Yard & Garden

Composting and Climate Change

September 25, 2023September 22, 2023Maryland Grows2 Comments

Composting is probably seen by most people as good for gardens and the environment. After all, compost helps make our soils and plants healthier and keeps green waste from our yards and kitchens out of landfills.

But is composting good in the context of our climate crisis? Doesn’t the composting process generate lots of carbon dioxide (CO₂), the principal greenhouse gas (GHG) that traps heat in Earth’s atmosphere? Can composting also mitigate climate change and make our yards and landscapes more climate-resilient? The answer to both questions is YES. This article will show that composting, at the home, community, and municipal/commercial level, is an important global warming mitigation and adaptation tool. As we’ll see, the ways that humans manage this natural process and use the compost can affect the climate benefits.

Composting basics

We don’t make compost! Huge populations of microorganisms do most of the work and we humans manage the process for our benefit. It’s nature’s way of recycling anything that lives and dies, like plants, animals, and microbes.

The decomposition process produces lots of carbon dioxide (CO₂), part of the world’s carbon cycling system shown in this graphic:

illustration of the carbon cycle - plants use carbon dioxide from the air and water from the soil to build carbohydrates — Plants exude carbohydrates through their roots to feed soil organisms. Those organisms release carbon dioxide through respiration. Illustration by Jocelyn Lavallee, Ph.D., Soil Scientist

This CO₂ release is considered biogenic (happens through natural biological systems), not anthropogenic (people-made), and is not included in the calculations of greenhouse gas (GHG) emissions that drive global warming and climate change.

The three primary GHGs are:

Carbon dioxide (CO₂) — 300-1,000 year atmospheric lifetime; 86% of total GHG emissions
Methane (CH₄) — 84X the global warming potential of CO₂; 12 year atmospheric lifetime; 7% of total GHG emissions
Nitrous oxide (NO₂) — 265X the global warming potential of CO₂; 100 year atmospheric lifetime; 6% of total GHG emissions

There are many factors that determine the potential for composting to generate methane and nitrous oxide, like the mix of materials being composted, temperature, moisture, pile size and configuration, and aeration. Compost piles and windrows that are waterlogged and low in oxygen (anaerobic) are more likely to generate these GHGs. Composting is “climate-friendly” when it’s done in the presence of air (aerobic). Home and community composters turn piles by hand to keep them aerated and large-scale composting facilities use mechanical turners and force air into windrows with blowers. Well-managed composting at any scale releases very little methane or nitrous oxide into the atmosphere.

Direct climate benefits of composting

Dumping food wastes and grass clippings in landfills generates large amounts of methane because the decomposition process is anaerobic. Landfills release about 17% of total U.S. anthropogenic methane emissions and food waste makes up 24% of landfill space. Burning organic wastes releases GHGs and toxins. Composting these organic wastes using best practices greatly reduces emissions.
Carbon sequestration: Compost continues to degrade after soil incorporation. Some of the carbon cycles through soil microorganisms and some is held tightly to clay particles, protected against decomposition, and becomes part of the long-term reserve of stored carbon.

Indirect climate benefits of composting

The mid-Atlantic climate is becoming wetter and warmer overall, punctuated by localized extreme weather events, like record-breaking rainfall and extreme drought and heat. Intense storms can cause soils and nutrients to wash away and warmer temperatures cause more rapid organic matter decomposition and turnover, especially if soils are tilled and uncovered.

