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Recent research shows that land use history is an important determinant of current ecosystem function. In the United States,
characterization of land use change following European settlement requires reconstruction of the original property mosaic.
However, this task is difficult in unsystematically surveyed areas east of the Appalachian Mountains. The Gwynns Falls watershed
(Baltimore, MD) was originally surveyed in the 1600-1700s under a system of warrants and patents (commonly known as ‘metes
and bounds’). A method for the reconstruction and mapping of warrant and patent properties is presented and used to map the
original property mosaic in the Gwynns Falls watershed. Using the mapped mosaic, the persistence of properties and property
lines in the current Gwynns Falls landscape is considered. The results of this research indicate that as in agricultural areas,
the original property lines in the Gwynns Falls watershed are persistent. At the same time, the results suggest that the property
mosaic in heavily urbanized/suburbanized areas is generally ‘reset.’ Further, trends in surveying technique, parcel size,
and settlement patterns cause property line density and property shape complexity to increase in the less urbanized upper
watershed. The persistence of original patterns may be damping expression of heterogeneity gradients in this urban landscape.
This spatial pattern of complexity in the original mosaic is directly opposite of hypothesized patterns of landscape heterogeneity
arising from urbanization. The technique reported here and the resulting observations are important for landscape pattern
studies in areas settled under unsystematic survey systems, especially the heavily urbanized areas of the eastern United States.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Sonja Brodt Karen Klonsky Louise Jackson Stephen B. Brush Sean Smukler 《Agroforestry Systems》2009,76(1):195-206
Although hedgerows, windbreaks, and other biodiversity-enhancing farm edge features offer the potential for ecosystem benefits
without occupying much crop space, relatively few farms in California, USA include such features. Our study identified the
practices currently used to manage non-cropped edges of fields, ponds, and watercourses in a case study area in California.
We also identified social, economic, and agronomic incentives and constraints to installing biodiversity-enhancing edge features.
More than one-third of the study farmers had installed native hedgerows, windbreaks, and/or grassed edges. Interviews demonstrated
the importance of socially influential farmers working in tandem with public and private agencies to build initial interest
in these practices. However, these features occupied less than four percent of all possible edge length. Constraints to increasing
adoption included high costs, fear of harbouring weeds and rodents, and lack of certainty about ecosystems benefits, highlighting
the need for cost-share programs and more regionally-focused agroecological research. 相似文献
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Brush SG 《Science (New York, N.Y.)》1990,248(4954):423
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Divergent biological effects of adenosine and dibutyryl adenosine 3',5'-monophosphate on the isolated fat cell 总被引：3，自引：0，他引：3
Adenosine 3',5'-monophosphate stimulated production of carbon dioxide and lipid from glucose, whereas its dibutyryl derivative inhibited this conversion. Addition of the dibutyryl derivative to the isolated fat cell further stimulated lipolysis induced by adrenocorticotropic hormone, whereas addition of adenosine 3',5'-monophosphate inhibited this lipolysis. Hence, measured by these two parameters, the biologic properties of adenosine 3',5'-monophosphate and its dibutyryl derivative are distinctly different. 相似文献
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Brush SG 《Science (New York, N.Y.)》1982,217(4563):891-898
The theories of Harold C. Urey (1893-1981) on the origin of the moon are discussed in relation to earlier ideas, especially George Howard Darwin's fission hypothesis. Urey's espousal of the idea that the moon had been captured by the earth and has preserved information about the earliest history of the solar system led him to advocate a manned lunar landing. Results from the Apollo missions, in particular the deficiency of siderophile elements in the lunar crust, led him to abandon the capture selenogony and tentatively adopt the fission hypothesis. 相似文献
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Brush CF 《Science (New York, N.Y.)》1898,7(178):730-734