Atmospheric Nitrogen Deposition to the New Jersey Coastal Waters and Its Implications

Abstract

Abstract. In situ measurements of atmospheric NO 3 À and NH 4 þ at Sandy Hook on the northern New Jersey (USA) coast and at Tuckerton on the southern New Jersey coast reveal significant temporal and spatial variations of these inorganic N constituents. The mean concentration of NO 3 À in precipitation was higher at Sandy Hook (44.6 lmol/L) than at Tuckerton (29.1 lmol/L). The mean concentration of NH 4 þ in precipitation exhibited a similar pattern, being higher at Sandy Hook (26.3 lmol/L) than at Tuckerton (18.3 lmol/L). Aerosol NO 3 À and NH 4 þ concentrations at Sandy Hook were also higher than those at Tuckerton. On an annual basis, the total atmospheric deposition of NO 3 À was estimated to be 51. were ,4 lmol/L. In this system, atmospheric deposition accounts for ;39% of the total N load. These results suggest that atmospheric deposition appears to be an important pathway of new N inputs to New Jersey coastal waters and a potentially significant N enrichment source for biotic production.

Impacts of fire and climate change on long-term nitrogen availability and forest productivity in the New Jersey Pine Barrens

“…Our landscape-level N deposition rate (1.1 g N·m −2 ·year −1 ) was just slightly lower than the rate currently observed in New Jersey (1.2 to 2.8 g N·m −2 ·year −1 (Gao et al 2007). Our average N leaching rates (0.3 g N·m −2 ·year −1 ) were higher than average estimates in nearby Chesapeake Bay (0.14 g N·m −2 ·year −1 ; Stacey et al 2000) but fell within the range of empirical observations in the region (0 to 0.57 g N·m −2 ·year −1 ).…”

“…Similarly, de Vries and Posch (2011) predicted that climate change may be a more important driver than N deposition in the forests of the future. In our study, rising precipitation increased N deposition rates by 30% over the century, which may exceed the N demands of the vegetation, especially given the high atmospheric deposition rates in New Jersey, which currently range from 1.2 (Gao et al 2007) to 1.8 g N·m −2 ·year −1 (Zhang et al 2012). Because there are strong feedbacks between disturbance, climate, and vegetation in the model, modest shifts in the climate and fire regimes result in compositional shifts, in this case towards more oak-dominated forests (Scheller et al 2012).…”

“…If N deposition in New Jersey starts to decline, as has been observed in much of the northeastern US over the past 10 years (www.epa.gov) and if [CO 2 ] continues to increase forest growth by 14%-23% (Norby et al 2005), then our simulations may be underestimating future declines in mineral N with climate change. We tried to be conservative in our estimate of N deposition such that our average rate (1.1 g N·m −2 ·year −1 ) was at the low end of the range currently observed in New Jersey (1.2 to 2.8 g N·m −2 ·year −1 ; Gao et al 2007). We also did not consider limitations by nutrients other than N, which may limit forest responses to fire and climate change (de Vries and Posch 2011).…”

Nitrogen deposition and its spatial pattern in main forest ecosystems along north-south transect of eastern China

“…In China, total NO x emission increased from 8.4 Tg N/yr in 1990 to 11.3 Tg N/yr in 2000, and total NH 3 emission increased from 10.8 Tg N/yr to 13.6 Tg N/yr over the same time period (Lu and Tian, 2007). Elevated N deposition to terrestrial ecosystems may lead to N saturation and cause a great deal of ecological risk (Matson et al, 2002), such as eutrophication of water bodies (Gao et al, 2007), soil acidification (Bouwman et al, 2002), plant nutrient imbalances, and undesirable changes in biodiversity (Stevens et al, 2010).…”

First Assessment of Inorganic Nitrogen Deposition Budget Following the Impoundment of a Subtropical Hydroelectric Reservoir (Nam Theun 2, Lao PDR)

“…Studies of N input to various water surfaces (coastal, lake, river, and ocean) indicate that atmospheric nitrogen deposition represents a significant amount of the total nitrogen input (Canham et al, ; Gao et al, ; Jung et al, ; Qi et al, ; Whitall et al, ). Recent N deposition‐monitoring studies also showed very high N deposition rates at several observation sites including agricultural catchments in different regions of East Asia (Pan et al, ; Shen et al, ; Sugimoto & Tsuboi, ).…”