Title: Long-term land-use change and feedback to the
global climate system
Goal/Aim:
·
Develop methodologies and a regional case study
for the reconstruction of land-use change over long time scales (102-103
years) using a combination of palaeoecological, historical and remote sensing
techniques.
·
Participate in a modelling exercise where
long-term land-use change contributes to the construction of past and future
climatic scenarios.
Background: Traditionally the biosphere
has been viewed as a passive recipient of
climate change. However, recent research into biophysical and
biochemical feed-backs to the climate system has suggested that these
feed-backs can account for significant amplification and even initiation of
climate trends that cannot be explained by physical climate models. Vegetation dynamics and biome shifts are the
most relevant aspects of the biosphere in this respect, but animals are
important in the control they exert on biome boundaries, particularly the
savannah-forest and savannah-grassland ecotones. A key arctic ecotone is the
forest limit that is sensitive to extreme climatic events, outbreaks of insect
pests and ungulate browsing pressure. There are significant differences in
albedo between tundra and forest areas that feedback into the climate system.
The project will form part of a new
international initiative where the research group LUCC (Land Use and Cover
Change Focus 1 Land Use Dynamics) collaborates with PAGES (Past Global
Changes). The student will have the opportunity to join an active international
research community and make many valuable contacts. The LUCC community at a
recent workshop endorsed the need to consider longer time scales for a better
understanding of non-linear changes and system behaviour. There is a need to
create an overlap between the LUCC (historical data) and the PAGES
(palaeorecords) time series to allow for "inter-calibration" of data.
There is a need to stimulate interdisciplinary collaboration which will be
aided by future LUCC-PAGES initiatives.
Project Description: The project involves the
reconstruction of land-use changes over longer time scales using techniques of
remote sensing and palaeoecological reconstruction. Remotely sensed data from a
test area will be used to calibrate recent palaeoecological (chiefly pollen
data). Then sub-fossil palaeoecological data will be used to reconstruct former
land use dynamics. Existing data will be used from regional pollen databases. Detailed
case study reconstructions will be upscaled using biomisation techniques and
the data will be used for input into regional and global climatic simulation
models to explore their sensitivity to past changes in land use. The role of
land use dynamics in potential future climatic scenarios will also be
investigated.
Methodology: Remote sensing. Interpretation
and quantitative analysis of historical maps. Interpretation and mapping of
pollen data preserved in lake sediments. Biomisation of pollen data and
upscaling of data for incorporation into regional and global climatic
simulation models.
Copenhagen
University contact person incl. Email
Professor John Anderson [email protected]