Chapter 07 - Structure, diversity, and composition of secondary forests of the Barro Colorado Nature Monument. Figure S2 - Aerial images of the Barro Colorado Nature Monument taken in 1955, 1966, 1973, 1979, and 1984 by the U. S. Defense Mapping Agency.
Aerial photographs taken by the United States Defense Mapping Agency of the Barro Colorado Nature Monument (BCNM), Panama. The stereoscopic photographs were taken from an altitude of 10,000 feet (3,048 m) on systematic, overlapping lines of flight. The original images and a composite image for each year are included.
The composite images are at 300 dpi and are assigned file names using the following format: BCNM_YYYY_composite.jpg, where YYYY refers to the year of the overflight (e.g., 1955). The bold black line indicates the approximate limits of the BCNM, and the red squares indicate eight 1-ha secondary and two old-growth 0.3-ha tree plots (see Denslow, J., and G. Guzman. 2000. Variation in stand structure, light and seedling abundance across a tropical moist forest chronosequence, Panama. Journal of Vegetation Science. 11: 201–212).
The individual stereoscopic photographs were scanned at XXX dpi resolution and assigned file names using the following format: BCNM_YYYY_colA_rowB.tif, where colA and rowB reference the position of each image in the grid of images that comprise the composite image for the corresponding year. Because overlap varied widely for contiguous images, this grid is not strictly rectangular and colA or rowB takes precedence depending on the orientation of flight lines. Flight lines were oriented north-south in 1955, 1979, and 1984 and northeast-southwest in 1973; colA takes precedence with values increasing from the westernmost flight line (i.e., col1 for all years) to the easternmost flight line (e.g., col2 for 1955); and values of rowB increase from the southernmost image (i.e., row1) to the northernmost image within each column. Flight lines were oriented east-west for 1966; rowB takes precedence with values increasing from the southernmost row (i.e., row1) to the northernmost row (i.e., row4, note the nearly hidden third row of images visible as a thin strip across the northern portion of Barro Colorado Island); and values of colA increase from the westernmost image (i.e., col1) to the easternmost image within each row.
The following publication uses these images to determine secondary forest ages across the BCNM: Dent, D. H., and A. Elsy. 2024. Structure, Diversity and Composition of Secondary Forests of the Barro Colorado Nature Monument. In The First 100 Years of Research on Barro Colorado: Plant and Ecosystem Science, ed. H. C. Muller-Landau and S. J. Wright, pp. XXX–XXX. Washington, DC: Smithsonian Institution Scholarly Press.
