Spatial and temporal patterns of nitrogen deposition in China: Synthesis of observational data

Abstract

[1] Anthropogenic nitrous pollutant emissions in China significantly increased during the last decades, which contributed to the accelerated nitrogen (N) deposition. In order to characterize spatial pattern of nitrogen deposition, we employed the kriging technique to interpolate sampling data of precipitation chemistry and ambient air concentration from site-network observations over China. The estimation of wet deposition in China was limited to aqueous NO 3 À and NH 4 + , while ambient NO 2 was the only species involved in the predicted dry deposition fluxes. To obtain wet deposition fluxes, precipitation concentration was multiplied by 20-year mean precipitation amounts with a resolution of 10 Â 10 km. Dry deposition fluxes were products of the interpolated ambient NO 2 concentration and deposition velocities modeled for the main vegetation types in China. The total deposition rates of wet and dry deposition peaked over the central south China, with maximum values of 63.53 kg N ha À1 yr À1 , and an average value of 12.89 kg N ha À1 yr À1 . With ambient NO 2 concentration data spanning from the year 1990 through 2003, we detected and evaluated trends in the time series of the annual values of atmospheric NO 2 concentration. Significant upward trends at 21 of 102 sites were exhibited, with median percent change of 61.45% over the period [1990][1991][1992][1993][1994][1995][1996][1997][1998][1999][2000][2001][2002][2003]. In addition, spatially continuous patterns of dry deposition fluxes based on ambient NO 2 measurements in two 5-year phases, 9 years apart, were carried out. On average, there was a rise of 7.66% in NO 2 dry deposition during 9 years throughout China.Citation: Lü, C., and H. Tian (2007), Spatial and temporal patterns of nitrogen deposition in China: Synthesis of observational data,

The composition, spatial patterns, and influencing factors of atmospheric wet nitrogen deposition in Chinese terrestrial ecosystems

“…Agricultural activity is the main source of reactive N if the ratio is larger than 1, whereas, industrial activity is the main source if the ratio is lower than 1. The ratio of NH 4 + /NO 3 − in China was 1.22, which indicates that, as a developing country with a large population, both agricultural and industrial activities collectively influence the deposition of atmospheric N. Meanwhile, the deposition of NH 4 + -N and NO 3 − -N for China was higher than that for America or Europe (Table 3), in agreement with previous studies (Cape et al, 2012;Enzai et al, 2014;Galloway et al, 2004;Lü and Tian, 2007).…”

“…Using the same methods, Lü and Tian (2007) The deposition of DON estimated in this study was approximately 0.52 kg N ha − 1 yr − 1 , which is lower than those of previous studies Zhang et al, 2012b). Some studies have reported that DON accounted for 15-35% of TDN at single sites or regional scales (Fang et al, 2008;Li et al, 2012;Zhang et al, 2012b).…”

“…Some studies have reported the observed results of atmospheric N deposition at a local scale (Chen and Mulder, 2007;Huang et al, 2013), from catchments (Chen et al, 2011;Yu et al, 2011), or from belt transects (Sheng et al, 2013;Zhan et al, 2014) in China. Data collection, meta-analysis, and models have been used to estimate regional N deposition in China (Lü and Tian, 2007;Jia et al, 2014). However, there is currently no representative national scale observation network for atmospheric N deposition in China.…”

Divergent Responses of Soil Buffering Capacity to Long-Term N Deposition in Three Typical Tropical Forests with Different Land-Use History

“…In 2002, we established long-term N deposition research sites in these forests at Dinghushan Biosphere Reserve of Southern China, where atmospheric N deposition rates are commonly above 19 kg N ha −1 yr −1 . 11,39,40 We hypothesize that (1) long-term N deposition declines soil buffering capacity in all forests, because of the intrinsic poor buffering capacity, and (2) the primary forest is less sensitive to N addition than the secondary forest and plantation, because primary forests generally have more closed biogeochemical cycles regarding major nutrients, and are more resilient to external disturbances than more recently disturbed forests. 41,42 Our long-term field experimental treatment offers a unique opportunity to examine soil buffering capacity among different forest types under changing environmental conditions in the same climate region and with the same soil pedogenesis.…”

Effects of experimental nitrogen additions on plant diversity in tropical forests of contrasting disturbance regimes in southern China

“…At the same time, anthropogenic N emissions and resultant N deposition have increased substantially in China, and are projected to increase further due to agricultural and industrial activities (Zheng et al, 2002;Galloway et al, 2004;Liu et al, 2010). Lü and Tian (2007) concluded that total N deposition rates are highest (65 kg N ha À1 yr À1 ) in south-central China, with a mean rate of 19 kg N ha À1 yr À1 , higher than most reported for North American and Europe (MacDonald et al, 2002;Bobbink et al, 2010), where threats to forest ecosystem health have been suggested (Percy and Ferretti, 2004).…”