Proximity effects of high voltage electric power transmission lines on ornamental plant growth

Abstract

The proximity effects of high voltage electric power transmission lines on Leyland Cypress (xCupressocyparis leylandii (Dallim. and A.B. Jacks.) Dallim) and Japanese Privet (Ligustrum japonicum Thunb.) growth were examined in a private nursery located in Sakarya, Turkey. Five transect were randomly chosen in both leylandii and privet lots in the nursery. In the summer of 2009, starting from under the power line 12 sampling point for every five meters away from the power line on each transaction was located. From these sampling points, five seedlings for each species were randomly chosen. From each sampling seedlings, five - seven leaves (for private) or spurs (for leylandii) were collected from lower-, middle- and upper-crown. For each sampling seedling diameter at breast height (dbh) were measured with a caliper. Within the laboratory, the projected surface area (SLA) of needles and leaves were determined using a leaf area meter. The relationship among measured seedling variables and the proximity to high voltage electric power transmission lines were evaluated using correlation. The effects of proximity to power-line on specific leaf area and seedling dbh were tested with an analysis of variance procedure (ANOVA). Tukey’s HSD test with alpha = 0.05 was performed to compare means. The result of the data revealed that the mean of seedling dbh at 55 m away from the power line was about 25% smaller than that of the seedlings underneath the power line. The data also showed that there was a gradual decrease at dbh value of the privet with the distance from the power line. Seedling mean dbh value at the 25^th m sampling point was about 10% lower than that of the seedlings underneath the power line. At the 40^th m sampling point this dbh value was about 17 and 8% lower than those of the seedlings underneath the power line and of the seedling at 25^th m sampling point, respectively. Specific leaf area after the 30^th m away from the power line has been decreasing. The SLA value at the 30^th m is about 17% lower than that of the seedling underneath the power line.

Key words: magnetic field, ornamental plant growth, power transmission line, Leyland Cypress, Japanese Privet.