Adding compost to soils makes them more resilient by:

Holding more water in the soil during periods of drought and extreme heat
Reducing erosion (washing away of soil during extreme rainfall) and nutrient run-off) due to improved soil structure (larger, more stable aggregates or crumbs)
Improving plant growth, by slow release of plant-available nutrients
Reducing the need for synthetic nitrogen fertilizers which require natural gas for their production
Reducing the need for potassium and phosphorous fertilizers (derived from mined mineral deposits that are dwindling worldwide)
Binding and degrading toxic metals and pollutants
Substituting compost for peat products can help reduce the release of CO₂ from commercial peat extraction from wetlands

illustration of how compost combats climate change - increases water holding capacity - sequesters carbon in soil — Poster by the Institute for Local Self-Reliance

Home composting

Managing and recycling as much yard waste as possible on-site is often the most climate-friendly approach because it reduces GHG emissions from transporting and processing or landfilling organic waste. You can do this by recycling grass clipping (“mow ‘em high and let ‘em lie”), mulch-mowing tree leaves and leaving them in place, or using them as mulch, composting yard and garden waste, and burying kitchen scraps. These practices help to recycle nutrients on-site and increase soil organic matter. Selecting or building a non-plastic composter can also help reduce GHG emissions.

Municipal/commercial composting

This is the next best option for organic wastes that cannot be managed on-site. Commercial and municipal composting operations do create GHG emissions from the trucks and equipment, powered by fossil fuels, that are used to collect, transport, and process organic waste and compost. The closer the source of organic waste to the facility the lower the emissions and the greater the benefits. On balance, composting on a large scale can also help mitigate climate change.

illustration showing that the carbon sequestration benefits of municipal composting outweigh the greenhouse gases generated by transportation, storage, and processing compost

To summarize: aerobic composting reduces GHG emissions compared to the landfilling and incineration of organic wastes. The resulting compost sequesters carbon when mixed into soils and improves soil health and resiliency. Composting at home and in your community is the most climate-friendly approach but commercial and municipal composting is another important tool that helps mitigate climate change.

References

Silver, W. L., Vergara, S. E., & Mayer, A. (2018). Carbon sequestration and greenhouse gas mitigation potential of composting and soil amendments on California’s rangelands. California Natural Resources Agency, 62.
Linzner, R., & Mostbauer, P. (2005, October). Composting and its impact on climate change with regard to process engineering and compost application-a case study in Vienna. In Proceedings of Sardinia Tenth International landfill Symposium, Cagliari, CISA publisher.
UME- How to Make Compost at Home
Institute for Local Self-Reliance- Community Composting
U.S. Composting Council- Greenhouse Gases and the Role of Composting: A Primer for Compost Producers (includes some research studies on GHG emissions and composting facilities)
Maryland Department of the Environment- Organics Diversion and Composting
U.S. EPA- Overview of Greenhouse Gases

By Jon Traunfeld, Extension Specialist, University of Maryland Extension, Home & Garden Information Center. Read more posts by Jon.

Goldenrods: The Garden Thyme Podcast

September 14, 2023September 13, 2023Maryland Grows4 Comments

goldenrods episode of The Garden Thyme Podcast

Gold and yellow hues are the undeniable colors of autumn. In this episode of The Garden Thyme Podcast, we discuss one of our favorite yellow-blooming perennial plants – goldenrod. With its pretty yellow flowers, long blooming seasons, and high wildlife value, what is not to love about these fantastic native plants? Mikaela also counts down her top pick of goldenrods for different gardens (~17:10). Her goldenrod bloom chart can be found here.

We also have our:

Native Plant of the Month – Pawpaw (Asimina triloba) (~22:45)
Bug of the Month – Goldenrod Bunch Gall Midge (~33:35)
Garden Tips of the Month (~39:15)

Listen to the podcast

If you have any garden-related questions, please email us at UMEGardenPodcast@gmail.com or look us up on Facebook.

For more information about the University of Maryland Extension (UME) and these topics, please check out the UME Home and Garden Information Center.

The Garden Thyme Podcast is brought to you by the University of Maryland Extension. Hosts are Mikaela Boley- Senior Agent Associate (Talbot County) for Horticulture, Rachel Rhodes- Agent Associate for Horticulture (Queen Anne’s County), and Emily Zobel-Senior Agent Associate for Agriculture (Dorchester County).

Theme Song: By Jason Inc

How Are Aquatic Plants Pollinated?

