Old growth forest 1059617 224902912 2008-07-10T22:40:14Z Richard New Forest 2962903 Grammar, usage ("harvestation"...), clarity, logic (eg tautologies), corrections. Many tropical forests have virtually no soil, of very low fertility. Start and end sentence on same side of brackets. [[Image:Muir woods redwoods.jpg|thumb|right|250px|Redwoods in old growth forest in [[Muir Woods National Monument]], [[Marin County]], [[California]].]]'''Old growth forest''', also called '''primary forest''', '''ancient forest''', '''virgin forest''', '''primeval forest''', '''frontier forest''' or (in the [[UK]]) '''[[Ancient Woodland]]''', is a type of forest that has attained great age and so exhibits unique [[biology|biological]] features. Old growth forests typically contain large live [[tree]]s, large dead trees (sometimes called "[[snag]]s"), and large [[log]]s, as well as many other common characteristics representative of [[forests]] in general. Due to the great age and height of many trees within old growth forests, they are often more shaded than other types of forests. Old growth forests usually have multiple horizontal layers of [[vegetation]] representing a variety of tree [[species]] and age-classes. Forest regenerated after severe disruptions, such as [[clear cutting|clear-cut]] or [[forest fire|fire]] is often called [[Second growth forest|second-growth]] or ''regeneration'' until enough time passes that the effects of the disturbance are no longer evident. Depending on the forest, this may take anywhere from a century to several millennia. [[Hardwood]] forests of the eastern [[United States]] can develop old-growth characteristics in one or two generations of trees, or 150-500 years. Old growth forests are often home to [[rare species]], [[threatened species]] and [[endangered species]] of plants and animals, making them [[ecology|ecologically]] significant. One example of a rare species reliant upon old growth forest is the [[Northern Spotted Owl]]. Levels of [[biodiversity]], the variation of life forms within unique old growth forest ecosystems, may be higher or lower in old growth forests compared to that in second-growth forests, depending on specific circumstances, environmental variables and geographic variables (where the forest is located). Logging in old growth forests is a contentious issue in many parts of the world. ==Definitions== [[Image:Iluvatar_redwood_400.jpg|thumb|300px|An Arborist in '[[Atlas grove]]' next to a coastal redwood called [[Iluvatar (tree) | Iluvatar]]. This is old growth forest.]] The concept of old growth forest is somewhat subjective because there are varying global and cultural definitions regarding what comprises old growth forest, and of the variables that define, constitute and embody to serve as common denominators to provide a singular definition of this term. It is generally agreed that old growth forests share these traits in common: * Possess relatively mature, old trees * Have long continuity on the same site * Are land areas that have not been subjected to [[logging]] and other significant activities by humans "[[Ancient Woodland]]" is a term used in the [[United Kingdom]] to refer specifically to [[woodland]] dating back to [[1600]] or before (in [[England]] and [[Wales]]), or [[1750]] (in [[Scotland]]). Before this, planting of new woodland was uncommon, so a wood present at these dates was likely to have developed naturally. By this definition Ancient Woodland may have been affected by human management, and may have no very ancient trees: the important characteristic is long continuity of woodland on the land. In the [[United States]], the term "old growth" is often, (but not always), used to characterize a forest that has experienced little direct disruption or disturbance by humans during contemporary historical epochs, although sometimes determining the long-term history of human land management can be difficult. Additionally, because landscapes are naturally dynamic and continue to change as time progresses, it is difficult to ascertain hypothetical old growth forest characteristics that may have come into fruition had humans not destroyed such a great deal of old growth forests. The role of natural disturbances in defining old growth is more ambiguous. For example some definitions exclude recently burned forests, even where [[forest fire|fire]] has been part of the natural forest dynamics for millennia. In other cases such natural disturbance