The majority of the Earth’s plant species rely on animal pollinators to reproduce, and our modern agricultural industry is heavily reliant on honey bees. Feral honey bees, which are non-native and often escape human management, can perturb native ecosystems when they become abundant. A new study by University of California San Diego biologists is calling attention to the threat posed by these feral honey bees to native pollinators in Southern California.

The researchers found that honey bees remove about 80% of pollen during the first day a flower opens, leaving scant resources for native bees. If the pollen and nectar used to create honey bee biomass were instead converted to native bees, populations of native bees would be expected to be roughly 50 times larger than they are currently.

While public concern often focuses on the plight of the honey bee, researchers say that such a level of honey bee exploitation is not well documented. This can pose an additional and important threat to native bee populations in places where honey bees have become abundant.

The study used pollen-removal experiments to estimate the amount of pollen extracted by honey bees using three common native plants as targeted pollen sources. The researchers found that just two visits by honey bees removed more than 60% of available pollen from flowers of all three species.

One step to address this situation could be increased guidance on whether and where large-scale contract beekeepers are allowed to keep their hives on public lands after crops have bloomed, to limit opportunities for honey bees to outcompete native species for scarce resources provided by native vegetation.

The Fig Trees That Fight Climate Change: A Revolutionary Carbon-Sequestering Mechanism

In a groundbreaking discovery, researchers have found that certain species of fig trees possess an extraordinary ability – they can turn themselves into stone, literally. This remarkable phenomenon, known as the oxalate-carbonate pathway, allows these trees to draw carbon dioxide from the atmosphere and store it in the surrounding soil as calcium carbonate rocks.

The research team, comprising scientists from Kenya, the US, Austria, and Switzerland, has been studying this unique ability of fig trees. They found that by using CO2 to create calcium oxalate crystals, which are then converted into calcium carbonate by specialized bacteria or fungi, these trees can sequester inorganic carbon more effectively than their counterparts that store organic carbon.

Dr. Mike Rowley, a senior lecturer at the University of Zurich, is leading the research effort. He explained that while trees have long been recognized for their ability to absorb CO2 through photosynthesis, the oxalate-carbonate pathway offers an additional benefit – the sequestration of inorganic carbon in the form of calcium carbonate.

This discovery has significant implications for climate change mitigation efforts. By choosing trees with this unique ability for agroforestry, we can not only produce food but also sequester more CO2 from the atmosphere. The team’s research highlights the potential for these trees to play a crucial role in reducing greenhouse gas emissions.

The study, which was presented at the Goldschmidt conference in Prague, focused on three species of fig trees grown in Samburu County, Kenya. The researchers identified how far from the tree the calcium carbonate was being formed and identified the microbial communities involved in the process.

One of the key findings was that Ficus wakefieldii, a specific type of fig tree, was the most effective at sequestering CO2 as calcium carbonate. The team is now planning to assess the suitability of this tree for agroforestry by quantifying its water requirements and fruit yields and conducting a more detailed analysis of how much CO2 can be sequestered under different conditions.

This research has far-reaching implications, not only for climate change mitigation but also for our understanding of the complex relationships between trees, microorganisms, and the environment. As Dr. Rowley noted, “There are many more species of trees that can form calcium carbonate, so this pathway could be a significant, underexplored opportunity to help mitigate CO2 emissions as we plant trees for forestry or fruit.”

The European Alps, known for their breathtaking beauty and harsh weather conditions, are expected to become even more treacherous in the years to come. A recent study by scientists at the University of Lausanne (UNIL) and the University of Padova has found that climate change is supercharging summer storms in the region, leading to an increased risk of flash floods.

The researchers analyzed data from nearly 300 weather stations across Switzerland, Germany, Austria, France, and Italy. They discovered that a 2°C rise in regional temperature could double the frequency of short-lived summer rainstorms, making them more intense and destructive.

One such extreme event occurred in June 2018, when the city of Lausanne experienced an intense rainfall episode, with 41 millimeters of precipitation falling in just 10 minutes. The resulting flood caused estimated damage of 32 million Swiss Francs and left a trail of destruction in its wake.

These short-lived events are still rare in Switzerland today but are likely to become more frequent as the climate warms. Warm air retains more moisture, intensifying thunderstorm activity, and the Alpine region is warming faster than the global average. This makes it particularly vulnerable to the impacts of climate change.

The scientists developed a statistical model incorporating physics principles to establish a link between temperature and rainfall frequency. They then used regional climate projections to simulate the future frequency of extreme precipitation events.

Their results show that an increase of just 1°C would already be highly problematic, with sudden and massive arrival of large volumes of water triggering flash floods and debris flows. This can lead to infrastructure damage and casualties, making it essential to understand how these events may evolve with climate change.

“We need to plan appropriate adaptation strategies, such as improving urban drainage infrastructure where necessary,” warns Nadav Peleg, researcher at UNIL and first author of the study.

Francesco Marra, researcher at UNIPD and one of the main authors of the study adds: “An increase of 1°C is not hypothetical; it’s likely to occur in the coming decades. We are already witnessing a tendency for summer storms to intensify, and this trend is only expected to worsen in the years ahead.”

The findings of this study should serve as a wake-up call for policymakers and residents of the Alpine region to take action now and prepare for the increased risk of flash floods brought about by climate change.