Aesthetic ratings of northern forest scenes : the effects of spatiochromatic stimulus attributes in silvicultural landscape images

Abstract

The Environmental Impact Assessment Act, through the use of The Social Impact Assessment (SIA) established public participation in environmental decision-making. The concern for landscape aesthetics has been one among many issues, and has received special prominence in the case of timber management in Ontario’s northern forests. Research on landscape perception has contributed to the debate. Typically such studies use rating methods to evaluate public perceptions of landscape quality, beauty and/or aesthetics. However, these studies did not consider whether luminance-, spatial- and/or chromatic variations influence aesthetic judgments in the natural environment. From that perspective, this study is an extension of earlier visual search studies that investigated the effects of specific spatial and chromatic properties of target stimuli into the realm of landscape perception. Based on the findings from this extensive body of work, we predicted that high levels of chromatic conspicuity and extrinsic (or unnatural) regularity in spatial patterning in a wilderness scene would have a negative impact on the public perception of forest landscapes. Three conditions representing landscape elements (targets) that simulate silvicultural practices were manipulated using Adobe Photoshop software. The targets were a checkerboard clear-cut, an irregular cut, and a roadway. The chromaticity of each target was defined by the target midtones (average across 400 pixels, or 1° subtense). The “neutral” chromaticity was equated across checkerboard and irregular patches. The chromaticity of the targets was modulated (7 steps) along red-green axes in Commission Internationale de l’Eclairage (CIE) 1931 chromaticity space. All presentations were done on a high-resolution colour monitor (CRT). Each of the targets was presented in five background conditions of oblique aerial photographs of coniferous trees with and without a lake to determine position bias and target/lake proximity effects. Each of the 16 observers per background condition (N=80) was presented 84 randomized landscapes from a total of 420 images. Data interpretation was conducted using a 4-way multifactor design with repeated measures on 3 factors (5 randomized backgrounds X 3 spatial targets X 7 target chromaticities X 4 quadrant locations). Results showed that varying the spatiochromatic properties of the silvicultural targets and their locations significantly influenced the perceived beauty of northern forest landscapes. Patches in a scene that had spatial regularity and a colour appearance that was shifted towards the “reds” were given the lowest ratings. Comparable situations can be observed in real scenes that have undergone recent harvesting operations.