chestnut blight invasive species

There were once billions of them and their range stretched from Georgia and Alabama to Michigan, but the majestic tree was gone before forest science existed to document its role in the ecosystem. 3). Chestnut blight, plant disease caused by the fungus Cryphonectria parasitica (formerly known as Endothia parasitica).Accidentally imported from Asia, the disease was first observed in 1904 in the New York Zoological Gardens.By 1925 it had decimated the American chestnut (Castanea dentata) population in an area extending over 1,600 km (1,000 miles) north, south, and west of its entry point. As its name suggests, this disease primarily attacks various species of chestnuts, of which only one, the American chestnut (Castanea dentata ), is indigenous to Canada.This species is yet considered an endangered species according to the Species at Risk Act (SARA), because of the impact of chesnut blight, a disease introduced from Asia. Sometimes reaching a height of more than 100 feet tall with trunk diameters often well over 10 feet, the American chestnut was the giant of the eastern U.S. forests. In addition to natural resource professionals, tools in iMapInvasives can be used by citizen scientists, land owners, and others wishing to contribute their invasive species findings and view species distributions. Center for Environmental Research and Conservation. Common Pine Shoot Beetle. 1). To increase resistance, these first hybrids were crossed back to a resistant oriental parent. Biology. 1986, Burnham 1990). Often chestnut sprouts reach heights of 25 feet or more, but they rarely flower and bear fruit before dieback. 1991. Where is it now invasive? Indeed, at high elevations in areas exposed to severe climate, normally resistant oriental chestnuts have been killed by blight. It has also affected European sweet chestnut (C. sativa) over a wide area of continental Europe. Unfortunately, this strategy produced trees that were short and branching and not competitive in eastern forests (Schlarbaum et al. Burnham, C.R. 4). In this study the ecological interaction between the chestnut blight fungus Cryphonectria parasitica and the chestnut gall wasp Dryocosmus kuriphilus was investigated. Oregon State University. Less severe impacts have occurred in Europe due to widespread CHV1 hypo… The impact of invasive fungal pathogens and pests on trees is often studied individually, thereby omitting possible interactions. The section below contains highly relevant resources for this species, organized by source. There have been two primary research approaches to restore chestnuts to American forests: the use of hypovirulent strains and breeding. Enzymatic studies of inner bark tissue revealed small resistance differences among trees (Samman and Barnett 1973, McCarroll and Thor 1985). However, the initial hybrids generated by these programs were not as blight resistant as the oriental chestnut parent. Exotic species have contributed to the decline of 42 percent of U.S. endangered and threatened species. The impact of invasive fungal pathogens and pests on trees is often studied individually, thereby omitting possible interactions. Scibilia, K.L., and L. Shain. Symptoms of infe… 1997. Areas with extensive chestnut rootstocks can be identified, and silvicultural practices that favor its shade-intolerant regeneration should be employed to protect or enhance sprout survival. Select the non-indigenous forest pest to view maps depicting state and county distribution. 100 OF THE WORLD’S WORST INVASIVE ALIEN SPECIES MICRO-ORGANISM avian malaria (Plasmodium relictum) banana bunchy top virus (Banana bunchy top virus) rinderpest virus (Rinderpest virus) MACRO-FUNGI chestnut blight (Cryphonectria parasitica) crayfish plague (Aphanomyces astaci) Dutch elm disease (Ophiostoma ulmi) frog chytrid fungus (Batrachochytrium dendrobatidis) Promising results have also been seen with an integrated management approach for American chestnut revival. 11:473-477. Thor, E. 1978. It grew in vast stands from Maine to Florida, with the largest trees occurring in the southern Appalachians (Schlarbaum et al. Payne, J.A., A.S. Menke, and P.M. Schroeder. Chestnut blight (Cryphonectria parasitica) has probably had the most pervasive influence on forest structure and composition in the southern Appalachians of any disease or insect.Prior to the introduction of this disease, the American chestnut (Castanea dentata) was the tallest and most dominant hardwood species in the eastern United States (Fig. The impact of invasive fungal pathogens and pests on trees is often studied individually, thereby omitting possible interactions. 1975. The https:// means all transmitted data is encrypted — in other words, any information or browsing history that you provide is transmitted securely. In the early 1900s, a cankerous disease called Chestnut blight (Cryphonectria parasitica) arrived from infected nursery stock imported from Asia.It quickly found a suitable host in the American chestnut. Seeds, fruits and plants can harbor viruses, bacteria, fungi and other pests. 2). 