September 11, 2023September 8, 2023Maryland Grows1 Comment

When we think about pollination, we tend to only think about terrestrial plants. However, a large number of plants are not and actually live fully or partially in the water. These plants also need to reproduce, and thus need to have their flowers pollinated to produce seed. How do they do it? In today’s post, I will try to give a (short) answer to that question, using some native plants as examples.

You may recall from previous posts, that flowering plants require pollination to be able to produce seeds and thus reproduce. Since we are terrestrial organisms ourselves, we tend to be more aware of other organisms and processes that share that trait with us, and pollination is no exception. However, there are lots of flowering plants that are completely or partially aquatic, and these plants also require pollination to produce seeds. Depending on the specific requirements of the plants in question, some of them may use different strategies for pollination.

Wind pollination

Many aquatic or semi-aquatic plants depend on wind to transfer pollen to the female reproductive structures. Especially under conditions distant from land, using wind as a means of pollen dispersal can be extremely advantageous. In fact, being distant from land tends to reduce the types and number of animals that can visit the flowers of aquatic plants. By depending more heavily on wind, these plants usually display light and abundant pollen that can be readily blown away and potentially deposited on the stigma of the female counterparts. A global evaluation of this indicated that about a third of all aquatic plants in the world are wind-pollinated.

small leaves on the surface of water - watershield plants — Watershields are very common wind-pollinated aquatics from our region. These plants display their small flowers well above water, first exposing their stigmas and the next day releasing pollen into the air. Photos: S. Elliott, S. Osborne (CC)

a red flower protruding from the surface of the water — Watershields are very common wind-pollinated aquatics from our region. These plants display their small flowers well above water, first exposing their stigmas and the next day releasing pollen into the air. Photos: S. Elliott, S. Osborne (CC)

In Maryland, an aquatic plant known to be wind-pollinated are watershields (Brasenia schreberi). This plant has non-showy flowers that display both anthers and stigmas. In order for the plant to promote cross-pollination (i.e., avoid receiving pollen from its own flowers), the flowers of these plants go through a complex blooming process that spans two days. This process involves on the first day the receptivity of the stigma (the female part that receives the pollen) and on the second day the maturation and release of the pollen grains. When the grains mature, they are swept by the wind and can reach stigmas from other flowers that are at that point going through their first flowering maturation step.

Animal pollination

It has been shown that a large number of aquatic plants are at least partially pollinated by insects or other animals. In fact, as is also the case in terrestrial plants, aquatic plants can sometimes use both wind and animals to transfer pollen, increasing the chances of some pollen eventually reaching the stigma. Animal-pollinated aquatic plants are pollinated by a large variety of organisms, but their identity will depend on the specific place where the plant is growing and the ability of the pollinator to reach the plant and even survive in that environment. For example, while large bees may be able to fly further away from land, smaller insects may mostly visit plants that are close to land.

a closeup of the flower of arrow arum - its yellow inside — The arrow arum or tuckahoe is an aquatic native that displays a nursery pollination system in association with small flies. Photos: Sheri, N. DeBarros (CC), K. Shulz (CC)

the leaves of arrow arum plants are pointed like arrows — The arrow arum or tuckahoe is an aquatic native that displays a nursery pollination system in association with small flies. Photos: Sheri, N. DeBarros (CC), K. Shulz (CC)

A special case of insect pollination of a Maryland native is that of the arrow arum or tuckahoe (Peltandra virginica). The species belongs to the Araceae family and displays a stunning pollination system. As is often the case in this family of plants (see also the skunk cabbage example we talked about in a previous post), the maturation of the female and male flowers is linked to the production of specific aromas. In the case of the arrow arum, these smells attract small flies, and in particular individuals of Elachiptera formosa. These flies seek the flowers to mate, feed on pollen, and eventually lay eggs on the plant, making this an example of what is called nursery pollination (the plant receives a pollination service in exchange for providing a brood site for the pollinator). By moving along the flower, these tiny flies move pollen from the anthers to the stigmas. Some of this pollen may come from the same plant, but other pollen may come from a different flower already visited by the flies.

