Tag: Biodiversity

Climate crisis forecasts a fragile future for wildflowers and pollinators

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A meadow of wildflowers, an important source of food for pollinating insects. Image by Ralphs_Fotos via Pixabay.
A meadow of wildflowers, an important source of food for pollinating insects. Image by Ralphs_Fotos via Pixabay.

By Spoorthy Raman, Mongabay (CC BY-ND 4.0).

  • A first-of-its-kind experimental study has found that climate change reduces the abundance of wildflowers and causes them to produce less nectar and fewer and lighter seeds.

  • These changes also impact pollinating insects visiting the flowers: they have to visit more flowers, more frequently, to gather the required food.

  • Fewer flowers imply reduced reproductive fitness in plants, as well as fewer food resources for invertebrates that rely on these plants for food, habitat and shelter.

  • Overall, climate change may disturb the composition of wildflower species and their pollinators, impacting agricultural crop yields, researchers say.

Think of climate change, and you’ll probably picture devastating floods, raging wildfires, or parched earth. For the environmentally savvy, coral bleaching or masses of refugees may also make it to the list. Not many of us would think of the vibrant wildflowers in nearby meadows as victims of climate change. But the future of these pretty blooms could be gloomy in the face of a warming planet, suggests a recent study published in the journal Frontiers in Plant Science.

This first-of-its-kind study, conducted in the U.K., found that wildflowers across Northern Europe would likely see a steep decline in abundance — up to 40%. In the experimental study, the researchers simulated the warmer, wetter conditions predicted for the region due to climate change. Under this new scenario, some species of plants produced flowers with 60% less nectar and fewer or lighter seeds. Due to these changes, pollinating insects had to visit more flowers to gather the needed pollen and nectar, and visited each flower more frequently.

“Our results demonstrate that climate warming could have severe consequences for some species of wildflowers and their pollinators in agricultural systems, and shows 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 U.K.

While theoretical studies have predicted that climate change could accelerate pollinator losses and wildflower declines, Moss’s study marks the first time scientists have put the theory to the test in an experimental setting. And previous climate change studies have focused on a small number of either plants or pollinating insects in a particular region, and not looked at the effects at a community level.

“This study adds to the weight of evidence that pollinators are at risk from multiple stressors,” said ecologist Jane Stout from Trinity College Dublin, who was not involved in the study. “They are losing places to feed and breed, and they are stressed by pesticides, disease and changes in climate.”

To do this, the researchers sowed spring wheat and a few native wildflowers, which grow on wheat farms, in small agricultural plots in a North Yorkshire farm. They then heated some of these plots with infrared heaters to increase the soil temperature by 1.5° Celsius (2.7° Fahrenheit) and they increased the water supply by 40% to mimic the predicted wetter conditions from future climate change for Northern Europe. The non-heated plots acted as a control in their experiments to compare their results with.

For two flowering seasons, 2014 and 2015, the researchers tracked the different plant species that grew in these plots, the number of flowers they produced, the volume of nectar in them, and the weight of the dried seeds resulting from the flowers. They also collected information about visiting insect pollinators, including their visiting patterns to both the experimental and untouched plots.

The study reported 25 plant species and 80 insect species in 2014, and 19 plant and 69 insect species in 2015. Higher temperatures and more precipitation didn’t change what species were found in the plots, with the most abundant wildflowers being 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 (Lamium purpureum).

Hoping for orange cornflowers next year, or maybe blue poppies. Source: Terry Lucas, CC BY 3.0 via Wikimedia Commons
Hoping for orange cornflowers next year, or maybe blue poppies. Source: Terry Lucas, CC BY 3.0 via Wikimedia Commons.

Not only did wildlife abundance plunge by up to 40% in the heated plots, most of the plants in these plots also had fewer seeds in the seed heads, and the seeds weighed much less than those in non-heated plots. The only exception was the generalist weed known as common field-speedwell. While it produced more and heavier seeds in the heated plots, its flowers secreted 65% less nectar, making it a less popular flower with pollinators.

“A key finding [of the study] is that not all wild plant species respond to experimental manipulation in the same way, and so the implications for plant communities, and their interactions with pollinators, are complex to predict,” Stout said. Nevertheless, the general decrease in both the abundance and the number of seeds produced is of concern, she added, “because loss of floral resources in the landscape is already a major driver of pollinator decline.”

