Trees and Nashville Wildlife Part 5: Slugs and Snails
While slugs are often considered pests and snails might be seen as friendlier, these animals both contribute to maintaining local ecosystems, and both have the potential to do some damage in residential yards. In this article on Nashville’s fauna, we’ll examine how snails and slugs play various roles in and around trees, and toward the end, we’ll share some tips on how to manage the gastropod populations in your yard.
What’s the Difference Between Snails and Slugs?
The main difference between snails and slugs is the shell: snails have external shells, while slugs don’t. This affects their lifestyles and ecological niches:
Snails are slower than slugs due to the weight of their shell.
Without a shell, slugs have more flexibility and are more agile, able to fit into smaller spaces than snails.
A snail’s shell offers protection from predators and dehydration, while a slug is more reliant on its slime and moist environments to remain hydrated and safe.
Despite these differences, snails and slugs are very closely related, with terrestrial and aquatic species that are all members of the mollusk group (which also includes oysters, clams, squid, and octopuses). Snails and slugs are both gastropods: small invertebrates that move around on their stomachs and perceive with their skin and tentacles. The word gastropod actually means “stomach-foot” in Greek, referring to how these animals journey across land and water on their bellies.
Can Slugs and Snails Climb Trees?
The slimy mucus that snails and slugs produce helps them slide along dry surfaces like soil and stone, including vertical ones like trees. Their muscular foot helps them grip and move as their slime reduces the friction, and while most slugs and snails live on the ground, they can work their way up into trees to find food and shelter.
Trees as Habitat for Snails and Slugs
Land gastropods seek out moist areas in gardens and wooded spaces. They find their way around by sensation, using scent, touch, and taste to find food sources like leaves, fungi, and other living and decaying organic matter. These snails and slugs live among leaf litter and plant debris, in moist hollows of tree trunks, in damp and shady areas under bushes, in logs, and in other dark, moist spaces that they find near sources of food.
Slugs and snails eat a variety of foods found in and around trees, including leaves, buds, bark, stems, berries, worms, rotting wood, and mushrooms. While they can be attracted to garden plants like lettuce, tender herbs, and certain flowers, they otherwise generally prefer decomposing organic material.
How Slugs and Snails Help Trees
Slugs and snails can have mixed effects on individual trees and the wider ecosystem that they interact with:
Nutrient decomposition: Gastropods, with their diverse diet, improve soil health and fertility by breaking down nutrients and making essential vitamins and minerals available to tree roots as they travel across environments.
Food sources for other wildlife: A variety of animals eat snails and slugs, which helps keep gastropod populations under control. Birds (like turkeys, woodpeckers, crows, robins, and wrens), mammals, reptiles, amphibians, and some insects, such as beetles, include slugs and snails in their diets.
Feeding effects: Snails and slugs can cause damage when they are present in large numbers and feed on plants and young trees in gardens and farms, but in appropriate numbers, their micro-stresses on trees from eating leaves, buds, and bark can help build resilience as a specimen matures.
Spread of disease: Gastropods can carry the danger of tree diseases (such as fungal spores and bacteria) in their fluids as they move from plant to plant. While this provides some natural exposure, an infected tree can become weak if a pathogen takes hold.
Types of Slugs and Snails
There are thousands of species of slugs and snails, and many are native to Tennessee and the southeastern U.S. In Nashville, the common brown snail, eastern forest snail, and eastern amber snail are just a few of the types of land snails that can be found in and around the city. The gray garden slug, amber slug, and southern red slug are some of the several types of good slugs that live in Nashville gardens and woodlands.
The slow-moving yet highly mobile and frequently hidden gastropods are heavily affected by environmental changes like urban development and expansion. Many types of slugs and snails are endangered due to habitat loss. Since most of Nashville’s green cover is private property, residents can make landscaping decisions that help improve environmental conditions for local wildlife.
Managing Your Nashville Yard for Snails and Slugs
In Nashville’s canopy ecosystem, snails, slugs, and trees all play interconnected roles in maintaining the balance of the environment. While snails and slugs may seem like small, often overlooked creatures, their relationships with trees and the wider ecosystem are significant.
Slugs and snails are naturally attracted to lowlands or wetlands where it stays damp longer. Oak, dogwood, and hickory trees, in particular, provide conditions that gastropods love: flakey bark and bushy foliage that offer moist, shady environments. In general, gastropods thrive in most types of vegetated ecosystems that maintain their preferred conditions.
Snail and slug populations can indicate ecosystem health, as their presence suggests a balanced environment with sufficient moisture and organic matter. On the other hand, when these favorable conditions are unmanaged, gastropod populations can rise to detrimental numbers.
When managing slugs and snails as pests, there are many natural strategies and formulated products that can be used to trap or discourage their presence. A landscape-oriented strategy would focus on managing the environment for conditions they don’t like: bright, ventilated, and without places to hide.
Bushes along fences and designated spots with tree debris can attract slugs and snails to those spaces, redirecting them from sensitive areas of the yard. Vegetable gardens and flower beds that are clear of weeds, overgrowth, and debris won’t be attractive to snails and slugs due to the lack of cover, moisture, and decaying organic material.
Help Us Build a Healthy Canopy
Urban forest organizations like the Nashville Tree Conservation Corps are important actors in the local environmental management community that help ensure our natural spaces are available for wildlife of all kinds. Groups like ours help build awareness around tree issues, collaborate with legislators and other types of decision-makers about the presence of trees, and partner with residents and other stakeholders to support Nashville’s area-wide canopy ecosystem.
As a non-profit, we rely on the generosity and collaborative nature of Nashvillians to fulfill our mission to support Nashville’s trees, so we welcome helping hands and financial donations! If you’re in need of a new tree for your yard, consider browsing NTCC’s tree sale to purchase one or more below retail price. You can also donate a tree for us to plant if you don’t have the space at home!
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