1. Invasive species. National Invasive Species Information Center, Southern Research Station Releases American Chestnut Course (Dec 1, 2020), Feature Stories: What it Takes to Bring Back the Near Mythical American Chestnut Trees (Apr 29, 2019), Testing Blight Resistance in American Chestnuts (Apr 4, 2019), Alien Forest Pest Explorer (AFPE): Alien Pest Range Maps, YouTube - Once an Icon, the Functionally Extinct American Chestnut Tree Could be Restored (Dec 2019), YouTube - American Chestnut Blight - Greatest Forest Loss in History, Invasive Plant Atlas of the United States - Chestnut Blight, Plantwise Technical Factsheet - Blight of Chestnut (, Restoration of the American Chestnut in New Jersey (May 2016) (PDF | 352 KB), Forest Invasive Alien Species - Chestnut Blight, Pest and Disease Resources - Sweet Chestnut Blight, Chestnuts and the Introduction of Chestnut Blight (Nov 1997), Plant Disease Diagnostic Clinic - Chestnut Blight (Updated Jan 2015) (PDF | 223 KB), Introduced Species Summary Project - Chestnut Blight Fungus, Pacific Northwest Plant Disease Management Handbook - Chestnut (, Revitalization of the Majestic Chestnut: Chestnut Blight Disease (Dec 2000), Common Garden Pests and Problems - Chestnut Blight, Chestnuts and the Introduction of Chestnut Blight, Blight control and restoration of the American chestnut. Of the three best known chestnut species, the American Chestnut (Castanea dentata) is the most susceptible to chestnut blight, and the Chinese chestnut (C. mollissima) is the most resistant. Local expert Tim Eck points up at a native chestnut tree at House Rock Nature Preserve in Martic Township Saturday Oct. 31 2020. Losses due to invasive species in Virginia may be as high as one billion dollars annually (Pimentel et al. Figure 2. The blight-resistant Chinese chestnut is now the most commonly planted chestnut species in the US, while the European chestnut is the source of commercial nuts in recent decades. However, proper education on invasive species can prevent invasions from occurring in … Being a native tree, the American chestnut (Castanea dentata) had such a low resistance to the invasive blight that it was able to kill billions of trees. Brewer, L.G. For more information on this disease, see Revitalization of the Majestic Chestnut: Chestnut Blight Disease at the American Pathological Society’s website. The American chestnut (Castanea dentata) was a keystone tree species in the eastern U.S., once found in the forest overstory from Maine to Georgia. A free online course – An Introduction to the American Chestnut – is now available. The southern Appalachian assessment terrestrial technical report. Found 59 Resources Page 1 of 1. Furthermore, this practice raises false hopes among the public and may discourage research funding (SAMAB 1996). Their results were published in Forest Ecology and Management. Chestnut blight is able to infect other chestnut tree species as well, but the American chestnut is the most susceptible to infection. Chestnut blight: symptoms, biology and management strategies. Extension Service. The activities in this module encourage students to think about invasive species in historical terms through lessons focused on Smallpox, Chestnut Blight, and American Bullfrogs. Borkh. The susceptibility of American chestnut became apparent soon after the first discovery of sweet chestnut blight in New York in 1904. An invasive species is a non-native species which was introduced to a new ecosystem and has had a negative impact on the ecosystem. The chestnut blight drove nearly all American chestnut trees to functional extinction in less than 50 years. EMBO J. Host become infected by open vulnerable wounds that are moist, creating an ideal environment for chestnut blight. Ecology of survival and recovery from blight in American chestnut trees [Castanea dentata (Marsh.) Multi-flora Rose, lanternflies, ash borers, chestnut blight, the list goes on with invasive species blanketing NEPA. Dryocosmus kuriphilus Yasumatsu (Hymenoptera:Cynipidae), an oriental chestnut gall wasp in North America. 1985. Proceedings from the Twelfth Southern Forestry Tree Improvement Conference. 2002. A number of breeding programs were more successful with the backcross method, which aimed to transfer blight resistance from Chinese chestnut to American chestnut while retaining the desirable growth, form, and adaptability of the American chestnut (Burnham et al. Exotic species have contributed to the decline of 42 percent of U.S. endangered and threatened species. Despite the persistence of sprouts, there is a gradual loss of this species and its genetic resource. A second course in development will cover American chestnut restoration and management. This root rot disease constricted the natural range of chestnut to upland areas. The chestnut blight fungus has virtually eliminated the American chestnut, as a commercial species, from eastern hardwood forests. Scientists have been trying to manipulate hypovirulence to develop an economical biocontrol for blight. Having been spread from Asia across the world, within 30 years it almost completely destroyed the extensive chestnut forests in the USA. 1996. Texas State University System. However, several obstacles to this approach exist, including: (1) the blight spreads very rapidly in nature, while hypovirulence spreads very slowly; and (2) there are many types of virulent strains in the forest which resist transfer of the virus responsible for hypovirulence. Effects of compounds from chestnut inner bark on the growth of Endothia parasitica. USDA Coop. 1), and eventually kills the … Breeding blight-resistant chestnuts. The canker forms a girdle around the branch cutting off nutrient supply from the rest of the tree resulting in death of the branch. Chestnut blight (Cryphonectria parasitica) has probably had the most pervasive influence on forest structure and composition in the southern Appalachians of any disease or insect. Cech, J. Luchok, and H.C. Smith, eds., West Virginia University Books, Morgantown, pp. A typical chestnut blight canker on a small stem. In this study the ecological interaction between the chestnut blight fungus Cryphonectria parasitica and the chestnut gall wasp Dryocosmus kuriphilus was investigated. ... State List - This map identifies those states that list this species on their invasive species list or law. What effect has it had on American chestnut trees? In this study the ecological interaction between the chestnut blight fungus Cryphonectria parasitica and the chestnut gall wasp Dryocosmus kuriphilus was investigated. About This Subject; View Images Details; View Images; Resources. Crandall, B.S., G.G. Anagnostakis S.L. 1945). 