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63-496: Having been formed approximately 200 million years ago, the lake is surrounded by limestone cliffs, which in turn are covered by primary forests . The lake comprises three zones named Pé Lầm, Pé Lù, and Pé Lèng. Three rivers , named Năng, Tả Han, and Nam Cường, are the main inflows of the lake. The Năng river enters the lake through a large waterfall called Đầu Đẳng. In the lake there are also three islands, named Án Mã, Khẩu Cúm, and Po Gia Mải (literally "Widow's Island"). Ba Bể Lake

126-418: A forest dynamics perspective, old-growth forest is in a stage that follows understory reinitiation stage. Those stages are: Of importance is that while the stand switches from one tree community to another, the stand will not necessarily go through old-growth stage between those stages. Some tree species have a relatively open canopy. That allows more shade-tolerant tree species to establish below even before

189-465: A free content work. Licensed under CC BY-SA 3.0 ( license statement/permission ). Text taken from The State of the World's Forests 2020. In brief – Forests, biodiversity and people​ , FAO & UNEP, FAO & UNEP. Coarse woody debris Coarse woody debris ( CWD ) or coarse woody habitat ( CWH ) refers to fallen dead trees and the remains of large branches on

252-432: A biodiversity that is different from other forest stages. The characteristic topography of much old-growth forest consists of pits and mounds. Mounds are caused by decaying fallen trees, and pits ( tree throws ) by the roots pulled out of the ground when trees fall due to natural causes, including being pushed over by animals. Pits expose humus -poor, mineral-rich soil and often collect moisture and fallen leaves, forming

315-577: A different potential to store carbon. For example, this potential is particularly high in the Pacific Northwest where forests are relatively productive, trees live a long time, decomposition is relatively slow, and fires are infrequent. The differences between forests must, therefore, be taken into consideration when determining how they should be managed to store carbon. A 2019 study projected that old-growth forests in Southeast Asia ,

378-767: A different spatial location relative to the main canopy, hence each one receives a different amount of light. 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 stand that is uniformly aged becomes senescent and degrades within a relatively short time to result in a new cycle of forest succession . Thus, uniformly aged stands are less stable ecosystems. Boreal forests are more uniformly aged, as they are normally subject to frequent stand-replacing wildfires. Forest canopy gaps are essential in creating and maintaining mixed-age stands. Also, some herbaceous plants only become established in canopy openings, but persist beneath an understory. Openings are

441-563: A healthy fungal ecosystem, and presence of indicator species. Old-growth forests are often biologically diverse , and home to many rare species , threatened species , and endangered species of plants and animals, such as the northern spotted owl , marbled murrelet and fisher , making them ecologically significant. Levels of biodiversity 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. Logging in old-growth forests

504-410: A moist, relatively mild climate, some old-growth trees have attained notable height and girth (DBH: diameter at breast height), accompanied by notable biodiversity in terms of the species supported. Therefore, for most people, the physical size of the trees is the most recognized hallmark of old-growth forests, even though the ecologically productive areas that support such large trees often comprise only

567-704: A result of industrial logging operations. In 2006, about 61,000 hectares of tall-eucalypt RFA old-growth forests remained unprotected. Recent logging attempts in the Upper Florentine Valley have sparked a series of protests and media attention over the arrests that have taken place in this area. Additionally, Gunns Limited , the primary forestry contractor in Tasmania, has been under recent criticism by political and environmental groups over its practice of woodchipping timber harvested from old-growth forests. Increased understanding of forest dynamics in

630-550: A result of tree death due to small impact disturbances such as wind, low-intensity fires, and tree diseases. Old-growth forests are unique, usually having multiple horizontal layers of vegetation representing a variety of tree species , age classes, and sizes, as well as "pit and mound" soil shape with well-established fungal nets . As old-growth forest is structurally diverse, it provides higher-diversity habitat than forests in other stages. Thus, sometimes higher biological diversity can be sustained in old-growth forests, or at least

