|Mountain pine beetle|
The mountain pine beetle (Dendroctonus ponderosae) is a species of bark beetle native to the forests of western North America from Mexico to central British Columbia. It has a hard black exoskeleton, and measures approximately 5 millimetres (1⁄4 in), about the size of a grain of rice.
In western North America, the current outbreak of the mountain pine beetle and its microbial associates has destroyed wide areas of lodgepole pine forest, including more than 16 million hectares (40 million acres) of the 5 million hectares (12 million acres) of forest in British Columbia. The current outbreak in the Rocky Mountain National Park in Colorado began in 1996 and has caused the destruction of millions of acres/hectares of ponderosa and lodgepole pine trees in that state. According to an annual assessment by the state's forest service, 264,000 acres (107,000 hectares) of trees in Colorado were infested by the mountain pine beetle at the beginning of 2013. This was much smaller than the 1.15 million acres (470 thousand hectares) that were affected in 2008 because the beetle has already killed off most of the vulnerable trees (Ward).
Mountain pine beetles inhabit ponderosa, whitebark, lodgepole, Scots, jack,and limber pine trees. Normally, these insects play an important role in the life of a forest, attacking old or weakened trees, and speeding development of a younger forest. However, unusually hot, dry summers and mild winters throughout the region during the last few years, along with forests filled with mature lodgepole pine, have led to an unprecedented epidemic.
It may be the largest forest insect blight seen in North America since European colonization.Monocultural replanting, and a century of forest fire suppression have contributed to the size and severity of the outbreak, and the outbreak itself may, with similar infestations, have significant effects on the capability of northern forests to remove greenhouse gases (such as CO2) from the atmosphere.
Because of its impact on forestry, the transcriptomeand the genome of the beetle have been sequenced. It was the second beetle genome to be sequenced.
Mountain pine beetles affect pine trees by laying eggs under the bark. The beetles introduce blue stain fungus into the sapwood that prevents the tree from repelling and killing the attacking beetles with tree pitch flow. The fungus also blocks water and nutrient transport within the tree. On the tree exterior, this results in popcorn-shaped masses of resin, called "pitch tubes", where the beetles have entered.The joint action of larval feeding and fungal colonization kills the host tree within a few weeks of successful attack (the fungus and feeding by the larvae girdles the tree, cutting off the flow of water and nutrients). In recent years, drought conditions have further weakened trees, making them more vulnerable and unable to defend against attack. When the tree is first attacked, it remains green. Usually within a year of attack, the needles will have turned red. This means the tree is dying or dead, and the beetles have moved to another tree. In three to four years after the attack, very little foliage is left, so the trees appear grey.
As beetle populations increase or more trees become stressed because of drought or other causes, the population may quickly increase and spread. Healthy trees are then attacked, and huge areas of mature pine stands may be threatened or killed. Warm summers and mild winters play a role in both insect survival and the continuation and intensification of an outbreak. Adverse weather conditions (such as winter lows of -40°) can reduce the beetle populations and slow the spread, but the insects can recover quickly and resume their attack on otherwise healthy forests.
Beetles develop through four stages: egg, larva, pupa and adult. Except for a few days during the summer when adults emerge from brood trees and fly to attack new host trees, all life stages are spent beneath the bark.
In low elevation stands and in warm years, mountain pine beetles require one year to complete a generation. At high elevations, where summers are typically cooler, life cycles may vary from one to two years
Female beetles initiate attacks. As they chew into the inner bark and phloem, pheromones are released, attracting male and female beetles to the same tree. The attacking beetles produce more pheromones, resulting in a mass attack that overcomes the tree's defenses, and results in attacks on adjacent trees.
Natural predators of the mountain pine beetle include certain birds, particularly woodpeckers, and various insects.
Management techniques include harvesting at the leading edges of what is known as "green attack", as well as other techniques that can be used to manage infestations on a smaller scale, including:
The concept of natural plant defense holds hope for eliminating pine beetle infestation. Beneficial microbial solutions are being researched and developed that work with the plant to activate and enhance its resistance mechanisms against insects and disease.
The US Forest Service tested chitosan,a biopesticide, to pre-arm pine trees to defend themselves against MPB. The US Forest Service results show colloidal chitosan elicited a 40% increase in pine resin (P<0.05) in southern pine trees. One milliliter chitosan per 10 gallons water was applied to the ground area within the drip ring of loblolly pine trees. The application was repeated three times from May through September in 2008. The chitosan was responsible for eliciting natural defense responses of increased resin pitch-outs, with the ability to destroy 37% of the pine beetle eggs. Dr. Jim Linden, Microbiologist, Colorado State University, stated the chitosan increased resin pitch-outs to push the mountain pine beetle out of the tree, preventing the MPB from entering the pine tree and spreading blue stain mold.
