Temporal (1958-1993) and spatial patterns of land use changes in Haut-Saint-Laurent (Quebec, Canada) and their relation to landscape physical attributes

In the last few years, landscape researchers have sought to understand temp oral and spatial patterns of landscape changes in order to develop comprehe nsive models of land cover dynamics. To do so, most studies have used simil ar methods to quantify structural patterns, usually by comparing various la ndscape structural indices through time. Whereas the necessity for compleme ntary approaches which might provide insights into landscape dynamics at so me finer scale relevant to local managers has been expressed, few studies h ave proposed alternative methodologies. Moreover, the important relationshi p between the physical constraints of the landscape and land use dynamics h as been seldom emphasized. Here we propose a methodological outline which w as applied to the study of a rural landscape of Southern Quebec, Canada, to detect spatial and temporal ( 1958 to 1993) patterns of land cover changes at field, patch and landscape level. We then relate these patterns to the underlying physical structure of landscape elements using GIS and canonical correspondence analyses. We use the different geomorphological deposit typ es as stable discriminant factors which may constrain land use. Canonical correspondence analyses showed relations of land use and land use changes to the physical attributes of the landscape elements, whereas spat ial analyses revealed very dynamic patterns at finer spatial and temporal s cales. They highlighted the fact that not only the physical attributes of t he landscape elements but also their spatial configuration were important d eterminants of land use dynamics in this area. Thus more land use changes o ccurred at the boundary between geomorphological deposit types than in ally other locations. This trend is apparent for specific small-size changes (e .g. forest to crop), but not for the large-size ones (e.g. abandoned land t o forest). Although land use changes are triggered by socioeconomic forces in this area, these changes are nevertheless constrained by the underlying physical landscape structure. A thorough comprehension of historical change s will enhance our capability to predict future landscape dynamics and devi se more effective landscape management strategies.