by Ethan Tapper Forests are complex, intricate and nuanced, and also massive, expansive and interconnected. To be responsible forest stewards we need to both zoom-out to understand our role in a giant landscape, and zoom-in to recognize the tiny pieces and parts that make forests work. We must (somehow) hold both of these realities in focus as we take care of our forests.
This month I want to zoom-in, to talk about invertebrates.
Simply put, invertebrates are organisms without spines, an incredibly diverse group of critters which includes everything from insects to sea sponges, squids, slugs and worms. What most people call “bugs,” are arthropods, a sub-group of invertebrates which includes insects, spiders, and even lobsters.
Invertebrates are an incredibly adaptive and resilient bunch, having been around since before the dinosaurs.
In terms of sheer abundance and diversity, they stand alone: of the approximately 2 million known species on Earth, about 97% are invertebrates (900,000 species are just insects), with somewhere between 8 million and 30 million species still undiscovered.
Besides accounting for a huge proportion of our biodiversity, the sheer amount of bugs on Earth is startling: there are around 200 million insects for every human on the planet, about 300 pounds of insects for every pound of human.
To put us in perspective, the combined mass of all the humans on Earth is about equal to that of all the ants, or the mass that all the spiders on Earth eat in one year.
In Vermont, there are more than 20,000 known species of invertebrates, compared to 58 species of mammals. These invertebrates support our ecosystems in countless ways, mostly unseen. They are what biologist E.O. Wilson calls “the little things that run the world,” subtly working behind the scenes to make our world work.
Invertebrates are the base of the forest food web, directly and indirectly feeding larger wildlife. Moth and butterfly caterpillars, for example, are critical sources of protein which songbirds rely on to feed their young in the spring.
Caterpillars and other bugs often have close, co-evolved relationships with one or a few different tree species, and so diverse forests are critical to providing habitat for them and the species that eat them.
Invertebrates are also decomposers, turning organic material like wood into soil. Soils are largely biological in nature – their physical and chemical composition a result of being passed through the bodies of countless tiny organisms, transformed by mites, springtails, nematodes and more.
A handful of forest soil may contain thousands of invertebrates of hundreds of different species, not to mention millions or even billions of organisms if you include bacteria, protozoa, algae, and fungi.
Invertebrates perform a huge number of other essential functions. Some, especially flying insects like flies, beetles, or Vermont’s more than 300 species of native bees, are pollinators,
helping more than two-thirds of Vermont’s plant species reproduce. Others, like ants, disperse the seeds of some of our native spring wildflowers. The list goes on.
Not all is good with bugs in the woods. Some invertebrates are non-native tree pests, like the Emerald Ash Borer (EAB) and Hemlock Wooly Adelgid (HWA).
Some non-native bugs which are celebrated in agriculture – the Eurasian honeybee and earthworms – can be problematic in our ecosystems.
Non-native invasive plants like honeysuckle, buckthorn, and barberry take over forests, providing habitat for only a tiny fraction of our invertebrates.
For many reasons, invertebrates are going extinct at an incredibly fast rate, with as many 100,000 species lost since the 1600’s and 40% of known invertebrate species thought to be under threat of extinction.
Invertebrate habitat is as diverse as they are. They live in rotting wood, in soil, in the leaves and branches of young, healthy trees and the complex bark of big, old trees.
On a large scale, the most important thing we can do for invertebrates is to protect our forests from fragmentation and loss, managing for diverse, intact, connected landscapes.
On a smaller scale, we can manage for complex forests, encouraging different sizes, ages and species of trees while also leaving some big “legacy” trees, dead-standing trees and lots of dead wood on the forest floor, and dealing with biodiversity threats like non-native invasive plants.
Great things come in small packages. As strange as it seems, healthy populations of bugs are critical to the integrity and the resilience of our forests and the beauty and function of our world.
Ethan Tapper is the Chittenden County Forester for the Vermont Dept. of Forests, Parks and Recreation. See what he’s been up to at: https://linktr.ee/ChittendenCountyForester
Managing Forests in a Changing Climate
Wednesday, September 15
7:00 – 8:00 PM
In a changing climate, forests are an asset – helping to mitigate carbon emissions, protect our air and our water quality, safeguard our precious biodiversity and more. However, forests are also at risk, struggling under the combined stresses of climate change, forest fragmentation and loss, non-native invasive pests and pathogens, and more.