Water pollination

Finally, many aquatic plants display flowers that are either completely submerged or floating on the surface of water. These plants usually use water currents to disperse their pollen. As with wind, this dispersal is very inaccurate, which usually leads to the release of a large amount of pollen. These plants have either pollen that floats on water or remains attached to the anthers which float to the stigma.

aquatic plants with tiny white flowers on the surface of water — The American pondweed is one of our native species that uses water as their means of pollen dispersal. Note the very small white flowers that are placed on the surface of water. Photo: C. Fisher

A very common native from Maryland that displays this type of pollination is the pond- or waterweed (Elodea canadensis). This species native to North America displays flowers that have either anthers or pistils, but not both. The flowers with anthers are often displayed over the water, from where they release the pollen, which lands and then travels on its surface. By moving on the surface of the water, the pollen can reach the slightly submerged stigmas of the pistilate (female) flowers, which are held on flowers that float at the very surface of the water. Because such a dispersal can lead to large pollen loss, pollen release in this species is only done when the wind is light and the water current is low. This promotes a more “controlled” dispersal and increases the chances of the pollen effectively reaching the stigmas.

By Anahí Espíndola, Assistant Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.

Anahí also writes an Extension Blog in Spanish! Check it out here, extensionesp.umd.edu, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!

Q&A: Late Bloomers for the Garden

September 7, 2023September 6, 2023Maryland GrowsLeave a comment

a red-spotted purple butterfly is feeding on nectar from a native Eupatorium plant with white flowers — Red-Spotted Purple butterfly on a native Eupatorium in September. Photo: M. Talabac

Q: A lot of my new native plant garden beds contain species that bloom in spring and early/mid-summer. What can I add for pollinators that blooms late?

A: Fortunately, there are numerous late-season nectar sources, though most are sun-loving species. They are very attractive to migrating Monarchs and any other butterfly on the wing in late summer and autumn, plus bees, wasps, beetles, flies, and plenty of other insects. Seed-eating birds also appreciate the food source once the seeds of those plants ripen by the end of the growing season; nature’s bird feeders.

Lots of late-flowering native plants are in the aster family, including: Ironweed (Vernonia); Goldenrods (Solidago and Euthamia); Asters (formerly genus Aster, now named Doellingeria, Eurybia, Ionactis, or Symphyotrichum); Cut-leaved Coneflower (Rudbeckia laciniata); Blazing-star (Liatris); Elephant’s-foot (Elephantopus); Beggarticks (Bidens); Wingstem (Verbesina); Helen’s Flower (Helenium); perennial Sunflowers (Helianthus); Climbing Hempvine (Mikania scandens); and the Eupatorium group (several common names and genera; Eupatorium, Eutrochium, Conoclinium, Ageratina).

Outside of the aster family, you can also consider Rosemallow (Hibiscus), Obedient Plant (Physostegia virginiana), Turtlehead (Chelone), Common Witchhazel (Hamamelis virginiana), Gentian (Gentiana), Tall Phlox (Phlox paniculata), Lobelia (Lobelia), and Flowering Spurge (Euphorbia corollata).

By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun and Washington Gardener Magazine. Read more by Miri.

Have a plant or insect question? The University of Maryland Extension has answers! Send your questions and photos to Ask Extension. Our horticulturists are available to answer your questions online, year-round.

Cicada Killer Wasps Are Scary But Good

August 25, 2023August 16, 2023Maryland Grows1 Comment

a close-up view of a cicada killer wasp showing its light yellow and black striped abdomen — Cicada killer wasps are good pollinators who keep cicadas in check.
Photo: Dawn Dailey O’Brien, Cornell University

It’s big. It’s creepy. It’s the cicada killer wasp and it has some local folks worried. But it’s a good guy. Honest.

