LTER 2000-2010: A DECADE OF SYNTHESIS
I.
STATEMENT OF PURPOSE
The US LTER Network has grown rapidly over the past 20 years, both in size and in the scope of its activities. This growth is generally welcomed and is viewed overall as a mark of the success of the network and its individual sites and investigators. From an initial group of 6 LTER sites and a few dozen investigators in 1980, the network has grown to 24 sites in 2001, involving the work of over 1200 scientists, students, and teachers from scores of institutions at all levels of research and education. The LTER enterprise is unique in the ecological community. It is not only large but also diverse in its personnel, diverse in the science performed, and designed from its beginnings with long-term goals in mind. Because it functions as a network of collaborating sites with related objectives, it is cooperative and provides remarkable opportunities for ecological and environmental research with a breadth and detail unmatched by other sources.
Growth and success have led to an ever-increasing number of demands on the LTER Network and its Network Office. These demands are many and varied and, although all are individually easy to justify, clearly not all can be met simultaneously. Similarly, there are many new research opportunities that might be handled appropriately by the network, but to try to handle them all would be chaotic and inefficient. There is, therefore, a clear need for the LTER Network and the Network Office to develop a well-defined set of priorities designed to maximize its effectiveness and scientific impact over the next 10 years.
Priorities
for any organization must be developed and understood in the context of its
overall aims and mission.
Organizational aims and mission, however, also tend to evolve
continuously and to lose focus over time, particularly under conditions of
rapid growth such as that experienced by the LTER network over the past two
decades. There is thus a clear need
periodically to refresh and, if necessary, refocus the core aims and mission of
the LTER network. As a guide to
priority-setting, therefore, the purpose of this document is to refresh
and to update the overall aims and mission of the LTER network so as to place
its diverse current activities in a clear and consistent context and to develop
clear priorities for the future.
2. BACKGROUND
The development of this document was stimulated first by the request of the US LTER National Advisory Board, who identified the need for priority-setting in the report of their December 1998 meeting. This recommendation was repeated after the NSF Site review of the LTER Network Office in May, 2000. The third stimulus was the need to prepare for the 20-year review of the LTER Program by NSF, to occur during 2001.
In response, the LTER Coordinating Committee voted to the Network's priorities at its August, 2000 meeting in Snowbird, Utah. After preliminary discussion and development of an outline at the Snowbird meeting, the LTER Executive Committee organized a series of meetings with the Scientific Initiatives Committee, the Lead Principal Investigators, the National Advisory Board, and the Coordinating Committee (Box 1). In addition to these meetings, all 24 LTER sites were asked to rank a detailed list of site and network activities and to indicate how they would allocate their resources among these activities. The final writing was done by the Executive Committee.
3. THE US LTER NETWORK: OVERALL AIMS AND MISSION STATEMENT
As a result of this series of
meetings and discussions, the US LTER Network has reaffirmed the following
statement of its aims and mission : The
central, organizing intellectual aim of the LTER program is to understand
long-term patterns and processes of ecological systems at multiple spatial
scales. The Mission of the LTER Network is to achieve this aim in six,
interrelated ways (Box 2):
·
Understanding: Gaining ecological
understanding of a diverse array of ecosystems at multiple spatial and temporal
scales
The mission of the LTER network begins with research based at individual sites, each of which has a unique theme. This site-based focus has allowed for key scientific advances at each of the sites, while the common focus on long-term research in a diverse array of ecosystems and landscapes has facilitated broad comparisons and syntheses across sites. Together the network of sites covers a wide range of subjects at multiple temporal and spatial scales.
·
Synthesis: Using the network of
sites to create general ecological knowledge through the synthesis of
information gained from long-term research and development of theory
The products of LTER research extend beyond the accumulation of knowledge about diverse, individual ecosystem types. At a higher level, synthesis of this site-based knowledge across the network provides the broader scientific understanding from which new theory is derived and general applications can be developed.
·
Information: Creating well
designed, documented databases that are accessible to the broader scientific
community
Long-term research demands long-term data. The creation, curation and dissemination of long-term databases is needed to assure that the data resources needed by researchers will continue to be available. These databases must include the additional information required to interpret data (i.e., metadata) as well as the data themselves. By adopting policies that promote the timely sharing of data (both inside and outside the LTER Network), the scientists can use the data in a variety of ways not anticipated by the original collector such as regional, national and global syntheses, thus providing a resource for the broader scientific community.
·
Legacies: Leaving a legacy of
well designed and documented long-term observations, experiments, and archives
of samples and specimens
Many ecological phenomena change at decadal to century and longer time scales, and it is essential to maintain experiments and observations across periods appropriate to the questions addressed. The orderly transfer of experiments and interim results from one generation of scientists to the next requires a research design and setting that allows for multiple samplings (some unanticipated), long-term protection from competing uses, and meticulous documentation of experimental protocols. Also essential is a means to store protocols and observations in a manner that is secure and consistently accessible to the scientific community for use in syntheses and cross-site comparisons (both inside and outside the LTER Network).
·
Education: Using the
uniqueness of the LTER programs and network to promote training, teaching, and
learning about long-term ecological research and the earth’s ecosystems.
One of the major lessons
from the first 20 years of LTER has been that success both within sites and
within the network requires a non-traditional approach to ecological research.
This approach is characterized by a commitment to long-term measurements that
may yield only a few useful initial results but that are essential to understanding
long-term change, by a willingness to work as part of large teams that may have
priorities that are different than one’s own, by a desire to interact closely
with others in order to share ideas and data, and by the need to develop a
broad interdisciplinary perspective.
The LTER approach to research, coupled with the ability to implement
long-term educational initiatives, allows for unique approaches to training of
future researchers and to learning and teaching ecological concepts. Evaluating
and disseminating this approach through the involvement of graduate and
undergraduate students, postdoctoral and international scientists, K-12
educators and students, and the general public will help ensure the success of
long-term ecology in the future.
·
Outreach: Providing knowledge to
the broader ecological community, general public, resource managers, and policy
makers to address complex environmental challenges
Humanity faces increasingly numerous and serious environmental problems that range from local to global in extent, and that must be tackled by institutions at local to international scales. The LTER network and emerging ILTER networks provide the most comprehensive and diverse system of sites for ecological observations on the globe, and research of the LTER network has repeatedly demonstrated the ability of long-term ecological science to address these environmental challenges. Increasingly, LTER research is finding applications in the work of federal, state, and local agencies that manage environmental resources. The synoptic and detailed knowledge of individual LTER sites, and the opportunities for multidimensional comparisons among sites, also represent significant opportunities for other disciplines including social sciences, earth sciences, and basic biological sciences that must be pursued. Finally, knowledge from this breadth of views permits us to identify and anticipate new issues and challenges, test existing ideas about causation, and help provide the science that underpins the processes of open, participatory and forward-looking decision-making.
4. SITE-NETWORK INTERACTIONS FACILITATE THE
LTER MISSION
Progress in achieving the LTER Mission begins with the work of individual scientists, students, and educators at the 24 LTER sites (Figure 1). It is their work at the site level that forms the foundation of knowledge, data, observational and experimental legacies, and training that will ensure a lasting impact of the overall LTER program. Data and knowledge gained from intensive field experience are also key to development of syntheses of site-level information into models that allow prediction of long-term change and responses to human and other disturbances. Site-level synthesis activities often lead to new insights that feed back to affect the future course and evolution of site-level research.
The Network infrastructure also promotes and facilitates cross-site and regional analyses, leading to larger-scale syntheses and to development and testing of ecological theory (Figure 1). In this work the maintenance of a network data base and protocols for data searching and sorting are particularly important. All of these efforts add to the basic body of scientific knowledge of long-term, large-scale ecological phenomena and, because students are deeply involved both at the site level and in intersite and network-level syntheses, they help to increase the numbers of people with appropriate expertise in both research and environmental problem-solving.
