Many people see the conventionally maintained lawns of the university campus as an opportunity to take shortcuts to class; however, when too many people follow the same route across a lawn, the grass becomes worn and exposed resulting in erosion. The development of these 'desired' trails can jeopardize the integrity of soils and vegetation and affect the aesthetic quality of the campus. If the path network does not accommodate peoples' travel needs, and this results in significant environmental degradation, then the path network is not a sustainable system.
The focus of this study is to design a sustainable path network which mitigates erosion impacts and maintains an appealing aesthetic appearance on campus. To evaluate the impacts of 'desired' trails, we selected a study site located on the south east part of campus between Parking Lot B and the Davis Centre (Figure 1.1 and Appendix A). The site has a designated Paved Path and four severely eroded trails. We chose it because we feel it is representative of other areas on campus with 'desired' trails.
We first determined a need for a more satisfactory path network during contacts with key authorities, who provided us with their perspective on the value of landscaping and the need to preserve the attractiveness of the campus. To to compare the intensity of use on all paths, we conducted a one-week 'traffic count' (a tally of path users' routes) during peak hours of Monday, Wednesday and Friday. We found the Paved Path to be most frequently used, but Trail 1 also had considerable usage. This was also evident from the high degree of erosion and root exposure found on this trail.
For our study we completed a survey to ascertain the origin and destination of people using the trails, and we questioned respondents on their opinion of the aesthetic appearance of the berm. An overall finding that path users considered the site unattractive supports the need for change. From the tally and survey information, as well as our research into trail erosion, cost and benefits of trail materials, and vegetation, we recommended a design for a sustainable path system. Our design would accommodate peoples' travel needs, but prevents deterrence from the designated paths, thereby reducing the impacts of erosion. Natural landscaping materials may contribute to a sustainable campus path system by altering peoples' walking patterns, providing durable paths, and creating an aesthetically pleasing site.
Figure 1.1: Trails 2 and 3 and the Paved Path Across the Berm
The south campus of the university consists of buildings and parking lots which are separated by grassy or landscaped areas ("berms"), and interconnected by a series of roads and paved paths. The paths are used primarily by students and staff of the university traveling by foot and bicycle.
Often, students and staff wear their own paths in the turf to get more quickly and efficiently from one place to the next. The consistent impact on these 'desired' paths may cause soil erosion and compaction, and may adversely affect vegetation, as well as being detrimental to the aesthetic appearance of the campus. Persistent use of desired paths suggests that existing paved walkways do not suit everyone's needs.
This problem presents an opportunity to develop more satisfactory systems of pathways and landscaping which meet the needs of their users while also contributing to campus sustainability.
In an ideal situation, the berms would not be covered with an intensively managed grass monoculture. Instead, plantings on the berms would require minimal human intervention and maintenance. Plant life would consist primarily of islands of naturalized vegetation, with a substantial portion of native plants attractive to insects, birds and mammals. Landscaping which incorporates food crops, berries, and plantings of hemp could also be useful to wildlife and humans. Paths would consist of suspended boardwalks above the ground, or made of bricks, gravel or another permeable material so as to allow rainwater to penetrate into the soil. Efforts in education and awareness would cause people using the walkway system to understand the negative effects of 'desired' paths and the issues of sustainablity in relation to the walkway system. Partly because of the increase in understanding about sustainability, non-polluting forms of transportation such as walking or cycling would be prevalent. Travelers would not feel the need to create 'desired' paths because the constructed paths would be extremely efficient, safe and convenient to use.
In our vision of sustainability for the campus, "Sustainability Through Ecological Consciousness", we concluded that true sustainability could not be reached unless all involved developed an ecological consciousness. Students and staff would be educated about the concerns of erosion, aesthetics, and vegetative health. Through a change in behavior, individuals would participate in regeneration of damaged sites.
Structural changes may also be useful in encouraging campus sustainablity. Structural changes could include alterations in landscaping, path and landscaping design, so as to render the walkway system more sustainable and eliminate the need for 'desired' paths. Because the achievement of desirable ecologically conscious behavior is beyond the scope of this project, we will predominantly examine structural changes.
One of the major concerns to address is the potential for soil erosion and compaction (Figure 2.1). A protective vegetative cover breaks the wind and disperses raindrops. On most surfaces, vegetation seems to be the most important control on soil erosion (Marsh, 1991). When the grass is worn away, soil is exposed and can be readily washed away by wind and rain.
When rain falls on bare ground it breaks down soil aggregates. Fine particles are moved to the surface, creating a seal which rainwater is unable to penetrate. This can result in sheet erosion from runoff, which can be aggravated by soil compaction. (Smith, 1992). With the desired paths, the constant wear and tear of people walking over the bare ground can likely result in significant soil compaction.
