control of infections in humans are important, the ecological and evolutionary selection pressures that cause diseases to emerge or develop resistance to treatment should be identified so that disease emergence and spread can be prevented. Our first challenge is to identify ecological conditions that lead to disease emergence. For example, the 1993 outbreak of Hanta virus pulmonary syndrome (HPS) caused by the Sin Nombre Hanta virus in the US Southwest was probably caused by a cascade of ecological events 36

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Environmental Issues of National Importance and the Role of NEON that led to increased exposure to the virus (Figure 2-2~. In particular, dry years followed by wet summer increased ecosystem productivity, thereby increasing food for rodents. Rodent predators had been reduced by hunting, so rodent abundance rose virtually unchecked, and this led to increased transmission of the virus in the deer mouse population and ultimately to humans. In addition to identifying ecological factors that promote disease emergence, we also need to understand the factors that promote disease spread and microevolution dynamics. For example, the virus complex that causes tick borne encephalitis (TBE) most likely originated in the Far East and spread from Japan (as Omsk virus) to the states of the former Soviet Union. From the Soviet Union, it spread to other Euro- pean countries, including Slovakia, Austria (as western TBE), Spain (as Spanish encephalitis), Scotland, and Norway (Gould et al. 2001~. Shifts in virus strains have been hypothesized to be caused by human-induced changes in host community and vector ecolo~v. Research has indicated OF that rapid late-summer cooling tends to synchronize the immature stages of the ticks, leading to tick-to-tick transmission of TBE on the host (Randolph et al. 2000, Rogers et al. 2001~. At the same time, large communities of mammalian hosts (such as a large flock of sheep) would promote disease transmission. Subtle seasonal changes in climate coupled with land-use changes that increase host availability can trigger disease outbreaks. Comprehension of the spread of TBE on the continental scale would provide us with insights about the ecological conditions that stimulate emergence and spatial flow of similar diseases. For instance, West Nile virus, which has spread across the United States in the last few years (Plate 2), is a close relative of TBE (Gould et al. 2001~. Detailed knowl- edge of climatic conditions that influence the mosquito life cycle and the availability and susceptibility of hosts is necessary for the prediction of the spread of West Nile virus. Within host and transmission dynamics should be linked to provide an understanding of how the disease spreads spatiotemporaDy. Such information can then be projected from the landscape to continental scale. Integration of ecological understanding 37

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NEON: ADDRESSING THE NATION'S ENVIRONMENTAL CHALLENGES FIGURE 2-2 A schematic overview of the cascade of ecological events that leads to increased hzlmar' risk to Manta Pzllmorzary Syndrome. The central ecological "er~girze' is the prodzlctior' of susceptible hosts ("Rodent demography "J throzlgh rodent reprodzlc- tior'. Susceptible hosts acquire infection from infected ir~di~vidz~als throz~gh contact transmission' ("Trar~smissior'"J. A cascade of increased risk is initiated whet' er'~viror'- mer~tal conditions Notably primary prodz~ctior'J favor rodent reprodz~ctior' arid recrzlitmer~t (Primary prodzlcti~vityJ arid ends with hzlmar'-roder~t association' leading to cross-species infection (Spillo~verJ. 38

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Environmental Issues of National Importance and the Role of NEON with epidemiology and microevolution dynamics would permit predic- tion of infection probabilities on a continental scale. A network for monitoring the spread of emerging diseases and for studying the ecological factors that promote disease outbreak and the evolution of diseases would help in identifying disease hot spots, where the next emerging disease would appear, and how it would influence 1 1 ' human, wildlife, and plant communities. A deep understanding of the ecology of wildlife, plant, and zoonotic diseases can help us to devise precautionary measures for and adaptive responses to disease emergence. INVASIVE SPECIES . Human commerce and transport fuel economic development but also inadvertently serve as a conduit for the transfer of non-native species into ~ . . . . new ecosystems. Once released into new environments, foreign species can become ecological dominants, disrupting agriculture, ecosystem function, or water flow, and displacing native species. Invasive species occur in every ecosystem in the United States, from shallow bays and rivers to lakes, forests, farms, and grasslands. The freshwater zebra mussel was brought to North America in the ballast water of commercial tankers, and was first discovered in 1988. Zebra mussels have now spread to many states in the United States (Plate 3) and causes expensive damage each year by clogging freshwater pipes. Most agricultural weeds are introduced species. Indeed, most invasive plant species were deliberately introduced into new habitats via the horticultural trade. Although only a small percentage of plant species introduced as ornamentals become invasive, thousands of novel plant species are aDowed to be imported into the United States every year because there are no known ways to identify beforehand the ones that will cause the next major invasion. The introduced gypsy moth destroys coniferous forests when it escapes insecticide control and spread from the suburbs of Boston to the coniferous forests of Oregon in the last century. San Francisco Bay has over 100 invading marine species, including the Atlantic shipworm, which is capable of eating wooden docks and 39