The study also found marked changes in the feeding behavior of pollinators in the heated plots. Hoverflies, honeybees and bumblebees, which were the most abundant insects, visited more flowers, and increased the frequency of their visits to the same flower to collect the nectar and pollen they needed.

“Fewer flowers and less nectar mean less food for pollinators,” Moss said, adding that such conditions may drive competition between pollinators and force them to choose less optimal flowers. “This could reduce their fitness and survival.”

Veronica persica (also known as field-speedwell) is a flowering plant in the plantain family Plantaginaceae. Source: AnRo0002, CC0, via Wikimedia Commons.
Veronica persica (also known as field-speedwell) is a flowering plant in the plantain family Plantaginaceae. Source: AnRo0002, CC0, via Wikimedia Commons.

A gloomy future for the blooms

Worldwide, two in five plants, including wildflowers, are threatened with extinction due to land use change for agriculture, housing and construction. In California, which is experiencing increasingly hotter and drier winters due to climate change, studies have recorded a decline of wildflower species by 15% in 15 years. In the U.K., human activities have destroyed about 97% of wildflower meadows since the 1930s, threatening once commonly seen plants like wild strawberry (Fragaria vesca), harebell (Campanula rotundifolia), and ragged robin (Silene flos-cuculi).

The loss of wildflowers also has a knock-on effect on thousands of insect species, including pollinators like bees and herbivores like aphids, grasshoppers and caterpillars. It also hits populations of natural pest controllers like spiders, ladybirds and lacewings that take shelter in the meadows. Studies show that, worldwide, a quarter of known bee species have not been seen since the 1990s, and loss of habitat is one of the primary reasons for the decline.

“[Climate change] risks crop pollination and our own food supply, but perhaps of more concern is the risk to wild plant pollination and our ecosystems and all the other benefits we get from them,” Stout said.

Tackling climate change by rapidly decreasing emissions would save at least some of the blooms, but in the meantime, there are other steps that could prevent a catastrophic future for wildflowers.

“The main things that will improve ecosystem resilience in the context of wildflowers and pollinators is to improve habitat quantity, quality and connectivity,” Moss said. “We need to leave more wild spaces for native plants and insects and try to connect these areas up so that these patches of high-quality habitat are not too small or too far apart.”

Citations:

Moss, E. D., & Evans, D. M. (2022). Experimental climate warming reduces floral resources and alters insect visitation and wildflower seed set in a cereal agro-ecosystem. Frontiers in Plant Science. doi:10.3389/fpls.2022.826205

(2020). State of the World’s Plants and Fungi 2020. Royal Botanic Gardens, Kew. doi:10.34885/172

Harrison, S. P., Gornish, E. S., & Copeland, S. (2015). Climate-driven diversity loss in a grassland community. Proceedings of the National Academy of Sciences, 112(28), 8672-8677. doi:10.1073/pnas.1502074112

Zattara, E. E., & Aizen, M. A. (2021). Worldwide occurrence records suggest a global decline in bee species richness. One Earth, 4(1), 114-123. doi:10.1016/j.oneear.2020.12.005

Humanity subsidizing ‘our own extinction,’ warns study

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Extinction Rebellion blockade of the Oberbaumbrücke. Credit: Leonhard Lenz, CC0, via Wikimedia Commons
Extinction Rebellion blockade of the Oberbaumbrücke. Credit: Leonhard Lenz, CC0, via Wikimedia Commons

World governments are spending $1.8 trillion annually to support fossil fuel emissions, deforestation, water pollution, and other harms to biodiversity and the planet.

By Julia Conley, Common Dreams (CC BY-NC-ND 3.0)

Releasing a new study showing that world governments spend at least $1.8 trillion annually to subsidize activities which worsen the climate crisis, global subsidies experts on Thursday said leaders must eliminate or redirect the financial supports as part of an ambitious Global Biodiversity Framework at an upcoming summit in China.

“Reforming the $1.8 trillion a year of subsidies that are harming the environment could make an important contribution towards unlocking the over $700 billion a year needed to reverse nature loss by 2030.

The B Team and Business for Nature, two organizations that push businesses around the globe to adopt sustainable practices, supported the study, titled Financing Our Survival: Building a Nature-Positive Economy Through Subsidy Reform.

