TEMPERATE FORESTS

Temperate forests occur in the northern and southern hemispheres, in regions between 30–60 degrees latitude, with seasonal climates. Northern hemisphere temperate forests occur in western and eastern North America, much of Europe, and northeastern Asia, between boreal forests to the north and grasslands, Mediterranean vegetation, or subtropical forests to the south. Many genera of trees occur across all of the temperate forest in the northern hemisphere, including broadleaved deciduous species of Acer, Betula, Fagus, Fraxinus, Populus, Quercus, Tilia and Ulmus, and coniferous species of Picea, Pinus, Pseudotsuga and Tsuga. In the southern hemisphere, major areas of temperate forest include southern South America, southeastern mainland Australia, Tasmania and New Zealand. Nothofagus species occur in all of these areas, but the other species present vary widely, including broadleaved evergreens Aextoxicon, Eucryphia, Laureliopsis, Weinmannia and evergreen conifers Araucaria, Fitzroya, and Pilgerodendron in South America; broadleaved evergreen Atherosperma and Eucalyptus, and coniferous Athrotaxis, Lagarostrobos and Phyllocladus in Australia; and podocarps Dacrydium, Libocedrus, Podocarpus, and Prumnopitys in New Zealand. Disturbance regimes include areas with large, intense disturbances (fires in the northern hemisphere, landslides, and volcanoes in the southern hemisphere), which are dominated post-disturbance by even-aged stands of early successional species, as well as gap dynamics regimes with uneven-aged, late-successional species. Very little primeval temperate forest remains due to high human population density and widespread conversion to farms and single-species plantations; however, conservationists have devoted much effort to conserving the few remaining intact forest ecosystems. Fragmentation, overgrazing by deer and cattle and invasive species are major conservation issues, potentially leading to loss of species richness. Large impacts from climate change are likely in these moderate to high latitude areas; there is plenty of room for expansion of temperate forests into the southern boreal biome as climate warms in the northern hemisphere, while little room for expansion of temperate forests exists in the southern hemisphere.