Some plants are just a little too weird

 Echium

Gardeners can’t help their obsessions with strange-looking plants. And usually, with the hard-core gardeners that I know, the weirder the better. But new research suggests that these far-flung oddities do not benefit much in the environment. Doug Tallamy, professor entomology at University of Delaware, and his student Karin Burghardt, conducted a three-year study to see how herbivores responded to planted yards full of either exotic or native plants. Not surprisingly, there was not as much insect diversity found on the exotic plants as compared to native plantings. They further found out that there were even less species on exotic plants that did not have a close native relative. For example, exotic Norway maples are kin to our native red maples, and shared nearly similar insect diversity. While the far flung exotics that had no close native relative supported little life. Burghardt noted that “If you think about it, you're driving around the suburban environment, and every time a new development goes in, you have a lot of decision making happening as to what plant species are going to be planted around those properties. If we do all that landscaping with non-native plants, are we limiting the wildlife and conservation support system that could be available within that given plot of land? What the gardens we constructed for the study are trying to replicate are landscaping decisions that people might make if they wanted to support native insect communities that in turn support much of the diversity around us.” Their paper was published in the October 2015 issue of Ecology Letters.

Conserving Vacant Lots in Detroit for Stormwater Control

One of the more impressive ideas for reusing vacant land in downtown Detroit is to create gardens for stormwater control. An article in the Detroit News by writer Kim Kozlowski (December 14, 2015) states that the Detroit Water and Sewerage Department and the Detroit Landbank Authority have partnered to utilize a few  open lots for rain gardens. Rain gardens store water temporarily before releasing it to city stormwater systems. And this is important in cities like Detroit that have had problems with overloaded storm systems that can dump urban water, and raw sewage, directly into the Rouge River. In 2014, polluted urban runoff from Detroit and its surrounding areas created undrinkable water supplies for parts of Michigan and Ohio. Joan Nassauer, professor of landscape architecture at University of Michigan, is leading the project’s effort to slow the urban runoff. Nassauer states in the article, “If during a storm we can keep much more water here just below the ground, that reduces the pressure on a city’s system and so there won’t be a big untreatable amount of water that comes into the system” (Article available from the Detroit News online at http://detnews.com/)

The Art Garden, Mississippi Museum of Art

Edgeland Excerpts: Is Native Purity a Viable Option?

Quoted from Dr. Colin Meurk: “But, what is “wild?” There is an appetite again for “rewinding” and using “cues for care” (Nassauer) in urban environments to make this acceptable. The niche envelopes can be as surely defined in these contrived ‘wild’ urban environments as in the real wild. With many environmental stress/disturbance combinations, native species will individually survive by chance at some points and places, in combination with some (weakened) exotic species, then reproduce and eventually find their ‘natural’ position in the gradients provided as self-sustaining populations. That may be the future of many lowland, open habitat herbs. Then invertebrates, birds and lizards will find these plants and establish their ‘natural’ interactions. Meta-populations of such plants may form on roofs, walls, pavements, rock gardens, lawns etc. These habitats can be seen as forming an archipelago in urban environments!"

Dr Colin Meurk is a senior ecologist at Landcare Research, New Zealand. Quotation from Global Roundtable Green Form and Function versus Green Nativism at the Nature of Cities.com (http://www.thenatureofcities.com/2015/11/05/green-form-function-versus-green-nativism-in-changing-urban-spaces-full-of-novel-ecosystems-and-natural-assemblages-is-native-purity-a-viable-option/)

It's Better to Leave Your Leaves

Experts from the National Wildlife Federation (NWF) reported that it's definitely better to leave your leaves, where they lay. Gardeners and landscapers know that plants grow better in mulched beds. Decomposing leaves contribute nutrients back to the soil, screen sunlight from hitting plants roots in summer, and protect from moisture loss due to evapotranspiration. But wildlifers are interested in the ground habitat that leaves provide. NWF says that worms, mammals, amphibians, reptiles, and many insects depend upon leaf litter in which to lay eggs or hide. Randall Hitchin, University of Washington Arboretum, says he rarely rakes leaves because "it changes the habitat, and makes it unfriendly for (insects)"(Dan Cassuto, KING 5 news, Nov. 3, 2015).  Areas that are currently in lawn grasses can be easily converted to planting beds by simply raking the leaves to areas underneath trees or around shrubs. Thick layers of leaves will choke out the existing turf and become soil habitat in no time. And the surrounding trees and shrubs (and critters) will immediately benefit.

Ovenbirds Take to Forest Fragments

 DickDaniels (http://carolinabirds.org/)

“And comes that other fall we name the fall.

He says the highway dust is over all.

The bird would cease and be as other birds

But that he knows in singing not to sing.

The question that he frames in all but words

Is what to make of a diminished thing.”

                --Robert Frost, The Oven Bird

Ovenbirds (Seiurus aurocapilla) are LBB’s (little brown birds) that are seen foraging for food on the forest floor across Canada and the eastern United States. While their breeding range is in the northern United States, they overwinter in the southern U.S. and Mexico. Ovenbirds breed and nest in older deciduous or evergreen forests and are rarely found in urban environments. Except for suburban landscapes.

In a paper entitled “Forest Fragmentation Effects on Ovenbird Populations in the Urban Region of Eastern Massachusetts, USA” published in Urban Habitats (2012), authors Morimoto, Frankel, Hersek and Wasserman found that large residential lots with forest cover can effectively serve as nesting habitat for these forest birds. The study notes that forest cover greater than 40% and small woodlots close to larger tracts of forest with high connectivity reduces edge predators such as cowbirds, which often plague the ovenbird’s nests.

The study concludes that “urbanization accounts for the majority of developed land in many areas in the Northeast (e.g., Steel 1999). Given this trend, it is of critical importance to recognize the value of the remaining forested habitats in these regions and to manage these landscapes in ways that will maximize their benefits to natural communities and species of interest. We recommend that municipal leaders, land managers, and planners take account of geographic location and regional landscape context when interpreting and then applying results of scientific studies to the management and conservation of viable bird populations in urban regions and elsewhere" (Morimoto, Frankel, Hersek, and Wasserman 2012). 

Book Excerpt: Planting in a Post-Wild World

"Tomorrow's designed landscape will be many things--more plant driven, site responsive, and interrelated--but one thing it will not be is stylistically the same as its predecessors. It is perhaps easy to assume that plantings layered with a diverse mix of species would be necessarily naturalistic in style. In many cases, this is true. But gardens of any style can benefit from applying natural principles. Whether the planting is formal or informal, classical or modern, highly stylized or naturalistic does not matter. What matters is that plants are allowed to interact with other plants and respond to a site. This is the essence of resilient planting."
--Thomas Rainer and Claudia West (2015), p. 243