Perspectives on LTER

Network News Spring 1987, Vol. 1 No. 1

Preparation of this article is an opportunity to present an LTER synthesis from the point of view of the Foundation. In doing so I would like to order the article in approximately the following manner:

  • What has LTER done during the first several years?
  • How close do actual accomplishments come to what was envisioned in the beginning?
  • Where might LTER go from here?

LTER may be “on the verge” of achieving a breakthrough in dealing with pattern - both spatial and temporal in ecological systems. The active consideration of pattern appears in the large majority of report documents from the projects. Spatial scales run from the microtopographic (tenths of meters) to some approximation of the landscape (around a kilometer). Temporal scales under common consideration span days to a few hundred years for experimental work and up to a few thousand years for observational work. Ecological patterns are being reckoned with in terms of

  1. How they appear and can be measured
  2. How parts of the pattern are distinct from each other
  3. How the array of distinguishable parts may change spatially over time
  4. How the distinguishable parts of the pattern function internally. Less attention is being given to the conditions that give rise to the patterns in the first place or the processes that cause them to be maintained or to change. The least attention continues to be focused on how the parts of the pattern relate to each other at the level of process or function

A few examples of parts of projects are pertinent to the consideration of pattern in ecosystems. CPER’s latter day revision of their original catena paradigm to account for the organizing effects of wind on certain soils is important. Originating primarily from the ANDREWS group the updated concept of “biological legacies holds promise for the unification of several lines of thought and study that appear at NIWOT, CEDAR CREEK, JORNADA, and NORTH INLET as well as others. The NORTHERN LAKES group’s realization that their subjects are a “system” with emergent characters such as measurable linkages and time delays may provide part of the vehicle for reconciling historically very different approaches to lakes, streams and terrestrial components. Similarly, the RIVERS project’s new views on “laterality” and “eddies” seem to suggest ways to unify some approaches to large and small streams as well as large rivers and marine systems. All of these examples contain major aspects of dealing with pattern, and all of them manifest the need to move to a level of effort that deals better with process and functional relationships among the parts of the pattern.

Some of the current LTER projects are contributing to a growing body of knowledge that challenges conventional thinking about the effects of acid deposition. Notably, the NORTHERN LAKES group have produced a synthesis that questions the relationship of acid loading to resultant changes, if any, in lake pH. The NIWOT group asserts that their soils and waters have historically received and continue to receive aeollan inputs that compensate for any acid deposition. These results jibe, at least conceptually, with observations from KONZA, JORNADA, CEDAR CREEK and others that things don’t always (or even often?) end up as one might expect from the way they start out. Longer-term results may be counter to what short-term results would indicate. I suspect there is also a substantive connection with OKEFENOKEE’s framework of theory having to do with “indirect effects.” With continued existence the LTER projects should grow in importance in terms of predictive and early diagnostic capabilities deriving from continual measurement of variables and regular visual scrutiny of the ecosystems. This kind of value has been demonstrated at COWEETA in relation to their early perception of indicative ozone damage to foliage.

LTER sites and research groups have become important to other federal and state agencies with research mandates and responsibilities. Such was always the case with sites like ANDREWS, COWEETA, and CPER that have traditionally housed major research endeavors funded by their mission agency stewards. However, the utility of the sites and personnel have been recognized more broadly as in the cases of the NORTHERN LAKES collaboration with EPA for experimental lake acidification and the KONZA collaboration with NASA in a landscape-scale study of nitrogen dynamics called “FIFE.”

Disturbance has from “day one” been a theme of LTER. Subsequent developments have refined the perception of disturbance to a degree that did not really exist in ecology before. Our view of disturbance is considerably more sophisticated than some analog of bulldozing an ecosystem. Disturbance comes in all shapes and sizes and with many kinds of timing. JORNADA’s small mammals operate at small scales but exert significant structural influences on the ecosystem as do gophers at NIWOT and CEDAR CREEK. KONZA’s long-pending large herbivore experiment should have a major tale to tell that ought to fit with studies at CEDAR CREEK and CPER. Fire dominates experiments at KONZA and CEDAR CREEK and has the potential for doing so at many other sites. The view of fire has been largely revised in a fashion that says that it is really the absence of fire (a human imposition) that is the disturbance not the periodic occurrence of fire. Recently the NORTH INLET group had to begin to deal with the effects of the most significant storm (reinforced by a congruence of heavenly bodies and timed for the regular high tide) that has occurred since major research efforts began there. Meaningful data and syntheses should result because LTER was in place.

