Explore the latest insights from top science journals in the Muser Press daily roundup, featuring impactful research on climate change challenges.
In brief:
Decoupled responses of soil microbial diversity and ecosystem functions to successive degeneration processes in alpine pioneer community
Many alpine ecosystems are undergoing vegetation degradation because of global change, which is affecting ecosystem functioning and biodiversity. The ecological consequences of alpine pioneer community degradation have been less studied than glacial retreat or meadow degradation in alpine ecosystems.
Researchers document the comprehensive responses of microbial community characteristics to degradation processes using field-based sampling, and conduct soil microcosm experiments to simulate effects of global change on microorganisms, and explore their relationships to ecosystem functioning across stages of alpine pioneer community degradation.
Their work provides the first evidence that alpine pioneer community degradation led to declines of 27% in fungal richness, 8% in bacterial richness and about 50% of endemic microorganisms. As vegetation degraded, key ecosystem functions such as nutrient availability, soil enzymatic activity, microbial biomass, and ecosystem multifunctionality progressively increased.
However, soil respiration rate and carbon storage exhibited unbalanced dynamics. Respiration rates increased by 190% during the middle stage of degradation compared to the primary stage and decreased by 38% in the later stage. This indicates that soil carbon loss or emission increases during the mid-successional stage, whereas in later successional stages, alpine meadows become significant carbon sinks.
Compared to microbial community characteristics (such as richness of total and functional taxa, network complexity), community resistance contributes more significantly to ecosystem functions. Especially, the bacterial community resistance is crucial for ecosystem functioning, yet it is greatly impaired by nitrogen addition.
Based on microbial network, community assembly, and community resistance analyses, researchers conclude that fungi are more vulnerable to environmental changes and show lower contributions to ecosystem functions than bacteria in degrading alpine ecosystems.
Their findings enhance the knowledge of the distinct and synergistic functional contributions of microbial communities in degrading alpine ecosystems and offer guidance for developing restoration strategies that optimize ecosystem functioning of degraded alpine plant communities.
Journal Reference:
Zhang, Y., Hogan, J.A., Ye, Y. et al., ‘Decoupled responses of soil microbial diversity and ecosystem functions to successive degeneration processes in alpine pioneer community’, Science China Life Sciences (2025). DOI: 10.1007/s11427-024-2692-5
Article Source:
Press Release/Material by Science China Press
Tree diversity increases carbon sequestration
Forests with many tree species can store significantly more carbon than those with only one species: An international study led by the University of Freiburg, published in Global Change Biology, supports this finding using data from the world’s oldest tropical tree diversity experiment.
Researchers found that forests planted with five tree species had substantially higher aboveground carbon stocks and greater fluxes between the carbon stores than monocultures. The results highlight the benefits of mixed-species forests for forest restoration initiatives that aim at mitigating climate change through carbon sequestration.
New data from the world’s longest-running experiment on tropical tree diversity
Growing evidence suggests that tree diversity enhances ecosystem functions like carbon sequestration. However, previous studies struggled to isolate this effect from other factors or focused on young plantations, making it uncertain whether the findings applied to older forests. To address this, the researchers analysed data from the world’s longest-running tropical tree diversity experiment, located in Panama.
The Sardinilla experiment, established in 2001 on a former pasture, comprises 22 plots with one, two, three or five native tree species, which have reached a comparatively advanced stage of stand development due to the rapid growth of trees in the tropics. The team examined data related to a range of different carbon stocks and fluxes ranging from carbon in aboveground tree biomass to carbon in leaf litter and in mineral soil.
The scientists found that planted forests with five tree species had significantly higher aboveground carbon stocks and greater carbon fluxes than those with only one species. For instance, the species-rich forests captured 57% more carbon in aboveground tree biomass than monospecific forests. However, there were no differences in carbon stocks and fluxes belowground.
Diverse forests sequester more carbon – even through hurricanes and droughts
Remarkably, the positive tree diversity effect on aboveground carbon stocks strengthened over time, despite repeated climatic extreme events such as a severe El Niño-driven drought and a hurricane that hit the experiment.
“This is important, because in the face of climate change, the long-term carbon balance of forests will depend largely on their stability to disturbances. Diverse forests exhibit greater ecological stability and the risk that the stored carbon is released back to the atmosphere is lower than in monocultures,” said Dr. Florian Schnabel, first author of the study, forest scientist at the University of Freiburg’s Faculty of Environment and Natural Resources, and head of the Sardinilla experiment.
More tree species, greater climate benefits
According to the researchers, these results show that tree mixtures should be preferred over monocultures in projects that plant new forests to sequester carbon. However, the team also emphasises that it is important to remain realistic about the potential of new forests to contribute towards mitigating climate change.
