90 years of forest cover change in an urbanizing watershed: spatial and temporal dynamics

• Published in: Landscape ecology Vol. 26; no. 5; pp. 645 - 659
• Main Authors: Zhou, Weiqi, Huang, Ganlin, Pickett, Steward T. A., Cadenasso, M. L.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.05.2011; Springer; Springer Nature B.V
• Subjects: Agricultural land; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Biomedical and Life Sciences; Climate change; Data processing; Ecology; Environmental Management; Forestry; Forests; Fundamental and applied biological sciences. Psychology; General aspects; General forest ecology; Generalities. Production, biomass. Quality of wood and forest products. General forest ecology; Historical account; Landscape; Landscape Ecology; Landscape/Regional and Urban Planning; Life Sciences; Nature Conservation; Research Article; Spatial distribution; Sustainable Development; Temporal variations; Urban areas; Urban environments; Urban planning; Urbanization; Watershed management; Watersheds; USA, Maryland, Baltimore; Forest fragmentation; Patch dynamics; Baltimore; Transition analysis; Change detection; Urban ecology; Gradient analysis; Forests; Urban area; Fragmentation; Dynamics; Watershed; Transition; Detection
• ISSN: 0921-2973; 1572-9761
• DOI: 10.1007/s10980-011-9589-z

Landscape structure in the Eastern US experienced great changes in the last century with the expansion of forest cover into abandoned agricultural land and the clearing of secondary forest cover for urban development. In this paper, the spatial and temporal patterns of forest cover from 1914 to 2004 in the Gwynns Falls watershed in Baltimore, Maryland were quantified from historic maps and aerial photographs. Using a database of forest patches from six times—1914, 1938, 1957, 1971, 1999, and 2004—we found that forest cover changed, both temporally and spatially. While total forest area remained essentially constant, turnover in forest cover was very substantial. Less than 20% of initial forest cover remained unchanged. Forest cover became increasingly fragmented as the number, size, shape, and spatial distribution of forest patches within the watershed changed greatly. Forest patch change was also analyzed within 3-km distance bands extending from the urban core to the more suburban end of the watershed. This analysis showed that, over time, the location of high rates of forest cover change shifted from urban to suburban bands which coincides with the spatial shift of urbanization. Forest cover tended to be more stable in and near the urban center, whereas forest cover changed more in areas where urbanization was still in process. These results may have critical implications for the ecological functioning of forest patches and underscore the need to integrate multi-temporal data layers to investigate the spatial pattern of forest cover and the temporal variations of that spatial pattern.