Ultimately, both site and network-level activities feed back to the development of scientific capital, which includes well-trained scientists, a well-informed citizenry, and the basic data and understanding that underpin them (Figure 1). This accumulation of scientific capital also leads to new research and new applications of LTER research, including new forms of support for both research and education. Growth of scientific capital also includes interactions with new scientific disciplines, leading to expansion of the scope and applications of LTER research.
5.
CORE RESEARCH TOPICS ENSURE BROAD SCOPE
A key feature of the LTER network is the relative independence of individual LTER sites with respect to the specific focus of their research, while at the same time all sites are required to maintain a broad-enough spectrum of research to allow intersite and network-level comparisons. The device used to ensure broad-spectrum research is the requirement that all sites perform at least some research in five "core" research areas (Box 3). Experience to date indicates that this compromise works well: The sites' freedom to develop their own lines of research has allowed each site to take maximum advantage of its own unique combinations of expertise and opportunity, and it has been a major factor in the high overall research productivity of the Network. The requirement that all sites maintain a wide range of research with minimum specification of topics, organisms, variables, and units of measurement has made possible several significant multisite comparisons and syntheses that could not have been anticipated with a more rigid, uniform research design for all sites.
The five core topic areas (Box 3) thus represent a compromise between the need to ensure research opportunities at the Network level while still promoting creative, independent, long-term research efforts at the individual sites. The overall purpose of the core topics is to ensure the development of a program of research with an appropriate balance of opportunities and effort at both the site and the Network levels, and that increases the total productivity of BOTH levels. The topic areas are NOT research objectives themselves, that are expected to be completed in the foreseeable future, but they do require that all sites collect data on a range of topics that are expected to be the subject of future LTER research. It is expected that as the intellectual scope of the LTER program evolves and grows it may be appropriate to revise the core areas occasionally, always with the aim of creating an appropriate balance between site- and network-level research.
Standardization of methods and units is a particularly important, continuing issue. Although additional multisite and network-level research could be done if we were to increase efforts to standardize and/or harmonize measurements, a monolithic design to the network as a whole (all sites identical) is not desired. As with the core areas, the present approach to standardization represents a balance between independence and initiative at the site level and the need for at least some means of cross-site and network level comparisons. Standardization efforts are continuing, however; in several cases thus far where particular comparisons are made at many LTER sites (such as comparisons of climate and soils), detailed "LTER standards" have been developed. Currently, the comprehensive understanding gained at LTER sites is attracting a wider range of monitoring and research from other institutions and agencies, who generally have well-developed standards. Agency programs are adding LTER sites to their monitoring efforts to capitalize on the system-level understanding at sites to help interpret their monitoring results.
6.
PRIORITY-SETTING: BACKGROUND AND EVOLUTION OF PRIORITIES
The LTER program has evolved
considerably over the past two decades although it has never wavered from its
central, organizing intellectual aim: to understand long-term patterns and
processes of ecological systems at multiple spatial scales. Each
decade of the program has seen major advances both scientifically and
organizationally. Broadly speaking, the
first decade of LTER (the 1980s) might be termed the Long-Term Research Decade,
the second decade (the 1990s) might be called the Large-Scale Research Decade,
and the program is currently in the first years of its third decade, the Decade
of Synthesis. Major accomplishments and
goals in the first two decades include the following:
Long-term Research Decade (1980s):
·
Recognition of
long-term frequencies that affect system dynamics, system resets (e.g., fire,
disturbance, climate cycles)
·
Understanding of
interactions among ecological processes that change at different rates
(interaction of "slow" versus "fast" responses)
·
Extension of
temporal analyses retrospectively (e.g. tree rings, paleo-studies) to
understand and forecast behavior.
