Do High-Voltage Power Transmission Lines Affect Forest Landscape and Vegetation Growth: Evidence from a Case for Southeastern of China

Xiang Li,Yuying Lin

doi:10.3390/f10020162

Abstract

The rapid growth of the network of high-voltage power transmission lines (HVPTLs) is inevitably covering more forest domains. However, no direct quantitative measurements have been reported of the effects of HVPTLs on vegetation growth. Thus, the impacts of HVPTLs on vegetation growth are uncertain. Taking one of the areas with the highest forest coverage in China as an example, the upper reaches of the Minjiang River in Fujian Province, we quantitatively analyzed the effect of HVPTLs on forest landscape fragmentation and vegetation growth using Landsat imageries and forest inventory datasets. The results revealed that 0.9% of the forests became edge habitats assuming a 150 m depth-of-edge-influence by HVPTLs, and the forest plantations were the most exposed to HVPTLs among all the forest landscape types. Habitat fragmentation was the main consequence of HVPTL installation, which can be reduced by an increase in the patch density and a decrease in the mean patch area (MA), largest patch index (LPI), and effective mesh size (MESH). In all the landscape types, the forest plantation and the non-forest land were most affected by HVPTLs, with the LPI values decreasing by 44.1 and 20.8%, respectively. The values of MESH decreased by 44.2 and 32.2%, respectively. We found an obvious increasing trend in the values of the normalized difference vegetation index (NDVI) in 2016 and NDVI growth during the period of 2007 to 2016 with an increase in the distance from HVPTL. The turning points of stability were 60 to 90 meters for HVPTL corridors and 90 to 150 meters for HVPTL pylons, which indicates that the pylons have a much greater impact on NDVI and its growth than the lines. Our research provides valuable suggestions for vegetation protection, restoration, and wildfire management after the construction of HVPTLs.

Highlights

To meet the constantly growing electricity demands and to reduce electricity transmission losses, countries in Europe, North America, and Asia are attempting to develop high-voltage power transmission lines (HVPTLs) including pylons [1,2]
To minimize the potentially negative effects on vegetation and closely associated wildfire, further knowledge on the impact of HVPTLs on vegetation and forests is required. To this end, taking one of the areas with the highest forest coverage in China as a case, we quantitatively analyzed the effect of HVPTLs on forest landscape patterns and vegetation growth using Landsat images and forest inventory datasets
The results revealed that 1.8% of the vegetation as a whole becomes edge habitat, assuming a 300 m depth-of-edge-influence by HVPTLs

Summary

Introduction

To meet the constantly growing electricity demands and to reduce electricity transmission losses, countries in Europe, North America, and Asia are attempting to develop high-voltage power transmission lines (HVPTLs) including pylons [1,2]. HVPTLs have become globally necessary components of power transmission infrastructure, covering 5.5 million km in 2014, with predictions that this will increase to 6.8 million km in 2020 [3]. The development of HVPTL in China is expected to increase, to reduce electricity transmission energy losses, since long distances exist between power stations and end-users [4]. With the rapid growth of the electricity grid, HVPTLs will inevitably cover more complex environments, such as mountains and forests, compared to plains and cultivated lands [5].

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