Ecological balance in our neighborhoods

I live in a historic neighborhood near downtown Asheville.  It's Asheville's oldest neighborhood, actually.  Our house was built 10 years ago on an infill site, between a  ~1920's apartment building and an older rental house.  Many houses in our neighborhood are distinctive Victorians, others are of equally historic design.

But, most importantly, because we're a historic neighborhood, we have regulations (administered through the Historic Resources Commission) about the exterior of our houses (and changes we might want to make), as well as landscape changes, including removing trees of more than 5" in diameter and review of even dying trees.

This may seem trivial to some, but does encourage preservation of our urban canopy, but we still can do more. (A friend marveled at the canopy view from a nearby hotel's rooftop bar recently, as she couldn't even see many houses, although she thought she spotted ours, which is quite close, and a distinctive adobe color.)  She wondered why our tree regulations needed to be so stringent; well, our canopy reflects that!

I wrote a recent piece for our neighborhood newsletter, which I've pasted below, prompted by a neighborhood list-serve back and forth about decreasing bird diversity and outdoor cats, as well as my continued thinking about the canopy forest, hearing Doug Tallamy, Nigel Dunnett, and Thomas Rainier speak at the Davidson Horticultural Symposium several weeks ago, as well as preparing recent talks that I've given.

It's on my mind, as I'm thinking about shaping a talk for the weekend after next, too.

Natural Neighborhoods: Ecological balance

Many of us enjoy watching (and hearing) birds in our landscapes, as well as in our historic neighborhood.  Pollinators such as butterflies, bumblebees, flower flies, sweat bees, and honeybees are equally welcome. But we don’t always recognize the attributes in our landscapes that support these animals and insects. 

Their presence is basically a reflection of available habitat:  do our gardens and landscapes support the diversity of their needs for food, shelter, and nesting sites?

For example, it’s native trees and shrubs that largely provide food for caterpillars that feed the nestlings of many birds that live in our neighborhood.  A nesting pair of chickadees needs roughly 4,000 caterpillars to successfully raise a single group of nestlings, according to entomologist Doug Tallamy (author of Bringing Nature Home).  He points out that many adult birds eat seeds and/or fruits, but most feed their young protein and lipid-rich caterpillars.  Oaks, pines, black cherries, and willows are some of the most important host plants for these caterpillars (the larvae of butterflies and moths).  A typical oak species may harbor upwards of 550 species of insects, providing food for a lot of young birds! In contrast, the species of caterpillars found on the leaves of non-native species are much fewer; Tallamy’s research documents 8 caterpillar species occurring on flowering quince and 5 species on ginkgo as examples

In Montford, we've been lucky to have a robust canopy of native oaks, hickories, pines, and other species, planted long ago, but also persisting as volunteers in remnant patches of forest throughout the neighborhood.

Squirrels in cavity

As our older canopy trees age out, we need to continue to replace the oaks and other native trees with natives (of all sizes of trees), while we leave the snags, where possible, to provide homes for woodpeckers, owls, and other cavity nesters. Preserving (and restoring) backyard edges, ravine forests, and greenway corridors also plays a vital role.

By including more natives, we help re-knit the fabric of our altered ecosystems in cities and towns, increasing ecological balance. The vibrancy of the urban forest in Montford (and Asheville) depends on us; let’s keep planting to maintain nature in our neighborhoods.

The City of Asheville has a list of recommended tree and shrub species (native and non-native) from the Asheville Tree Commission on their website (ashevillenc.gov).  Look on the Urban Forestry page for a link to this list.

view of the ravine forest below our house (restoration in progress!)