693-432: A severe disturbance, such as wildfire, insect infestation, or harvesting, is often called second-growth or 'regeneration' until enough time passes for the effects of the disturbance to be no longer evident. Depending on the forest, this may take from a century to several millennia. Hardwood forests of the eastern United States can develop old-growth characteristics in 150–500 years. In British Columbia , Canada, old growth

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756-486: A source of raw materials. These services include making breathable air, making pure water, carbon storage, regeneration of nutrients, maintenance of soils, pest control by insectivorous bats and insects, micro- and macro-climate control, and the storage of a wide variety of genes. The effects of old-growth forests in relation to global warming have been addressed in various studies and journals. The Intergovernmental Panel on Climate Change said in its 2007 report : "In

819-412: A substrate for seedling trees. Intact soils harbor many life forms that rely on them. Intact soils generally have very well-defined horizons, or soil profiles . Different organisms may need certain well-defined soil horizons to live, while many trees need well-structured soils free of disturbance to thrive. Some herbaceous plants in northern hardwood forests must have thick duff layers (which are part of

882-400: A thick organic layer that is able to nurture certain types of organisms. Mounds provide a place free of leaf inundation and saturation, where other types of organisms thrive. Standing snags provide food sources and habitat for many types of organisms. In particular, many species of dead-wood predators, such as woodpeckers , must have standing snags available for feeding. In North America,

945-417: A useful number to measure. So, some forests may be excluded from being categorized as old-growth even if they have old-growth attributes just because they are too young. Also, older forests can lack some old-growth attributes and be categorized as old-growth just because they are so old. The idea of using age is also problematic, because human activities can influence the forest in varied ways. For example, after

1008-584: A very small portion of the total area that has been mapped as old-growth forest. (In high-altitude, harsh climates, trees grow very slowly and thus remain at a small size. Such trees also qualify as old growth in terms of how they are mapped, but are rarely recognized by the general public as such.) The debate over old-growth definitions has been inextricably linked with a complex range of social perceptions about wilderness preservation, biodiversity, aesthetics, and spirituality, as well as economic or industrial values. In logging terms, old-growth stands are past

1071-414: Is a contentious issue in many parts of the world. Excessive logging reduces biodiversity, affecting not only the old-growth forest itself, but also indigenous species that rely upon old-growth forest habitat. Some forests in the old-growth stage have a mix of tree ages, due to a distinct regeneration pattern for this stage. New trees regenerate at different times from each other, because each of them has

1134-469: Is a featured geographical science and is a biodiversity reservoir. It is a part of the Ba Bể National Park . It is home to a range of animals and plants. Once upon a time, there was a poor old woman. Villagers distrusted her because she seemed dirty and ugly-looking. Fortunately, she was eventually helped by a good-hearted mother and her son. The truth was that the old lady was a fairy. She told

1197-669: Is affected. Climate change showed an impact on the mortality of some dominant tree species, as observed in the Korean pine . Climate change also showed an effect on the composition of species when forests were surveyed over a 10- and 20-year period, which may disrupt the overall productivity of the forest. According to the World Resources Institute , as of January 2009, only 21% of the original old-growth forests that once existed on Earth are remaining. An estimated one-half of Western Europe's forests were cleared before

1260-502: Is an important indicator for evaluating and restoring this type of forest. In certain subtropical areas such as Australia where bushfire constitutes a major hazard, the amount of CWD left standing or lying is determined by what may be considered safe in the course of reasonable fire prevention. When fires occur, some invertebrates find shelter either within or beneath dead tree logs. In Canada, bears seek out dead tree logs to tear open and look for and feed on ants and beetles ,

1323-615: Is defined as 120 to 140 years of age in the interior of the province where fire is a frequent and natural occurrence. In British Columbia's coastal rainforests , old growth is defined as trees more than 250 years, with some trees reaching more than 1,000 years of age. In Australia, eucalypt trees rarely exceed 350 years of age due to frequent fire disturbance. Forest types have very different development patterns, natural disturbances and appearances. A Douglas-fir stand may grow for centuries without disturbance while an old-growth ponderosa pine forest requires frequent surface fires to reduce

