LD3-1: Water bodies in Interior Alaska have contracted over the past 40 years as a result of permafrost degradation and subsurface drainage, with minor effects of earlier thaw, annual warming and evapotranspiration that have co-occurred.

One possible mechanism for this landscape-level change is internal drainage as talik formation occurs.	With time, internal drainage (especially over the winter) can occur.

How common is the loss of surface water bodies in the Alaskan boreal forest region? We will use aerial photography and spectral imagery
to quantify the amount of change in the area of closed basin water bodies in several extensive areas of wetlands in interior Alaska. This study will
document changes in the area of water bodies over the past 40 years. The following is an example from the Yukon Flats ecoregion of interior Alaska.

Yukon Flats 1978:	Yukon Flats 2000:

Wildfire may cause significant changes in wetland landscapes by removing the insulating organic mat and promoting the rapid
development of talik and associated internal drainage. We will investigate whether this is a common occurance by examining
the change in water bodies inside and outside of burn scars from historic aerial photography to the present.

To complement remote sensing analysis of wetland changes, we will select basins that show significant drainage over the past 40 years for
field sampling. We will obtain soil cores of these basins across moisture gradients, and use radiocarbon dating to contstruc a chronosequence of
wetland plant communities. We will use data on carbon fluxes (BG3-2), remotely sensed estimates of surface water change, and a regional model of
carbon and methane dynamics (Zhuang et al submitted) to develop a regional understanding of how fire, permafrost, climate, and associated
land-cover change influence to tragectories of regional soil carbon storage and methane emissions in these systems.