Long-Term Vegetation Research on Two Extensive Green Roofs in Berlin

Glossary

Analysis of variance (ANOVA)

Statistical method that yields values that can be tested to determine whether a significant relation exists between variables.

Evapotranspiration

Moisture transfer from the earth to the atmosphere via evaporation of water from transpiring plants.

Extensive Green Roof

A low-management type of green roof that has soil depths ranging from three to seven inches. Due to the shallow soils and the extreme environment on many roofs, plants are typically low-growing groundcover species that are extremely sun and drought tolerant.

Lysimeter

An instrument that measures the amount of water-soluble matter in soil.

Multivariate analysis of variance (MANOVA)

An extension of analysis of variance (ANOVA) covering cases where there is more than one dependent variable and where the dependent variables cannot be simply combined.

Penman-Monteith equation

A standard equation used to compute evapotranspiration rates (and thus water requirements) in crop plants. For more information, see http://www.fao.org/docrep/X0490E/x0490e06.htm.

Regression analysis

Any statistical method in which the mean of one or more random variables is predicted conditioned on other (measured) random variables (see http://en.wikipedia.org/wiki/Regression_analysis).

Species richness

The number of different species found in a particular habitat.

Succession

The sequential change in vegetation and the animals associated with it, either in response to an environmental change or induced by the intrinsic properties of the organisms themselves.