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NEON: ADDRESSING THE NATION'S ENVIRONMENTAL CHALLENGES destroying seawalls. Overall damage to the economy by invasive species has been estimated to be $137 billion per year (Pimentel et al. 2000~. Because no ecosystem in the United States is immune to the damage caused by invaders, and because invaders often jump from one ecosystem to another, any response must involve a national-level effort to track and control invaders. The most rapid invaders tend to be fast-growing species that have escaped their natural controls. Recent data suggest that invasion rates increase when native parasites do not target invading species (Torchin et al. 2003) or when local biodiversity is artificially Towered (Stachowicz et al. 1999~. However, there are no general principles for differential susceptibility of ecosystems to invasion, and management to reduce invasion currently consists solely of reducing foreign species introduc- tions. As global trade increases, invasions are likely to multiply. The global visage of future human commerce wiD contribute to the creation of a global ecosystem biased toward weedy species unless invasion can be understood as an ecological process sufficiently to allow forecasting of the invasiveness of species and prediction of which potential biological agents would both be effective in controlling an exotic species and have the fewest detrimental effects on natural and managed ecosystems. Observations of invading species tend to be idiosyncratic, and data on the rate of spread of species through different ecological communities are sparse. For example, green crabs invaded the coast of Maine in the 1930s from a 19th century introduction in New Jersey but there have been few observations of the pace of invasion. Similarly, few experiments on the susceptibility of different ecosystems to invasion have been conducted, and none have examined how a single species invades multiple habitats. The national problem of species invasions cannot be addressed without a national system for tracking invasions and a set of research facilities dedicated to understanding why some ecosystems are more than others prone to invasions and why some species are more likely than others to become invasive. Studies of where invading species enter the United States, their routes of spread and points of control, the speed at 40

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Environmental Issues of National Importance and the Role of NEON which they move through different ecosystems, and the concomitant changes in native species aD require monitoring systems that are coordi- nated across different ecosystems on a continental scale. Such monitoring efforts combined with experimentation would generate models that assess ecosystems' vulnerability to species invasion. LAND USE AND HABITAT ALTERATION In the National Research Council report Grand Challenges in Envi- ronmental Sciences (NRC 2001), the challenge related to land and habitat use was described aptly: Humans have dramatically altered the Earth's surface. These changes in land cover the land surface and immediate sub- surface, including biota, topography, surface water and ground- water, and human structures are so large and rapid that they constitute an abrupt shift in the human-environment condition, surpassing the impacts of aD past epoch-level events (e.g., the domestication of biota, the industrial revolution) since the rise of the human species. Indeed, they approach in magnitude the land-cover transformations that have occurred at transitions from glacial to interglacial climate. Whether anthropogenic in origin or the result of natural events, such as wildfire, changes in land and habitat use can affect a fuD suite of environmental characteristics both locally and nationally. Land-use practices in one region can affect people and ecosystems 1,000 miles or more away. For example, intensive agriculture in the upper Midwest affects water quality in the lower Mississippi and fisheries in the Gulf of Mexico (Downing et al. 1999~. The damming of rivers a major form of habitat use can provide water for agricultural and urban use and can provide hydroelectric power. However, damming can also affect fisheries and threaten species with extinction. Because materials and organisms are transported from one site to another through the atmosphere, groundwater, streams, and rivers, land-use and habitat alteration in one region can have substantial effects on other regions. Thus, land-use and 41