Aggressively searching out, removing, and destroying the brood in infested trees is the best way to slow the spread of mountain pine beetles; however, it may not protect specific trees. Spraying trees to prevent attack is the most effective way to protect a small number of high-value trees from mountain pine beetles. Carbaryl, permethrin and bifenthrin are registered in the United States for use in the prevention of pine beetle infestations. Carbaryl is considered by the EPA to likely be carcinogenic to humans. It is moderately toxic to wild birds and partially to highly toxic to aquatic organisms. Permethrin is easily metabolized in mammalian livers, so is less dangerous to humans. Birds are also practically not affected by permethrin. Negative effects can be seen in aquatic ecosystems, as well as it being very toxic to beneficial insects. Bifenthrin is moderately dangerous to mammals, including humans; it is slightly more toxic to birds and aquatic ecosystems than permethrin, as well as extremely toxic to beneficial insects.
Colorado's forests are densely wooded, making them much more susceptible to bark beetle attack. Current legislation is in place to help with the growing beetle problem. Colorado Senators Mark Udall and Michael Bennet announced that Colorado will receive $30 million of the $40 million being diverted by the U.S. Forest Service to fight the millions of acres of damage caused by the mountain pine beetle in the Rocky Mountain region.
Fall and burn is the technique being used in Alberta where there is hope of limiting the outbreak to western Canada, preventing its spread to northern Saskatchewan and further towards eastern Canada where jack pine may be vulnerable as far east as Nova Scotia.
Wood from beetle-affected trees retains its commercial usefulness for 8 to 12 years after the tree has died, but its value drops rapidly, for within several months, the escaping moisture blows large checks and cracks from the outer perimeter of the wood deep into the heart of the tree. The remaining moisture escapes more slowly, causing small cracks throughout the timber. This causes difficulties for modern high-output automated sawmill operations and greatly increases the lumber losses and the labor to produce high quality wood products. This so-called 'shelf life' is dependent on a number of factors, including economic and stand site conditions. In areas where it is wetter, the trees tend to rot at the base and fall faster, especially if they are larger.The fungus that is carried by the beetles and kills the trees causes blue staining of the sapwood at the perimeter of the tree, but it does not affect the wood's strength, nor are there any harmful human health effects. Blue stain is, however, considered to be a defect in the lumber grading standards and thus is considered a 'down-grade' resulting in a lower commodity market price. All these factors have severely limited the production of blue-stain wood products.
The timber can be used for any wood product from standard framing lumber to engineered wood products, such as glue-laminated products and cross-laminated panels. The epidemic in British Columbia is also creating opportunities for the emerging bio-energy industry. Though there are many small wood working and craft shops that are making furniture and crafts out of the exotic appearing blue-stained wood, and despite the massive supply and the increasingly apparent need to utilize this dead timber, there are very few companies that have created product lines that require large volumes of dead trees. This is largely due to the significant difficulties and increased expense inherent to processing dead timber, and the correspondingly lowered profitability. Blue-stained pine is now available at some big box stores like Lowes.
There has been concern that the huge number of beetle-killed trees may pose a risk of devastating forest fires. Forest thinning to mitigate fire danger is expensive and resource-intensive.Attention is turning to ways to turn this liability into a source of cellulosic ethanol.
Leaders in western U.S. states and Canadian provinces have promoted legislation to provide incentives for companies using beetle-killed trees for biofuel or biopower applications. Sellable commodities resulting from MPB damage can help subsidize the cost of forest thinning projects and support new job markets. Colorado's Department of Energy recently provided $30 million toward construction of the state's first cellulosic ethanol plant, to convert beetle kill into ethanol. Lignin, a byproduct of the process, can be sold for applications in lubricants and other goods.
The long-held belief that beetle infestations and resulting deadkill lead to more devastating forest fires is currently being challenged. Although some disagree[ citation needed ], ongoing NASA studies have shown beetle kill may actually reduce available small fuels and consequently limit the effect and reach of fires.