“The average yearly net CO2 uptake of the planted forests was 5.7 tonnes CO2 equivalents per ha and year. It would thus need one-year tree growth on 11 ha of this type of forest to compensate for the emissions of a single one-way flight between Frankfurt and Panama City,” said Dr. Catherine Potvin, head of the Sardinilla experiment until 2024 and co-initiator of the study, from McGill University in Montréal, Canada.
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Dr. Florian Schnabel is a forest scientist at the Faculty of Environment and Natural Resources at the University of Freiburg and head of the Sardinilla experiment. His research focuses on the relationships between biodiversity and ecosystem functions of forests, sustainable forest management in the face of global change and the effects of climate extremes on forests. He is an Associate Investigator of the Future Forests Cluster of Excellence initiative.
The Sardinilla experiment is part of TreeDivNet, the world’s largest network of tree diversity experiments.
Journal Reference:
Schnabel, F., Guillemot, J., Barry, K.E., Brunn, M., Cesarz, S., Eisenhauer, N., Gebauer, T., Guerrero-Ramirez, N.R., Handa, I.T., Madsen, C., Mancilla, L., Monteza, J., Moore, T., Oelmann, Y., Scherer-Lorenzen, M., Schwendenmann, L., Wagner, A., Wirth, C., Potvin, C., ‘Tree diversity increases carbon stocks and fluxes above- but not belowground in a tropical forest experiment’, Global Change Biology 31: e70089 (2025). DOI: 10.1111/gcb.70089
Article Source:
Press Release/Material by University of Freiburg
Study reveals Africa will reach 1.5 °C climate change threshold by 2040 even under low emission scenarios
New research highlighted in the journal CABI Reviews suggests that all five subregions of Africa will breach the 1.5 °C climate change threshold – the limit stipulated by the Paris Agreement – by 2040 even under low emission scenarios.
A team of scientists, from the University of Zimbabwe, and the International Livestock Research Institute (ILRI) in Kenya, conducted a literature review to develop a framework for just transition pathways for Africa’s agriculture towards low emission and climate resilient development under 1.5 °C of global warming.
They found that despite Africa emitting less than 4% of global greenhouse gas emissions in the atmosphere, the 1.5 °C climate change threshold will be approached by 2040 in all five subregions of Africa, even under low emission scenarios.
Just transition pathways for Africa’s agriculture are urgently required
The scientists stress that just transition pathways for Africa’s agriculture are urgently required for sustainable production systems that enhance food security and poverty reduction, while optimising mitigation co-benefits.
Professor Paul Mapfumo, Vice Chancellor of the University of Zimbabwe and lead author of the paper, said novel climate conditions are posing a serious threat to humanity and ecological systems, presenting and aggravating social injustices at different levels.
Distributive, procedural and recognition injustices include, the scientists say, inherent inequalities, gender disparities or narrow employment opportunities which they argue will be inevitably amplified and reinforced by the changing climate.
Prof Mapfumo said: “African agriculture-based livelihood systems will be invariably the most affected because of their reliance on climate-sensitive agriculture and limited adaptive capacity due to low economic development linked primarily to historical contingency.
“They have experienced considerable losses and damages from climate change, and this will worsen with increasing intensity of climate hazards.
“Neither the existing or planned incremental adaptation mechanisms, nor the anticipated benefits of migratory measures, are sufficiently comprehensive to match the pending novel climate conditions.”
Reprogramming of the cropping, livestock and fishery systems for climate proofing
Prof Mapfumo and his colleagues argue that the just transition pathways for Africa’s agriculture should be anchored on reprogramming of the cropping, livestock and fishery systems for climate proofing with a specific focus on a range of underpinnings.
These include financing the advancement of science, technology and innovation; restoring neglected or underutilised crops and livestock genetic pools; regenerating soil fertility and advancing soil health; restoring degraded land; protecting natural ecosystems and biodiversity; accessing quality education training and information technologies; and developing markets and creating novel distribution and trade opportunities.
Prof Mapfumo added: “Such efforts should also focus on mechanising and greening Africa’s agriculture as driven by a deliberate ‘Green Industrial Revolution’ for the new normal induced by climate change.
“Sustainability of climate change response and a just transition pathway framework for Africa also lies in corresponding transformation of education systems and research capacities tailored to drive economic development for Africa.”
The scientists conclude that the developed just transition framework offers opportunities for social inclusion, equity, building capacity for self-mobilisation and self-organisation of communities for climate action, and investments in the transition pathways for building a climate resilient agriculture towards zero poverty and meaningful contribution towards zero carbon.
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The African Group of Negotiators Experts Support (AGNES) funded the study.