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NEON: ADDRESSING THE NATION'S ENVIRONMENTAL CHALLENGES habitat alteration have to be examined and understood on regional to continental scales. In the United States, agriculture and forestry greatly influences land- use practices. After the settlement of the United States in the 16th to 19th centuries, massive changes in land and aquatic habitats occurred in North America. The forests of the East were cut to produce pastures and plowable fields. The prairies of the central states became the grana- ries of the nation. The forests of the Northwest were clearcut to provide timber for the nation. The rivers of the West were dammed so that the dry lands of the region could be used to cultivate produce. Those land and habitat use and management practices have provided many of the initially desired benefits, but also have had a range of unintended impairment to ecosystems. For instance, the NRC report on Grand Challenges in Environmental Sciences (NRC 2001) states that Human use of land, that is, what people do to exploit the land cover, has been the primary culprit in the estimated 2.95 minion km2 Of soils whose biotic function has been significantly dis- rupted by chemical and physical degradation including 1.13 million km2 disrupted by deforestation and 0.75 million km2 by grazing. In addition, agriculture currently consumes 70 percent of total freshwater used by humankind, much of which is accounted for by the rapid expansion of irrigation, which annually withdraws some 2000-2500 km3 of water. Land and habitat use can increase disease spread, harm species or even threaten them with extinction, decrease the flow of essential and valuable ecosystem services, and affect the production of food, fiber, and fuel (NRC 2001~. We concur with the National Research Council report, which concluded that land-use and land-cover dynamics and their spatial patterns play a significant role not only as drivers of environmental change, but also as factors increasing the vulnerability of places and people to environmental perturbations of ad kinds. Improved information on and understanding of land-use and land-cover 42

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Environmental Issues of National Importance and the Role of NEON dynamics are therefore essential for society to respond effectively to environmental changes and to manage human impacts on environmental systems. A nationwide network of facilities would allow comparative environ- mental studies biodiversity, biogeochemistry and water aualitv of ecosystems subject to different land use practices. 1 J SIX LARGE-SCALE ENVIRONMENTAL CHALLENGES On the basis of observations, facts, and analyses (set forth in detail earlier in this chapter), the committee identified six critical environ- mental challenges that are of national concern and that can be addressed only by research performed in a coordinated manner on regional to continental scales research that would require a network like the National Ecological Observatory Network (NEON). Only a nationwide network of sites that have a common infrastructure for experiment and observation can adequately address each of those challenges. Plates 4-7 illustrate examples of large-scale infrastructure and experiments that contribute to the advancement of ecology and environmental science. Just as nuclear accelerators have proved to be essential for advancing our knowledge of subatomic physics, networks of infrastructure that facilitate and accommodate weD-replicated ecological experiments are essential for advancing our knowledge in ecolo~v and environmental science. O Of ENVIRONMENTAL EDUCATION AND OUTREACH AS NATIONAL NEEDS The National Science Board, in its recent report Environmental Science and Engineeringfor the 21st Century: The Role of the National Science Foundation, stresses that the National Science Foundation is being looked to for leadership in environmental research, education, and scientific assessment by citizens, other federal agencies, professional societies, scientists, and government officials, and notes that "Scientific 43

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NEON: ADDRESSING THE NATION'S ENVIRONMENTAL CHALLENGES understanding of the environment, together with an informed, scientifi- caDy literate citizenry, is requisite to improved quality of life for genera- tions to come" (NSB 2000~. Fulfilling that role and the educational . . expectations Is a challenge that NSF could meet with careful planning. Scientific progress in the six themes described above requires an interdisciplinary approach. Although multidisciplinary research is collaboration among scientists in different fields, interdisciplinary research requires the integration of multidisciplinary knowledge. Yet few environmental scientists have the broad training required to conduct interdisciplinary research (NRC 2001~. Undergraduate education faces similar challenges because how scientists design, perform, and analyze experiments and how they col- laborate, and exchange information are undergoing rapid and dramatic transformations. Links between the physical and biological sciences, technology, and mathematical disciplines are becoming essential. In contrast, undergraduate biolo~v education has chanced relatively little OJ O J during the last 2 decades. Training and education of future biologists are geared mostly toward the biology of the past, rather than to the biology of the present or future (NRC 2003a). As is true of research, under- graduate science education needs an interdisciplinary transformation to meet the needs of 21st century biology. The role of science in K-12 education requires national attention. The nation has established scientific literacy as a central goal for K-12 education, but to date this goal"eludes us in the United States" (AAAS 1989~. Scores of national and state studies have concluded that as judged by international norms, national standards, and state require- ments the US K-12 education system is failing to educate many of its students. The reform of education in science, mathematics, and tech- nolOO~y should be one of America's highest priorities (AAAS 1989~. Students who do not understand the natural world, do not have the knowledge and skills needed to make informed decisions, or do not understand the workings of the ecosystem in which they live cannot function as responsible stewards. Education to understand the relation- ship between humans and the rest of the biosphere should draw from 44