The presence of a 'desired' trail may also cause water to run off the berm in streamlets over the trail. This could increase the water's ability to erode as its velocity increases, and thus result in further erosion of gullies. Gully erosion frequently starts on recreational hiking trails, as well as livestock trails, and trails created by off-road vehicles (Smith, 1992). The desired paths can be likened to recreational trails.
Figure 2.1: Root Exposure on Trail 1
If desired paths occur around trees, shrubs and other (non-turf) vegetation, compaction of the soil and exposure of roots may compromise vegetation health (Figure 2.2). Potentially, this could result in stress, illness, or death for trees and shrubs.
If the health of trees and shrubs on the berm is damaged, there may be detrimental secondary effects on wildlife that depends upon the vegetation. In addition, vegetation may be rendered less desirable for human use (for example, shade cover may be compromised due to illness). The replacement of sick or dying trees and shrubs would represent a financial cost to humans as well.
The erosion of 'desired' paths adversely affects the aesthetic appearance of the campus. In a discussion with a member of Plant Operations, we learned that the appearance of the campus is a very important consideration for the university administration (Galloway, 1997).
Figure 2.2: Damage to Tree on Trail 3
To make this project manageable, we decided to focus our study on the berm located between the Davis Centre and Parking Lot B. This berm was selected in a visual survey of the campus due the severe extent of damage observed. Specifically, we will study the four desired paths located on the berm to either side of a paved path that leads to Parking Lot B. Section 3.0 describes the boundaries of the system.
Specifically this project determined:
The berm is the smallest component in a nested land-use system. The system that contains the berm system inside has two components: biophysical and socioeconomic-political.
The biophysical element of the land use system consists of energy, vegetation and man-made structures (for example: parking lots and buildings). Since the flow of energy that influences the vitality of plant life originates from diverse and distant sources such as the sun and even fertilizing companies, it is included in the outermost layer of the diagram.
The socioeconomic-political element of the land-use system consists of humans and the influences they have on the Earth. This can include administrative bodies and organizations that make decisions regarding land use, and also the people who use the grounds for recreation, building, gardens and roads (the biophysical aspects). As space is limited, the largest community represented in our diagram is that of Kitchener- Waterloo.
3.1 University Campus
This is the largest boundary for the system study because this is where key contact actors within the University Administration reside.
Plant Operations is funded by the University Administration. Some of this money is directed toward landscaping and maintenance. Tom Galloway of Plant Operations, one of the people in charge of landscape options, is an example of a key actor. Les van Dongen, a horticulturist with the landscaping and maintenance crew, also has responsibility as to the design of the campus.
The decisions of key actors within the University Administration can affect the study site positively, negatively or neutrally. Examples of potential decisions include: not making any changes to the present operation (the present rate of erosion would continue); designing paths in the area that follow the desired ones of students, faculty and staff; implementing structural landscape techniques such as dense shrubs so that people would be hesitant to walk on the grass; educating people about the effects of erosion; or implementing alternative structures to deter them from walking off the paths.
3.2 Study Site
The berm study site is located in the south east part of campus between Parking Lot B and the Davis Centre. The Canadian National Railroad (CNR) tracks and a gravel path run lengthwise between the berm and the parking lot. Many people walk over the berm as they come from or go to various buildings on campus.
The focus is on the system inputs (red, pink and blue boxes on the diagram), and outputs (green boxes) (Figure 3.1). Energy enters the berm system in the form of sunlight, water or rain, carbon dioxide and nutrients such as fertilizer. Without these elements, the plants on the berm would not be able to survive.
The oxygen output is placed outside the berm system nest since oxygen is a gas with no fixed position. The aesthetic and habitat outputs are contained within the borders of the berm study area since they are stable.
Rain has an important effect on the health of the berm system in the places where grass is eroded away. In storms a deluge of rain may wash away exposed soil or any groundcover that is weakened by people walking on it. Rain also provides neccessary moisture for plant survival.
The efficiency of vegetation's use of energy depends primarily on its type. A plant may not be able to survive if the energy input is not enough to meet its needs. Conversely, the plant will thrive if the energy input is sufficient. Native vegetation may thrive, for example, in an area where exotic vegetation with a higher water demand than is provided by nature cannot. The health, type and quantity of the vegetation determines the amount of animal habitat, the aesthetic quality of the berm, and the amount of oxygen that is produced or carbon dioxide sequestered.
Other influences on the system include:
Figure 3.1: System Diagram of Study Site