Long-term research on forest dynamics in the Pacific Northwest: a network of permanent forest plots
Citation
Long-term research on forest dynamics in the Pacific Northwest: a network of permanent forest plots: Forest biodiversity in North, Central, and South America and the Caribbean: Research and Monitoring, v. 21, p. 96-106.
Summary
Changes in the composition, structure, and functions of forest ecosystems typically occur over long periods of time. In the Pacific Northwest region of the United States, for example, it is not unusual for individual dominant trees to survive for 500 years or longer (Franklin and Dyrness, 1973; Waring and Franklin, 1979). Significant compositional and structural changes may continue to occur 750 years after a stand-initiating disturbance (Franklin and Spies, 1991). Documenting and understanding these changes requires a variety of approaches. At least five complementary approaches have been taken to increase, scientific understanding of these intrinsically slow changes: chronosequences (Pickett, 1989); palynology and other paleoecological [...]
Summary
Changes in the composition, structure, and functions of forest ecosystems typically occur over long periods of time. In the Pacific Northwest region of the United States, for example, it is not unusual for individual dominant trees to survive for 500 years or longer (Franklin and Dyrness, 1973; Waring and Franklin, 1979). Significant compositional and structural changes may continue to occur 750 years after a stand-initiating disturbance (Franklin and Spies, 1991). Documenting and understanding these changes requires a variety of approaches. At least five complementary approaches have been taken to increase, scientific understanding of these intrinsically slow changes: chronosequences (Pickett, 1989); palynology and other paleoecological methods (e.g. Davis, 1981); stand reconstruction (e.g. Henry and Swan, 1974); simulation models (e.g. Shugart, 1984); and direct, long-term observations of permanent plots (e.g. Peet, 1981). All five techniques provide unique opportunities and limitations. Long-term observation of permanent sample plots is the only approach that provides real data on patt,erns and rates of change in forest ecosystems. Information collected on permanent plots provides the ultimate test of the validity of the other approaches. Therefore, the knowledge of natural ecosystem dynamics provided by permanent plot data is necessary in developing sustainable approaches to ecosystem management (Lubchenco et at., 1991; Swanson and Franklin, 1992). For example. long-term observations can quantify levels and dynamics of natural forest structures for use as guides in ecosystem management (e.g. Franklin et at., 1981). Long-term observations provide the definitive measure of long-term productivity and, thus, sustainable harvest levels. In addition, repeated observations on permanent plots provide data about the relationships of disturbance frequency and intensity to persistence of different plant and animal species. Dynamic relationships between forests and aquatic ecosystems can also be documented in long-term plots
