Publications

Publications Found: 1371
Wintertime CO2 Efflux From Arctic Soils: Implications For Annual Carbon Budgets
Fahnestock, J. T., Jones, M. H., Welker, J. M.

Estimates of annual carbon loss from arctic tundra ecosystems are based nearly entirely on measurements taken during the growing season in part because of methodological limitations but also reflecting the assumption that respiration during winter is near zero. Measurements of CO2 flux during winter, however, indicate …


Journal: Global Biogeochemical Cycles, Volume 13 (3): 775-779 (1999), ISBN . DOI: 10.1029/1999gb900006 Sites: US-Upa

Seasonal And Annual Respiration Of A Ponderosa Pine Ecosystem
Law, B. E., Ryan, M. G., Anthoni, P. M.

The net ecosystem exchange of CO2 between forests and the atmosphere, measured by eddy covariance, is the small difference between two large fluxes of photosynthesis and respiration. Chamber measurements of soil surface CO2 efflux (Fs), wood respiration (Fw) and foliage respiration (Ff) …


Journal: Global Change Biology, Volume 5 (2): 169-182 (1999), ISBN . DOI: 10.1046/j.1365-2486.1999.00214.x Sites: US-Me4

Photosynthetic Acclimation To Elevated Atmospheric CO2 Concentration In The Florida Scrub-Oak Species Quercus Geminata And Quercus Myrtifolia Growing In Their Native Environment
Li, J., Dijkstra, P., Hinkle, C. R., Wheeler, R. M., Drake, B. G.

Long-term effects of elevated CO2 concentration (ambient plus 350 μmol mol−1) on leaf photosynthetic acclimation of two species of a scrub-oak community, Quercus myrtifolia Willd. and Quercus geminata Small, were studied. Plants of both species were grown in open-top chambers in their natural …


Journal: Tree Physiology, Volume 19 (4-5): 229-234 (1999), ISBN . DOI: 10.1093/treephys/19.4-5.229 Sites: US-KS2

Effect Of Spring Burning On The Surface Energy Balance In A Tallgrass Prairie
Bremer, D. J., Ham, J. M.

Spring burning of dead biomass in tallgrass prairie is a common practice that may influence heat and water vapor transport from the landscape. Bowen ratio methods were used to measure the surface energy balances and evapotranspiration (ET) from burned (B) and unburned (UB) prairie near Manhattan, KS, USA. Data were collected from …


Journal: Agricultural And Forest Meteorology, Volume 97 (1): 43-54 (1999), ISBN . DOI: 10.1016/s0168-1923(99)00034-9 Sites: US-KFB, US-Kon

Carbon And Water Vapor Exchange Of An Open-Canopied Ponderosa Pine Ecosystem
Anthoni, P. M., Law, B. E., Unsworth, M. H.

Eddy covariance measurements of carbon dioxide and water vapor exchange were made above a ponderosa pine (Pinus ponderosa Dougl. ex P. and C. Laws.) forest located in a semiarid environment in central Oregon. The stand is a mixture of old-growth and young trees. Annual net carbon gain by the ecosystem (NEE) was 320 ± 170 gC m−2year−1


Journal: Agricultural And Forest Meteorology, Volume 95 (3): 151-168 (1999), ISBN . DOI: 10.1016/s0168-1923(99)00029-5 Sites: US-Me4

Long-Term Observation Of The Atmospheric Exchange Of CO2 With A Temperate Deciduous Forest In Southern Ontario, Canada
Lee, X., Fuentes, J. D., Staebler, R. M., Neumann, H. H.

This paper reports the results of the analysis of eddy covariance CO2 data obtained at a successional forest of maple and aspen at Camp Borden in southern Ontario, Canada, between July 1995 and December 1997. Main findings are (1) The Michaelis-Menton model explains >50–65% of the observed variance of the daytime …


Journal: Journal Of Geophysical Research: Atmospheres, Volume 104 (D13): 15975-15984 (1999), ISBN . DOI: 10.1029/1999jd900227 Sites: CA-Cbo

Are Monoterpene Emissions Influenced By Humidity?
Schade, G. W., Goldstein, A. H., Lamanna, M. S.

Monoterpene mixing ratios and fluxes were measured above a ponderosa pine plantation in the Sierra Nevada mountains from July to October 1998. Data were obtained during a variety of weather regimes including periods of extreme heat and dryness as well as during rain. Monoterpene emissions were highly elevated during and after the …


Journal: Geophysical Research Letters, Volume 26 (14): 2187-2190 (1999), ISBN . DOI: 10.1029/1999gl900444 Sites: US-Blo

Micrometeorology, Biophysical Exchanges And NEE Decomposition In A Two-Story Boreal Forest — Development And Test Of An Integrated Model
Gu, L., Shugart, H. H., Fuentes, J. D., Black, T., Shewchuk, S. R.

An integrated model of canopy micrometeorology and exchanges of mass and energy was developed and tested for a two-story boreal forest. Roles of different elements of this forest ecosystem in determining net ecosystem exchanges (NEEs) of sensible heat, water vapor and CO2 were analyzed by using the model. In this model, …


Journal: Agricultural And Forest Meteorology, Volume 94 (2): 123-148 (1999), ISBN . DOI: 10.1016/s0168-1923(99)00006-4 Sites: CA-Oas

Responses Of Net Ecosystem Exchanges Of Carbon Dioxide To Changes In Cloudiness: Results From Two North American Deciduous Forests
Gu, L., Fuentes, J. D., Shugart, H. H., Staebler, R. M., Black, T. A.

We analyzed half-hourly tower-based flux measurements of carbon dioxide (CO2) from a boreal aspen forest and a temperate mixed deciduous forest in Canada to examine the influences of clouds on forest carbon uptake. We showed that the presence of clouds consistently and significantly increased the net ecosystem exchanges …


Journal: Journal Of Geophysical Research: Atmospheres, Volume 104 (D24): 31421-31434 (1999), ISBN . DOI: 10.1029/1999jd901068 Sites: CA-Cbo

Nitrogen Dry Deposition At An Ameriflux Site In A Hardwood Forest In The Midwest
Pryor, S. C., Barthelmie, R. J., Jensen, B.

This paper presents observations of ammonia, nitric acid and size segregated chemically speciated aerosols above the canopy of a secondary successional deciduous forest in Indiana during spring. Average nitric acid concentrations range between 0.1–1 µg m−3 and vertical gradients from 1 to 9 ng m−3 / m. …


Journal: Geophysical Research Letters, Volume 26 (6): 691-694 (1999), ISBN . DOI: 10.1029/1999gl900066 Sites: US-MMS