This section needs to be updated. The reason given is: The "current" outbreak abated in 2015.March 2021)(
The current outbreak of mountain pine beetles is ten times larger than previous outbreaks. 40 million acres (160,000 km2) of BC's forests affected. Under the presumption that the large areas of dead pine stands represent a potential fire hazard, the BC government is directing fuel management activities in beetle areas as recommended in the 2003 Firestorm Provincial Review. Harvesting affected stands aids fire management by removing the presumed hazard and breaking the continuity of the fuels. These fuel management treatments are specifically designed to reduce interface fire threats to communities and Native Americans located in the infestation zone. The interface is the area where urban development and wilderness meet.Huge swaths of central British Columbia (BC) and parts of Alberta have been hit badly, with over
As of May 2013, the Pine Beetle is aggressively devastating forests in all 19 Western States and Canada, destroying approximately 88 million acres of timber at a 70–90% kill rate. Over 13,000 miles of power lines are being endangered with falling trees that increasingly raise the risk of fires that could cause widespread problems for millions of people. The mountain pine beetle has affected more than 900 miles (1,400 km) of trail, 3,200 miles (5,100 km) of road and 21,000 acres (85 km2) of developed recreation sites over 4,500,000 acres (18,000 km2) in Colorado and southeastern Wyoming; other outbreaks encompass the Black Hills of South Dakota and extend as far south as Arizona, and as far north as Montana and Idaho. The US Forest Service is working on a hazard tree removal strategy, prioritizing high-use recreation areas, such as campgrounds, roads and National Forest Service lands adjacent to vulnerable public infrastructures such as power lines and near communities.
Previously, cold spells had killed off bark beetles which are now attacking the forests.The longer breeding season is another factor encouraging beetle proliferation. The combination of warmer weather, attack by beetles, and mismanagement during past years has led to a substantial increase in the severity of forest fires in Montana. According to a study done for the U.S. Environmental Protection Agency by the Harvard School of Engineering and Applied Science, portions of Montana will experience a 200% increase in area burned by wildland fires, and an 80% increase in air pollution from those fires.
Researchers from the Canadian Forest Service have studied the relationship between the carbon cycle and forest fires, logging and tree deaths. They concluded by 2020, the pine beetle outbreak will have released 270 megatonnes of carbon dioxide into the atmosphere from Canadian forests. There is yet to be an accepted study of the carbon cycle effect over a future period of time for North American forests, but scientists believe we are at a 'tipping point' of our Western Forests becoming a source of carbon off-put that is greater than that of a 'carbon sink'.Other scientists say that this "tipping point" will reverse itself as new forest life is established. This new growth will remove more carbon dioxide than the mature trees they are replacing would have. According to a 2016 study from the Pacific Institute for Climate Solutions rising levels of carbon dioxide may cancel out the pine beetle impact in British Columbia by 2020. The fertilization effect of the increased CO2 levels has returned BC forests to a carbon sink as of 2016 per Werner Kurz of the Canadian Forest Service.
Hydrologists from the University of Colorado have investigated the impacts of beetle-infested forests on the water cycle, in particular, snow accumulation and melt. They concluded that dead forests will accumulate more snowpack as a result of thinner tree canopies and decreased snow sublimation. These thinned canopies also cause faster snowmelt by allowing more sunlight through to the forest floor and lowering the snowpack albedo, as a result of needle litter on the snow surface.Augmented snowpack coupled with dead trees that no longer transpire will likely lead to more available water.
Pinus albicaulis, known by the common names whitebark pine, white bark pine, white pine, pitch pine, scrub pine, and creeping pine, is a conifer tree native to the mountains of the western United States and Canada, specifically subalpine areas of the Sierra Nevada, Cascade Range, Pacific Coast Ranges, and Rocky Mountains from Wyoming northwards. It shares the common name "creeping pine" with several other plants.
A bark beetle is one of about 6,000 species in 247 genera of beetles in the subfamily Scolytinae. Previously, this was considered a distinct family (Scolytidae), but is now understood to be a specialized clade of the "true weevil" family (Curculionidae). Although the term "bark beetle" refers to the fact that many species feed in the inner bark (phloem) layer of trees, the subfamily also has many species with other lifestyles, including some that bore into wood, feed in fruit and seeds, or tunnel into herbaceous plants. Well-known species are members of the type genus Scolytus, namely the European elm bark beetle S. multistriatus and the large elm bark beetle S. scolytus, which like the American elm bark beetle Hylurgopinus rufipes, transmit Dutch elm disease fungi (Ophiostoma). The mountain pine beetle Dendroctonus ponderosae, southern pine beetle Dendroctonus frontalis, and their near relatives are major pests of conifer forests in North America. A similarly aggressive species in Europe is the spruce ips Ips typographus. A tiny bark beetle, the coffee berry borer, Hypothenemus hampei is a major pest on coffee plantations around the world.