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1386-428: Is important actor contributing to soil nutrients cycles. CWD, while itself not particularly rich in nitrogen, contributes nitrogen to the ecosystem by acting as a host for nonsymbiotic free-living nitrogen-fixing bacteria . Scientific studies show that coarse woody debris can be a significant contributor to biological carbon sequestration . Trees store atmospheric carbon in their wood using photosynthesis . Once

1449-415: Is improved as well. During dry weather, CWD slows evaporation of soil moisture and provides damp microhabitats for moisture-sensitive organisms. In fire-prone forests , coarse woody debris can be a significant fuel during a wildfire . High amounts of fuels can lead to increased fire severity and size. CWD may be managed to reduce fuel levels, particularly in forests where fire exclusion has resulted in

1512-433: Is more accurate in forests where the species that constitute old-growth have long lifespans and succession is slow. Common cultural definitions and common denominators regarding what comprises old-growth forest, and the variables that define, constitute and embody old-growth forests include: Additionally, in mountainous, temperate landscapes (such as Western North America), and specifically in areas of high-quality soil and

1575-919: Is not the most commercially viable timber—in British Columbia, Canada, harvesting in the coastal region is moving to younger second-growth stands. A 2001 scientific symposium in Canada found that defining old growth in a scientifically meaningful, yet policy-relevant, manner presents some basic difficulties, especially if a simple, unambiguous, and rigorous scientific definition is sought. Symposium participants identified some attributes of late-successional, temperate-zone, old-growth forest types that could be considered in developing an index of "old-growthness" and for defining old-growth forests: Structural features: Compositional features: Process features: Old-growth forests provide ecosystem services that may be far more important to society than their use as

1638-557: Is seen as extremely economically unproductive, as timber can only be collected from falling trees, and also potentially damaging to nearby managed groves by creating environments conducive to root rot. It may be more productive to cut the old growth down and replace the forest with a younger one. The island of Tasmania , just off the southeast coast of Australia, has the largest amount of temperate old-growth rainforest reserves in Australia with around 1,239,000 hectares in total. While

1701-486: The Middle Ages , and 90% of the old-growth forests that existed in the contiguous United States in the 1600s have been cleared. The large trees in old-growth forests are economically valuable, and have been subject to aggressive logging throughout the world. This has led to many conflicts between logging companies and environmental groups . From certain forestry perspectives, fully maintaining an old-growth forest

1764-910: The Pacific Northwest of North America, CWD concentrations were found to be from 72 metric tons/hectare (64,000 pounds/acre) in drier sites to 174 t/ha (155,000 lb/acre) in moister sites. Australian native forests have mean CWD concentrations ranging from 19 t/ha (17,000 lb/acre) to 134 t/ha (120,000 lb/acre), depending on forest type. Coarse woody debris and its subsequent decomposition recycles nutrients that are essential for living organisms, such as carbon , nitrogen , potassium , and phosphorus . Saprotrophic fungi and detritivores such as bacteria and insects directly consume dead wood, releasing nutrients by converting them into other forms of organic matter which may then be consumed by other organisms It has almost no physiologically important nutrients, so must be first enriched for consumption by transport of nutrients from outside. Thus CWD

1827-717: 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

1890-479: The Trees for Life group found the black tinder fungus beetle ( Bolitothorus reticulatus ) is dependent on a particular fungus ( Fomes fomentarius ), which itself grows only on dead birch . Another insect, the pine hoverfly ( Blera fallax ), requires rotting Scots pine in order to reproduce. In the temperate deciduous forests of eastern North America, CWD provides habitat ranging from salamanders to ferns. It

1953-474: The United Nations defines primary forests as naturally regenerated forests of native tree species where there are no clearly visible indications of human activity and the ecological processes are not significantly disturbed. One-third (34 percent) of the world's forests are primary forests. Old-growth features include diverse tree-related structures that provide diverse wildlife habitats that increases