·
Broadening
of the LTER view from a focus on
ecosystems to an emphasis on ecological
systems generally
·
Evolution of a
“Magnet” role of LTER sites in attracting broad array of other scientific
activities addressing multiple processes and interactions in ecological systems
·
Development of
data and information management at LTER sites
·
Development of
networking and Network Office functions
·
Expansion from 6
to 17 sites and Network Office
Large-scale Research Decade (1990s):
·
Increased focus on spatial scaling of
ecological patterns and processes and spatial-temporal interactions
·
Expansion of research on the role of
human land use and natural and anthropogenic legacies
·
Broader representation of ecosystem
types including human-dominated urban systems
·
Collaboration with physical, social
and economic sciences
·
Cross-site comparisons testing
generalizations
·
Synthesis (often for science themes
not directly addressed by core areas)
·
Expanded collaborations with non-LTER
sites and programs including development of international interactions (ILTER)
·
Development of LTER Network
Information System and increased network-level data use and data exchange in
cross-site and synthesis activities
·
Increased use of LTER as an
experiment to evaluate NSF initiatives (site augmentation, urban ecosystems,
social science collaborations, schoolyard LTER)
·
Establishment of National Advisory
Board
·
Expansion to 24 sites and over 1200
scientists, students, and educators
7. THE THIRD DECADE OF LTER: A DECADE
OF SYNTHESIS
The LTER
Network is now poised for a Decade of Synthesis, in which the data and
knowledge gained over the past twenty years, plus current studies, are brought
together to reach new levels of understanding of long term ecological patterns
and processes. This synthesis is
expected to lead to new research directions and new data gathering as well,
driven by the new insights to be gained from the unique opportunities now
available. Synthesis opportunities
exist at the site level, at the network level, and through incorporation of new
perspectives brought by other scientific disciplines to LTER. The range of topics is very broad, from
intensive multidisciplinary analyses of patterns and processes in individual
ecosystem types to comparisons among ecosystems across a wide range of climate,
biodiversity, and interactions with human populations. To help maximize the impact of LTER research
over the next decade, five key goals have been identified (Box 4).
Goal 1: Maintain
the quality of science and integrity of core measurements at LTER sites.
Research at the 24 individual LTER sites is the foundation of the LTER program and will continue to be so over the next decade. Each LTER site has three principal, overlapping goals. These are:
1. To increase the understanding of ecological patterns and processes that characterize each site, through long-term research, experimentation, monitoring, and synthesis (i.e., by intensive analysis of the ecosystems and their biotic and abiotic components at each of the 24 sites).
2. To maintain a broad-based, multidisciplinary program of long-term ecological research at the site so as to ensure diverse opportunities for future (often unanticipated) multisite and network-level research (i.e., research in the Five Core Research Areas defined in Box 3).
3. To conduct long term ecological research on focused issues that are chosen by the investigators at the site.
Achieving these goals in the context of long-term ecological research requires each site to achieve a fine balance of its human and other resources, maintaining continuity of key long-term measurements and experiments while always allowing for development of new ideas, new methods and measurements, and new disciplines that build on the existing research base. Management of this effort also requires consistent communication with the Network and with the Network Office, to ensure success in achieving Network goals. Major tasks include:
· Identifying core measurements, experiments, and research questions, and planning for their evolution and stewardship
o Site: define what a core activity is for that site, define which are the core measurements, make a commitment to collect them, preserve samples, share with other PIs at the site ASAP.
o Network: define core areas of research (Box 3), define network science themes,
o Network Office: promote comparable measurements among sites, compile and distribute lists of core measurements collected by each site
· Continually adding to the core database to add basic understanding of the system. Build data in multiple dimensions as well as over time (in other words not all "core data" have to be long-term time series.) Basic descriptions of soils and of the genetics, population and community characteristics of flora and fauna, and organic matter and element distribution provide important context for interpretation and recognition of change.
o Site: set aside funds for 2-3 year studies to complete studies in areas not included (“fill in the holes”); develop long-term plans for the components of the system that will be studied over the next 10 years. Core descriptions and measurements should not be archived and forgotten, but must be continually examined to guide the direction of future measurements
o Network: share expertise among sites to help sites explore new planned research areas.
o Network Office: provide support for Network activity, e.g. promoting database compatibility for core measurements at the sites.