Understanding how to manage and take care of forests in such an uncertain future is a complex undertaking: we must balance managing forests for climate resilience and adaptation, carbon sequestration and storage, wildlife habitat and biodiversity, while also considering the benefits of local renewable resources to justice, equity and human health.
Join the Sierra Club, Ethan Tapper, the Chittenden County Forester and Tim Stout, Principal of Northam Forest Carbon, for a virtual discussion of how to take care of our forests in a changing climate.
Register here: https://act.sierraclub.org/events/details?formcampaignid=7013q000002FUzuAAG&mapLinkHref=
Forestry, Birds and Recreation at the Hinesburg Town Forest:
Can We Have Trails, Forest Management and Songbird Habitat Too?
Sunday, September 19, 10:00 AM – 12:00 PM
Hayden Hill Road East Trailhead, Hinesburg Town Forest, Hinesburg, VT
Join Fellowship of the Wheel, Audubon Vermont, and the Chittenden County Forester for a free, public walk and discussion of forest management, recreation, and forest bird conservation on the site of an upcoming forest management project at the Hinesburg Town Forest.
From warblers and thrushes to vireos and flycatchers, Vermont provides summer breeding habitat for some of the greatest diversity of neotropical migratory songbirds found anywhere in the lower 48 states. Many of these species are at risk due to loss of suitable habitat, forest fragmentation, introduced species, incompatible forest management, and climate change. Bird conservation in the 21st century requires a proactive, multi-disciplinary approach.
Over the past decade Audubon Vermont has been working closely with landowners, foresters, maple syrup producers, legislators, and others to raise awareness of the important role our state’s forests play in hemispheric bird conservation. At this event, Steve Hagenbuch, Audubon’s senior conservation biologist and forester, will help us assess current forest habitat conditions and consider opportunities for future management. Ethan Tapper, the Chittenden County Forester, will also discuss forests, forest management, and how the management of the Hinesburg Town Forest will be done with both forest birds and recreation in mind.
The Hinesburg Town Forest (HTF) is an 864-acre parcel owned and managed by the Town of Hinesburg for over 70 years. It provides critical wildlife habitat and natural good and services, demonstrates responsible forest management and offers over 17 miles of trails annually used by tens of thousands of hikers, bikers, and wildlife watchers. It is also the birthplace of the Foresters for the Birds program, a which seeks to promote forest management with bird habitat in mind.
Over the next two winters, the northeastern portion of the HTF will be managed from the HTF’s Hayden Hill East trailhead. The goal of this project is to increase the diversity, complexity and resilience of forests in this portion of the HTF, encourage the development of great wildlife habitat and to demonstrate responsible, regenerative forest management using an open, transparent and inclusive process. While some sections of trails will need to be closed during the project, it is being structured to allow the Hayden Hill East trailhead to remain open, and for most trails to remain open to the public throughout.
To learn more about this project, check out the links and resources here at: https://linktr.ee/HinesburgTownForest. To learn more about similar projects in the south of the HTF and at the Andrews Community Forest in Richmond check out Story Maps on these projects here: https://arcg.is/09zfC1 and here: https://arcg.is/0yCGi.
This will be an in-person event and will require uphill walking over uneven surfaces. To join us, meet at the Hayden Hill East trailhead at 10:00 AM on Sunday, September 19. Please bring your questions about forest management, birds, recreation, the interaction between them, and anything else you need to be prepared for weather and trail conditions.
ODDS AND ENDS
I was pleased to be able to showcase some of the work we've done at the Hinesburg Town Forest on WCAX's "Wildlife Watch" segment. You can watch the segment here
and learn more about past and upcoming projects at the HTF at the links below.
Check out an archive of my monthly columns here.
The forest management project at the Andrews Community Forest in Richmond, which started last summer, recently concluded. I've created a story map about the project, which you can check out here: https://arcg.is/0yCGi
Check out my YouTube channel, sign up for my email list, stay posted about my various projects and see other links and resources at my Linktree, here.