Canopy Gaps Improve Landscape Aesthetic Service by Promoting Autumn Colour-Leaved Tree Species Diversity and Colour-Leaved Patch Properties in Subalpine Forests of Southwestern China

Abstract

BackgroundLandscape aesthetic service is a crucial ecosystem service in subalpine forests of the mountain and ravine regions of the Tibetan Plateau; it can provide important ecological and economic value, improving the livelihood of the local people. Canopy gap is recognized as the key mechanism in the maintenance of species diversity and forest stability and is known to further affect ecosystem service functioning. However, the mechanisms and interactions of forest stability maintained by gap formations and forest aesthetic service functioning via gap dynamics are not fully understood. We used very high-resolution images to quantify gap characteristics and examined the effects of canopy gaps on autumn colour-leaved tree species diversity, colour-leaved patch structure characteristics, and landscape aesthetic service in 21 subalpine autumn colour-leaved forest plots in southwestern China. We then used path analysis to determine the relationships between these factors.ResultsThe number of gaps and total gap area were the key gap characteristics affecting landscape aesthetic service; particularly, medium canopy gaps (51–100 m2) played a more important role. The path model showed that increasing the total gap area along with the number of medium canopy gaps had direct positive effects on autumn colour-leaved tree species diversity, colour-leaved patch diversity, and total colour-leaved patch area, thus improving the landscape aesthetic service.ConclusionCanopy gaps indirectly improve landscape aesthetic service by significantly affecting colour-leaved species diversity, colour-leaved patch diversity, and colour-leaved patch area. Our results suggest that forest managers may be able to manipulate the numbers and proportion of medium canopy gaps to protect and preserve autumn colour-leaved tree species diversity and colour-leaved landscapes, promoting the landscape aesthetic service of subalpine autumn colour-leaved forests and, in turn, ensuring the coordinated development of economic, social, and ecological benefits for the underdeveloped rural montane areas of southwestern China.