The dormant vines of Kudzu (Pueraria montana var. lobata)
amongst Chinese Privet (Ligustrum sinense) and Leatherleaf
Mahonia (Mahonia bealei) along the tree line behind the house
Since an antiquity we can only subtly recall or guess at, the lives of humans have been fully intertwined with those of plants. The botanical myriad is undoubtedly the more generous factor in the relationship, providing our species with almost all of our basic physical needs. Shelter, food, heat, medicine, and clothing are but a few. Plants literally take the light of the sun, the air from the atmosphere, and the elements of the Earth and process them into something we can consume or use, a very powerful and respectable feat. Humans, on the other hand, rarely give back any sort of appreciation and seem to forget that our survival is wholly dependent upon the alchemy of botany. Most generosity on our part comes in the form of planting, watering, cultivating-essentially nurturing plants so that they can continue to harvest them in order to meet the demand for the satisfaction of a physical need. This is sort of a Catch-22, considering that a whole host of plants were probably destroyed for the sake of cultivating a plant or implementing its usage.
As a result of our clever manipulation of the plant world, we have been able to explode our population and subsequently destroy more plants as we expand. We then replace the destroyed species with those plants which we have chosen to supply our physical needs or satisfy our aesthetic desires. These particular species have sojourned with us for a long time and many seem to have adopted our behavior patterns, traveling with us across oceans and invading the lands that have been disturbed. Like us, they have moved out of sync with ecology and taken advantage of the natural world without so much as a thank you. Merciless, tenacious, and allelopathic-our exotic invasive species like to bully the more delicate species and establish dominance in systems that do not know how to adjust to their presence. At the turning point of our relationship with nature, when we have failed in our separation from the ecological web, we have almost exhausted that very botanical myriad that supported our lives to begin with. Now, we are turning back towards an appreciation of the natural world, remembering its importance, and making efforts to preserve and restore its integrity. A new question arises: what do we do with these rebellious plants, these foreign invaders who have ridden our coattails and colonized and plundered new frontiers? The answer is simple: we must direct the remaining aspects of our own destructive tendencies and KILL THEM WITHOUT MERCY.
***
Historical disturbance, gardening trends, and distribution by government agencies can all be linked to the presence of the naturalized exotic plant species in and around the present landscape of the Norris property. Any time an area of forest is cleared, the resulting abundance of light, available soil moisture, and open (competition-free) ground allows for the rapid colonization of early successional plants. Natural succession within a plant community of indigenous species takes a long time to progress through stages. You first have a hodgepodge of grasses and annual weeds, followed by herbaceous perennials, later by shrubs and saplings, which eventually become large and shade out the ground layer. The early successional tree species then form a dense canopy, which is eventually penetrated by more long-lived climax species who then retain dominance for a long, long time until a new disturbance arrives. Problematic invasive species do not heed these rules. The woody species seed into disturbed areas quickly and grow very fast, outcompeting native species and forming monocultures within a period of a few years. What remains is a low level of biodiversity, a habitat which indigenous fauna has not evolved to exist within, an impenetrable tangled mess, and a whole new crop of seed or spreading roots poised to invade the next disturbed area.
Several of the exotic plants in the Norris area were once widely used for ornamental or structural purposes. Chinese Privet makes a great hedge, as it is both evergreen and fine-textured. Privet also responds well to heavy pruning, which causes the branching structure to become more dense creating a wall of foliage. The notions of property and privacy have given this plant a major role to play in the human landscape. Another tough ornamental plant is the Leatherleaf Mahonia, a shade-tolerant evergreen Asiatic plant. It was (and still is) often planted below windows, where its yellow flowers provided olfactory enjoyment and its spiny leaves deterred would-be burglars from entering. Perhaps the most well-known of the exotic species on the Norris property is the Japanese Honeysuckle, whose profuse sweet-scented flowers bloom from Spring well into Fall. Appreciated by many a child and a longstanding element of pastoral America, it is by far the most destructive of all exotic plants. Its seed is carried in the gut of birds far into remote reaches, where it takes root in sun or shade, choking out everything in its path from the ground plane to the tops of canopies. Its shrubby cousin, Amur Bush Honeysuckle, is also common in the area. Equally as tenacious, this species dominates the shrub layer and leaves the ground plane vacant.
An incorrect assumption that Kudzu was the answer for erosion control issues caused it to be widely promoted and planted by government agencies in the early to mid-20th century. It has clearly not served its purpose or displayed mild-mannered behavior. Its random taproots do little to hold the soil among its heaps of vines, and its quest for sunlight pushes it up and over the tops of trees, suffocating them and toppling them with the shear weight of its mass.
Why such a thorough investigation of the nature of exotic invasive plants? Two reasons: one, to illustrate the importance of why we must remove them when creating a new landscape; and two, to show how the actions of man upon the environment have disrupted the ecological balance even when man itself is no longer administering the affectation. As we rethink how we live in, interact with, and take from the world around us, we must be ever cognizant of the kaleidoscopic effects of our decisions. It is then truly up to us to at least attempt some sort of restorative process within places were the fruits of this labor can be seen. I think we have that in the small chunk of land at Norris. We begin with the removal of the invasive species, ensuring success for the what is planted thereafter and expanding our canvas. Secondly, we will begin to establish a mosaic of plantings that will bring back biodiversity, suitable habitat, and potentially a perpetual balance of species interactions. The return of indigenous vegetation, along with some well-mannered historically popular ornamentals, will most certainly address the functional needs (privacy, water filtration, erosion control). Also, our innate desire for sensual experience within a place to call home will be satiated with color, fragrance, form, texture, and a whole host of diminutive creatures ready to call it home as well.
***
Last Thursday, January 27th, three of my fellow Masters of Landscape Architecture students and I visited the site. Valerie Friedmann has been working with the project for over a year and has done a superb job of bringing the rest of us up to speed. Her and I visited the site the first week of the semester and began to formulate a list of tasks that will bring us closer to completion of the landscape. The Thursday visit was the first time that Justin Allen and Corrin Breeding were introduced to the site, and I was elated that both shared in the excitement over the opportunity to apply our skills to such a (excuse my use of a pop culture adjective) COOL project. I have worked with both gentlemen before on the Zero Energy House project, and am more than confident in their knowledge of landscape construction, physical strength, work ethic, and ability to produce superior results. After introducing them to the landscape and painting a picture of the proposed layout, we got to try our hands at a little surveying. A need to locate the outflow pipe from the rainwater cistern and understand its grade change had us doing something we had not done in a while: surveying. The 'riding the bike' analogy is an appropriate parallel to the process of shooting azimuths and calculating distances via stadia readings. We were a little rusty at first, got the hang of it again, and before we knew it, we were coasting with the information needed to make sure that a two-dimensional plan was going to be feasible in a three-dimensional interface. As we begin to prepare for the installation of the landscape infrastructure, there is another task to address:
KILL SOME EXOTIC INVASIVE PLANTS.