Looking like yellowjackets on steroids, 2-inch-long cicada killer wasps are yellow and black and a bit intimidating. But it’s all a show.

Unless you’re a cicada, you have no worries. These wasps help control the annual cicadas buzzing in our trees.

In fact, male cicada killer wasps don’t have stingers at all and females aren’t likely to sting unless you step or sit on one.

In addition to their ginormous size, cicada killer wasps worry folks because they do figure eights over lawns, looking like they are Up To No Good.

Nope. Those are just males establishing or defending territory. Boys will be boys.

The dudes have been hanging out since July, scoping out territory while waiting for the ladies to arrive. Their manly posturing results in often spectacular wing-whirling combat, all bluster and bluff.

Check out the video of a close encounter with University of Maryland entomologist Mike Raupp’s Bug of the Week feature.

Following a brief romantic interlude, the female cicada killer wasp digs a finger-sized nesting chamber in the ground, leaving telltale piles of excavated soil.

Then she climbs trees in search of the cicadas which she uses to feed her young.

When she finds a cicada, she stings it to paralyze it, then flies the cicada down to the ground, dragging it to her nest. This is no mean feat since cicadas are much larger than she is. That’s one determined mama.

She stuffs the cicada into her nest, lays an egg on it, and seals the opening. When the egg hatches, the larva will chow down on the cicada which is, unfortunately, still quite alive. Ah, the circle of life.

Well fed, the larva will wrap itself in a case, pupate and stay underground before emerging as an adult next summer.

Interestingly enough, female cicada killer wasps can choose the sex of their babies. If they give them one cicada as food, they turn out to be boys. Given two cicadas, they become larger females.

A female cicada killer wasp’s work is never done. As soon as she seals one nest, she makes a new one and goes cicada hunting again, helping to keep their population in check.

See female cicada killer wasps in action in this Bug of the Week profile.

Cicada killer wasps also are good pollinators, moving pollen from plant to plant as they feed on nectar as adults.

Cicada killer wasps congregate around some petunias.
Photo: John Lefebure

What should you do if you find cicada killer wasps in your yard? Not a thing. Tolerating them is best since they’re only around for a few weeks and are beneficial. Chemical controls are not necessary.

But if you’re bothered by the holes they make in your lawn, wet down the area with a sprinkler. Cicada killer wasps don’t like to build nests in moist soil.

They also avoid nesting in dense lawns. So their nests are a clue that your lawn may need some beefing up.

Cicada killer wasps may be big and a little scary looking. But I hope you’ve gained some appreciation for these fascinating insects and enjoy watching them dance over your lawn.

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension.

This article was previously published by Herald-Mail Media. Read more by Annette.

A Lawn Retrospective on the Summer of 2023: Looking Ahead to the Fall Season

August 21, 2023August 17, 2023Maryland GrowsLeave a comment

Many lawns showed drought-stress symptoms in early summer. Photo: M. Talabac, University of Maryland Extension (UME)

It seems like ages ago, but during late spring and early summer we were in the midst of a long dry spell–and then things changed! Many areas in the region have seen more typical summer rainfall since late June. Since then, summer annual weeds and sedges were given new life with all of the wet conditions. For many homeowners, it has been a difficult summer keeping weeds like kyllinga, nutsedge, and crabgrass at bay during the wet, humid weather.

Crabgrass and thin spots in a lawn. Photos: C. Carignan, UME

University of Maryland research (and others) has indicated that the best way to deter crabgrass is to mow higher. Experiment plots mowed in the 3.5-to-4-inch range have consistently had less crabgrass invasion than plots mowed at 2 or 3 inches. While this late summer weather has led to a lot of crabgrass and sedge invasion, homeowners can take solace in the fact that relief is in sight as far as the calendar is concerned. Late August/early September is the perfect time of year to re-seed with cool-season grasses like tall fescue to undertake a full-scale renovation or a lawn “rejuvenation.”

First, let’s define a few terms:

Complete renovation involves killing the existing sod to bare soil and re-seeding or installing sod.

