Tree Care Glossary & Encyclopedia

The measurable benefits that trees and forests provide to humans, including air purification, stormwater management, carbon sequestration, and urban heat reduction.

A geographically defined area classified by its average annual minimum temperature, used to determine which plant species can survive winter in a given location.

A plant species that provides nutrition or habitat for a specific pest or pathogen, supporting its survival and reproduction.

A non-native organism whose introduction causes or is likely to cause ecological or economic harm, outcompeting native species and disrupting ecosystems.

A plant species that occurs naturally in a particular region, having evolved there over thousands of years without human introduction.

The percentage of ground area covered by the vertical projection of tree crowns, a key metric for measuring urban forest health and planning.

The collective population of trees within a city or developed area, including street trees, park trees, residential yard trees, and remnant natural areas.