is incorporated in the old-growth concept. However, it is sometimes difficult to distinguish the ecological effects of natural disruption from human-caused disruption. Furthermore, many forests that have never experienced direct manipulation by humans have been subjected to indirect effects in the form of [[invasive species]], removal of native species (including [[megafauna]]),[[climate change]], and regional modifications of ecological [[disturbance]] regimes (e.g., fire suppression). == Characteristics == [[Image:Hawkwoods1.jpg|right|300px|thumb|Down wood decaying.]] Many botanists specifically define old growth in terms of meeting several criteria, under which system forests with sufficient age and minimal disturbance are considered old growth. Typical characteristics of old-growth forest include presence of older trees, minimal signs of human disturbance, mixed-age stands, presence of [[canopy (forest)|canopy]] openings due to tree falls, pit-and-mound [[topography]], fallen timber in various stages of [[decay]], standing snags (dead trees), multi-layered canopies, intact [[soil]]s, a healthy [[fungus|fungal]] ecosystem, and presence of [[indicator species]]. === Mixed age === The mixed age of the forest is an important criterion in ensuring that the forest is a relatively stable ecosystem in the long term. A [[climax community|climax]] stand that is uniformly-aged is a less stable ecosystem, because it becomes senescent and degrades within a relatively short time to result in a new cycle of forest [[ecological succession|succession]]. === Canopy openings === Openings in the [[forest canopy]] are essential in creating and maintaining mixed-age stands. Also, some [[Herb|herbaceous plant]]s only become established in canopy openings but persist beneath an understory. Openings created by natural disturbance events such as wind, ice and mixed-severity fire retain much structural enrichment from dead trees, unlike openings created by logging. === Topography === The characteristic topography of much old growth forest consists of pits and mounds. Mounds are caused by decaying fallen trees, and pits by the roots pulled out of the ground when trees fall due to natural causes, or are pushed over by animals. Pits expose [[humus]]-poor, [[mineral]]-rich soil and often collect moisture and fallen leaves soon form a thick [[organic material|organic]] layer and so able to nurture certain types of organisms, while mounds provide a place free of leaf inundation and saturation, where other types of organisms thrive. === Standing snags === Standing snags provide food sources and habitat for many types of organisms. In particular, many species of dead-wood predators such as [[woodpecker]]s must have standing snags available for feeding. In North America the [[spotted owl]] is well-known for needing standing snags for nesting habitat. === Decaying ground layer === Fallen timber contributes [[carbon]]-rich [[organic matter]] directly to the [[soil]], thus providing a substrate for [[moss]]es, fungi and for [[seedling]]s, and in creating microhabitats by creating relief on the forest floor. In some ecosystems, such as the temperate [[rain forest]] of the North American [[Pacific coast]], fallen timber may become ''nurse logs'', providing a substrate for seedling trees. === Soil === Intact soils harbor many life-forms and usually have well-defined [[soil profile]]s. Different organisms may need different soil profiles, while many trees need well-structured soils free of disturbance. Some herbaceous plants in northern hardwood forests need thick duff {{Clarifyme|date=July 2008}}<!-- What is duff? --> layers (which are part of the soil profile). [[fungus|Fungal]] ecosystems are essential for efficient ''[[in-situ]]'' recycling of nutrients back into the entire ecosystem. == Importance == *Old growth forests often contain rich communities of [[plant]]s and [[animal]]s that settle there thanks to the long period of forest stability. These varied and sometimes rare species may depend on the unique environmental conditions created by these forests. *Old growth forest serves as a reservoir for species which cannot thrive or easily regenerate in younger forest, and so can be used as a baseline for research. * Plant species that are native to old growth forests may someday prove to be invaluable towards curing various human ailments, as has been realized in numerous plants in [[tropical rainforests]].