Trees are an important part of the terrestrial ecosystem, providing essential habitats including many kinds of forest for communities of organisms. Epiphytic plants such as ferns, some mosses, liverworts, orchids and some species of parasitic plants (e.g., mistletoe) hang from branches; these along with arboreal lichens, algae, and fungi provide micro-habitats for themselves and for other organisms, including animals.
Silviculture is the practice of controlling the establishment, growth, composition, health, and quality of forests, which are areas that have a high density of trees. Cultivated trees are planted and tended by humans, usually because they provide food (fruits or nuts), ornamental beauty, or some type of wood product that benefits people.
Tree care is the application of arboricultural methods like pruning, trimming, and felling/thinning in built environments. Road verge, greenways, backyard and park woody vegetation are at the center of attention for the tree care industry.
Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, plants were treated as one of two kingdoms including all living things that were not animals, and all algae and fungi were treated as plants.
There are about 300,000 species of living Viridiplantae, of which 85–90% are flowering plants. (Note: as these are from different sources and different dates, they are not necessarily comparable, and like all species counts, are subject to a degree of uncertainty in some cases.)