· Continual improvements to data access and integration
o Site: systematic review and use of data, make data available to other sites for cross-site comparisons. Develop data management system that allows for easy search and retrieval.
o Network: encourage the sites to share data with other sites and non-LTER scientists, seek opportunities to increase core data comparability (e.g., after science synthesis efforts), share expertise in data management
o Network Office: promote database management activities and do research to improve data quality and efficiencies of data management.
o Network: share experiences, provide expertise to other sites, provide sites with guidelines for minimum standard capabilities for various measurement categories.
o Network Office: foster sharing of technology ideas (i.e., provide travel funds for sites to interact, website of ideas/what’s new)
· Include fresh perspectives, expertise, collaborations and comparisons (e.g. increase breadth of standard ecological expertise)
o Network: serve as a source for some of the expertise and organize workshops around themes including techniques.
o Network Office: provide funds for start up costs of efforts. Organize All-Scientist Meetings to include outside expertise.
· Legacies/archives.
o Site: maintain quality and continuity of measurements, plan for studies to be passed from one generation to the next, and provide facilities to store samples and data.
o Network: set minimum standards for archives, define possible investments in archiving infrastructure, and recommend types of samples to be archived.
o Network Office: facilitate development of resources to store data and samples. Compile and distribute lists of archived data and samples that are related to core measurement programs, provide relationships to other archives.
Goal 2: Increase the pace of
synthesis through activities such as site volumes, network-wide synthesis
projects, multi-site synthesis projects, and database development
A wide range of synthesis activities are already under way within the LTER Network, with a wide range of products including a series of books about individual LTER sites, focused collections of papers, review articles, conceptual papers, quantitative multisite comparisons, and diverse modeling and scaling papers. A strong consensus has been reached within the LTER community that over the next decade these activities should be expanded and should become viewed as part of the normal course of operations at both the site level and the network level. There is also strong agreement that these are also important opportunities to include researchers and research results from outside the LTER network. The components of this synthesis effort should include:
· Site volumes: Two volumes have already been published (KNZ and NWT), and several others are nearing publication. These volumes are valuable because they provide in one place a synthesis and summary of what is known about a particular ecosystem or landscape, its environment, its plant, animal, and microbial components, and its interactions with neighboring systems and the globe. The volumes also describe interactions with human populations, and the responses of these systems to both human and natural change in environment at multiple time scales. In addition to summarizing knowledge about individual sites, the volumes are an important part of the foundation for multisite comparisons and other synthesis activities leading to general understanding of controls over ecological patterns and processes globally. By the end of the decade, a complete set of volumes for all currently existing sites should be available, produced at a rate of 2-3 per year.
· Network-wide syntheses:
o
Focused Topic
Meetings. For several years LTER Network has used its fall Coordinating
Committee meetings to explore scientific themes that are of interest throughout
the sites. The topics for these
meetings are chosen by the hosts of the CC meetings and have included
"Biodiversity and Productivity", "Climate Variability and
Ecosystem Response", "Primary Production", and "Social Science and Long Term
Ecological Research". Often the
meetings have been followed up by smaller, focused meetings to allow further
discussion, data preparation, or quantitative analyses of multiple data sets.
Products are diverse and include major review articles (e.g., Waide et al.
1999), individual journal articles (e.g., Mittelbach et al. 2001), a book
(Greenland et al. in prep), and collections of related papers based on
presentations at the meeting (in prep).
