Early spring is good for trees, bad for bees: research
As some Canadians in some parts of the country face lots of snow and severe winter storms, most of them look forward to brighter and warmer days in the spring.
And while spring may not come as quickly as some hope this year, it could be a blessing or a curse for some aspects of the environment, according to two studies. separate rescue.
Early spring can be good for plants, while bad for bees, according to Lund University research, North Carolina State University researchers say.
EARLY SPRING CAN BE GOOD FOR PLANTS
If spring arrives earlier in the year, researchers from North Carolina State University say it could affect the amount of leaves a tree produces, and thus increase the amount of carbon the tree can capture and store in photosynthesis process.
In the study published in Global Biogeochemical Cycles, the authors note that the amount of leaves a plant can produce is called “green,” while the decline in vegetation growth is called is “brown”.
The researchers used satellites to measure the “greenness” of plants between 2000 and 2014 as well as sensors to calculate how much carbon the plants remove from the atmosphere each year during photosynthesis .
Study co-author Josh Gray, an associate professor of forestry and environmental resources at North Carolina State University, says climate change is the biggest reason for the difference in “green” and “brown color”. ” every year.
“As we work to predict future climate, one big question is: What will happen to vegetation, one of the largest carbon stores on earth?” Gray said. “We know temperatures will increase and growing seasons will be longer in most places, but there are still many unknowns about how that will affect the carbon cycle between plants and the atmosphere. Our new results allow us to be more confident about what those changes will look like.”
In addition to when seasons begin and how long they last, Gray said warmer weather could hamper photosynthesis and contribute to the growth of new plants in some parts of the world.
Xiaojie Gao, a graduate student at North Carolina State’s Center for Geospatial Analysis and first author of the study, said an earlier spring could be good for plants because they have a better photoperiod. compound longer and increase the amount of carbon they can capture.
“However, a longer fall could make the situation worse. In the fall, plants tend to release carbon,” says Gao.
The study concluded that “greening” trends are more important for “carbon uptake”—the amount of carbon that plants can take up—than changes in the length of the seasons.
“There are some places where we have more leaves than before, especially in the higher latitudes,” says Gray. “There are also places where spring can come early, autumn can come late. All of these changes affect the amount of photosynthesis taking place, but the amount of leaves a plant produces is more strongly linked to carbon uptake than changes in the length of the growing season.”
Bad news for cows
Meanwhile, a new study from Sweden’s Lund University shows that the queen bee is ending hibernation earlier in the year due to climate change.
Queen bees are the only bees that survive the winter by hibernating, after which they fly off in search of a nest to lay eggs and start building colonies.
According to the study, rising temperatures caused by climate change could lead to an earlier spring arrival that causes bees to wake up earlier—an average of five days earlier than 20 years ago.
This phenomenon increases the risk of further loss of wasp species and reduces the ability of crops and wild plants to pollinate, said researcher Maria Blasi Romero.
“Across Sweden, we found that rising temperatures due to climate change clearly affect the time when queens wake up and fly off to find new nests,” said Romero.
However, warmer weather earlier in the year is not the only reason for the changes in bee behaviour. The study notes that the loss of grasslands and pastures in Sweden over the past century is another major factor.
Scientists who looked at the queen wasp 117 years ago, have found that the first flights of bumblebees in intensively farmed areas now take place about two weeks earlier than more than 100 years. before.
In addition, of the 10 bee species the researchers looked at, those that started flying as early as spring now started flying earlier, while others didn’t change when they ended their dormancy. winter.
This risks leading to wasps not getting enough food and a mismatch between when plants flower and when bees are active, says researcher Anna S Persson.
“We see a clear risk that many species of wasps are at risk of local extinction, especially those that typically emerge in late summer. This could also lead to a decline in wasp populations in general and that would have consequences for crop pollination and the functioning of ecosystems. Wasps are important pollinators, especially in northern latitudes like Scandinavia,” says Persson.
There are a number of ways to help reduce the impact of climate change on pollinators like bumblebees, the Lund University researchers added, including conserving natural grasslands, mowing roadside grasses, and mowing down roads. late in the season after the flowering period, design flower bands and hedges in a way that favors pollinators and increase seeding of partially flowering clover.