Overseeding involves using an aerator or de-thatcher to open up the turfgrass canopy and then applying seed to increase density and sustain the stand.

Repairing bare spots involves raking up old debris by hand or loosening it with a de-thatcher, then seeding.

More detailed information on these techniques can be found on the University of Maryland Extension Lawn Renovation and Overseeding resource page.

How do you decide what to undertake? If your lawn is thin, overrun with crabgrass, has a high percentage of broadleaf weeds, or is an otherwise “unsalvageable mess” you would probably consider a full renovation. If your lawn is a little weak in places, but otherwise dense and relatively healthy, overseeding would be more appropriate. Ensuring good “seed to soil” contact and maintaining adequate moisture in the seedbed is critical for successful germination.

Another key element in lawn renovation and overseeding is seed selection. There are a number of varieties (cultivars) of tall fescue available, however, some have performed better than others in the UMD evaluation trials and these are listed as “recommended varieties” in UMD Extension Bulletin TT-77-Recommended Turfgrass Cultivars (PDF). Although these varieties may be difficult to find at “big box” stores, many local garden retailers seek them out to stock them, and homeowners can often purchase them from local landscape professional suppliers or find them online at sites like seedsuperstore.com.

By Geoffrey Rinehart, Senior Lecturer, Turfgrass Management, Institute of Applied Agriculture, University of Maryland. Read more articles by Geoff.

Insects: Our Most Under-Appreciated Neighbors

August 15, 2023August 15, 2023Maryland Grows2 Comments

Why should I want bugs, insects, and creepy crawlies in my yard or green space?

Insects are an incredibly diverse group of organisms, with 91,000 described species in the United States and likely an equal number yet to be described by scientists. Only an exceedingly small fraction of these species ever have negative impacts on humans as “pests” (<1% of species). Often the overabundance of pest species is due to human agricultural and landscape practice choices. The vast majority of insects in shared spaces with humans like yards and parks are going about their own lives. In addition to being fascinating creatures deserving of habitat in their own right, they also often contribute to unnoticed but very important tasks that help humans, termed “ecosystem services.” The next time you see one of these critters in your yard, consider thanking them rather than smashing them.

What are ecosystem services?

Ecosystem services are benefits that humans gain from the environment. Examples of ecosystem services include water filtration, raw material production, erosion control, and pollination. Some ecosystem services, like the maintenance of atmospheric gasses (e.g. plants remove carbon dioxide and produce oxygen that humans breathe), are noticeable and directly impact our everyday lives. On the other hand, services like decomposition may go unnoticed because they indirectly affect us.

Insects (and their arthropod relatives like spiders and earthworms) play vital roles in many ecosystem services. This is often due to insects interacting with plants in some way, though insects also provide food for many other animals. Below are some examples of the ecosystem services that insects contribute to.

Water filtration

Filter-feeding insects positively affect water quality because they remove particles of dead organic material. Insects retain many of the nutrients they filter out of the water, thus reducing the likelihood of algal blooms, their associated toxins, and dissolved oxygen “dead zones.” This is crucial because clean water provides habitat for other plants and animals like fish and amphibians. It also means less effort is required to purify water for human use.

Types of insects that improve water quality:

Blackflies, mayflies, stoneflies, and caddisflies (Note: the underlined insect groups are not “true” flies in the taxonomic Order Diptera; they are part of other orders.)

Other types of organisms that improve water quality:

Mussels, crayfish, snails

More information: Why Care About Aquatic Insects

an illustration of the diversity of insects in an aquatic environment — Source: https://www.nsf.gov/news/mmg/mmg_disp.jsp?med_id=66886&from=

Biocontrol

Biocontrol is when natural enemies are used to suppress pests and reduce the amount of damage they cause. Natural enemies are insects that are antagonistic to pest insects. There are three types of natural enemies: predators, parasitoids, and pathogens. Preserving natural enemy populations is crucial to reducing our reliance on pesticides because when natural enemies are active, pest outbreaks are less likely to occur in the first place. Predators need food all year, so they also need alternate prey available in order to prevent pest outbreaks. Pesticides eliminate beneficial insects in addition to pests, so they should be used only as a last resort.

