Oral Session #41: N Dynamics: Additions, Retention and Transformations.

Presiding: G.P. Zogg, University of New England.
Tuesday, August 8, 2000
8:15 AM to 12:15 PM
Cottonwood Room I - Sports Event Center

8:00 AM	Why does biodiversity not affect nitrogen losses from two unpolluted old-growth forest ecosystems? HEDIN, L.O. , J.J. ARMESTO, C.A. PéREZ and S.S. PERAKIS
8:15 AM	Understorey palm stemflow and throughfall in a Mexican Rainforest. ALVAREZ-SáNCHEZ, J. , R. LEóN-RICO
8:30 AM	Canopy type effects on nitrogen flow in southwestern ponderosa pine forests. ROBERTS, J.M. , S.C. HART
8:45 AM	The effects of spatial resolution of plant-soil heterogeneity on the dynamics of nitrogen transformation in two model forest systems . TONITTO, C. , T.M. POWELL
9:00 AM	Uptake of nitrogen dioxide (NO2) in tropical tree leaves: Implications for tropospheric photochemistry? SPARKS, J.P. , R.K. MONSON
9:15 AM	Differentiation in 15N uptake and the organization of an arctic tundra plant community. MCKANE, R. , L. JOHNSON, G. SHAVER and K. NADELHOFFER, E. RASTETTER, A. GIBLIN, B. FRY, K. KIELLAND
9:30 AM	Effects of soil organic matter quality and microclimate on soil nitrogen transformations in arctic treeline ecosystems. MACK, M. , J. BERINGER, C. COPASS and F.S. CHAPINIII
9:45 AM	Nitrogen mineralization in epiphytic soil in old-growth Fitzroya cupressoides forest, southern Chile. ARMESTO, J.J. , C. PEREZ, M. CARMONA and R. GUEVARA
10:00 AM	Break
10:15 AM	Species and functional types affect ecosystem response to fertilization in arctic tundra. BRET-HARTE, M.S. , F.S. CHAPINIII, J.R. WHORLEY and E.A. GARCIA, V. SACRE
10:30 AM	Effects of fertilization on patterns of carbon allocation and gross primary production in a tropical plantation forest. GIARDINA, C.P. , M.G. RYAN, D. BINKLEY and J.H. FOWNES
10:45 AM	Effect of tree species on nitrogen cycling in the Catskill Mountains, NY: Fertilization studies. LOVETT, G.M. , K.C. WEATHERS, M.A. ARTHUR
11:00 AM	Effect of tree species on nitrogen retention in the Catskill Mountains, NY: 15N Studies. TEMPLER, P. , G. LOVETT, K. WEATHERS and S. FINDLAY, T. DAWSON
11:15 AM	The influence of nitrogen availability on the establishment of Fremont cottonwood seedlings along the Yampa River. ADAIR, E.C. , D. BINKLEY
11:30 AM	Nitrogen dynamics in arid ecosystems in response to carbon and nitrogen addition. SCHAEFFER, S.M. , S.A. BILLINGS, R.D. EVANS
11:45 AM	Response of soil nitrogen dynamics to elevated CO2 in a Mojave Desert ecosystem. BILLINGS, S.A. , S.M. SCHAEFFER, R.D. EVANS
12:00 PM	Disruption of nitrification affects carbon cycling in the Patagonian shrub-grass steppe. AUSTIN, A.T. , O.E. SALA, R.B. JACKSON and N. LOPEZ, B. MENDEZ