According to the authors—Doug Koplow of subsidy research firm Earth Track and Ronald Steenblik of the International Institute for Sustainable Development—a lack of transparency regarding the use of subsidies means that the amount of government money being spent on the destruction of nature could be much higher than the research shows.

Photo by Evan Nitschke from Pexels
Photo by Evan Nitschke from Pexels

“Nature is declining at an alarming rate, and we have never lived on a planet with so little biodiversity,” said Christiana Figueres, former executive secretary of the United Nations Framework Convention on Climate Change (UNFCCC) and a member of The B Team. “At least $1.8 trillion is funding the destruction of nature and changing our climate, while creating huge risks for the very businesses who are receiving the subsidies… Harmful subsidies must be redirected towards protecting the climate and nature, rather than financing our own extinction.”

The report identifies at least $640 billion in annual fossil fuel subsidies, $520 billion used by the agricultural sector, $350 billion in water management and wastewater infrastructure, and $155 billion subsidizing logging and unsustainable forest management, all of which account for the majority of annual subsidies.

The equivalent of at least 2% of the global GDP is being spent by governments to finance water pollution and air pollution, soil erosion, deforestation, biodiversity loss, planet-heating fossil fuel emissions, risks to ecosystems in oceans and waterways across the globe, and other harms to nature and humanity, the authors said.

To help finance climate crisis mitigation measures in the Global South—as wealthy nations pledged they would in 2009, promising $100 billion annually—and redirect government funds toward a transition to renewable energy and a reversal of nature loss, hundreds of billions of dollars in subsidies must be eliminated or repurposed, according to the report.

A draft of the Global Biodiversity Framework calls for $500 billion per year in reformed subsidies—a target that “needs to be strengthened” in April at the U.N. Biodiversity Conference (COP 15) in Kunming, China.

“The case is clear: reforming the $1.8 trillion a year of subsidies that are harming the environment could make an important contribution towards unlocking the over $700 billion a year needed to reverse nature loss by 2030 as well as the cost of reaching net zero carbon emissions by 2050,” wrote the authors. “This needs to happen alongside aligning all private financial flows to nature-positive and increasing public and private finance to deliver innovative financial solutions that help protect, restore, and conserve nature.”

“With political determination and radical public-private sector collaboration,” they added, “we can reform these harmful subsidies and create opportunities for an equitable, nature-positive and net-zero economy. To do so, we must bring awareness, transparency, and disclosure on subsidies from both governments and business.”

Ahead of the biodiversity conference in April, said Business for Nature, negotiators must strengthen the Global Biodiversity Framework draft by including a commitment to reform “ALL harmful subsidies, including indirect and direct incentives.”

“Climate action is at a crossroads, in part because of the large scale of public money flowing to harmful industries and practices,” said Mary Robinson, former president of Ireland and member of The B Team. “We need to see thorough subsidy reform from governments and businesses, with social and environmental considerations at the heart, to ensure a just and equitable transition for all.”

E.O. Wilson’s lifelong passion for ants and conserving the World’s biodiversity

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E.O. Wilson in February 2003. Source: Jim Harrison, CC BY 2.5, via Wikimedia Commons

Life as we know it can be sustained only if we preserve functioning ecosystems on at least half of planet Earth.

By Doug Tallamy, The Conversation (CC BY-NC-ND 4.0).

E. O. Wilson was an extraordinary scholar in every sense of the word. Back in the 1980s, Milton Stetson, the chair of the biology department at the University of Delaware, told me that a scientist who makes a single seminal contribution to his or her field has been a success. By the time I met Edward O. Wilson in 1982, he had already made at least five such contributions to science.

Wilson, who died Dec. 26, 2021 at the age of 92, discovered the chemical means by which ants communicate. He worked out the importance of habitat size and position within the landscape in sustaining animal populations. And he was the first to understand the evolutionary basis of both animal and human societies.

Each of his seminal contributions fundamentally changed the way scientists approached these disciplines, and explained why E.O.—as he was fondly known—was an academic god for many young scientists like me. This astonishing record of achievement may have been due to his phenomenal ability to piece together new ideas using information garnered from disparate fields of study.

Big insights from small subjects

In 1982 I cautiously sat down next to the great man during a break at a small conference on social insects. He turned, extended his hand and said, “Hi, I’m Ed Wilson. I don’t believe we’ve met.” Then we talked until it was time to get back to business.

