Biological and physical controls regulating variation of seasonal and interannual ecosystem carbon exchange in a scrub oak ecosystem in central Florida were determined by measuring net ecosystem exchange of CO2 (NEE) between the atmosphere and vegetation using the eddy covariance technique continuously for 6 years (April 2000–March 2006). Total net ecosystem production (NEP) was nearly 20 t C m...

Despite decades of research, the effects of spectral quality on plant growth, and development are not well understood. Much of our current understanding comes from studies with daily integrated light levels that are less than 10% of summer sunlight thus making it difficult to characterize interactions between light quality and quantity. Several studies have reported that growth is increased und...

Atrazine, metolachlor, carbaryl, and chlorothalonil are detected in streams throughout the U.S. at concentrations that may have adverse effects on benthic microbes. Sediment samples were exposed to these pesticides to quantify responses of ammonium, nitrate, and phosphate uptake by the benthic microbial community. Control uptake rates of sediments had net remineralization of nitrate (-1.58 NO3 ...

An ongoing field study of the effects of elevated atmospheric CO2 on a brackish wetland on Chesapeake Bay, started in 1987, is unique as the longest continually running investigation of the effects of elevated CO2 on an ecosystem. Since the beginning of the study, atmospheric CO2 increased 18%, sea level rose 20 cm, and growing season temperature varied with approximately the same range as pred...

Accurate simulations of terrestrial carbon assimilation and canopy transpiration are needed for both climate modeling and vegetation dynamics. Coupled stomatal conductance and carbon assimilation (A gs) models have been widely used as part of land surface parameterizations in climate models to describe the biogeophysical and biogeochemical roles of terrestrial vegetation. Differences in various...

type : Poster Session : S1: Traits Submitted by : dominique carrer Authors and Speakers : Dominique Carrer Information about other authors : Dominique Carrer 1, Jean-Louis Roujean 1, Sebastien Lafont 1, and Jean-Christophe Calvet 1 1 Météo-France, CNRM/GAME, 42 avenue Gaspard Coriolis, 31057 Toulouse Cedex, France The carbon assimilation of vegetation depends on CO2 concentration, radiant solar...

The humidity data retrieved from the TIROS Operational Vertical Sounder (TOVS) measurements is assimilated into the Goddard Earth Observing System (GEOS) data assimilation system. The study focuses on the impact of the TOVS humidity on assimilated humidity, precipitation, clouds, and radiation. The GEOS assimilation system utilizes the TOVS humidity effectively at levels below 300 mb, while the...

Labile carbon (C), which is principally comprised of non-structural carbohydrates, is an essential intermediary between C assimilation and structural growth in deciduous forests. We developed a new approach that combined meteorological and biometric C cycling data for a mixed deciduous forest in Michigan, USA, to provide novel estimates of whole-ecosystem labile C production and reallocation to...

Growth of regular echinoids, expressed as test diameter through time, generally shows a sigmoidal pattern. However, when urchin size is considered in terms of test volume we show that growth of the deep-sea echinoid Echinus affinis is ultimately linear, rather than saturating. We construct a simple allometric model of energy allocation that produces linear growth in volume in mature urchins by ...