Danshuei River Estuary (DRE) total and inorganic nitrogen in the dissolved (TDN, DIN) and particulate (TPN, PIN) phases were analyzed to study their distribution and partitioning. The carbon contents in particles were also analyzed. The upper estuary contained higher ammonium concentration (304-557 μM), leading to TDN completely dominating (>95%) the total N (TDN + TPN) pool within the DRE. Ammonium played a crucial role in controlling the speciation variation of DIN and partitioning between dissolved and particulate phases. Nitrification seemed to occur in the salinity >30 region where elevated percentages of nitrite and nitrate were observed. PON dominated the particulate N and contributed an average of 62% of the TPN pool. A constant organic C/N ratio (6.55) was observed in particles, indicating that POM was mainly from phytoplankton detritus. The N distribution coefficient values, log(K), ranged from 3 to 4, suggesting that the affinity of DIN for particles was weak.
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http://dx.doi.org/10.1016/j.marpolbul.2021.111981 | DOI Listing |
J Environ Manage
December 2024
School of Agriculture, Food and Wine, Faculty of Sciences, Engineering and Technology, Waite Campus, University of Adelaide, Urrbrae, 5064, Australia. Electronic address:
Coastal wetland rehabilitation can provide nature-based solutions for climate change mitigation. The high carbon accumulation rate and carbon secured, potentially for several millennia, as soil organic carbon (SOC), is among the reasons. Measuring SOC storage and accrual over time are the main tools to understand rehabilitation success.
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December 2024
Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA.
The supply of nitrogen (N) and the efficiency with which it is used by phytoplankton serve as two fundamental controls on the productivity of many marine ecosystems. Shifts in nitrogen use efficiency (NUE) can decouple primary production from N-supply but how NUE varies across systems is poorly known. Through a global synthesis of how total N (TN) is apportioned among phytoplankton, particulate, dissolved inorganic, and dissolved organic pools, we demonstrate that NUE underlies broad variations in primary production.
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December 2024
Anhui Provincial Key Laboratory of Forest Resources and Silviculture, Anhui Agricultural University, Hefei, 230036, China.
Exploring the components of soil organic carbon (SOC) and aggregate stability across different elevations is crucial to assessing the stability of SOC in subtropical forest ecosystems under climate change. In this study, we investigated the spatial variation of active carbon (C) compositions, aggregate distribution, and stability in Chinese fir (Cunninghamia lanceolata) plantations across an elevation gradient from 750 to 1150 m a.s.
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December 2024
Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Falmouth, USA.
Coral reef sponges efficiently take up particulate and dissolved organic matter (DOM) from the water column and release compounds such as nucleosides, amino acids, and other dissolved metabolites to the surrounding reef via their exhalent seawater, but the influence of this process on reef picoplankton and nutrient processing is relatively unexplored. Here we examined the impact of sponge exhalent on the reef picoplankon community and subsequent alterations to the reef dissolved metabolite pool. We exposed reef picoplankton communities to a sponge exhalent water mixture (Niphates digitalis and Xestospongia muta) or filtered reef seawater (control) in closed, container-based dark incubations.
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December 2024
Grassland Technique Extension Station of Gansu Province, Lanzhou, 730000, Gansu, China.
Near-natural restoration is acknowledged as an effective strategy for enhancing soil organic carbon (SOC) sequestration in degraded grasslands. However, the alterations in SOC fractions, stability, and relative sequestration capacity after restoration of degraded alpine meadows remain uncertain. In this study, we utilized the degraded alpine meadows on the northeastern edge of the Tibetan Plateau as a research area, with grazing as the control (CK) and restoration of 20 years of banned grazing (BG) and growing season resting grazing (RG).
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