We used gas exchange techniques to estimate maximum rate of carboxylation (Vcmax), a measure of photosynthetic capacity, in the understory and upper crown of a closed deciduous forest over two seasons. There was extensive variability in photosynthetic capacity as a result of vertical canopy position, species type, …
Journal: Tree Physiology, Volume 20 (9): 565-578 (2000). DOI: 10.1093/treephys/20.9.565 Sites: US-WBW
Changes in leaf physiology with tree age and size could alter forest growth, water yield, and carbon fluxes. We measured tree water flux (Q) for 14 ponderosa pine trees in two size classes (12 m tall and ∼40 years old, …
Journal: Oecologia, Volume 124 (4): 553-560 (2000). DOI: 10.1007/s004420000403 Sites: US-Me4
This paper summarizes and analyses available data on the surface energy balance of Arctic tundra and boreal forest. The complex interactions between ecosystems and their surface energy balance are also examined, including climatically induced shifts in ecosystem type that might amplify or reduce the effects of potential climatic …
Journal: Global Change Biology, Volume 6 (S1): 84-115 (2000). DOI: 10.1046/j.1365-2486.2000.06015.x Sites: US-Upa
The long-term effects of elevated (ambient plus 350 μmol mol−1) atmospheric CO2 concentration (Ca) on the leaf senescence of Quercus …
Journal: Global Change Biology, Volume 6 (7): 727-733 (2000). DOI: 10.1046/j.1365-2486.2000.00347.x Sites: US-KS2
Journal: Ecological Applications, Volume 10 (1): 60-72 (2000). DOI: 10.2307/2640986 Sites: US-Upa
We conducted ecosystem carbon and water vapour exchange studies in an old-growth Pinus ponderosaforest in the Pacific North-west region of the United States. The canopy is heterogeneous, with tall multiaged trees and an open, clumped canopy with low leaf area. Carbon assimilation can occur throughout relatively mild winters, …
Journal: Global Change Biology, Volume 6 (6): 613-630 (2000). DOI: 10.1046/j.1365-2486.2000.00339.x Sites: US-Me5
Journal: Tree Physiology, Volume 20 (11): 745-753 (2000). DOI: 10.1093/treephys/20.11.745 Sites: US-GLE
Fluxes of CO2, water vapor, and sensible heat were measured by the eddy covariance method above a young ponderosa pine plantation in the Sierra Nevada Mountains (CA) over two growing seasons (1 June–10 September 1997 and 1 May–30 October 1998). The Mediterranean-type climate of California is characterized by a protracted …
Journal: Agricultural And Forest Meteorology, Volume 101 (2-3): 113-129 (2000). DOI: 10.1016/s0168-1923(99)00168-9 Sites: US-Blo
Acetone was one of the most abundant volatile organic compounds (VOCs) observed in the Sierra Nevada Mountains (California, USA). Mixing ratios were measured hourly above a ponderosa pine plantation using an automated in situ dual-channel GC-FID system throughout July 1997, …
Journal: Atmospheric Environment, Volume 34 (29-30): 4997-5006 (2000). DOI: 10.1016/s1352-2310(00)00321-6 Sites: US-Blo
Ponderosa pine is one of the most sensitive species to ozone and a dominant species in the Sierra Nevada Mountains. To assess the factors controlling ozone deposition to the forest and to study the forest …
Journal: Journal Of Geophysical Research: Atmospheres, Volume 105 (D17): 22123-22136 (2000). DOI: 10.1029/2000jd900168 Sites: US-Blo