LTER has become known to other, separately funded scientists at the parent institutions as well as to scientists at other places. LTER has attracted a measure of national level attention that in one way may be exemplified by the continuing unresolved discussion about various types and levels of “LTER” association including petitioning the ESA for a section on “long-term ecological research.” LTER has become known internationally through many inquiries and contacts with the projects themselves and with NSF by non-US scientists, institutions, and research sponsoring agencies. Several scientists from LTER projects have spent major portions of sabbatical leave abroad pursuing research and synthesis projects initiated under or augmented by LTER support. Uncounted students, both graduate and undergraduate, have received LTER support for their educations as have post-docs arid junior faculty members. The reputation continues to accumulate, and It is by a large proportion mostly positive even if that positivity remains a bit guarded.

To leave administrative/organizational aspects of LTER entirely untouched would be a disservice. In that context scientists, their students and technical personnel, and institutional officials now believe that the projects are not ephemeral or idiosyncratic occurrences. A degree of “institutionalization” has been conferred on the projects. They compete generally very well for institutional resources as a result of their relative stability. At one end of the spectrum the internal structure of institutions has changed to accommodate LTER. At the other end LTER has fitted into an empty niche.

How close actual accomplishments come to what was envisioned at first? Such a question will always be a difficult one to answer, but under LTER the answer may be more tenable than it was, for instance, with respect to US/IBP. IBP was oversold from the beginning with regard to what could be delivered and in the post mortem analysis was predestined to come up short against any yardstick derived from the original promises. LTER’s most significant promise was that “there exists a major family of ecological research that can only or best be accomplished by projects that are planned for and executed over long periods of time.”

This promise was, of course, predicated on the hypothesis that short-term projects run a large risk of yielding results that may differ significantly, both qualitatively and quantitatively, from results derived over much longer periods of time. This conservative hypothesis is now continually being supported by LTER project results.

What lies ahead? My own current classification of LTER-associated opportunities identifies three categories:

  1. Project specific or intra-project
  2. Among network participants or inter-project
  3. Distributed or extra-LTER

In the project specific realm it will always be incumbent upon participants to perform the best, most technically sound research possible under the prevailing conditions. However, the LTER mandate (and its associated responsibility) goes well beyond that baseline level of performance. It embodies expectations of scientific aggressiveness and imagination, as well as the judicious exercise of opportunism while adequately tending the core research. It is also pertinent to remind ourselves that LTER core project support was never intended to provide all the resources necessary to study adequately any of the research sites. Please recall that LTER core support was originally intended to provide a “glue” to use in melding and integrating past, present and future research at the site supported from a diversity of sources. Support for such complementary research must be competed for aggressively from a diversity of funders.

At the inter-project level there are many miles to go during the foreseeable future. LTER has not achieved even a good approximation of mutuality of scientific interests among the funded projects. Although a sizable number of network workshops have been organized and conducted there is a notable lack of demonstrable results. It is probably reasonable to view the inter-project activities to date as part of the learning process.

Likewise, it is reasonable to expect that the time is at hand to actually achieve things that can provide solid evidence of a new level of synthesis and comparative ecosystem science having to do with regional-to-global- scale ecosystems. The network of LTER sites, projects and scientists represents the best opportunity for doing so. However, to do so will require that a critical number of LTER scientific leaders address themselves to creative thinking centered upon the secondary use of data, and ideas that have accumulated in the pipeline. This does not say that such syntheses can be forced; however, it does say that LTER leaders must strive to create the conditions that will promote such syntheses.

With regard to extra-LTER associations and potential for accomplishment a start has been made by individuals, by projects, and by the LTER network. The task at hand now is to solidify and continue to expand those associations in a fashion that demonstrates growth in numbers of associates, complexity of thought, and quality of derivative scientific products. That can only be accomplished by demonstration through performance and the assurance that NSF, as well as other extramural funders, will be receptive to excellent proposals for meaningful research.

Finally, emphasis must be placed on the importance of aggressively pursuing some items that have received much discussion but little development or implementation so far. Of paramount importance is the actual computer-based linking of LTER projects, each with all the others, at the level of daily operations. All the hardware exists and so does nearly all the software.

What is still missing is the will and the drive to incorporate the use of this form of communication as an ordinary method of doing business. New points of view must be adopted. Paradigms centering on “the system of definition” are now archaic and must be supplanted by paradigms that address landscapes, regions, and the ecosphere. Recognition and analysis of hierarchical organization in ecological systems is receiving increased attention. LTER seems to be ideal for testing hypotheses about hierarchies. Fractal geometry seems to possess many characteristics that may be tailor-made for hierarchical representation and analysis. New methods must be adopted, adapted, improved or invented to underwrite the new conceptual approaches. Remote sensing technologies and geographic information systems appear to have a lot to offer. Aggressive leadership must identify and act on opportunities as they are presented. IGBP and NSF’s Global Change initiative may be such an opportunity.

LTER represents a challenge to ecologists. The challenge is to sustain the growing momentum by seizing - or even creating - new opportunities.

by James T. Callahan
Associate Program Director
Ecosystem Studies
National Science Foundation