{{cn|date=July 2008}} *Old growth forests also store large amounts of [[carbon]] above and below the ground (either as humus, or in wet soils as [[peat]]). They collectively represent a very significant store of carbon. Destruction of these forests releases this carbon as [[greenhouse gases]], and may increase the risk of global [[climate change]].<ref>http://www.grida.no/climate/ipcc_tar/wg1/235.htm IPCC Climate Change 2001: Working Group I: The Scientific Basis</ref> == Logging == The large trees in old growth forests are often economically valuable, so these forests have been subjected to aggressive [[logging]] around the world. This has led to much controversy between logging companies and environmental groups. An example of this was that over [[Spotted Owl]]s in the 1980s and 1990s. It has been well-documented{{Attribution needed|date=July 2008}} that corporate and government interests, specifically the timber industry working in unison with the United States federal government and state governments, have long relied upon the use of propaganda techniques to encourage humans to devalue the merits of old growth forests, in favor of exploiting these lands to realize short-term profits, at the direct expense of long-term biodiversity. In Australia, the regional forest agreement (RFA) attempted to prevent the clearfelling of defined "Old Growth Forests". This led to struggles over what constitutes "Old Growth". For example in Western Australia, the [[timber]] industry tried to limit the area of Old Growth in the [[karri]] forests of the Southern Forests Region; this led to the creation of the [[Western Australian Forests Alliance]], the splitting of the Liberal Government of Western Australia and the election of the [[Geoff Gallop|Gallop]] Labor Government. Old Growth Forests in this region have now been placed inside [[National Parks]]. A small proportion of Old Growth Forest also exists in South-West Australia, and is protected by a Federal laws from logging, which hasn't occurred there for more than twenty years. == Locations of remaining intact forests == {{main|List of old growth forests}} In 2006 [[Greenpeace]] identified that the world's remaining intact old growth forest area was distributed among the continents as follows:<ref>http://www.intactforests.org/ IntactForests.org</ref> <br> * 35% in [[Latin America]]. The [[Amazon rainforest]] is mainly located in [[Brazil]], which clears a larger area of forest annually than any other country in the world.<ref name="GP">[http://www.greenpeace.org/international/campaigns/forests/our-disappearing-forests/intact-forest-landscapes Intact Forest Landscapes | Greenpeace International<!-- Bot generated title -->]</ref> * 28% in [[North America]]. North America harvests 10,000 square kilometres of ancient forests every year. Many of the fragmented forests of southern [[Canada]] and the [[US]] lack adequate animal travel corridors and functioning ecosystems for large mammals.<ref name=GP/> * 19% in Northern [[Asia]]. Northern Asia is home to the second largest [[boreal forest]] in the world. The [[Siberian tiger]] once roamed across huge areas of Northern Asia but today can only be found in a small area of intact forest near the [[Sea of Japan]]. Only about 400 remain in the wild and 800 in zoos.<ref name=GP/> * 8% in Africa. Africa has lost most of its intact forest landscapes in the last 30 years. The timber industry is responsible for destroying huge areas of intact forest landscapes and continues to be the single largest threat to these areas. * 7% in South Asia Pacific. The [[Paradise Forests]] of [[Asia Pacific]] are being destroyed faster than any other forest on Earth. Much of the large intact forest landscapes have already been cut down, 72% in [[Indonesia]] and 60% in [[Papua New Guinea]].<ref name=GP/> * Less than 3% in Europe. In Europe, more than 150 square kilometres of intact forest landscapes are cleared every year and the last areas of the region’s intact forest landscapes in European Russia are shrinking rapidly.<ref name=GP/> ==Effect on global warming== Old growth forests store large amounts of carbon, which is stored in wood, soil humus and peat. When forests are cut, the trees' wood, soil humus and peat all decay, releasing the carbon as carbon dioxide or methane.