Published November, 2016
The key message we took away from our latest forum on helping native bees and other pollinators? Diversity is what matters: we need habitat diversity as well as maintaining bee diversity.
A trio of experts in their individual field of work informed the audience on exactly what the issues are and how we, as every day folk, can make a difference. We kicked off the evening with Dr. Peter Kevan, Professor Emeritus at Guelph University. Kevan went into detail about why we need to be taking care of our native bee populations in the first place. According to Kevan, in Canada, we don’t have a decline in honeybee population--or at least, not like what the US is experiencing! Instead, honeybees are essential because wild bees are being eliminated. Native bees are getting cut out of the picture for obvious reasons, including habitat lose. But we need pollinators in agriculture, so we buy honeybees.
What's more, wild bees increase production yield. “Botanically, this relationship is not fully understood,” Kevan said, about the benefits of bee diversity to crop yield. But it's a very important one. Delicious fruits like blueberries are better serviced by wild bees—they can take on 70 species of pollinating bees. The orchard bee is cold tolerant, forages widely and doesn’t sting. Bumblebees pollinate greenhouse tomatoes. (Kevan pointed out that Canadians can be proud that we were one of the countries putting forward this bee technology).
What can we do to protect bees from the point of view of agriculture?
Kevan suggests we consider fields with windbreaks. In the field, practice low tillage and rotation, "everything that we can do to diversify the habitat." Make use of berms and hedges, conservation strips in fields and floral resources across the seasons. Remember that weeds are important resources.
In our city gardens, Kevan suggests that we can do our part for solitary bees by making sure to leave habitat such as twigs and bare ground for hole and ground nesters.
Biodiversity in Cities: Ecosystem functioning, and Green Infrastructure.
Next up was the captivating Dr. Scott MacIvor, a postdoctoral researcher and lecturer at the University of Toronto (Department of Biological Science and the Faculty of Landscape Architecture).
MacIvor shared with the audience that so much has been learned in the past 6 years; at least 6 papers are published daily on bees.
It was fascinating to hear that wild bees are generally happy, they can count to 4, and they are much more diverse that we thought. “Every female is her own queen,” MacIvor said.
And with over 364 kinds of wild bees in our region, “Bees are important, bees are diverse and we know more about wild bees than anywhere else in the world.” That’s something to be proud of!
Benefits of pollinators, native plants: green space, green city.
MacIvor works with designers who are tasked with creating habitat for bees. “There’s something about bees that make them so suited to our urban landscape,” MacIvor said. But while some adapt, others don’t—that is, some are winners and some lose out. And make no mistake, we are losing species. The extirpated “rusty patched bumblebee” is one such example.
When it comes to the impact honeybees have on wild bees, "it is negative," according to MacIvor. There’s competition for food and other resources as well as competition for research dollars. As well, honey bees spread disease.
There is so much to learn about the habits of bees. "75% of bees are ground nesting, but we don’t know where they are nesting," said MacIvor. In Toronto, where MacIvor lives and researches, public parks have sandy soils that are very accommodating to bee species.
"Honeybees are willing to die to safe their queen. Rarely, if ever are we stung by the wild bees that permeate our city," MacIvor said.
When we have more different bee species visiting a particular flower, we have more yields. "That is, it’s not the frequency of visits, it’s the diversity of visits, the buzz, the time of day," MacIvor explained.
Changing Public Opinion: Tickle bees (Miner bees).
MacIvor shared a story about an elementary school in Portland that changed public perception of bees as being dangerous when the kids noticed a large population of bees in the adjacent ball field. Rather than calling in exterminators, they called the Xerces Society, a non-profit organization that works to preserve invertebrates and their habitats. Now the bees are not only the subject of science classes at the school, but they've been named the school's official mascots, the Tickle Bees, since they don’t sting, but simply tickle. There is now a fence around bee aggregation with a sign to let people know not to disturb the bees.
When ecologist Stefan Weber describes his work collecting native plant seeds, it brings to mind a rescue mission of sorts.
“We see these tiny wonderful remnant populations that you know are destined to be killed because you’re in the site of a future highway,” Weber says. “Chainsaws are buzzing in the background as you hurry to gather seeds to save before it’s too late.”
Weber works for St. Williams Nursery and Ecology Centre, the biggest for-profit nursery in Ontario, so in spite of the ‘do-good’ thrust, Weber reminds me it’s a business that sells bulk seeds: “We make money doing this.”
