New insights into divergent nitrogen fixation in subtropical forests
2025-07-07
(Press-News.org)
Nitrogen fixation is a critical ecological process that converts atmospheric nitrogen into bioavailable forms, essential for plant growth and carbon sequestration. This study, published in Forest Ecosystems, focused on two primary forms of biological nitrogen fixation (BNF): symbiotic nitrogen fixation (SNF), which occurs within the root nodules of nitrogen-fixing plants, and asymbiotic nitrogen fixation (ANF), which is carried out by free-living microorganisms in soil and litter. Understanding the environmental controls on these processes is crucial for predicting how ecosystems will respond to changing conditions.
The research was conducted in the Chebaling National Nature Reserve in Guangdong Province, China. The team examined two altitudinal gradients in forests with different parent materials—granite and slate. They collected soil, litter, moss, and leaf samples from 19 sites across 57 plots, measuring SNF and ANF rates using established methods.
The study revealed that SNF rates consistently declined with increasing altitude, driven by increased soil nitrogen availability and decreased air temperature. In contrast, ANF rates exhibited a hump-shaped pattern, initially increasing at lower altitudes but decreasing at higher altitudes. This divergence suggests that different factors regulate SNF and ANF, with soil properties such as phosphorus, iron, and moisture influencing ANF at lower altitudes, while climatic factors like air temperature become more significant at higher altitudes.
Regarding different parent materials, SNF rates were higher on granite than on slate, whereas ANF rates exhibited the opposite trend. It demonstrated that lithology is also an important driver for both SNF and ANF, shaping their divergent patterns through differences in soil nutrient availability.
These findings underscore the importance of distinguishing between SNF and ANF in ecological studies and Earth system models. “By identifying the shifts in controlling factors along altitudinal gradients—from soil nutrients to climatic drivers—our study provides valuable insights for assessing N fixation dynamics in diverse ecosystems.”, the study concludes. The results also highlight the role of lithology and climate in shaping nitrogen fixation processes, emphasizing the need for spatially specific approaches in future research.
END
ELSE PRESS RELEASES FROM THIS DATE:
2025-07-07
Immune checkpoint pathways regulate T cell function and play pivotal roles in the treatment of both cancer and autoimmune diseases. One key component of these pathways is Lymphocyte Activation Gene 3 (LAG-3)—a classical immunosuppressive receptor that has long posed unresolved questions regarding its biological mechanisms.
In a new study published on June 30 in Cell, researchers from the Institute of Biophysics of the Chinese Academy of Sciences, the Grossman School of Medicine at New York University, and the School of Medicine at Zhejiang University have ...
2025-07-07
A pairing of two experimental drugs inhibits tumor growth and blocks drug-induced resistance in ovarian cancer, according to a preclinical study led by Weill Cornell Medicine investigators. The research reveals a promising strategy against this hard-to-treat malignancy, and more generally demonstrates a powerful new approach for the identification of effective regimens to treat genetically diverse cancers.
Ovarian cancer is genetically diverse in the sense that it can be driven by mutations in many different genes. This complicates the standard strategy of developing drugs to target common driver mutations. In the study, published July 7 in Cell Reports Medicine, the researchers applied a ...
2025-07-07
“Space ice” contains tiny crystals and is not, as previously assumed, a completely disordered material like liquid water, according to a new study by scientists at UCL (University College London) and the University of Cambridge.
Ice in space is different to the crystalline (highly ordered) form of ice on Earth. For decades, scientists have assumed it is amorphous (without a structure), with colder temperatures meaning it does not have enough energy to form crystals when it freezes.
In the new study, ...
2025-07-07
About The Study: The health of U.S. children has worsened across a wide range of health indicator domains over the past 17 years. The broad scope of this deterioration highlights the need to identify and address the root causes of this fundamental decline in the nation’s health.
Corresponding Author: To contact the corresponding author, Christopher B. Forrest, MD, PhD, email forrestc@chop.edu.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jama.2025.9855)
Editor’s Note: Please see the article for additional information, including other authors, author ...
2025-07-07
About The Study: In this randomized double-blind clinical trial of healthy adults administered cannabidiol (CBD), 5 mg/kg/d for 28 days, 8 (5.6%) experienced liver enzyme level elevations and 7 (4.9%) met protocol defined criteria for potential drug-induced liver injury. Participants did not experience clinical symptoms related to liver function during this 28-day study and hepatic enzymes returned to normal within 1 to 2 weeks following discontinuation. The findings of this study underscore the need for further investigation on the long-term effects of CBD use, its impact on various populations, and the safety of lower doses ...
2025-07-07
A team of Chinese researchers led by Prof. GAO Caixia from the Institute of Genetics and Developmental Biology (IGDB) of the Chinese Academy of Sciences has developed a groundbreaking method that could transform the field of protein engineering. The new approach, called AI-informed Constraints for protein Engineering (AiCE), enables rapid and efficient protein evolution by integrating structural and evolutionary constraints into a generic inverse folding model—without the need to train specialized artificial intelligence (AI) models.
The study, published in Cell on July 7, addresses many of the challenges ...
2025-07-07
Scientists at the Jules Stein Eye Institute at the David Geffen School of Medicine at UCLA have discovered that certain retinal cells can rewire themselves when vision begins to deteriorate in retinitis pigmentosa, a genetic eye disease that leads to progressive blindness. In a study using mouse models, researchers found that rod bipolar cells, neurons that normally receive signals from rods that provide night vision, can form new functional connections with cones that provide daytime vision when their usual partners stop working. The study appears in Current Biology.
Why it matters
Retinitis pigmentosa affects millions of people worldwide and is a leading cause of inherited ...
2025-07-07
A study led by Cambridge researchers has shed light on how neural stem cell grafts could help restore myelin in the central nervous system. The findings suggest that neural stem cell-based therapies hold promise as a potential treatment for chronic demyelinating disorders, particularly progressive multiple sclerosis.
Multiple sclerosis (MS) is an autoimmune disease where the body's immune system mistakenly attacks the central nervous system, leading to the destruction of myelin, the protective sheath surrounding nerve fibres. This damage is a leading cause of neurological disability in young adults.
In the early stages ...
2025-07-07
Highlights:
Mosquitoes that carry pathogens often develop resistance to insecticides.
Biopesticides offer an ecologically friendly way to control the pests and mitigate resistance, but options are limited.
Researchers recently identified bacteria in Crete producing metabolites that quickly kill mosquito larvae in lab tests.
The compounds might be useful for the development of new biopesticides, though developing the right formulations and delivery method remains a challenge.
Washington, D.C.—Mosquito-borne diseases kill more than 700,000 people every year, according to the World Health Organization, ...
2025-07-07
UCLA Health researchers have identified four distinct pathways that lead to Alzheimer's disease by analyzing electronic health records, offering new insights into how the condition develops over time rather than from isolated risk factors.
The study, published in the journal eBioMedicine, examined longitudinal health data from nearly 25,000 patients in the University of California Health Data Warehouse and validated findings in the nationally diverse All of Us Research Program. Unlike previous ...
LAST 30 PRESS RELEASES:
[Press-News.org] New insights into divergent nitrogen fixation in subtropical forests