<ref name="NYT">{{cite web |url=http://query.nytimes.com/gst/fullpage.html?res=9A02E3DA113BF931A1575AC0A9669C8B63 |title= Planting New Forests Can't Match Saving Old Ones in Cutting Greenhouse Gases, Study Finds |accessdate=2008-06-04 |publisher=New York Times |date=September 22, 2000 }}</ref> Logging practices often include burning of the logged area, releasing further CO<sub>2</sub>. While old growth forests are often perceived to be in equilibrium — releasing as much carbon dioxide as they capture; or even in a state of decay<ref>[http://www.wired.com/science/planetearth/magazine/16-06/ff_heresies_04forests Old-Growth Forests Can Actually Contribute to Global Warming], Wired magazine, May 19, 2008</ref>, studies of soils in undisturbed tropical rain forests, Siberian woods and in German national parks have found that soils contain enormous amounts of carbon derived from fallen leaves, twigs and buried roots that can bind to soil particles and remain for 1,000 years or more. Replacing old growth forests with plantations is counter-productive from a carbon-storage view, as the new forest may take centuries to recapture the carbon lost. Further, the loss of [[biodiversity]] in a plantation monoculture lessens the performance of ecosystems regarding biomass production, nutrient retention and carbon dioxide absorption.<ref>Shahid Naeem, Lindsey J. Thompson, Sharon P. Lawler, John H. Lawton & Richard M. Woodfin, "Declining biodiversity can alter the performance of ecosystems", Nature, 368:734-736, 21 April 1994.</ref> ==References== {{reflist|2}} ==See also== *[[Ancient Woodland]] ==External links== *[http://www.greenpeace.org/usa/campaigns/forests Campaigns to protect the world's ancient forests] from [http://www.greenpeace.org/usa/ Greenpeace USA] *[http://www.fs.fed.us/pnw/oldgrowth.htm Old-growth forest information] from [http://www.fs.fed.us/ U.S. Forest Service] *[http://www.schools.wafa.org.au/index.html Old Growth Forests of Western Australia] from [http://waforestalliance.org/ Western Australian Forest Alliance] *[http://www.oregonwild.org/oregon_forests Oregon forests and old-growth information] from [http://www.oregonwild.org Oregon Wild] *[http://forests.org/ Forest Protection Portal] - Works to end deforestation, preserve primary and old-growth forests, conserve and sustainably manage other forests, and to commence the age of ecological restoration *[http://ran.org/issues/forests/ Protect The World's Rainforests] from [http://ran.org Rainforest Action Network] *[http://www.forestcouncil.org/ Native Forest Council] - Committed to fully protect and preserve every acre of publicly owned land in the United States *[http://www.reo.gov/library/reports/old_growth_definitions.htm Old-Growth Forest Definitions] from [http://www.reo.gov U.S. Regional Ecosystem Office] *[http://www.umpqua-watersheds.org/ Timber sales (including old growth) in Oregon's Umpqua, Coquille, and Coos Watersheds] from Umpqua Watersheds, Inc. *[http://www.primalnature.org/examples.html Examples of Eastern U.S. Old-Growth Sites] from [http://www.primalnature.org Primal Nature] *[http://www.fs.fed.us/pnw/pubs/gtr285/ Wildlife and Vegetation of Unmanaged Douglas-Fir Forests] from [http://www.fs.fed.us/ U.S. Forest Service] *[http://www.slovenia.info/?naravne_znamenitosti_jame=5149&title=Virgin+forests+in+Kočevska+region Slovenian Old-growth forests] - Virgin forests in the Kočevska region *[http://www.uoregon.edu/~arronfre/pmwiki/index.php?n=Main.GoogleMapFinds Collection of Google map links of clear cuts in or around old growth] *[http://www.fs.fed.us/pnw/pubs/marcot.pdf "Of Spotted Owls, Old Growth, and New Policies: A History Since the Interagency Scientific Committee Report"] - USDA General Technical Report (pdf) *[http://www.fsl.orst.edu/cfer/pdfs/mang_bio.pdf Managing for Biodiversity in Young Forests] - U.S. Geological Survey Biological Science Report (pdf) *[http://www.gptaskforce.org/article.php?id=11 The Gifford Pinchot National Forest] - One of the oldest National Forests in the United States, located in Southwest Washington State, from [http://www.gptaskforce.org/index.php The Gifford Pinchot Task Force] *[http://www.greenpeace.org/china/en/campaigns/forests/ Greenpeace China - Campaign to protect ancient forests] *[http://www.alaskaclimatechange.org/ Forest disturbances from climate changes in Alaska] [[Category:Conservation]] [[Category:Old growth forests| ]] [[bs:Prašuma]] [[de:Urwald]] [[el:Παρθένο δάσος]] [[fr:Forêt vierge]] [[hr:Prašuma]] [[id:Hutan tua]] [[it:Foresta equatoriale]] [[ja:原生林]] [[pl:Puszcza (leśnictwo)]] [[sr:Прашума]] [[fi:Aarniometsä]] [[sv:Urskog]] [[vi:Rừng nguyên sinh]]