PARENT SESSION
Organized Oral Session 42: Applying ecological theories to multiple spatio-temporal scales and to different landscapes in Europe
Organizer(s): J Loeffler and U Steinhardt
Thursday, August 11, 8:00 AM - 11:30 AM, Meeting Room 511a, Level 5, Palais des congrès de Montréal
Landscape and vegetation changes in Swedish mountains in multiple scales.
Ihse, Margareta1, 1 University of Stockholm, Stockholm, Sweden
ABSTRACT- The Swedish mountain range is one of the largest wilderness areas in Europe. The main vegetation is heath tundra of dwarf shrub and grass, and a few meadows. The heaths are sensitive to changes from trampling and vehicles. Remote sensing methods and data from Colour InfraRed /CIR) aerial photographs, Landsat TM and Ikonos satellite data, have been used as a main tool with additional field data, to survey and monitor landscape and vegetation changes. Maps in scale 1:100 000 to 1: 50 000 were developed for nature conservation and environmental planning, in scale 1:10 000 for monitoring of vegetation changes during time span of 5 to 15 years, and for studies of erosion processes. Different classification systems were developed, adapted to the aims and the possibilities of remotely sensed data. The medium scale maps are based on the theories of Uppsala school, where vegetation is classified according to physiognomy and life form in heaths, meadows and mires, and further developed with soil moisture, nutrition, topography, and snow distribution. The large scale maps are based on ideas of sensitivity of different vegetation types to trampling, where decrease of lichen cover and development of patches of humus and mineral soils are signs of vegetation degradation and erosion. The medium scale maps could not be used in their original form to detect the spatial small changes. A method were developed, using multiple scales to identify and map the changes of a few square meters over very large areas. The dry heaths were identified in the medium scale maps in certain altitudes, on certain terrain forms. Changes in vegetation and lichen cover, in 10 classes were detected only in large scale maps and in field sata, and were found in certain positions in the dry heath. Grazing caused a decrease of lichen height by 1/3. Trampling caused a decrease of lichen cover in up to 40 % of the area, with a rate of 2 % per year. New tracks caused drainage of mires. Signs of wind erosion were found on boulders without crust lichens. The changes were detected by using a multiple scale approach to identify and map spatial small vegetation changes of a few square meters (50 to 1000) to over thousands of km2.
Key words: mountain vegetation, vegetation change, colour infrared photos, multiple scales