- Contributed Oral Session 101: Biogeochemistry
Wednesday, August 10, 1:30 PM - 5:00 PM, Meeting Room 520 A, Level 5, Palais des congrès de Montréal
ESA Public Affairs Committee Meeting
Tuesday, August 9, 7:00 AM - 8:30 AM, Meeting Room 512 B, Level 5, Palais des congrès de Montréal
ESA Vegetation Classification Panel Business Meeting
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Ecology / Ecological Monographs Editors Meeting
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ESA Research Committee Meeting
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ESA International Relations Committee Meeting
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ESA Biogeosciences Section Grad Student Breakfast
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Federation of the Americas
Wednesday, August 10, 8:00 AM - 9:00 AM,
VIP awards Recipient / Governing Board Reception (Invitation Only)
Monday, August 8, 5:00 PM - 5:45 PM, Belvedere Patio 715, Level 7, Palais des congrès de Montréal
Contributed Oral Session 87: Rare, Threatened, and Endangered Species: Flora; Habitat
Wednesday, August 10, 8:00 AM - 11:30 AM, Meeting Room 522 A, Level 5, Palais des congrès de Montréal
FT - 13: Charlevoix, an ecotouristic visit (Three nights)
, 8:00 AM - 2:00 PM, Viger Bus Terminal, Palais des congrès de Montréal
Contributed Oral Session 67: Fire Ecology: Restoration and Dynamics
Tuesday, August 9, 1:30 PM - 5:00 PM, Meeting Room 520 C, Level 5, Palais des congrès de Montréal
WK - 11: Tidball: Ecology education: Global cooperation and perspectives
Sunday, August 7, 8:00 AM - 5:00 PM, Meeting Room 511 C, Level 5, Palais des congrès de Montréal
WK - 2: Krasny: Teaching ecology in urban gardens
Saturday, August 6, 9:00 AM - 4:00 PM, Meeting Room 513 C, Level 5, Palais des congrès de Montréal
Nitrogen retention and partitioning following fire in boreal black spruce forests: the importance of plant functional types.
Mack, Michelle*,1, Bret-Harte, Marion2, Chapin, Stuart2, Schuur, Edward1, Valentine, David2, 1 University of Florida, Gainesville, FL, USA2 University of Alaska Fairbanks, Fairbanks, AK, USA
ABSTRACT- Loss of nitrogen (N) following disturbance can limit primary productivity during secondary succession and over ecosystem development. We used an ecosystem-scale 15N tracer addition experiment to examine the effects of fire on N retention and partitioning in two boreal black spruce (Picea mariana) forests near Fairbanks, Alaska, that burned in July 1999. The tracer was applied to the surface of burned and control stands in August 1999 and was recovered in plants and soil in 2000, 2001, and 2002. In the year following fire, retention of the tracer was reduced by 50% in burned relative to unburned stands, where all applied tracer was recovered. By year three, only 15% of added tracer remained in burned stands, while 90% of applied tracer remained in unburned stands. In the latter, mosses and lichens consistently accounted for 80% of tracer retention over all years and moss abundance was negatively related to the rate of tracer accumulation in trees. In burned stands, there was more total N and more tracer found in the mineral soil than in unburned stands in all years, with a greater proportion of the tracer in soil layers below the pre-fire rooting zone. Within the burned stands, the amount of tracer in deeper soil layers was negatively correlated with both the amount of remaining forest floor organic matter and the biomass of graminoid species. Our results suggest that the effects of fire on the retention and partitioning of N in boreal black spruce forests depend upon fire severity and the consequent loss or recruitment of key plant functional types.
Key words: Boreal forest, Fire, Nitrogen retention, Plant functional types