Resin acid refers to mixtures of several related carboxylic acids, primarily abietic acid, found in tree resins. Nearly all resin acids have the same basic skeleton: three fused rings having the empirical formula C19H29COOH. Resin acids are tacky, yellowish gums that are water-insoluble. They are used to produce soaps for diverse applications, but their use is being displaced increasingly by synthetic acids such as 2-ethylhexanoic acid or petroleum-derived naphthenic acids.
The Chilcotin River /tʃɪlˈkoʊtɪn/ located in Southern British Columbia, Canada is a 241 km (150 mi) long tributary of the Fraser River. The name Chilcotin comes from Tŝilhqot’in, meaning "ochre river people," where ochre refers to the mineral used by Tŝilhqot’in Nation and other Indigenous communities as a base for paint or dye. The Chilcotin River, Chilko River and Lake, and Taseko River and Lake make up the Chilcotin River watershed. This 19,200 km2 watershed drains the Chilcotin Plateau which reaches north to south from the Nechako Plateau to Bridge River county and east to west from Fraser River to the Coast Mountains. It is also one of twelve watersheds that make up the Fraser River Basin. Made up of seven major tributaries, Chilcotin River starts northeast of Itcha Mountain, flowing southeast until it joins the Fraser River south of Williams Lake or 22 km upstream from Gang Ranch.
Verbenone is a natural organic compound classified as a terpene that is found naturally in a variety of plants. The chemical has a pleasant characteristic odor. Besides being a natural constituent of plants, it and its analogs are insect pheromones. In particular, verbenone when formulated in a long-lasting matrix has an important role in the control of bark beetles such as the mountain pine beetle and the Southern pine bark beetle.
Fir and spruce forests are greatly affected by slight fluctuations in climate. Temperature is the primary determinate for spatial patterns of fir and spruce. The two dominant trees in this type of forest are Picea engelmannii and Abies lasiocarpa. Although thick-barked trees, such as the Pinus resinosa, frequently survive fire, the thin bark of spruce make them more vulnerable. Trees such as the Douglas fir withstand much of the fire due to the thicker bark they have. The scale of the burn mosaic during a fire, relative to species niche requirements and mobility, can have major impacts on flora and fauna dynamics.
Boggs Mountain Demonstration State Forest is a state forest in Lake County, California that covers the northwest of Boggs Mountain. It was founded in 1949, and came into operation in 1950 when most of the site had been clear cut. The purpose was to demonstrate good practices in restoring and managing a forest. The state forest was open for recreational use, including camping, hiking, mountain biking etc. The 2015 Valley Fire destroyed 80% of the trees. The state forest as of 2021 was replanting saplings.
Werner Kurz is a Canadian research scientist at Canada's Pacific Forestry Centre in Victoria, British Columbia. He is leading the development of an accounting system to assess potential climate change known as the National Forest Carbon Accounting System for Canada. Currently, his research focuses on using forest land to its maximum carbon efficiency, reducing the impact of natural disasters, and managing forests. Kurz holds a PhD in forest ecology from the University of British Columbia. He has made significant contributions to the Intergovernmental Panel on Climate Change (IPCC) and the work of the IPCC was recognized by the joint award of the 2007 Nobel Peace Prize.
Blue stain fungi is a vague term including various fungi that cause dark staining in sapwood. The staining is most often blue, but could also be grey or black. Because the grouping is based solely on symptomatics, it is not a monophyletic grouping.
The mountain pine beetle has killed large numbers of the lodgepole pine trees in the northern mountains of the US state of Colorado. The more recent outbreak of another bark beetle pest, the spruce beetle, is threatening higher-elevation forests of Engelmann spruce. Chemical prevention is effective but too costly for large-scale use. Dead trees increase the incidence of wildfires, and may contribute to climate change as they decay. Uses have been found for the dead wood including composting and in construction, and potentially to make biochar.
Dendroctonus rufipennis, the spruce beetle, is a species of bark beetle native to British Columbia, Newfoundland and Labrador, Nova Scotia, Ontario, Quebec, Northern Manitoba, the Yukon, Colorado, Wyoming, Montana, and Maine. They are known to destroy forests of spruce trees including Engelmann, White, Sitka, and Colorado blue spruce. Adults average 4 to 7 mm in length.
