February 22, 2017

Saving Native Bees in the Garden

A bumble bee enjoying a purple globe thistle. Photo: UMass Amherst 

In The Humane Gardener: Nurturing a Backyard Habitat for Wildlife, writer and naturalist Nancy Lawson describes how each of us can help save native bee populations. Her recent online post, "How to really save the bees," previews some of the small, but important steps for home gardeners. 

How many bee species can you name off the top of your head? "Most people, when they think about bees, they have an image that pops into their head, and that's the honeybee," says Rich Hatfield of the Xerces Society for Invertebrate Conservation. But around the world there are approximately 25,000 known types of bees. The honeybee is not even native to North America - yet there are 4,000 bee species that are, including mason bees, mining bees, sweat bees, bumblebees, and many more. They all play critical roles in pollinating the fruits and seeds that compose the majority of the North American diet. 

Up close and personal with a Carpenter bee. Photo: UC Davis

As you have likely read in the news, bee populations face an enormous threat of extinction. One common approach to contributing to "save the bee" campaigns is to purchase more hives, but doing so might actually harm native bee populations. Bringing in bees from an external source can increase competition for flowers - sources of nectar and pollen. It can also increase the risk of disease transmission among species. Instead, Lawson offers several simple actions gardeners can take to help their local bee populations thrive. 

First, let your yard be messy. Most bees nest in sunny, unmulched patches of dirt and raise their young underground. Many others nest in cavities: they lay eggs in logs, twigs and other natural features. Hard as it may be to resist the urge to tidy up the garden, Lawson suggests that we let some fallen leaves lie. We can also prop up twigs against trees, create small piles of brush, and scatter long pieces of wood among plants to provide desirable nesting grounds for bees. 

Second, grow a variety of plants. While many bees are "dietary generalists," about a third of those native to the mid-Atlantic and Northeastern U.S. rely on certain plant species for pollen. Bee experts recommend planting a variety of native blooms, along with herbs and traditional cottage garden flowers such as marigolds, violets, pansies and evening primrose. 

A pollinator-friendly garden. Photo: Xerces

Finally, go chemical-free if possible. Lawson reminds us that many pesticides can contaminate pollen and nectar, so it's important to consider the impacts of adding chemicals to the garden. While honeybees may withstand the application of certain levels of pesticides, other species may be more vulnerable. A 2015 study published in Nature showed that seeds treated with neonicotinoid pesticides negatively impacted wild bee populations: bumblebee colonies produced fewer queens and bee density in treated fields was half that of the fields left untreated. Meanwhile, the treatments had no effect on honeybee populations. 

So rather than purchasing more hives and increasing resource competition for native bee populations, we should focus on fostering a healthy environment in our gardens that will give native bees a chance to recover and thrive. 

The Humane Gardener is on presale order now and will be released by Princeton Architectural Press on April 18, 2017. 
Scientists Find Carbon Pools Deeper in the Soil 

Photo: Restoration Soil

Can soils capture and hold more carbon than scientists generally believe? Most soil studies test carbon down to 12 to 18 inches. But we've long suspected that was an underestimation, and now there's evidence from an Agriculture Research Service study indicating that managing for deeper soil carbon has great potential for climate mitigation. 
Can woolly mammoths save the world? 

How to restore Siberian grasslands to keep the permafrost from melting and massive amounts of frozen carbon in the ground. A wonderful TEDx Talk about Sergei Zimov's work with grazing animals and eco-restoration in "Pleistocene Park." 

Scenario 300 - How to Rapidly Move Carbon Out of the Skies and into the Ground

Photo: Modern Farmer

Come join us for a potluck and discussion with our restoration ecologist, Jim Laurie, as we explore the bright side of global warming. By regenerating ecosystems we can pull gigatons of carbon out of the atmosphere and plant it in hungry, degraded soils around the planet, where it will do worlds of good. 

When: Sunday, February 26, 2017 at 6 PM 

Where: Cambridge, MA. See our Meetup page for address. 

RSVP here. We hope you can join us! 
Talk with Luke Griswold-Tergis on his work with "Pleistocene Park" scientist, Sergei Zimov

When: Monday, March 13, 2017 at 5 PM

Where: Haller Hall, Harvard Museum of Natural Science

Check out the Meetup page for more info! 
Michael Kravčík's National Tour for A U.S. Action Plan for the Restoration of Natural Water Cycles and Climate

Dates and Locations TBD, stay tuned for updates! 

Check out Voices of Water for Climate - Michal's organization webpage here for more information. 
For up-to-date info on our events

About Biodiversity for a Livable Climate

Through education, policy and outreach, our mission is to promote the power of the natural world to stabilize the climate and to restore biodiversity to ecosystems worldwide. Collaborating with organizations around the globe, we advocate for the restoration of soil, and of grassland, forest, wetland, coastal and ocean ecosystems - along with the associated carbon, water and nutrient cycles  - to draw down excess atmospheric greenhouse gases, cool the biosphere, and reverse global warming, for the benefit of all people and all life on earth. 

Learn more about our ongoing projects and upcoming events and find additional information and resources at bio4climate.org