Varied approaches are used in ecosystem analysis, depending on the specific purpose of the analysis. The systems approach attempts to clarify and understand relationships among various factors in the ecosystem. A biological analysis emphasizes such variables as balance, competition, variability and survival. Some use social and/or material flow analyses. A single ecosystem analysis may include several approaches.
In recent years, software packages for ecosystem analysis have been increasing. These packages have become increasingly easy to use. According to a United Nations University report, many of the software packages use Microsoft Visual Basic, making them easy to link to one another. The large and ever-increasing amount of geographic data that is available free or inexpensively on the Internet is also proving helpful for ecosystem analysis.
Cities have varying levels of impact on the environment, depending on their level of development. Those that are less "developed" tend to impact their immediate region. As the cities develop, their activities tend to have wider impact. Over time, environmental concerns move from issues such as overcrowding, lack of basic services and pollution of local waterways to issues of resource depletion and climate change that affect the entire planet.
The Aquatic Ecosystems Analysis Lab at UC Davis works to help conserve watersheds by analyzing aquatic habitats and making the results available to decision-makers. Specific activities include surveying fish populations, water quality analysis and analysis of micro-organisms.
Mapping Forestry, a publication of the Environmental Services Research Institute, provides examples of how decision-making can be informed by ecosystem analysis. Use of detailed maps and Geographic Information Systems analysis can assist in making practical decisions about the best places to build roads or in setting priorities among fire-damaged areas for restoration. Urban ecosystem analyses can inform similar decisions by providing information about current densities, traffic flow and the like in various parts of the city.