The events that reshape ecosystems can be infrequent and often unpredictable.

Major droughts, hurricanes, the arrival of a new species, or a shift in ocean currents can dramatically affect the way an ecosystem looks and functions. Legacies from past events can cause two sites that look superficially similar to behave in very different ways.

Yet most ecological studies are funded just a few years at a time.

In 1980, the National Science Foundation funded the first Long-Term Ecological Research (LTER) sites to provide a longer view.

Today, research programs at 28 LTER sites support ecological discovery on the influence of long-term and large-scale phenomenon.

LTER sites also serve the wider ecological community by:

Making almost 40 years of sustained observations publicly available

Developing and maintaining large-scale experiments, which provide starting conditions for process-level studies, help to parameterize and test model, and spur cross-site synthesis

Providing long-term context and deep knowledge of place for researchers working on shorter-term projects

Training hundreds of graduate students in interdisciplinary and collaborative team science

LTER sites are the core of the network

Each LTER site involves dozens of researchers, typically including microbial, community, and landscape ecologists, but also hydrologists, geochemists, social scientists, economists and even the occasional artist, historian, or philosopher.

The shared knowledge of place offers unusual common ground for exploring disciplinary intersections.

two students sampling grasses
square plots of diverse herbs and shrubs

Education and outreach helps LTER science make an impact

The longer tenure of LTER sites also makes them particularly well-suited to developing the relationships needed to engage with stakeholders, educators, and the public.

All LTER sites have an education and outreach component, although the exact nature of the program varies by site. Remote forested sites may deal mainly with foresters and landowners, while urban sites may more closely engage community residents.

Data, especially data management, play a crucial role

The value of LTER’s long-term data resource is immense and LTER data managers have been leaders in the movement to ensure that ecological data is accessible and usable.

Dedicated information managers document and archive LTER data in public repositories so that they can be re-used by the broader scientific community.

The Environmental Data Initiative (EDI) is LTER’s primary data repository and has a strong record of serving FAIR (Findable, Accessible, Interoperable, and Reproducible) data. Occasionally, LTER datasets reside in disciplinary- or geographically-focused repositories and EDI maintains metadata referencing the full dataset.

Network Vision, Mission, & Goals


LTER envisions a society in which exemplary science contributes to the advancement of the health, productivity, and welfare of the global environment that, in turn, advances the health, prosperity, welfare, and security of our nation.

Thus, LTER’s mission is to provide the scientific community, policy makers, and society with the knowledge and predictive understanding necessary to conserve, protect, and manage the nation’s ecosystems, their biodiversity, and the services they provide.


The LTER Network was founded in 1980 by the National Science Foundation with the recognition that long-term research could help unravel the principles and processes of ecological science, which frequently involves long-lived species, legacy influences, and rare events. As policymakers and resource managers strive to incorporate reliable science in their decision making, the LTER Network works to generate and share useful and usable information.



To understand a diverse array of ecosystems at multiple spatial and temporal scales.


To create general knowledge through long-term, interdisciplinary research, synthesis of information, and development of theory.


To reach out to the broader scientific community, natural resource managers, policymakers, and the general public by providing decision support, information, recommendations, and the knowledge and capability to address complex environmental challenges.


To promote training, teaching, and learning about long-term ecological research and the Earth’s ecosystems, and to educate a new generation of scientists.


To inform the LTER and broader scientific community by creating well-designed and well-documented databases.


To create a legacy of well-designed and documented long-term observations, experiments, and archives of samples and specimens for future generations.

Core Themes

Five core research themes have been central to LTER Network science from the conception of the Network. Research in these core areas requires the involvement of many scientific disciplines, over long time spans and broad geographic scales. Data on the core areas are collected to establish and understand the existing conditions in an ecosystem before any experimental manipulation is begun.

The common focus on core areas facilitates comparison among and across sites in the Network.

Primary Production – Plant growth in most ecosystems forms the base or “primary” component of the food web. The amount and type of plant growth in an ecosystem helps to determine the amount and kind of animals (or “secondary” productivity) that can survive there. Read LTER research stories related to primary production.

Population Studies – Populations of plants, animals, and microbes change in space and time, moving resources and restructuring ecological systems. Read LTER research stories related to population studies.

Movement of Organic Matter – An entire ecosystem relies on the recycling of organic matter (and the nutrients it contains), including dead plants, animals, and other organisms. Decomposition of organic matter and its movement through the ecosystem is an important component of the food web. Read LTER research stories related to organic matter movement.

Movement of Inorganic Matter – Nitrogen, phosphorus, and other mineral nutrients are cycled through the ecosystem by way of decay and disturbances such as fire and flood. In excessive quantities nitrogen and other nutrients can have far-reaching and harmful effects on the environment. Read LTER research stories related to mineral cycling.

Disturbance Patterns – Disturbances often shape ecosystems by periodically reorganizing structure, allowing for significant changes in plant and animal populations and communities. Read LTER research stories related to disturbance patterns.

Two additional themes emerged with the addition of urban LTER sites, but it has become clear that they are also relevant for the rest of the Network:

Land Use and Land Cover Change: examine the human impact on land use and land-cover change in urban systems and relate these effects to ecosystem dynamics. Read LTER research stories related to land use and land cover change.

Human-Environment Interactions: monitor the effects of human-environmental interactions in urban systems, develop appropriate tools (such as GIS) for data collection and analysis of socio-economic and ecosystem data, and develop integrated approaches to linking human and natural systems in an urban ecosystem environment. Read LTER research stories related to human-environment interactions.

Well into its fourth decade, the LTER’s long-term experiments continue to reveal cutting edge ecological processes only gleaned through long-term study.

We can’t wait to see what the next forty years bring.

Recent Stories

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    New research by Harvard Forest (HFR) LTER scientists suggest that widespread death of the whiteback pine tree from beetle infestations and tree disease outbreaks may be affecting seed production and hence the future of the tree–a mountain tree important to wildlife and water resources in the western United States and Canada. In a paper published……


  • Science360 Radio interviews focus on LTER

    A series of interviews with Long Term Ecological Research (LTER) scientists conducted by Science360 Radio to commemorate Earth Day continues with Mark Williams’ research at the Niwot Ridge LTER program. The interviews will be up all week and are available on the Science360 radio home page at For more information please see


  • Where Does Charcoal, or Black Carbon, in Soils Go?

    FOR IMMEDIATE RELEASE Where Does Charcoal, or Black Carbon, in Soils Go? Scientists find surprising new answers in wetlands such as the Everglades April 18, 2013 — Scientists have uncovered one of nature’s long-kept secrets–the true fate of charcoal in the world’s soils. The ability to determine the fate of charcoal is critical to knowledge……


  • Read the LTER Network News Spring 2013

    The latest Long Term Ecological Research (LTER) Network newsletter is out. The first this year, LTER Network News Spring 2013, Vol. 26 No. 1 includes stories about the recent LTER min-symposium and the Ecological Reflections exhibit at NSF, various news items from around the Network and sites, education, a scientific report, a new children’s book,……


  • NSF publishes Discovery booklet

    The National Science Foundation (NSF) publication has published a booklet of ten collected LTER Discovery articles written by Cheryl Dybas in NSF’s Office of Legislative and Public Affairs. The booklet is now available for download in PDF form on the LTER Network website (