Article
Ecology
Gustaf Granath, Christopher D. Evans, Joachim Strengbom, Jens Folster, Achim Grelle, Johan Stromqvist, Stephan J. Kohler
Summary: This study found that wildfires result in significant direct losses of C and N elements in ecosystems, with soil respiration and aquatic losses also playing important roles. While aquatic C and N losses were minor and did not increase post-fire, other elements like Ca and S showed ecologically relevant increases in fluvial export and concentration. The study also highlighted the presence of faster and slower-release nutrient pools in stream concentrations, with nutrient fluxes largely returning to pre-fire conditions three years after the fire.
Article
Biodiversity Conservation
Dawid Kupka, Piotr Gruba
Summary: This study revealed that forest soils have different sorption capacities for DOC released from litter of different tree species under varying pH conditions, indicating the significant effects of soil pH and litter chemical composition on DOC stabilization.
ECOLOGICAL INDICATORS
(2022)
Article
Geosciences, Multidisciplinary
Hewen Niu, Shichang Kang, Chandan Sarangi, Guotao Zhang, Mengxue Chen, Yuzhong Zhang, Huili Qin
Summary: This study systematically determines the organic and inorganic constituents in water bodies of the cryosphere region in the eastern Tibetan Plateau and finds that high-elevation water bodies have lower organic carbon content. Additionally, it suggests that atmospheric deposition and anthropogenic activities contribute to the observed patterns in organic carbon and nitrogen content.
Article
Environmental Sciences
Xinyuan Wei, Daniel J. Hayes, Ivan Fernandez
Summary: Fires can significantly impact the flux of dissolved organic carbon (DOC) from soils, leading to an immediate decrease in riverine DOC concentration draining the watershed by 26 +/- 15%, with an average recovery time of approximately 9 months. The larger the proportion of the watershed that burned, the greater the concentration decrease and the longer the post-fire recovery period.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Forestry
Jianfeng Hou, Fei Li, Zhihui Wang, Xuqing Li, Rui Cao, Wanqin Yang
Summary: Dissolved carbon (DC) in forest streams plays a crucial role in maintaining the structure and productivity of adjoining aquatic ecosystems as well as informing biogeochemical links between mountain forests and adjoining rivers. However, the functions of forest stream DC dynamics are rarely incorporated into river management. This study investigated the seasonal dynamics of DC in 15 representative forest streams in a geographically fragile subalpine-gorge catchment in the upper reaches of the Yangtze River. The results showed that precipitation, temperature, water discharge rate, and sediment depth regulated the stocks and export rates of DC and its components. Forest streams are important links between the carbon biogeochemical cycle of subalpine forests and adjoining streams.
Article
Environmental Sciences
Peidong Xu, Lei Shi, Xin Yang, Haoming Yang, Kuanhu Dong, Changhui Wang
Summary: Soil dissolved organic matter (DOM) plays a critical role in regulating the cycling of terrestrial biogeochemistry. N addition significantly increased soil DOM concentration, with a greater impact on dissolved organic nitrogen (DON) than dissolved organic carbon (DOC). The level of N addition was positively correlated with soil DOC and DON concentrations, and the influence of N addition on soil DOC concentration decreased with higher initial soil total nitrogen (TN). Mean annual precipitation (MAP) facilitated the leaching out of soil DON and had a negative impact on its concentration under N addition. Increased soil depth and initial soil pH affected the soil DOC and DON concentrations, with DOC accumulating in the top soil and DON leaching to deeper soil. This study provides a mechanistic understanding of the influence of N addition on terrestrial ecosystem C and N dynamics at the regional scale.
LAND DEGRADATION & DEVELOPMENT
(2023)
Article
Environmental Sciences
Mengyue Wu, Yini Ma, Huixiang Xie, Rong Ji
Summary: Photodissolution has the potential to efficiently remove microplastics from the surface ocean, and temperature and incident sunlight composition play critical roles in this process.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Adam S. Wymore, Penny J. Johnes, Susana Bernal, E. N. Jack Brookshire, Hannah M. Fazekas, Ashley M. Helton, Alba Argerich, Rebecca T. Barnes, Ashley A. Coble, Walter K. Dodds, Shahan Haq, Sherri L. Johnson, Jeremy B. Jones, Sujay S. Kaushal, Pirkko Kortelainen, Carla Lopez-Lloreda, Bianca M. Rodriguez-Cardona, Robert G. M. Spencer, Pamela L. Sullivan, Christopher A. Yates, William H. McDowell
Summary: A comprehensive assessment of nitrogen species in stream water reveals shifts in dissolved nitrogen pool composition from highly heterogeneous to primarily inorganic nitrogen under nutrient enrichment from human disturbances. With increasing total dissolved nitrogen concentrations, inorganic nitrogen dominates the pool while dissolved organic nitrogen decreases. These changes in stoichiometry may have significant implications for global biogeochemical cycles of carbon and nitrogen in freshwater ecosystems.
