PARENT SESSION
Poster Session 13: Landscape Ecology / Geomorphology
Tuesday, August 9, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Sixty years of landscape fragmentation due to road and housing development in north-central Wisconsin.

Gritt, John^*,1, Radeloff, Volker¹, Hawbaker, Todd¹, ¹ University of Wisconsin - Madison, Madison, WI, USA

ABSTRACT- Road and housing development changes landscapes by fragmenting wildlife habitat, altering hydrology, spreading exotic species, and polluting natural areas. In northern Wisconsin there has been widespread development over past decades. Our objective was to estimate development rates for both roads and houses and to quantify the resulting landscape patterns. Roads and houses were mapped for 5 dates between 1938 and 1992 throughout a 555 km2 study site in north-central Wisconsin. To simulate the variable ecological effects from roads and houses, buffers were established at 50, 100, 250 and 500 meters from all roads or houses. Landscape indices were calculated for the terrestrial areas outside these buffers. In 1992 there were 20 houses / km2 and 4.8 km of roads / km2, compared to 4.3 houses and 2.1 km of roads / km2 in 1938. The number of patches created by roads increased four fold since the 1930s, and the maximum roadless patch decreased from 32 km2 in 1938 to 13.5 km2 in 1992. Over the same time period, the spatial arrangement of houses changed from a primarily clustered pattern around lakes to a pattern that is increasingly spreading into adjacent areas. In 1960, 67% of houses were less than 100 (m) from a lake but in 1992 only 55% were within that same distance. Landscape fragmentation due to road and housing development creates patterns on the landscape that are not easily reversible and may require increased planning and tighter regulations to maintain ecosystem functions and services.

Key words: landscape fragmentation