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2016-531: The biodiversity of the forested ecosystem . Virgin or first-growth forests are old-growth forests that have never been logged. The concept of diverse tree structure includes multi-layered canopies and canopy gaps, greatly varying tree heights and diameters, and diverse tree species and classes and sizes of woody debris. As of 2020 , the world has 1.11  billion   ha (2.7 billion acres) of primary forest remaining. Combined, three countries (Brazil, Canada, and Russia) host more than half (61 percent) of

2079-535: The spotted owl is well known for needing standing snags for nesting habitat. Fallen timber, or coarse woody debris , contributes carbon -rich organic matter directly to the soil , providing a substrate for mosses , fungi, and seedlings , and 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

2142-652: The Liberal Government of Western Australia and the election of the Gallop Labor Government. Old-growth forests in this region have now been placed inside national parks . A small proportion of old-growth forests also exist in South-West Australia and are protected by federal laws from logging, which has not occurred there for more than 20 years. In British Columbia , Canada , old-growth forests must be maintained in each of

2205-520: The animal kingdom, invertebrates such as termites , ants , beetles , and snails , amphibians such as salamanders , reptiles such as the slow-worm , as well as birds and small mammals . One third of all woodland birds live in the cavities of dead tree trunks. Woodpeckers , tits , chickadees , and owls all live in dead trees, and grouse shelter behind woody debris. Some plants use coarse woody debris as habitat. Mosses and lichens may cover logs, while ferns and trees may regenerate on

2268-446: The atmosphere. Proponents of harvesting the forest argue the carbon stored in wood is available for use as biomass energy (displacing fossil fuel use), although using biomass as a fuel produces air pollution in the form of carbon monoxide , nitrogen oxides , volatile organic compounds , particulates, and other pollutants, in some cases at levels above those from traditional fuel sources such as coal or natural gas. Each forest has

2331-454: The buildup of fuels. Reductions in CWD for fire safety should be balanced with the retention of CWD for habitat and other benefits. CWD of 3 to 8 inches (7.6 to 20.3 cm) in diameter is classified as 1000-hour fuel by fire managers, referring to the amount of time needed for the moisture content in the wood to come to equilibrium with the surrounding environment. In Glen Affric , Scotland ,

2394-541: The current Ba Bể Lake. [REDACTED] Media related to Ba Be Lake at Wikimedia Commons This article about a location in Vietnam is a stub . You can help Misplaced Pages by expanding it . Primary forest An old-growth forest (also referred to as primary forest ) is a forest that has developed over a long period of time without disturbance . Due to this, old-growth forests exhibit unique ecological features. The Food and Agriculture Organization of

2457-421: The economic optimum for harvesting—usually between 80 and 150 years, depending on the species. Old-growth forests were often given harvesting priority because they had the most commercially valuable timber, they were considered to be at greater risk of deterioration through root rot or insect infestation, and they occupied land that could be used for more productive second-growth stands. In some regions, old growth

2520-408: The flow of water and sediment. Turtles of many species may also use coarse woody debris for basking. Musk turtles may lay their eggs under logs near wetlands. Coarse woody debris, particularly on slopes, stabilizes soils by slowing downslope movement of organic matter and mineral soil. Leaves and other debris collect behind CWD, allowing for decomposition to occur. Infiltration of precipitation

2583-436: The forest will switch back to understory reinitiation stage. Using the stand dynamics definition, old-growth can be easily evaluated using structural attributes. However, in some forest ecosystems, this can lead to decisions regarding the preservation of unique stands or attributes that will disappear over the next few decades because of natural succession processes. Consequently, using stand dynamics to define old-growth forests

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2646-472: The forests is vital to climate change mitigation . Old-growth forests tend to have large trees and standing dead trees, multilayered canopies with gaps that result from the deaths of individual trees, and coarse woody debris on the forest floor. The trees of old-growth forests develop distinctive attributes not seen in younger trees, such as more complex structures and deeply fissured bark that can harbor rare lichens and mosses. A forest regenerated after

