2015 has been declared the "International Year of Soils" by the United Nations. Soils play a crucial role in food security, hunger eradication, climate change adaptation, poverty reduction and sustainable development. The health and preservation of soils world-wide, and the associated beneficial impacts on wildlife, clean air and clean water, have become concerns shared by many researchers, policy makers, farmers, landscapers and laypersons alike.
A major focus of the LELE initiative is on the benefits of leaf mulching for your lawn, as well as for your landscape and veggie garden beds. But we also recognize that it is important to strike a balance with other habitat needs, and thus our recommendations include leaving whole leaves in place in wooded areas and scrubby margins. This is because many insects such as butterfly and moth species overwinter as pupae in leaf litter and scrub. Maintaining some leaves unchopped (unmown) provides over-wintering areas for many important beneficial insects and small animals including salamanders, earthworms and certain bird species.
The National Wildlife Federation writes on its blog that “You shouldn’t feel obligated to rake up every last leaf in your yard this fall. Leave leaves on the ground — they have a lot of benefit to wildlife and your garden." The article goes on to state that "the leaf layer is its own mini ecosystem! Many wildlife species live in or rely on the leaf layer to find food and other habitat, including salamanders, chipmunks, box turtles, toads, shrews, earthworms, many insects species... Many butterfly and moth species overwinter as pupae in leaf litter."
In a related blog posting, the NWF outlines 6 Excuses to Avoid Yard Work This Fall regarding the benefits of leaf mulching and of simply leaving leaves alone in margin areas:
- Provide Habitat for Wildlife
- Provide Nutrients for Organisms
- Reduce Waste
- Increase Fertility of Your Soil
- Reduce Pollution
- Save Time
Life In the Leaf Litter (.pdf file). It's a fascinating guide to the diversity of soil organisms and the crucial role that invertebrates play in woodland ecosystems. The booklet was based on a leaf litter survey conducted by the Museum's Division of Invertebrate Zoology.