Impact of photovoltaic power plant construction on the net primary productivity of vegetation in the Tala Shoal areas

Abstract: Many photovoltaic power plants have been built in China in recent years, due to the clean and renewable solar energy resources. However, ecological consequences are inevitably caused on the local and regional scales. Current studies focused mainly on the ecological impact of solar panels using in-situ meteorological observations, particularly subjected to very local scales and short periods. It is necessary to implement it at the regional scale for long periods. In this study, the moderate resolution satellite data was utilized to investigate the impact of photovoltaic power plant construction on the net primary productivity (NPP) of vegetation in Tala Shoal. The difference between actual and potential NPP was calculated to quantify the impact of solar panels on the spatiotemporal variations from 2010 to 2020. Firstly, the actual and potential NPP were computed using MOD15A2 and meteorological data, according to the CASA and the regional evapotranspiration model, respectively. The estimated actual NPP was verified as reliable with the MODIS NPP product data (MOD17A3). Secondly, a linear regression was used to analyze the temporal trend of the actual and the NPP that was influenced by human activities. A relative contribution index was then constructed to determine the influence magnitude of human activities on the NPP. The contribution of human activities was analyzed using land cover data. Thirdly, three typical areas were selected as the solar power plants that were constructed in different years. The NPPs were compared in the solar power plant construction area and the surrounding control area. The temporal trend of NPP was analyzed in the three typical areas to find the changing pattern of NPP in the period before and after the solar power plant construction. As such, the different impacts were revealed for the solar panels that were constructed in different years in the local areas. The results showed that: 1) There was an increasing trend in the actual and potential NPP in the study area from 2010 to 2020, with the annual average actual and potential NPP values of 58.03, and 204.05 g/m2, respectively, indicating the low in the northwestern areas and high in the southern areas; 2) The average contribution of human activities to the NPP changes was 68.9%, indicating the dominant factors driving the NPP changes. 3) There were different ecological impacts of solar panels that were built in different years over time. In the short term, the solar panels caused a decrease in the NPP, indicating a destructive effect on the vegetation due to mechanical excavation. By contrast, the solar panels caused an increase in the NPP in the long term, probably due to the increased temperature and humidity under the solar panels, and the reduced wind speed for better vegetation growth. Consequently, there was a different impact of solar photovoltaic panels on the dynamic changes in vegetation net primary productivity. The finding can also provide the scientific basis for vegetation restoration and high-quality development in Tala Shoal.