2709-447: The forests, destroying the forests in the process, to generate short-term profits, while environmentalists seek to preserve the forests in their pristine state for benefits such as water purification , flood control , weather stability, maintenance of biodiversity, and nutrient cycling . Moreover, old-growth forests are more efficient at sequestering carbon than newly planted forests and fast-growing timber plantations , thus preserving

2772-488: The ground in forests and in rivers or wetlands . A dead standing tree – known as a snag – provides many of the same functions as coarse woody debris. The minimum size required for woody debris to be defined as "coarse" varies by author, ranging from 2.5–20 cm (1–8 in) in diameter. Since the 1970s, forest managers worldwide have considered it best environmental practice to allow dead trees and woody debris to remain in woodlands, recycling nutrients trapped in

2835-441: The ideal woodland in terms of recycling and regeneration. In healthy temperate forests , dead wood comprises up to thirty per cent of all woody biomass . In recent British studies, woods managed for timber had between a third and a seventh less fallen debris than unmanaged woods that had been left undisturbed for many years, while in recently coppiced woods the amount of CWD was almost zero. In old growth Douglas fir forests of

2898-427: The landscape patterns and habitat conditions normally maintained in nature . This coarse filter approach to biodiversity conservation recognizes ecological processes and provides for a dynamic distribution of old growth across the landscape. And all seral stages—young, medium, and old—support forest biodiversity. Plants and animals rely on different forest ecosystem stages to meet their habitat needs. In Australia ,

2961-525: The late 20th century led the scientific community to identify a need to inventory, understand, manage, and conserve representative examples of old-growth forests with their associated characteristics and values. Literature around old growth and its management is inconclusive about the best way to characterize the true essence of an old-growth stand. A better understanding of natural systems has resulted in new ideas about forest management, such as managed natural disturbances, which should be designed to achieve

3024-620: The local Regional Forest Agreement (RFA) was originally designed to protect much of this natural wealth, many of the RFA old-growth forests protected in Tasmania consist of trees of little use to the timber industry. RFA old-growth and high conservation value forests that contain species highly desirable to the forestry industry have been poorly preserved. Only 22% of Tasmania's original tall-eucalypt forests managed by Forestry Tasmania have been reserved. Ten thousand hectares of tall-eucalypt RFA old-growth forest have been lost since 1996, predominantly as

3087-408: The logging of 30% of the trees, less time is needed for old-growth to come back than after removal of 80% of the trees. Although depending on the species logged, the forest that comes back after a 30% harvest may consist of proportionately fewer hardwood trees than a forest logged at 80% in which the light competition by less important tree species does not inhibit the regrowth of vital hardwoods. From

3150-413: The long term, a sustainable forest management strategy aimed at maintaining or increasing forest carbon stocks, while producing an annual sustained yield of timber, fibre, or energy from the forest, will generate the largest sustained mitigation benefit." Old-growth forests are often perceived to be in equilibrium or in a state of decay. However, evidence from analysis of carbon stored above ground and in

3213-481: The majority of which are in Indonesia and Malaysia , are able to sequester carbon or be a net emitter of greenhouse gases based on deforestation scenarios over the subsequent decades. Old-growth forests have the potential to impact climate change, but climate change is also impacting old-growth forests. As the effects of global warming grow more substantial, the ability of old-growth forests to sequester carbon

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3276-456: The mother and son that the village and surrounding area were about to be struck by a natural disaster. Despite her warnings, no one believed her, except for the mother and son, who began to build a boat. The next night, a terrible rainstorm began to engulf the village. The mother and son, who had prepared their boat beforehand, survived and saved many people from drowning. The village was subsequently submerged in water and gradually formed into

3339-524: The province's ecological units to meet biodiversity needs. In the United States , from 2001, around a quarter of the federal forests are protected from logging. In December 2023, Biden's administration introduced a rule, according to which, logging is strongly limited in old growth forests, but permitted in "mature forests", representing a compromise between the logging industry and environmental activists. In 2006, Greenpeace identified that

