SEASONAL VARIATION IN LIGHT TRANSMISSION AND CANOPY GAPS OF DECIDUOUS ROADSIDE VEGETATION: ASSESSMENT WITHIN FOREST LANDSCAPE

Authors : Melih ÖZTÜRK, Ercan GÖKYER

Pages : 1-11

Doi:10.31195/ejejfs.333089

View : 50 | Download : 9

Publication Date : 2015-12-30

Article Type : Research Paper

Abstract :Deciduous roadside vegetation exhibits seasonal patterns of foliage with varying colors and numbers. Hence the alternating percentage of the gaps within the roadside canopy allows changing percentages of light transmission throughout the year. The leafless roadside vegetation in winter is sequentially subject to budburst, flushing, and development stages until the summer, when the leaves are fully developed both in size and number. Then, defoliation follows senescence, and fading and fall stages occur in sequence until the vegetation becomes leafless in the winter. The percentage of light transmission, canopy gaps, and sunlight duration are different in these different stages. In this study, the seasonal pattern of light transmission and canopy gaps of deciduous vegetation along a rural road section that is surrounded by forest landscape and that connected two cities was monitored. The road selected for the study was located in Bartın watershed in Turkey. Hemispherical photographing and image processing techniques were used to analyze the percentage of light transmission and canopy gaps throughout a foliage year in between 2012 and 2013. During 22 field visits, 220 hemispherical photographs were taken from 10 points along 700 m of the experimental site. Percentage of light transmission, and canopy gaps data were evaluated together with the daily sunlight duration data from the meteorological station. The correlations insert ignore into journalissuearticles values( r ); between mean sunlight duration insert ignore into journalissuearticles values( msd ); and 1); the percentage of mean light transmission insert ignore into journalissuearticles values( mplt ); and 2); the percentage of mean canopy gaps insert ignore into journalissuearticles values( mpcg ); were -0.68 and -0.75, respectively. Both of the correlations were highly significant insert ignore into journalissuearticles values( P < 0.01);. The seasonal patterns of mplt , mpcg , and msd were assessed considering both the roadside vegetation and the surrounding landscape, emphasizing travelers’ and drivers’ perceptions.
Keywords : deciduous canopy, hemispherical photographs, intercity road, rural landscape, seasonal patterns

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