Effects of climate change on decomposition in Arctic Tussock Tundra: A modeling synthesis

Conference · Tue Jun 01 04:00:00 EDT 1993 · Bulletin of the Ecological Society of America; (United States)

OSTI ID:6043468

Moorhead, D L ^[1]; Reynolds, J F ^[2]

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1. Texas Tech Univ., Lubbock (United States)
2. Duke Univ., Durham, NC (United States)

A model of litter decomposition was used to examine the potential effects of climate change on the decay of dead organic matter in a tussock tundra soil of northern Alaska, USA. Under current conditions (714% mean soil water content, 4.5[degrees]C mean soil temperature, 93-d season length), the model estimated a net release of 5.28g N[times]m[sup [minus]2][times]yr[sup [minus]1] and 79.5g CO[sub 2]-C[times]m[sup [minus]2][times]yr[sup [minus]1] from soil organic matter, respectively. These values are consistent with observations from field and laboratory studies of decomposition and plant growth. With changing climate, the greatest increase in net N release from dead organic matter (199% of current value), occurred at 600% soil moisture, 140-d season and 8.5[degrees]C mean summer temperature. The least amount of N was immobilized (46% of current value) at the present temperature, 70-d season and 1000% soil moisture content. Season length had little affect on the size of the mineral N pool, although pool size does respond to temperature and soil moisture content; ranging from 12-25 mg N[times]m[sup [minus]2]. Model results also indicate that patterns of net C and N mineralization need not be similar. Net C mineralization, estimated as cumulative CO[sub 2] efflux, is roughly proportional to total C transfer through the decomposer community. However, net N mineralization is not as closely related to mineral N pool size because of the high immobilization potential of tussock tundra soils.

• OSTI ID: 6043468
• Report Number(s): CONF-930798--
• Conference Information: Journal Name: Bulletin of the Ecological Society of America; (United States) Journal Volume: 74:2
• Country of Publication: United States
• Language: English

Related Subjects

560400* -- Other Environmental Pollutant Effects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALASKA
BIOLOGICAL EFFECTS
CARBON
CHEMICAL REACTIONS
CLIMATIC CHANGE
DECOMPOSITION
DEVELOPED COUNTRIES
ELEMENTS
GROWTH
MATHEMATICAL MODELS
MATTER
MINERALIZATION
MOISTURE
NITROGEN
NONMETALS
NORTH AMERICA
ORGANIC MATTER
PLANT GROWTH
SOILS
TUNDRA
USA