Climate change has adversely affected both terrestrial and marine ecosystems, and is expected to further affect many ecosystems, including tundra, mangroves, coral reefs, and caves. Increasing global temperature, more frequent occurrence of extreme weather, and rising sea level are among some of the effects of climate change that will have the most significant impact. Some of the possible consequences of these effects include species decline and extinction, behavior change within ecosystems, increased prevalence of invasive species, a shift from forests being carbon sinks to carbon sources, ocean acidification, disruption of the water cycle, and increased occurrence of natural disasters, among others.
The ecology of the Rocky Mountains is diverse due to the effects of a variety of environmental factors. The Rocky Mountains are the major mountain range in western North America, running from the far north of British Columbia in Canada to New Mexico in the southwestern United States, climbing from the Great Plains at or below 1,800 feet (550 m) to peaks of over 14,000 feet (4,300 m). Temperature and rainfall varies greatly also and thus the Rockies are home to a mixture of habitats including the alpine, subalpine and boreal habitats of the Northern Rocky Mountains in British Columbia and Alberta, the coniferous forests of Montana and Idaho, the wetlands and prairie where the Rockies meet the plains, a different mix of conifers on the Yellowstone Plateau in Wyoming and in the high Rockies of Colorado and New Mexico, and finally the alpine tundra of the highest elevations.
Agent-based models have many applications in biology, primarily due to the characteristics of the modeling method. Agent-based modeling is a rule-based, computational modeling methodology that focuses on rules and interactions among the individual components or the agents of the system. The goal of this modeling method is to generate populations of the system components of interest and simulate their interactions in a virtual world. Agent-based models start with rules for behavior and seek to reconstruct, through computational instantiation of those behavioral rules, the observed patterns of behavior. Several of the characteristics of agent-based models important to biological studies include:
The European spruce bark beetle, is a species of beetle in the weevil subfamily Scolytinae, the bark beetles, and is found from Europe to Asia Minor and some parts of Africa.
The deforestation in British Columbia has occurred at a heavy rate during periods of the past, but with new sustainable efforts and programs the rate of deforestation is decreasing in the province. In British Columbia, forests cover over 55 million hectares, which is 57.9% of British Columbia's 95 million hectares of land. The forests are mainly composed of coniferous trees, such as pines, spruces and firs.
The Canadian forestry industry is a major contributor to the Canadian economy. With 39 percent of the land acreage of Canada covered by forests, the country contains 9 percent of the world's forested land. The forests are made up primarily of spruce, poplar and pine. The Canadian forestry industry is composed of three main sectors: Solid wood manufacturing, pulp and paper and logging. The Forests and forestry are managed by The Department of Natural Resources Canada, the Canadian Forest Service, in cooperation with several organizations which represent government groups, officials, policy experts and numerous other stakeholders. Extensive deforestation by European settlers during the 18th and 19th centuries has been halted by more modern policies. Today less than 1 percent of Canada's forests are affected by logging each year. Despite, the low percentage of land that is logged, Canada is the second largest exporter of wood products, and produces 12.3% of the global market share. Economic concerns related to forestry include greenhouse gas emissions, biotechnology, biological diversity and infestations of pests, such as the mountain pine beetle.
Ips is a genus of beetles in the family Curculionidae, the true weevils. They are bark beetles, members of the subfamily Scolytinae. Species are distributed throughout the Northern Hemisphere. Some are known as introduced species in Australia and Africa. Many species are pests of forest trees, especially pines and spruces. They are known commonly as engraver beetles, ips engraver beetles, and pine engravers.
Dendroctonus valens, the red turpentine beetle, is a species of bark beetle native to the forests of North America, Mexico, Guatemala and Honduras. It has been introduced to China where it has become invasive. In its native range it causes little damage, but in China it is a destructive pest and has killed more than six million pine trees.
The current bark beetle infestation in the Rocky Mountain region of the United States was first detected in 1996. It involved the Mountain pine beetle, which has since spread across millions of acres of dense forest land. In addition, Spruce beetle populations have also been growing in the area in recent years and are further contributing to the existing outbreak. One of the main factors limiting bark beetle population growth is the temperature they can survive at and climate change has raised the average temperature in the region resulting in warmer winters and hotter, drier summers. This not only sped up the bark beetle reproduction process by providing more time per year for them to complete their developmental stages, moisture stressing due to hotter temperatures also weakens the trees’ defense against attacks by reducing resin production. Furthermore, forest management has also played a significant role as many forests in the region have very dense tree populations which facilitates faster spreading from tree to tree, as well as weakening tree defenses further by stressing them through excessive competition.
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