Title: Reconstructing Historic Ecotones Using the Public Land Survey: The Lost Prairies of Redwood National Park
Abstract: Abstract Restoration of natural systems depends, in part, on reconstructing historic landscapes to serve as reference ecosystems. The most effective historic landscape reconstruction relies on multiple lines of evidence at different temporal and spatial scales. This study analyzes original Public Land Survey (PLS) records and compares the results with previous work that relied on dendroecology and aerial photograph evidence of vegetation change. Notations in the land survey regarding the location of prairie-woody vegetation ecotones in the Bald Hills of Redwood National Park were transcribed into a geographic information system. CitationSugihara and Reed (1987) measured the degree of coniferous forest encroachment into prairies and oak woodlands, estimating a 29 percent loss in the spatial extent between 1850 and 1983. The location of 1875–1882 land survey records of ecotones provides evidence that transects across the prairies might have narrowed by as much as 44 percent. Furthermore, this study found evidence of both oak woodland and coniferous forest encroachment into prairies, and that the diminishment of prairies further inland might result primarily from the expansion of oak woodland. A reconstruction of the historic landscape that relies on both field and archival evidence is the best approach to defining reference ecosystems. La restauración de los ecosistemas naturales depende parcialmente de la reconstrucción de los paisajes históricos que sirvan como ecosistemas de referencia. La reconstrucción de paisajes históricos más efectiva depende de múltiples líneas de evidencia en diferentes escalas temporales y espaciales. En este estudio se analizan los registros originales del Sistema Público de Agrimensura de Tierras (Public Land Survey, PLS) y se comparan los resultados con trabajos previos que se basaron en dendroecología y en pruebas de cambios en la vegetación proporcionadas por fotografías aéreas. Se transcribieron notaciones en la agrimensura de la tierra referentes a la ubicación de ecotonos de vegetación pradera-boscosa en Bald Hills del Redwood National Park en un sistema de información geográfica. Sugihara y Reed (1987) midieron el grado de invasión de bosques de coníferas en las praderas y bosques de robles, calculando una pérdida aproximada del 29 por ciento de área entre 1850 y 1983. La ubicación de los registros de agrimensura de ecotonos entre 1875 y 1882 proporciona evidencia de que los transectos en las praderas se pudieron estrechar tanto como un 44 por ciento. Más aún, en este estudio se encontró evidencia de la invasión de bosques de robles y de coníferas en las praderas, y que la disminución de las praderas tierra adentro pudo haber sido resultado principalmente de la expansión de los bosques de robles. La reconstrucción del paisaje histórico que se basa en evidencia de campo y datos de los archivos es la mejor estrategia para definir ecosistemas de referencia. Key Words: Californiaecological restorationecotonesPublic Land Surveyvegetation reconstruction关键词: 加利福尼亚州生态恢复生态交错带公共土地测量植被重建Palabras clave: Californiarestauración ecológicaecotonosSistema Público de Agrimensura de Tierrasreconstrucción de la vegetación Acknowledgments I would like to thank Ted Sickley for assistance in GIS data preparation, Rich Mrozinski for guidance in part of the GIS analysis, Susie Van Kirk for her assistance in the archival research, and Stephen Veirs for guidance in the formative stages of the project. I am also very grateful to Tom Vale, Matt Turner, Melinda Daniels, the anonymous reviewers, and the section editor Richard Aspinall for their constructive comments on the article. Notes a Indicates a measurement of the gap between prairies, rather than a cross-section of a prairie. Because these do not represent a conversion from 100 percent prairie to a different vegetation type, these transects were omitted from the calculation of averages. 1 The remaining 7.5 percent of prairie boundary points are found in a vegetation type classified as “unknown” in the 1998 GIS coverage. These unknown polygons are adjacent to the park's southeastern boundary in the Bald Hills.
Publication Year: 2008
Publication Date: 2008-02-05
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 30
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot