Circulation

Small (young) trees grow into large trees. When small trees are planted in a space, the intended impact of the space is minor, compared to when the trees approach maturity and fill in and grow into a canopy, shading the space.

Many plants undergo changes with the seasons throughout the year. Deciduous trees and shrubs lose their leaves in the fall in anticipation of the approach of winter. Before the leaves drop, they change color in autumn from shades of green to multitude shades of yellow, orange, red, purple, and brown. With the onset of spring, the leaf buds on bare brown branches swell, gradually turning from pale, light shades of green to increasingly more intense shades of the leaf color they eventually will achieve on maturity by early summer. All these changes are part of a continuum or natural process and it is the knowledge of this process of change that is understood by a landscape architect. This palette of change is considered when specific species of plants are selected and placed in the designed landscape. Landscape architects also consider the metamorphic changes of plants over the span of time when designing spaces and places.

As the installed plants mature, the spatial qualities and scale of the designed landscape evolve. Planted spaces become more in scale to the visitors of these spaces, perhaps as spaces where there is a more comfortable feeling. Comfortable in terms of scale and more agreeable spaces to be in as the shading aspect of the trees is realized. Landscape architects will select and place plants to moderate the effects of wind, sunlight, and views. Deciduous trees planted along the face of a south-facing building will shade it and reduce heat gain from the summer sun. These same trees will lose their leaves in the fall, reversing the effects of sun, allowing for heat gain into the building. Plants can serve to screen undesirable views. As the plants grow, their potential for blocking or reducing undesirable views increases over time, eventually providing visual privacy. The physical permutations of change that plants undergo in a year’s time or over tens or even hundreds of years are challenging to learn and for a landscape architect to master. To add a further dimension to the challenge is that each region of a state, provenance, country, and continent has unique aspects of time-related changing, that must be learned and understood. The physical changes from season to season or year to year have aesthetic implications to be learned as well. Horticultural knowledge of the plants and their time-related changes can enhance or moderate some of these changes. The landscape architect at the outset of the design process must account for the ramifications of soil, climate, longitude, and hydrology when developing a plant design palette. With the sound understanding of these factors, more informed decisions will be made with respect to plant species selection and their impact on the designed landscape.

Circulation (both vehicular and pedestrian) is an element in the landscape that provides the organizing structure for a plan of a new neighborhood, the site design of open space, a campus plan, and any project that has a variety of program elements requiring access, the

internal connection between facilities and use area, and way-finding requirements. One of the steps in the process of developing a site plan for a park or neighborhood, for instance, is to organize various program elements in a bubble diagram, then connect the various elements to the park programmed elements with vehicular and pedestrian circulation (Figure 2.2). A continuation of the site design process discussion can be found in Chapter 3.

The walkway in Figure 2.3A connects the upper central quadrangle on the UCLA campus to the lower athletic fields through the use of a terraced flight of stairs. The walkway extends the bilateral symmetry of the upper academic quadrangle making up the dramatic change in elevation with the stairway system. The lower axis has as its terminus the distant hills while the upper axis is aligned with a grouping of academic buildings that provide the peripheral frame of the central activity area of the original campus. The pedestrian and bicycle path in Figure 2.3B skirts along the edge of one of the retention ponds at the Water Ranch Park in Gilbert, Arizona. The path allows the visitor access to several wildlife viewing locations and connects several ponds, each having vegetative habitat to attract a great variety of visiting bird species. The walk in Figure 2.3C is an example of the concept of conceal and reveal. The idea is to align the walkway to provide a glimpse of what is ahead, creating an element of surprise and hence interest for the pedestrian. The planting of a vegetative screen further enhances the concealment effect. An “S” curve in the walkway alignment is often used to create a concealed then revealed experience as shown in Figure 2.4. Notice how the movement of the walk draws your eye in the direction of the circulation as well as creating a dynamic visual composition within the space.

Figure 2.2 Park master plan diagram with circulation. Courtesy of Reich Associates, landscape architects. Figure 2.3 Examples of three very different pedestrian walkway design concepts: A: Simple lineal; B: Serpentine; C: Bilateral symmetry.