Journal Reference:
Mapfumo, Paul; Rurinda, Jairos; Cramer, Laura; Mushore, Terrence D. and Wamukoya, George, ‘Developing just transition pathways for Africa’s agriculture towards low emission and climate resilient development under a 1.5°C global warming’, CABI Reviews (2025). DOI: 10.1079/cabireviews.2025.0006
Article Source:
Press Release/Material by CABI
LA’s urban trees absorb more carbon than expected, USC Dornsife study finds
Los Angeles’ trees are working harder than we thought.
A new study from Public Exchange and USC Dornsife College of Letters, Arts and Sciences finds that some trees in central L.A. absorb significantly more carbon dioxide than expected — offsetting a surprising share of fossil fuel emissions during the warmer months when trees are most active.
The research, recently published in Environmental Science & Technology, provides one of the most detailed measurements to date of how urban trees impact air quality. Researchers found that vegetation in the study area absorbed up to 60% of daytime fossil fuel CO2 emissions in spring and summer and about 30% annually — placing Los Angeles among cities with the highest recorded CO2 uptake rates.
To track CO2 in real time, the research team launched what they call the Carbon Census array, deploying 12 high-resolution BEACO2N sensors across a 15-by-6-mile section of L.A.’s Mid-City. The sensors mapped how CO2 concentrations changed as air moved through the urban landscape, enabling researchers to factor in wind speed and direction and urban density to determine to what extent local greenery was offsetting emissions.
“You can think of emissions like passengers on a train,” said Will Berelson, who led the research and is professor of Earth sciences, environmental studies and spatial sciences at USC Dornsife. “As the wind moves pollution through the city, some gets picked up and some gets dropped off. These sensors let us see that process in real time.”
Unlike some models that estimate CO2 levels based on fuel sales and traffic data and other models that assess the CO2 that lands on a particular sensor, this study, which ran from July 2021 to December 2022, measured CO2 directly, yielding a more precise and localized estimation of emissions.
To differentiate CO2 generate by fossil fuels from CO2 emitted by living organisms, the researchers used CO (carbon monoxide). CO is co-emitted with CO2 when fossil fuels burn, and it has a similar atmospheric behavior.
Although the study focused on a section of L.A., the findings provide valuable insights that could apply to other urban areas.
L.A. trees are helping — but they’re not enough
One of the study’s biggest surprises was that trees absorb the most CO2 during summer, despite it being L.A.’s driest season. Satellite imagery shows L.A.’s urban greenery is remarkably verdant in summer, likely due to irrigation, groundwater access from leaky pipes and resilient tree species.
Still, trees can’t keep pace with emissions. As expected, CO2 levels spiked during rush hour, reinforcing the fact that, while greenery helps, it can’t offset pollution from cars, buildings and industry on its own.
The study’s findings help inform the USC Urban Trees Initiative, a partnership between USC, the City of Los Angeles and community-based organizations focused on expanding urban greenery in communities that need it most. By identifying where trees absorb the most carbon, the research provides data-driven insights that could help guide future planting efforts.
“Nature is helping us,” Berelson said, “but we can’t rely on it to do all the work.” In fact, the study estimates that urban vegetation absorbs only about 30% of annual fossil fuel emissions in the study area, underscoring the urgent need for clean energy, improved public transit and broader emissions reductions.
Looking ahead to more carbon emissions tracking
Building on the study’s success, the USC team has expanded its sensor network, adding eight more of the BEACO₂N sensors to the east of the original study area and west into Santa Monica. These sensors, developed as part of the University of California, Berkeley’s BEACO2N project, provide high-resolution emissions data rarely available in urban areas.
“Our goal is to monitor more areas of L.A. to define baseline values of CO2 emission and identify where vegetation is making the biggest impact and where more greenery is needed,” explained Berelson, who holds the Paxson H. Offield Professor in Coastal and Marine Systems.
He believes this real-time monitoring approach could serve as a blueprint for cities worldwide to track and reduce emissions more effectively.
Los Angeles has set a goal to become carbon-neutral by 2050, and while its urban greenery provides a natural boost, Berelson stresses that cutting fossil fuel use remains the most critical step in fighting climate change.
Journal Reference:
Jinsol Kim, William M. Berelson, Nick Everett Rollins, Naomi G. Asimow, Catherine Newman, Ronald C. Cohen, John B. Miller, Brian C. McDonald, Jeff Peischl, and Scott J. Lehman, ‘Observing Anthropogenic and Biogenic CO2 Emissions in Los Angeles Using a Dense Sensor Network’, Environmental Science & Technology 59 (7), 3508-3517 (2025). DOI: 10.1021/acs.est.4c11392
Article Source:
Press Release/Material by University of Southern California
Featured image credit: Gerd Altmann | Pixabay
