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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 '
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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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Representative terms from entire chapter:
invasive species
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 (
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
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
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
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
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
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
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
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
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
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
