You probably think of devastating floods, raging wildfires, and parched land when you think of climate change. Many of us would not associate the vibrant wildflowers in nearby meadows with climate change. However, a recent study published in the journal Frontiers in Plant Science suggests that the future of these lovely blooms may be bleak in the face of global warming.
This ground-breaking study, conducted in the United Kingdom, discovered that the abundance of wildflowers across Northern Europe would likely decline by up to 40%. The researchers simulated the warmer, wetter conditions predicted for the region as a result of climate change in the experimental study.
Findings of Research:
Some plant species produced flowers with 60% less nectar and fewer or lighter seeds under this new scenario. Because of these changes, pollinating insects had to visit more flowers in order to gather the necessary pollen and nectar, and they had to visit each flower more frequently.
"Our findings show that climate change could have serious consequences for some wildflower species and their pollinators in agricultural systems and that their community composition is likely to change in the future," said lead author Ellen D. Moss, a research associate at Newcastle University in the United Kingdom.
Previous climate change research has focused on a small number of plants or pollinating insects in a specific region, rather than the effects on a community level.
"This study adds to the body of evidence that pollinators are under threat from multiple stressors," said Trinity College Dublin ecologist Jane Stout, who was not involved in the study. "They are losing feeding and breeding grounds, and they are stressed by pesticides, disease, and climate change."
To accomplish this, the researchers planted spring wheat and a few native wildflowers that grow on wheat farms in small agricultural plots on a farm in North Yorkshire. They then heated some of these plots with infrared heaters to raise the soil temperature by 1.5° Celsius (2.7° Fahrenheit), and they increased the water supply by 40% to simulate the wetter conditions predicted for Northern Europe as a result of future climate change. The non-heated plots served as a control in their experiments, with which they compared their results.
The researchers tracked the different plant species that grew in these plots for two flowering seasons, 2014 and 2015, as well as the number of flowers they produced, the volume of nectar in them, and the weight of the dried seeds produced by the flowers.
They also gathered data on visiting insect pollinators, such as their patterns of visitation to both the experimental and control plots.
In 2014, the study found 25 plant species and 80 insect species, and in 2015, it found 19 plant species and 69 insect species. Higher temperatures and more precipitation had no effect on the species found in the plots, with corn marigold (Glebionis segetum), cornflower (Centaurea cyanus), common field-speedwell (Veronica persica), shepherd's purse (Capsella bursa-pastoris), chickweed (Stellaria media), and red dead-nettle being the most abundant (Lamium purpureum).
The study also discovered significant changes in pollinator feeding behaviour in the heated plots. Hoverflies, honeybees, and bumblebees, the most abundant insects, visited more flowers and increased the frequency with which they returned to the same flower to collect nectar and pollen.
Gloomy Future for Blooms
Due to land-use changes for agriculture, housing, and construction, two out of every five plants, including wildflowers, are threatened with extinction worldwide. In California, which is experiencing increasingly hotter and drier winters as a result of climate change, studies have found that wildflower species have declined by 15% in the last 15 years.
The extinction of wildflowers affects thousands of insect species, including pollinators such as bees and herbivores such as aphids, grasshoppers, and caterpillars. It also affects populations of natural pest controllers such as spiders, ladybirds, and lacewings that seek refuge in meadows. According to studies, a quarter of known bee species have not been seen since the 1990s, and habitat loss is one of the primary causes of the decline.
"Climate change threatens crop pollination and our own food supply, but perhaps more concerning is the threat to wild plant pollination and our ecosystems, as well as all the other benefits we derive from them," Stout explained.
Combating climate change by rapidly reducing emissions would save at least some of the blooms, but there are other steps that can be taken in the meantime to avoid a disastrous future for wildflowers.
"The main things that will improve ecosystem resilience in the context of wildflowers and pollinators are habitat quantity, quality, and connectivity," Moss explained. "We need to leave more wild spaces for native plants and insects, and we need to try to connect these areas so that these patches of high-quality habitat are not too small or too far apart."
