03885nas a2200157   4500008004100000245014800041210006900189260003800258300001300296520321200309653002203521100001903543700001903562700001703581856012903598       1991                        eng d00aLongterm ecological questions and considerations for taking longterm measurements: Lessons from the LTER and FIFE programs on tallgrass prairie0 aLongterm ecological questions and considerations for taking long  aChichesterbJohn Wiley &amp; Sons  a153 -1723 a<p>The earth, with its global problems of overpopulation, over-use and abuse of fossil fuel and nuclear energy, and production of toxic wastes, has often been compared to a sick patient. Illness is recognized as a significant deviation from known, long-term trends. Long-term monitoring represents a minimal activity for responsible individuals and agencies interested in placing current environmental problems into perspective. Long-term measurements are directed at questions involving phenomena not interpretable or perhaps not useful when viewed over short (annual or less) time scales, but are related to the long-term &quot;health&quot; or functioning of the system. At a minimum, the Long-term Ecological Research (LTER) data therefore provide the context in which short-term observational or experimental results can be interpreted (Magnuson, 1990). A much more interesting, albeit potentially less relevant, use of LTER data involves the study of a set of complex questions that cannot be resolved with short-term studies. The juxtaposition of basic and applied science within the context of a single research effort is a strength of the LTER program. This chapter attempts to identify a set of long-term ecological questions that are useful to a national or international network of research sites. While there exists a nearly infinite list of interesting questions that could be addressed with long-term studies, a realistic and goal-oriented list of measurements is presented. The criteria for selecting these questions involved identiying variables that 1) are useful for intersite comparisons, 2) are not strongly biased by spatial scaling factors, and 3) can provide the necessary linkages between atmospheric/climatological variables and biological measurements. &quot;Focused studies of the interactions between the atmosphere and the biosphere that regulate trace gases can improve both our understanding of terrestrial ecosystems and our ability to predict regional- and global-scale changes in atmospheric chemistry&quot;. The list of proposed variables for study was devvelpoped from the &quot;core LTER measurements&quot;, a guideling used since the inception of the LTER effort from recommendations suggested in Earth System Science, and from practical experience with the recent NASA- ISLSCP (International Surface Land Climatology Project) conducted on the Konza Prairie LTER site. While appropriate examples are taken from many systems, particular emphasis has been given to questions that have interested researchers studying grasslands. We build on the work of Strayer et al. (1986). Their extensive overview of long-term studies provided useful definitions of research productivity, of what constitutes &quot;long- term research&quot;, and reasons for the &quot;successes&quot; of previous and existing long-term research efforts. Their findings emphasized that individual scientists and not specific research protocols or experimental designs were largely responsible for successful long-term research efforts. Here, however, we suggest that certain constraints on research designs are important if a goal of the research is to benefit directly a regional or global network</p>10atallgrass prairie1 aSeastedt, T.R.1 aBriggs, J., M.1 aRisser, P.J.  uhttp://lter.konza.ksu.edu/content/longterm-ecological-questions-and-considerations-taking-longterm-measurements-lessons-lter