Using extensive historical
and present-day land use/cover data, we explore the linkages between
past and present land use decisions their impacts on the northern
forest ecosystem and the services it provides.
Jack Mustard, Laura Schneider, and Matt Vadeboncoeur
The northern forest has
a long history of strong anthropogenic influence, dating back more
than three centuries. We are studying an area in central Grafton
County, NH, (Figure 1) with a mix of historical land use ranging from
commercial clear-cutting to small-scale agriculture. The influence
of human management of these ecosystems can still be seen more than
a century after abandonment, and has profound impacts on forest structure,
species composition, soils, nutrient cycles, and carbon accumulation.
It is therefore essential to examine the role of a forest’s
history in determining its potential for future carbon uptake.
The few available measures of the effects of land use on carbon storage
are based on the rates of land use change, usually obtained from aggregated
data on agricultural and forestry activities. Spatially explicit data
on historic (e.g. Figure 2) and current land use linked to estimations
of carbon storage are almost absent for this region. We seek
to increase our understanding of the effects of land use change trends
on landscape-level carbon fluxes by estimating changes in carbon storage
in the context of historical disturbance patterns.
- To document the pattern
of land cover changes in our study area over the last 150 years.
- To link spatially explicit
land cover change patterns to estimates of carbon stock changes
over the past 150 years.
- To use remote sensing
data (TM and ETM+) to estimate current carbon fluxes resulting from
land use changes.
- To construct scenarios
that illustrate the influence of different regional patterns of
land use change on future carbon storage in forest ecosystems.
Our study area is Grafton County, NH. Data on the structure
and composition of the forest is available from numerous studies at
Hubbard Brook and Bartlett Experimental Forests, The Bowl Natural
Area, and at abandoned farm sites studied by Rhoads and Hamburg.
Detail of H.F. Walling’s 1860 map of Grafton County, showing
the location of each farm in the county at that date. These data can
be combined with tabular data from agricultural census schedules to
create a spatially-explicit land use database.
Detail of a modern aerial photograph of the same area shown in figure
2a. The pattern of historic land use is clearly visible even
today.ts. Landsat scenes are also available upon request.