Three hours later I approached him again, this time without trepidation because surely now we were the best of friends. He turned, extended his hand, and said “Hi, I’m Ed Wilson. I don’t believe we’ve met.”

Wilson forgetting me, but remaining kind and interested anyway, showed that beneath his many layers of brilliance was a real person and a compassionate one. I was fresh out of graduate school, and doubt that another person at that conference knew less than I — something I’m sure Wilson discovered as soon as I opened my mouth. Yet he didn’t hesitate to extend himself to me, not once but twice.

Thirty-two years later, in 2014, we met again. I had been invited to speak in a ceremony honoring his receipt of the Franklin Institute’s Benjamin Franklin Medal for Earth and Environmental Science. The award honored Wilson’s lifetime achievements in science, but particularly his many efforts to save life on Earth.

My work studying native plants and insects, and how crucial they are to food webs, was inspired by Wilson’s eloquent descriptions of biodiversity and how the myriad interactions among species create the conditions that enable the very existence of such species.

I spent the first decades of my career studying the evolution of insect parental care, and Wilson’s early writings provided a number of testable hypotheses that guided that research. But his 1992 book, “The Diversity of Life,” resonated deeply with me and became the basis for an eventual turn in my career path.

Though I am an entomologist, I did not realize that insects were “the little things that run the world” until Wilson explained why this is so in 1987. Like nearly all scientists and nonscientists alike, my understanding of how biodiversity sustains humans was embarrassingly cursory. Fortunately, Wilson opened our eyes.

Throughout his career Wilson flatly rejected the notion held by many scholars that natural history—the study of the natural world through observation rather than experimentation—was unimportant. He proudly labeled himself a naturalist, and communicated the urgent need to study and preserve the natural world. Decades before it was in vogue, he recognized that our refusal to acknowledge the Earth’s limits, coupled with the unsustainability of perpetual economic growth, had set humans well on their way to ecological oblivion.

Wilson understood that humans’ reckless treatment of the ecosystems that support us was not only a recipe for our own demise. It was forcing the biodiversity he so cherished into the sixth mass extinction in Earth’s history, and the first one caused by an animal: us.

Upper Guinean Forest change from 1975 to 2013
Upper Guinean Forest change from 1975 to 2013. Source: USGS.

E.O. Wilson long advocated conserving the world’s biodiversity hot spots—zones with high numbers of native species where habitats are most endangered. This image shows deforestation from 1975 to 2013 in one such area, West Africa’s Upper Guinean Forest. USGS

A broad vision for conservation

And so, to his lifelong fascination with ants, E. O. Wilson added a second passion: guiding humanity toward a more sustainable existence. To do that, he knew he had to reach beyond the towers of academia and write for the public, and that one book would not suffice. Learning requires repeated exposure, and that is what Wilson delivered in “The Diversity of Life,” “Biophilia,” “The Future of Life,” “The Creation” and his final plea in 2016, “Half-Earth: Our Planet’s Fight for Life.”

As Wilson aged, desperation and urgency replaced political correctness in his writings. He boldly exposed ecological destruction caused by fundamentalist religions and unrestricted population growth, and challenged the central dogma of conservation biology, demonstrating that conservation could not succeed if restricted to tiny, isolated habitat patches.

“Conservation is a discipline with a deadline.”

—Edward O. Wilson

In “Half Earth,” he distilled a lifetime of ecological knowledge into one simple tenet: Life as we know it can be sustained only if we preserve functioning ecosystems on at least half of planet Earth.

But is this possible? Nearly half of the planet is used for some form of agriculture, and 7.9 billion people and their vast network of infrastructure occupy the other half.

As I see it, the only way to realize E.O.’s lifelong wish is learn to coexist with nature, in the same place, at the same time. It is essential to bury forever the notion that humans are here and nature is someplace else. Providing a blueprint for this radical cultural transformation has been my goal for the last 20 years, and I am honored that it melds with E.O. Wilson’s dream.

There is no time to waste in this effort. Wilson himself once said, “Conservation is a discipline with a deadline.” Whether humans have the wisdom to meet that deadline remains to be seen.

Doug Tallamy is a professor in the Department of Entomology and Wildlife Ecology at the University of Delaware, where he has authored 103 research publications and has taught insect related courses for 40 years.