With all the cicada buzz in our area these days, it may be hard for some to imagine that insects are in trouble.
In 2019, a study of insect populations in Germany reported a precipitous decline in insects in the study area. The degree to which insects are declining is difficult to know based on one study, but it’s true that insects are missing from places where they were once plentiful.
The firefly is one example. According to Firefly Conservation and Research, survey data indicates that firefly numbers are declining globally.
Loss of habitat is one of the primary drivers of the population decline of insect species. At the bottom of the food chain, insect decline puts many other species at risk, impacting the biodiversity that makes our ecosystems resilient.
As a response to the observable loss in biodiversity in our state, the Delaware General Assembly created a statewide Ecological Extinction Task Force in 2017. The task force was made up of legislators, biologists, entomologists and botanists, along with other stakeholders from groups like the Nature Conservancy and the Delaware Chamber of Commerce.
The task force arrived at 86 recommendations to reverse the trend of the decline of biodiversity of local native plant and animal species. The recommendations promote conservation practices, incentives and education for local governments, developers and landowners. One of those recommendations is to create incentives for landowners to reduce lawn area and replacing it with native plants.
Why should we reduce our lawns and replace them with native plants? It turns out there are good reasons. Our considerable investment in the bright green, perfectly cut, weed-free expanses of grass come at considerable cost to wildlife.
Start with the seed – one type of seed produces only one type of plant. Using weedkiller or herbicide guarantees that it stays a monoculture. Two widely used lawn grasses, tall fescue and Kentucky Blue, are imported from other parts of the world. These grasses are not food sources for our native insects. Less food for insects means less food all the way up the food chain. Despite all the care and lush growth, lawns support surprisingly little life – ironically, not even grasshoppers.
Another environmental impact comes from fertilizers. To produce that lush green requires fertilizers high in nitrogen. The nitrogen and the potassium in fertilizers can wash from lawns into streams and rivers, degrading them by disrupting chemical balances in numerous ways, such the algal blooms that choke the ecosystem by depleting oxygen. If bad enough, fish and other aquatic creatures are at risk.
Finally, there’s the months of a weekly ritual of mowing. Gas-powered mowers generate air pollution, greenhouse gases and ground-level ozone. Mowers and blowers are a source of noise pollution and a danger to wildlife of all sorts, from moths to box turtles. A little less lawn means less of all of that.
A relatively simple and ecologically friendly method for converting some of your lawn to beds for those native plants begins with choosing an area. Lay a rope or garden hose out into the desired shape. Use pulverized lime to outline your shape and then remove the hose or rope. Set your mower low and mow that area. Mow again at a lower setting until you can’t lower it anymore. Cover the area with layers of paper. One or two layers of contractor’s paper is the easiest, but layers of newspaper or cardboard work as well. (Landscape cloth is not biodegradable and makes a barrier between the soil, preventing, among other important processes, emergence of insects and the mixing of organic material from above.)
Lastly, cover the paper with at least 1 inch of hardwood mulch or 2 inches of leaf mulch. How much mulch you need will depend on what type of paper you use. In a month or so, your new bed is ready to be planted. No tilling, no turf removal, just push the mulch aside and dig the holes.
Converting a lawn to habitat with a selection of native trees, shrubs and perennials yields surprisingly quick results. As the habitat develops over time, a stroll in your yard can become a nature hike.
Across the country, we have replaced wildlife habitat with millions of acres of lawn and ornamental plants. An excellent resource for more why and how to reverse the trend in the decline of biodiversity is “Nature’s Best Hope” by University of Delaware Professor of Entomology Doug Tallamy.
The Conservation Advisory Commission was created in 1977 to advise the city of Newark in the development, management and protection of its natural resources, with appropriate consideration of Newark’s human and economic resources. It meets the second Tuesday of each month at 7 p.m. in council chambers. The public is invited to attend and provide input. Commission members provide this monthly column to inform area residents on conservation issues.