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Environmental Issues of National Importance and the Role of NEON multiple scientific disciplines social science, geology, geography, meteorology, chemistry, physics, ecology, and economics. Yet few curricula and textual material include such an integrated approach, and K-12 teachers have usually received little training in environmental science and are rarely equipped with the knowledge and skills needed to work beyond textbooks (PCAST 1998~. In part as a result of deficiencies in science education, "Americans are ill prepared to understand the complex and intractable environmental issues that wiD be our greatest challenges in the years ahead," according to the 1999 National Report Card on Environmental Readinessfor the 21st Century (NEETF 1999~. The majority of the public harbor serious misconceptions on such issues as global warming, air pollution, and water quality. A 1998 survey of adult Americans by Roper Starch Worldwide reported that when specifically tested on environmental knowledge, most Americans had misinformation and expressed "beliefs" that were myths. Americans averaged just 2.2 correct responses out of 10; even random guesses would have produced 2.5 correct answers (NEETF 1998~. Moreover, the survey reported a strong correlation between environ- mental knowledge and behavior. Activities or behavior that benefit the environment increase proportionally with environmental knowledge. Despite their lack of knowledge, most Americans remain supportive of environmental protection and the desire to make the environment and economy a win-win issue, are engaged in environmental activities and courses, and 95% American adults support the teaching of environmental education in our schools (NEETF 1997~. An increase in public under- standing of and involvement in ecology and environmental science would make Americans more informed citizens and more likely to support environmental policy that best balances the multiple tradeoffs that . society faces. 45

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the invasion process anct information about species traits and ecosystem states that influence invasions. The observatory's major infrastructure might be expected to include populations. as Major physical sites, each with containment facilities appropriate for experimental introduction of invasive species into contained communities. Experiments would be designed to determine the mechanisms of interaction among native and invasive species and to enhance our capabilities to assess an ecosystem's vulnerability to species invasion. Control hardware and software to monitor environmental alterations and to adjust local conditions. A major site serving as a central sequencing center, which could include an existing sequencing center and be equipped with molecular genetic instrumentation and such equipment as sequencers, cloning facilities, chip printers, ant! microarray readers. Facilities at each site to house local synoptic collections. Microscopes, digital photographic tools, microarray rea(lers and gene specific probes would likely be needed. Experimental plots at some or all major sites outfitted with equipment needled to alter local environments, such as carbon dioxide abolition rings or soil warmers, so as to determine the possible selective advantages that climate change or environmental change may confer on . . Invasive species. PCR-sequencing facilities to determine origin and genetic structure of invasive The invasive species observatory could establish linkages to such agencies and programs The National Invasive Species Council. An interdepartmental council that helps to coordinate and ensure complementary, cost-efficient, and effective federal activities regarding . . Invasive species. NBll invasive species information node ~ SIN). With its partners, this is involved in research projects to understand, document, monitor, predict, and control invasive species. USDA 's Animal and Plant Health Inspection Service (APHIS9. This has an invasive species program. USDA also has an invasive-species Website with links to a number of databases (~. Land and Habitat Use and Management A NEON observatory dedicates! to land and habitat use would have to be structured to allow determination of the local, regional, and continental effects of alternative land and habitat use patterns. Its central focus would be on scaling local effects up to regional or national by linking atmospheric effects and effects of aquatic transport of organisms and materials. Such an observatory could be structured in several ways and would have numerous potential facility needs. At a minimum, it would need a set of nested sites spanning a large geographic range- from midwest croplands, to suburban and urban lands, to the Gulf of Mexico and a large range of land uses growing different agricultural crops in different ways, managing pastures ant! forests in different ways, urban and suburban areas with different types of sewage treatment, and 46