Ecology is the study of the totality of living systems and the geologic, atmospheric, and hydrological systems that come together to support the living systems. Thus, ecology as a science is surrounded and intersects with many other scientific disciplines. A subset of these disciplines includes physiology, genetics, hydrology, atmospheric science, geology, behavior, biochemistry, and biology (Smith and Smith 1998, 3–5). Ecological systems and the animals and plants that make up the system maintain stability by a combination of positive and negative feedback. Positive feedback accelerates a response. Negative feedback retards a response. The combination of multiple positive and negative feedback loops creates a nonlinear system. Nonlinear systems are stable within limits, which is a very important characteristic. A linear system will grow or decline along its linear path when perturbed, and thus cannot create a stable environment (Smith and Smith 1998, 10–13).
Architecture at its core is a puzzle where the pieces change shape as the architect brings the order of the design together. Architecture like ecology is surrounded and supported by multiple disciplines. The architectural puzzle includes parts of each of the supporting disciplines. The decision to expose or hide the HVAC ducts, the decision to expose or hide the structure and which direction the structure runs, the location and design of the elevator lobby, and the orientation and type of light fixtures are examples of architectural decisions that are then followed up by engineering calculations to fill in the details of the design. As all these pieces of the puzzle come together they affect each other and the larger design concept, causing nonlinear interactions that eventually create a stable solution (Figure 6.1).
Living systems embedded in an ecosystem inhabit niches along environmental gradients or around feeding and or breeding areas. Far from the center of the niche, survival is not possible. Moving toward the center of the niche is an area where growth is possible and inside that is an area where reproduction is also possible. At the center of the niche is the optimum point for the organism (Smith and Smith 1998, 12).
FIGURE 6.1 The architectural puzzle includes engineering information from many disciplines.
Architecture and urban design also have their niches. The siting of houses in different climates is an example. In warm humid environments, a location high on a hill would allow for better cross ventilation whereas in a hot arid environment a house would be better off low in a valley near water elements and in the cold night air pool. In a temperate environment, a site part way up a south slope provides a balance between solar access and wind protection in winter and access to cross ventilation in summer (Brown and DeKay 2001, 88). On a commercial scale niches exist around transit stops for service related businesses, and in downtown business districts for office buildings. In downtown areas there is often a vertical niche structure with stores and restaurants at the ground level and offices above. An urban plan for a region creates niches for industry, residences, schools, shopping, downtown business, and historic districts. Planned unit developments and New Urbanism place uses closer together so that people can live, shop, and work without traveling great distances.
Almost all life on earth depends on photosynthesis. Photosynthesis takes in carbon dioxide and solar energy and uses these and water to create sugars, which then are made into carbohydrates and proteins used by the plant. In the process the plant gives off oxygen and water. Animals eat plants for their carbohydrates and proteins, and they breathe the oxygen the plants created exhaling the carbon dioxide that the plants need (Smith and Smith 1998, 21).
In dry climates there is a modification to the photosynthesis process. Water is scarce, so the process is divided into two parts. The leaf opens up at night to take in the carbon dioxide. The carbon dioxide is stored chemically as malate and asparate for later use. This process limits the amount of water that is exhausted since it is cooler at night. Then during the day the carbon dioxide is reconstituted and combined with solar energy to create the sugars that then become the carbohydrates and proteins needed by the plant for growth (Smith and Smith 1998, 23).
The architectural response to a warm humid climate, where water is not a problem, is to open the design as wide as possible for cross ventilation while limiting direct solar penetration. Bounced solar is used for illumination. In hot arid climates, houses are built with high thermal mass and ventilated at night to cool the thermal mass down. During the day, the house is closed to the outside to hold on to the cool stored from the night before. Windows are small to let in a minimum amount of solar heat during the day.
The conditions for life are driven by the Sun’s energy interacting with the oceans and atmosphere of the earth. More solar energy reaches the equatorial regions than the polar regions. The atmosphere is warmed at the equator and water is evaporated into the warm air, which rises and travels north. As the air rises and moves north it cools and thus cannot hold as much water in vapor form resulting in rain (Smith and Smith 1998, 31–32). The psychrometric chart (Figure 6.2) illustrates how air at higher temperatures can hold more water in vapor form than air at colder temperatures.
FIGURE 6.2 The psychrometric chart maps the air water vapor thermodynamic mixture. Warmer temperatures can hold more water in vapor form than colder temperatures.
When the air descends in the middle latitudes it warms up, which dries the air out creating a strip of deserts around the world above and below the equator. The rotation of the earth deflects these air currents creating the easterly trade winds in the low latitudes and westerly trade winds in the higher latitudes. These are called trade winds because sailing ships used them to move goods around the world before steam ships. The oceans also move heat from the tropics to the poles. The Gulf Stream is part of this elaborate ocean current system. The Gulf Stream moves warm water near the surface from the tropics up the east coast of the United States and then over toward the UK. The warm water of the Gulf Stream makes northern Europe much warmer than it should be at its latitude. The Gulf Stream cools in the north Atlantic between England, Iceland, and Norway and descends and returns cold water in a deep water current back toward the poles. These ocean currents generally flow in a westerly direction near the equator and in an easterly direction in higher latitudes because of the rotation of the earth (Smith and Smith 1998, 33–38).
At a more local level, as moist air comes against a mountain range it is forced to rise, which causes it to cool, which causes the moisture in the air to rain or snow out. As the air moves down the back side of the mountain range, the air has lost most of its moisture and it descends, which causes it to warm up and dry out further. Thus the windward side of a mountain range is wet and the leeward side of a mountain range tends to be dry. This is an example of two microclimates created by a mountain range. Nature lives in the general climate and the micro-climate (Smith and Smith 1998, 41).
Plants need sunlight for photosynthesis. Plants have adapted to different levels of light. Sun plants need larger amounts of sunlight to achieve an optimum amount of photosynthesis while shade plants have adapted to need lesser amounts of sunlight to achieve optimum growth (Smith and Smith 1998, 50).