The Network is committed to
supporting one of these synthesis efforts every year, initiated at its fall
Coordinating Committee meeting.
o
All Scientist
Meetings. In the first 20 years of LTER, there were four All Scientist
meetings. These meetings were remarkably successful at stimulating diverse
cross-site research and synthesis activities by students and scientists at all
levels. In addition to
centrally-planned plenary sessions, most of the meeting time was available to
any individual or group for discussions on topics and in formats of their
choosing. After the fourth meeting at
Snowbird in 2000, funds were made available for follow-up workshops on over 20
different topics; these activities are currently in progress. A consensus exists that these meetings were
valuable in stimulating synthesis at all levels, particularly among students
and other non-PI participants. Additional
support will be needed, but the goal is to hold All Scientist meetings every
three years over the next decade (in 2003, 2006, and 2009), including support
for follow-up activities that lead to publications or other synthesis
activities such as the design of new multisite comparisons or new and novel,
integrated multidisciplinary research.
o Books and special journal issues. At irregular intervals the Network will continue to produce special volumes such as the recently-published volume on standard methods of soil ecological research at LTER sites (Robertson et al. 1998), and special journal issues such as the special issue of BioScience on LTER research that was published in 1990 (Callahan, Franklin, Magnuson, and Swanson articles). Articles for a second LTER issue of BioScience are now nearing completion (Hobbie), and a book on primary production methods is in the planning stages. Within the next decade the goal is to produce at least two books and two special journal issues on LTER research, aimed at the general scientific reader.
o
Committee on
Scientific Initiatives. The
Committee on Scientific Initiatives (COSI) is a standing committee of the LTER
Network, charged with identifying and helping to develop new opportunities for
LTER in research, education, and outreach.
Over the next decade, COSI should
meet annually to develop synthesis recommendations and research priorities.
· Multisite syntheses and working groups. Over the past decade there has been a large increase in the number of smaller groups of investigators interested in bringing together ideas and data on a wide range of topics that are best addressed at LTER sites or using long-term data and experiments. Often these include investigators from outside the LTER network; frequently these are instigated by those outside the network who see an opportunity created by LTER research. Many of these groups were formed at the last All Scientists meeting in 2000, with follow up support from the Network. Over the next decade the goal is to regularize this activity including support for small meetings and planning sessions. About 6-8 of these groups per year should be supported (=20-25 following each triennial All Scientist meeting).
·
Support for individual investigators, students, and
postdocs. Over the past 20 years,
occasional investigators, students, and postdoctoral fellows have developed
individual synthesis activities within the LTER network as part of their
sabbatical leaves, with support from NCEAS, and from a variety of other
sources. Again, these activities should be regularized over the next decade, so
that at any time at least one senior investigator, 2-3 postdoctoral fellows,
and 2-4 graduate students can participate in synthesis activities as their
primary effort. By the end of the decade, a separate program of support for
student participation in synthesis efforts and cross-site research should be
established.
·
Database development and informatics. Virtually all of these synthesis efforts
require the bringing together of diverse, long-term data sets, with associated
problems of compatibility, coding, transformation, sorting, and searching. There
is thus a particular need to establish within the next decade a program of logistical support for
LTER-related synthesis efforts, with a focus on database development and
informatics techniques optimized for ecological research.
Goal 3: Increase
experimental and comparative cross-site research
The creation of the LTER network has also created important opportunities for new research, particularly cross-site research focused on explaining the variation in ecological processes and patterns within the major biomes and among contrasting ecosystem types. The wealth of knowledge about each LTER site, particularly their long-term records of observation of multiple interacting variables, provides essential context for interpretation and analysis of similarities and differences among sites. Key questions, such as the relative sensitivity of different systems, populations, or processes to a particular kind of environmental change, can be answered more clearly in the context of this extensive background of information.
Cross-site research includes both experimental manipulations and comparative, long-term observations. The feature that distinguishes cross-site research from the more qualitative comparisons and multisite syntheses described under Goal 2 above is that cross-site research is designed from the beginning for comparative purposes. Detailed decisions about units of measurement, definitions of variables, and experimental treatments are not necessarily the same as would be made when only a single site is involved. In practice, implementation of cross-site research may be as simple as adding a new set of complementary measurements at one site, to match those already made at another; on the other hand it may involve carefully developed compromises in the selection of an experimental treatment, reflecting contrasting initial conditions and investigator perspectiv