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At least 2.6 million small, artificial water bodies dot the landscape of the conterminous United States; most are in the eastern half of the country. These features account for approximately 20% of the standing water area across the United States, and their impact on hydrology, sedimentology, geochemistry, and ecology is apparently large in proportion to… (More)
Measurements of the production and consumption of organic material have been a focus of aquatic science for more than 80 years. Over the last century, a variety of approaches have been developed and employed for measuring rates of gross primary production (Pg), respiration (R), and net ecosystem production (Pn = Pg − R) within aquatic ecosystems. Here, we… (More)
Two methods are commonly used to measure the community metabolism (primary production, respiration, and calcification) of shallow-water marine communities and infer air-sea CO2 fluxes: the pH-total alkalinity and pH-O2 techniques. The underlying assumptions of each technique are examined to assess the recent claim that the most widely used technique in… (More)
Articles T he process of eutrophication represents the bio-geochemical response to heavy nutrient loading (Nixon 1995, Cloern 2001). Typical consequences of eutrophication include (a) elevated primary production in response to elevated nutrient delivery and (b) elevated respiration in response to the rapid production of organic matter. In cases of… (More)
Shallow, seaward portions of modern coral reefs produce about 4 kilograms of calcium carbonate per square meter per year, and protected areas produce about 0.8 kilogram per square meter per year. The difference is probably largely a function of water motion. The more rapid rate, equivalent to a maximum vertical accretion of 3 to 5 millimeters per year,… (More)
Autoradiagraphs and x-radiographs have been made of vertical sections through the centers of reef corals from Eniwetok. Radioactivity bands in the coral structure are caused by strontium-90 and are related to specific series of nuclear tests, thus making possible calculation of long-term growth rates. These data indicate that the cyclic variations in radial… (More)
This work describes a genetic programming (GP) approach that creates vegetation indices (VI's) to automatically detect the sum of healthy, dry, and dead vegetation. Nowadays, it is acknowledged that VI's are the most popular method for extracting vegetation information from satellite imagery. In particular, erosion models like the " Revised Universal Soil… (More)
Corals and algal pavement produce calcium carbonate more slowly on the windward reef slope of Enewetak Atoll than on the reef flat despite the high standing crop of reef-building organisms on the slope. The capacity of reefs to remain at or near sea level is therefore not determined primarily by growth on the seaward slope.
In topographically complex terrains, downslope movement of soil organic carbon (OC) can influence local carbon balance. The primary purpose of the present analysis is to compare the magnitude of OC displacement by erosion with ecosystem metabolism in such a complex terrain. Does erosion matter in this ecosystem carbon balance? We have used the Revised… (More)
Marine macrophyte biomass production, burial, oxidation, calcium carbonate dissolution, and metabolically accelerated diffusion of carbon dioxide across the air-sea interface may combine to sequester at least 10(9) tons of carbon per year in the ocean. This carbon sink may partially account for discrepancies in extant global carbon budgets.