By Mel Bellar
I am a little obsessed with lines and edges in the landscape and any landscape, is full of them. Think about it. Walls, paths, driveways, fences, beds, streams and lawns all have edges and these edges create lines that can be intentional and pleasing to the eye, or not. These are things that I talk about, write about and think about all of the time, but today I am exploring a different and more complex kind of edge, the ecotone.
It is Winter so I am going to some conferences to get inspired, see what’s up in the landscape design and horticulture worlds, network, and hang with other landscape geeks. Sometimes I get a lot out of it and sometimes I just get one useful tidbit or concept. I have attended the New Directions in the American Landscape annual symposium several times The focus of the conference is usually ecological-minded landscape design which involves natural design, native plants, good sustainable and organic practices; all good stuff. This year it was all over the place, even trying to bring social consciousness into the landscape design purview! There was some interesting information about agro-environmental practices, cultural integration, soil science, incorporating history into design, etc. There even was a woman who did augmented reality audio for visiting gardens; this involves wearing a special headset that lets in outside sound with her soundtrack. The idea is to augment the real sounds, but it also mixes in imagined conversations from the past and future, all to provide you with historical context and future possibilities. This is supposed to make your visit more meaningful, providing you with a more expansive experience. Now that is on the edge! What I got out of the conference was the ecotone. This concept came up a few times and while it is something that I have heard before, now it is a real bee in my bonnet.
“An ecotone describes an area that acts as a transition or boundary between two ecosystems.” The two ecosystems can be a field and forest, a stream and the bank, dry and wet, or two countries for that matter. Ecotones are important and super interesting because, since they are influenced by two ecosystems, they have a greater density and diversity of flora and fauna. This is called the edge effect. It is a whole thing! It also makes sense that certain species can be unique or at least primarily prevalent in a particular ecotone. I love this concept and the way it can be applied to almost any boundary where two contrasting environments intermingle. While I have no specific examples, I bet that there are many areas between two countries where a sort of Spanglish or Tex/Mex food develop that are unique to that ecotone. I would love to wax on about possible cool ecotones but there are some real ones that we can talk about that are pertinent. The woodland edge is the ecotone that I most often deal with and that I find challenging. When nature is left to its own devices and the field is not mown right up to the woodland, this transition between the woodland and open area can provide a richer habitat for a larger variety of birds and wildlife than either of abutting environs. The birds from both communities overlap and some are drawn specifically to the ecotone, as it has just the right mix of structural vegetation layers, food diversity, and foraging places. The rich-layered vegetation also provides cover and food for deer and small mammals. This brings to mind the ecotone between our roads and woodlands where there is abundant growth that attracts the deer and other creatures for us to run over. Part of our deer problem, both in the roads and our gardens, is because of the lack of ecotones. We mow or brush-hog right up to the woods, and the lack of forest fires to create natural clearings in the forest adds to the issue. You know I hate the deer and could go on here. According to the Nature Conservancy the woodland edge should be 10 feet to 25 feet wide, irregularly shaped (to avoid predator line of sight and provide more edge”) and populated by a wide variety of species getting progressively taller as you approach the woodland. This presents a challenge for me as a good steward of the environment and a designer who wants things to have a certain aesthetic value. We have so many invasive species that love to hang out in the ecotone(s) like multiflora rose, Tartarian honeysuckle and Japanese knotweed, to mention a few. It is difficult to figure out a way to clean up and revamp a woodland edge to be nice-looking and still ecologically responsible without it costing a fortune. It is an interesting problem. I may try to explore this more in a future column. Exciting! You can always email me at firstname.lastname@example.org with suggestions for topics. ~
Mel Bellar is the owner of Zone4 Landscapes and a passionate Andes gardener