Vegetation responses to extreme climatic indices in coastal China from 1986 to 2015

Abstract

Climate extremes have resulted in substantial vegetation changes in the marine-terrestrial transitional zone. As a climatically-sensitive region, coastal China is currently experiencing prominent environmental climate change. To identify how climatic extremes affect ecosystem function, we calculated eleven indices of climatic extremes and four mean indices for six sub-regions of coastal China. Deseasonalized thirty-year (1986-2015) net primary productivity (NPP) was used as an indicator of ecosystem productivity, and its relationships with the climate indices were investigated at multiple scales (annual and seasonal) explicitly. The results demonstrated that: (1) annual NPP indicated an overall greening trend (in 73.71% of the study area) and partial degradation (in 26.29% of the study area) over the last thirty decades years; (2) coastal areas had experienced warming overall, with higher increases in nighttime temperatures relative to daytime temperatures; (3) in southern areas, maximum/ minimum daily maximum temperature had driven increases in NPP, whereas in northern areas, this effect varied between vegetation types; (4) Diurnal temperature range (DTR) and NPP were negatively correlated in the north and positively correlated in the south; and (5) Maximum 1-day precipitation promoted vegetation production across the whole study area. Maximum 5-day precipitation promoted vegetation growth in the north but had the opposite effect in the south. Our study advances understanding of vegetation dynamics and its driving mechanisms, and provides support for scientifically informed ecological management practices in coastal China.

Keywords: Coastal China; Correlation; Extreme weather; Net primary productivity; Spatial-temporal dynamics.