Long-Term Research at the USDA Forest Service's Experimental Forests and Ranges

摘要

The network of experimental forests and ranges administered by the US Department of Agriculture Forest Service consists of 77 properties that are representative of most forest cover types and many ecological regions in the nation. Established as early as 1908, these sites maintain exceptional, long-term databases on environmental dynamics and biotic responses. Early research at these sites focused on silviculture, ecosystem restoration, and watershed management. Over time, many of the properties have evolved into a functional network of ecological observatories through common large-scale, long-term experiments and other approaches. Collaboration with other institutions and research programs fosters intersite research and common procedures for managing and sharing data. Much current research in this network focuses on global change and interdisciplinary ecosystem studies at local to global scales. With this experience in developing networks and compiling records of environmental history, the experimental forests and ranges network can contribute greatly to formation of new networks of environmental observatories.nnProperties dedicated to the study of the environment, ecosystems, and natural resources have long been an integral part of the national and global infrastructure for science, education, and information. These properties have guided the management of natural resource systems, such as watersheds, forests, and rangelands. Key discoveries with wide-ranging impact on environmental policy and natural resource management have emerged from long-term studies at field research facilities. Sustained ecosystem research at Hubbard Brook Experimental Forest in New Hampshire, for example, revealed the existence of acid rain in North America and the ramifications of this form of pollution—as well as other human alterations of the atmosphere—for forests and watersheds (Likens 2004). Fundamental characterization of old-growth forests, and of the dynamics of forests of the Pacific Northwest, based on studies at the H. J. Andrews Experimental Forest in Oregon influenced a major shift in forest management policy in that region and beyond (USDA FS/USDI BLM 1994, Franklin et al. 2002). Research in the Luquillo Experimental Forest in Puerto Rico documented the effects of hurricanes on Caribbean forests, setting the stage for understanding how disturbances influence tropical forests (Walker et al. 1996). These examples demonstrate how sustained, interdisciplinary studies at research sites can lead to discoveries based on designed studies or on simple serendipity. The experimental forests and ranges and the research groups working there in long-term collaborations are seedbeds for discovery.nnEvolving social issues and science questions calling for increasingly broadscale and interdisciplinary ecological research have contributed to two developments in the field. First, research programs at individual sites have evolved over time to blend sustained long-term, interdisciplinary studies with new short-term studies to sharpen the focus on contemporary issues. Second, there has been a trend toward collections of research sites functioning increasingly as research networks that span regions and continents. These steps have been critical in making the results of ecological sciences relevant to societal problems across a range of scales.nnIn light of continuing changes in these vital national systems of research properties, and of the prospects for developing major new ecological and environmental observatory networks (e.g., the National Ecological Observatory Network, or NEON; www.neoninc.org) and hydrological observatories (the Consortium of Universities for the Advancement of Hydrologic Science, Inc., or CUAHSI; www.cuahsi.org), it is timely to reflect on existing capabilities and lessons learned as a basis for planning future research networks and their accompanying research agendas. The US Department of Agriculture (USDA) Forest Service's experimental forests and ranges provide valuable historical records of environmental change, experience in operating networks of research properties, and coverage of important types of ecosystems and natural resource systems.nnIn this article we describe the network of experimental forests and ranges of the USDA Forest Service, highlight a handful of this network's scientific contributions to date, and comment on its potential for contributing to the national research agenda. We pay particular attention to the network's representation of the nation's ecosystems and its relevance to research addressing environmental change and natural resource management issues in the United States. We illustrate the evolution of research activity in this network, from individual studies focused on isolated sites and local research needs to research that increasingly takes advantage of networks of sites considered across broad temporal and geographic environmental gradients. We argue that the complexity of the environmental challenges facing humanity in the new millennium (Millennium Ecosystem Assessment 2005) requires a research focus that addresses environmental complexity at the scales of time and space where the problems are rooted. To do so, site-specific research must be reinforced with networks of sites arrayed along environmental gradients that collectively represent the broad scale of ecological space that is of interest to resource conservation.