GLOBAL BIOGEOCHEMICAL CYCLES
(2021)
Article
Environmental Sciences
John H. Trefry, Austin L. Fox
Summary: This study showed that the concentrations of nitrogen and phosphorus in different tributaries increased with flow during heavy storm events, with statistically significant equations used to describe the relationship between concentration and flow rate. The different land uses in the drainage basins resulted in varying fluxes per square km, with higher yields of dissolved organic nitrogen and dissolved inorganic phosphorus in the tributary with thicker, more organic- and P-rich soils.Additionally, major weather events such as drought followed by excess rain and flooding were found to impact the nutrient fluxes and subsequent algal blooms in the Indian River Lagoon.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Engineering, Civil
Ewen Silvester, Terry Karis, Anne Yusuf, John Pengelly, Samantha Grover, Gavin N. Rees
Summary: The study found that storm events mobilized dissolved organic carbon and nitrogen, with proteins playing a key role and exhibiting different dynamics at different stages of the storm. This suggests that there is spatial and temporal separation of molecular groups within the pools of dissolved organic carbon and nitrogen, leading to changing composition of DOC through a storm cycle.
JOURNAL OF HYDROLOGY
(2021)
Article
Environmental Sciences
Daniel Graeber, Youngdoung Tenzin, Marc Stutter, Gabriele Weigelhofer, Tom Shatwell, Wolf von Tuempling, Jorg Tittel, Alexander Wachholz, Dietrich Borchardt
Summary: We investigated the macronutrient-access hypothesis, which suggests that the balance between stoichiometric macronutrient demand and accessible macronutrients controls nutrient assimilation by aquatic heterotrophs. In a proof-of-concept experiment, we found that the ratios of bDOC:reactive N and bDOC:reactive P exerted a strong, predictable stoichiometric control on nutrient uptake. The study provides insights into the ecological stoichiometry and biogeochemistry of nutrient uptake in freshwater ecosystems, but further experiments are needed to validate the hypothesis.
Article
Ecology
Yang Yang, Stephen C. Hart, Emma P. McCorkle, Erin M. Stacy, Morgan E. Barnes, Carolyn T. Hunsaker, Dale W. Johnson, Asmeret Asefaw Berhe
Summary: Researchers analyzed water samples from eight low-order and mixed-conifer watersheds in the Sierra Nevada, California over five years to understand the temporal variation of water chemistry, finding that stream concentrations of DOC and dissolved N in Mediterranean headwater basins are highly variable over time due to climatic variabilities and management practices.
Article
Environmental Sciences
William H. McDowell
Summary: Dissolved organic matter (DOM) is a heterogeneous mixture of organic compounds that is produced through microbial degradation and abiotic leaching, and it plays an important role in aquatic ecology and watershed management. The challenges in studying DOM include monitoring long-term changes, using sensors for short-term dynamics, understanding its role in the carbon cycle and greenhouse gas evasion, and exploring its evolutionary significance in various environments.
Article
Forestry
Viktor V. Startsev, Evgenia Yakovleva, Ivan N. Kutyavin, Alexey A. Dymov
Summary: Fires have significant impacts on boreal ecosystems, including changes in soil properties and accumulation of pyrogenic carbon. This study investigated the effects of old fires on soils and soil organic matter in spruce forests and found that fires can lead to variations in soil characteristics and the presence of pyrogenic carbon.
Article
Environmental Sciences
Guoxiang Niu, Gege Yin, Xiaohan Mo, Qinggong Mao, Jiangming Mo, Junjian Wang, Xiankai Lu
Summary: This study investigates the impact of long-term nitrogen (N) inputs on soil dissolved organic matter (DOM) composition. The results demonstrate that N additions significantly alter DOM characteristics and increase recalcitrant DOM components, which benefits soil organic carbon (SOC) storage.
ENVIRONMENTAL RESEARCH LETTERS
(2022)