With his team, Weber goes into the wild, collects a small amount of seed to be scaled up for agricultural practices on the farm and greenhouses, and then propagates the plants.
Source identifying all of their seeds, the nursery grows over 500 different species ranging from native wildflowers, trees and shrubs to grasses, and even aquatics.
As a seed specialist, Weber is in charge of “everything seed.”
This includes timing when a crop is ready to be harvested, collection of that crop, the drying, the processing, the cleaning.
This large-scale restoration work involves growing every single seed into a plant.
It takes one or two generations to get a room full of plants –like a substantial field of plants. In years, that’s like two years to scale up from ‘wild’ to ‘field restoration status.’
It’s a rewarding occupation. Weber, who’s been with the nursery for two years, describes how they get to go everywhere: “We find things that conservation authorities don’t know are there. We see territory that they don’t get a chance to see.”
Still feeling tempted to tidy up your garden for the winter time? Think again. Xerces Society says that one of the best things a gardener can do in the fall and winter for pollinators is LEAVE THE LEAVES ALONE: let it be messy.
The reason why moths, butterflies, native bumblebees and solitary bees, beetles, snails, spiders etc are begging you to control your OCD this fall and leave "dead" matter alone (there is nothing dead about pesticide-free garden), is because leaves and such, provide shelter from the cold and food for these little critters. Leave "litter" provides protection from predators. So why would you rack them away?
At the very least, leave some leave and twig piles.
In fact, as Xerces Society points out, the vast majority of butterflies and moths overwinter in the landscape as an egg, caterpillar, chrysalis, or adult: "Red-banded hairstreaks lay their eggs on fallen oak leaves, which become the first food of the caterpillars when they emerge.
Luna moths and swallowtail butterflies disguise their cocoons and chrysalis as dried leaves, blending in with the “real” leaves. There are many such examples."
Remember too, that these critters are food for birds, chipmunks and other wildlife.
Solitary bees will take winter refuge under a pile of bark or dried leaves, or nest in cavities in hollowed out stems and decomposing logs.
When you permit yourself to be a laidback gardener, you help to support a rich population of native pollinators in the following spring and summer.
Interested in other reasons for why a little messiness is good for your garden?
Read the entire article here.
The wildlife value of a messy garden.
So this fall and winter, please don't make a fuss over a bit of mess, and be proud that your gardening is adding value to wildlife habitat, and a diversity of insects!
So this is some sobering, sobering news. A report came out last week in the journal Plos One, talking about a study tracking the devastating decline in flying insect populations over the last 27 years on nature reserves in Germany. More than a 75% decline in total flying insect biomass (the total mass of organisms in a given area or volume) in protected areas. An excerpt from the abstract reads,
Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services. Our understanding of the extent and underlying causes of this decline is based on the abundance of single species or taxonomic groups only, rather than changes in insect biomass which is more relevant for ecological functioning. Here, we used a standardized protocol to measure total insect biomass using Malaise traps, deployed over 27 years in 63 nature protection areas in Germany (96 unique location-year combinations) to infer on the status and trend of local entomofauna. Our analysis estimates a seasonal decline of 76%, and mid-summer decline of 82% in flying insect biomass over the 27 years of study. We show that this decline is apparent regardless of habitat type, while changes in weather, land use, and habitat characteristics cannot explain this overall decline. This yet unrecognized loss of insect biomass must be taken into account in evaluating declines in abundance of species depending on insects as a food source, and ecosystem functioning in the European landscape.
The paper ends with the following:
The widespread insect biomass decline is alarming, ever more so as all traps were placed in protected areas that are meant to preserve ecosystem functions and biodiversity. While the gradual decline of rare insect species has been known for quite some time (e.g. specialized butterflies [9, 66]), our results illustrate an ongoing and rapid decline in total amount of airborne insects active in space and time. Agricultural intensification, including the disappearance of field margins and new crop protection methods has been associated with an overall decline of biodiversity in plants, insects, birds and other species in the current landscape [20, 27, 67]. The major and hitherto unrecognized loss of insect biomass that we report here for protected areas, adds a new dimension to this discussion, because it must have cascading effects across trophic levels and numerous other ecosystem effects. There is an urgent need to uncover the causes of this decline, its geographical extent, and to understand the ramifications of the decline for ecosystems and ecosystem services.