3402-607: The shade-tolerant species and regenerate the canopy species. In the boreal forest of Canada , catastrophic disturbances like wildfires minimize opportunities for major accumulations of dead and downed woody material and other structural legacies associated with old growth conditions. Typical characteristics of old-growth forest include the presence of older trees, minimal signs of human disturbance, mixed-age stands, presence of canopy openings due to tree falls, pit-and-mound topography , down wood in various stages of decay, standing snags (dead trees), multilayered canopies, intact soils ,

3465-462: The soil has shown old-growth forests are more productive at storing carbon than younger forests. Forest harvesting has little or no effect on the amount of carbon stored in the soil, but other research suggests older forests that have trees of many ages, multiple layers, and little disturbance have the highest capacities for carbon storage. As trees grow, they remove carbon from the atmosphere, and protecting these pools of carbon prevents emissions into

3528-516: The soil profile). Fungal ecosystems are essential for efficient in-situ recycling of nutrients back into the entire ecosystem. Stand age can also be used to categorize a forest as old-growth. For any given geographical area, the average time since disturbance until a forest reaches the old growth stage can be determined. This method is useful, because it allows quick and objective determination of forest stage. However, this definition does not provide an explanation of forest function. It just gives

3591-469: The top of logs. Large fragments of CWD that provide such habitat for herbs , shrubs , and trees are called nurse logs . CWD can also protect young plants from herbivory damage by acting as barriers to browsing animals. The persistence of coarse woody debris can shelter organisms during a large disturbance to the ecosystem such as wildfire or logging . Fallen debris and trees in streams provide shelter for fish , amphibians and mammals by modifying

3654-524: The trees die, fungi and other saprotrophs transfer some of that carbon from CWD into the soil . This sequestration can continue in old-growth forests for hundreds of years. By providing both food and microhabitats for many species , coarse woody debris helps to maintain the biodiversity of forest ecosystems. Up to forty percent of all forest fauna is dependent on CWD. Studies in western North America showed that only five per cent of living trees consisted of living cells by volume, whereas in dead wood it

3717-549: The understory reinitiation stage. The shade-tolerant trees eventually outcompete the main canopy trees in stem-exclusion stage. Therefore, the dominant tree species will change, but the forest will still be in stem-exclusion stage until the shade-tolerant species reach old-growth stage. Tree species succession may change tree species' composition once the old-growth stage has been achieved. For example, an old boreal forest may contain some large aspen trees, which may die and be replaced by smaller balsam fir or black spruce. Consequently,

3780-616: The wood and providing food and habitat for a wide range of organisms, thereby improving biodiversity . The amount of coarse woody debris is an important criterion for the evaluation and restoration of temperate deciduous forest. Coarse woody debris is also important in wetlands, particularly in deltas where woody debris accumulates. Coarse woody debris comes from natural tree mortality, plant pathology , insects , wildfire , logging , windthrows and floods . Ancient , or old growth , forest, with its dead trees and woody remains lying where they fell to feed new vegetation, constitutes

3843-432: The world's primary forest. The area of primary forest has decreased by 81 million ha (200 million acres) since 1990, but the rate of loss more than halved in 2010–2020 compared with the previous decade. Old-growth forests are valuable for economic reasons and for the ecosystem services they provide. This can be a point of contention when some in the logging industry desire to harvest valuable timber from

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3906-413: The world's remaining intact forest landscapes are distributed among the continents as follows: [REDACTED]  This article incorporates text from a free content work. Licensed under CC BY-SA 3.0 ( license statement/permission ). Text taken from Global Forest Resources Assessment 2020 Key findings​ , FAO, FAO. [REDACTED]  This article incorporates text from

3969-422: Was as high as forty percent by volume, mainly fungi and bacteria . Colonizing organisms that live on the remains of cambium and sapwood of dead trees aid decomposition and attract predators that prey on them and so continue the chain of metabolizing the biomass. The list of organisms dependent on CWD for habitat or as a food source includes bacteria , fungi , lichens , mosses and other plants , and in

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