Fun fact: Fireflies spend much of the year as larval predators belowground, feeding on pests like grubs in turfgrass yards. If no prey is available in yards, then there will be no display of adult fireflies in the summer.

Types of insects used for biocontrol:

Beetles, lacewings, wasps, and dragonflies

Other types of organisms used for biocontrol:

Fungi, birds, amphibians, reptiles, and mammals

More information: Approaches to the Biological Control of Insect Pests.

a tiny black wasp next to insect eggs — Source: https://blog.pensoft.net/tag/parasitoid-wasp/

Seed dispersal

Seed dispersal is when seeds are moved away from the parent plant. Seeds are moved when insects knock them off while feeding or when insects collect and then move seeds to a new location. Seed dispersal is important because it reduces resource competition between the parent plant and offspring plants. It also makes germination and seedling survival more likely, especially in arid climates.

Types of insect seed dispersers:

Ants (most effective), beetles, wasps, thrips, and some moths

Other types of seed dispersers:

Fruit-eating animals (frugivores), such as some monkeys, lizards, and bats
Unwitting animal dispersers of sticky seeds like this

More information:

Seed Dispersal – The Australian Museum

The Conservation Physiology of Seed Dispersal

Source: https://www.science.org/content/article/don-t-crush-ant-it-could-plant-wildflower

Decomposition & nutrient cycling

Nutrient cycling and decomposition are two important processes that rely on one another. Nutrient cycling is when soil nutrients are taken up by plants, insects eat plants, and then those nutrients are reintroduced into the soil when dead insects and droppings are broken back down into nutrients via decomposition. Decomposer insects help clear dead animals and plants off the ground which would otherwise accumulate everywhere. They also help create soil texture and circulate nutrients back into the soil, which plant populations and productivity depend on.

Types of insect decomposers:

Many beetles, springtails, termites, wood cockroaches, and some fly larvae (maggots)

Other types of decomposers:

Fungi, earthworms, pillbugs, and millipedes

More information: Decomposers

Source: https://www.atlasobscura.com/articles/flightless-dung-beetles-south-africa

Supporting food webs

Insects are a main source of protein and nutrition for many animals (and even some plants). They play a crucial role in transferring energy from plants to larger animals that eat insects like spiders, birds, frogs, fish, bats, foxes, opossums, and bears. This wide food base that they provide allows for functioning, stable ecosystems that are resilient to disruptions.

Fun fact: By weight, there are roughly 300 times more insects than humans on Earth.
There are so many animals that eat insects, but here are just a few examples:

Terrestrial bird species, in particular, feed their babies almost exclusively with insects, and if there are fewer insects, baby birds are less successful at fledging from nests.
Popular fish like salmon, bass, and trout eat insects, especially when they’re young.
Grizzly bears will eat tens of thousands of moths a day to prepare for hibernation.

chameleon eating an insect — Source: https://a-z-animals.com/blog/what-do-chameleons-eat-16-foods-in-their-diet/

Pollination

Pollination is the transfer of pollen between flowers, resulting in flower fertilization and seed/fruit production. It is an unintentional consequence of pollinators going from flower to flower to feed themselves. Pollination is crucial for human survival, as 80% of plant-based foods and products rely on animal pollination. According to the USDA, pollinated crops are worth $18 billion in the US alone. Foods requiring pollination include apples, blueberries, chocolate, coffee, grapefruit, peaches, peppermint, sugarcane, tequila, and vanilla.

Fun fact: beetles were likely the first insect pollinators– starting 200 million years ago!
Types of insect pollinators:

Bees, wasps, beetles, flies, ants, butterflies, and moths

Other types of pollinators:

Birds and bats