4-8 How do Ecologists Learn about Ecosystems?
What Is Field Research? Muddy Boots Ecology
Field research involves going into nature and observing and measuring the structure of ecosystems and what happens in them. Most of what we know about the structure and functioning of ecosystems described in this chapter has come from such research.
Field research allows researchers to study ecosystems under more natural circumstances than can be achieved in a laboratory and with more proximity than can be gained with remote sensing. However, it is more difficult to control relevant variables in field experiments than in laboratory experiments.
How Are Ecosystems Studied in the Laboratory? Life under Glass
During the past 50 years, ecologists have increasingly supplemented field research by using laboratory research to set up, observe, and make measurements of model ecosystems and populations under laboratory conditions. Such systems make it easier for scientists to carry out controlled experiments. In addition, such laboratory experiments often are quicker and cheaper than similar experiments in the field.
However, laboratory results cannot take into account all the variables that we could during field research.
What Is Remote Sensing? Collecting Information from Above
In contrast to the close and controlled circumstances of laboratory research, remote sensing involves collecting data from an aerial view high above the Earth’s surface. There are two main types of data collecting:
Passive collection involves monitoring radiation that is emitted or reflected by the object or area that is being studied. Commonly, sunlight is the source of radiation.
Active collection requires that energy be emitted to scan the object or area; sensors then detect the radiation that is reflected or backscattered. Lidar (light detection and ranging) systems illuminate the distant target with pulses of light from a laser and then measure the time taken for the light to return; in this way, precise distances such as the height of forest canopy relative to the ground can be calculated.
Remote sensing allows large amounts of information to be collected quickly from vast areas of land, sea, or atmosphere. Since the data are collected from afar using aircraft or satellites, it is possible to study areas that are extremely remote, dangerous, or sensitive to disturbance.
What Are Geographic Information Systems? Specialized Computer Software
A geographic information system (GIS) is specialized computer software that can combine different types of information, including data from remote sensing and from field studies, in a database using the same set of geographic coordinates.
GIS has many applications in environmental science. For example, natural resource management, climate change, efforts to protect species at risk, and pollution control all have aspects that vary in time and space, making them prime candidates for the application of GIS.
What Is Landscape Ecology? The Study of Spatial Patterns
Landscape ecology is the scientific study of how spatial patterns in the environment affect the abundance, distribution, and interaction of organisms. A landscape is an arbitrarily defined area of land that generally is larger than a single ecosystem but smaller than a biome.
Landscape ecology is an important component of environmental science and draws upon ecology and geography to develop a broad-scale understanding of how several ecosystems, communities, or habitat patches relate to each other and how they are changing through time.
What Is Systems Analysis? Simulating Ecosystems
Since the late 1960s, ecologists have made increasing use of systems analysis to develop mathematical and other models that simulate ecosystems. Computer simulation of such models can help us understand large and very complex systems.
Researchers can change values of the variables in their computer models to project possible changes in environmental conditions, help anticipate environmental surprises, and analyze the effectiveness of various alternative solutions to environmental problem.
However, simulations and projections made using ecosystem models are no better than the data and assumptions used to develop the models.
Why Do We Need Baseline Ecological Data? Understanding What We Have
Before we can understand what is happening to an ecosystem, community, or population, and how best to prevent harmful environmental changes, we need to know its current condition. In other words, we need baseline data about its components, physical and chemical conditions, and how well it is functioning.
Ecologists call for a massive program to develop baseline data for the world’s ecosystems. If we do not know how many elephants are in Africa, we cannot determine whether their populations are declining or increasing.