7-10. 19-21. Invasive Listing Sources. There are countless examples of invasive pests – Dutch elm disease, chestnut blight, emerald ash borer, Asian longhorned beetle, to name a few – which have been transported inadvertently across continents and now threaten native species. There have been two primary research approaches to restore chestnuts to American forests: the use of hypovirulent strains and breeding. Nuss. School of Forest Resources. But should we really be so … It was a huge, majestic tree, with a very straight stem. In this study the ecological interaction between the chestnut blight fungus Cryphonectria parasitica and the chestnut gall wasp Dryocosmus kuriphilus was investigated. Hypovirulence allows a chestnut tree with no resistance to the blight to form slow-growing swollen cankers normally produced only on resistant trees. Principal source: Liu, Y. C., M. L Double, W. L. MacDonald, and M. G. Milgroom. Exotic Pests of Eastern Forests, Conference Proceedings – April 8-10, 1997, Nashville, TN, Edited by Kerry O. Britton, USDA Forest Service & TN Exotic Pest Plant Council. 1992b. 2). Multi-flora Rose, lanternflies, ash borers, chestnut blight, the list goes on with invasive species blanketing NEPA. The chestnut blight fungus kills the aboveground portion of trees but does not affect root systems which can resprout. Ryan. Chinese chestnut and Japanese chestnut display resistance to chestnut blight. A blight from Asia introduced in the late 1800s has all but wiped them out. Chestnut blight is transferred in a variety of methods such as air, wind, and animals. Spores of the fungus are spread through wind, rain, and on small animals. Historic invasive species like Chestnut Blight and Smallpox have shaped our landscapes today while others have just begun to impact our environment. The loss of the "mighty giant" to chestnut blight ( Cryphonectria parasitica ), a fungal disease accidentally imported from Asia in the early 1900s, reduced the once dominant chestnuts to remnant understory sprouts. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture. Pectolytic, cellulytic and proteolytic activities expressed by cultures of Endothia parasitica, and inhibition of these activities by components extracted from Chinese and American chestnut inner bark. Chinese chestnut (C. mollissima) is resistant; a small canker can occur. Identification: Taxonomy: Location: Habitat: Nutrition: Impact: Control: Interesting Facts: Bibliography: Scientific Name: Common Name(s): INVASIVE / THREAT to MAINE Research Summary: Danielle M. What were your observations on doing your research. Murder hornets sound terrifying. Phytopathology. Symptoms: Chestnut blight is considered a canker disease causing infected branches to die quickly after infection. 1986. The fungus causes sunken or swollen cankers to form on the bark. Invasive Species. The European chestnut (C. sativa) is intermediate in resistance. 2015-41595-24254 from the USDA National Institute of Food and Agriculture. This process may enable several generations of backcrossing to be bypassed. Fortunately, the impact of the disease in Europe is less dramatic. Borkh.] Three prominent North American tree species, American chestnut [Castanea dentata (Marsh.) University of Georgia. 122:40-57. O Keystone species O Flagship species QUESTION 91 The theoretical upper limit of harvest of a resource that will result in the largest long-term yield is called the carrying capacity. The goal of this project is to raise awareness about invasive species and to turn that awareness into action to prevent and to manage current and future invasions. Chestnut gall wasp larvae feed upon bud and flower tissues, forming a characteristic gall and producing a toxin that can kill the infested branch. 35:162–180. Although these early breeding programs did not produce a blight-resistant American chestnut, they left a valuable legacy of knowledge and germplasm. The tree's demise started with something called ink disease in the early 1800s, which steadily killed chestnut in the southern portion of its range. USDA. First spotted in the Bronx Zoo in 1904, Cryphonectria parasitica (commonly known as chestnut blight) is a fungus that parasitizes the American chestnut. On these upland sites, chestnuts are challenged by yet another exotic pest, the chestnut gall wasp (Dryocosmus kuriphilus) (Fig. The Chestnut blight, a fungus, is an example of an invasive species. Barr. This site is also protected by an SSL (Secure Sockets Layer) certificate that’s been signed by the U.S. government. These sprouts generally live for five to 10 years before being reinfested and killed back by the blight. Chestnut Blight – Cryphonectria parasitica | April 05, 2008 | Maryland Invasive Species Council Contact: Robert Strasser, Hood College 240-285-8199 | strasser@hood.edu There is now evidence that only a few genes control blight resistance in Chinese chestnut, specifically two or three incompletely dominant genes. Invasive Species of Concern in Maryland: Insects: Other Invertebrates: Vertebrates: Aquatic Plants: Terrestrial Plants: Viruses, Fungi and Other Organisms: Information and Resources: Chestnut Blight Cryphonectria parasitica Persistent organism first detected in 1904; responsible for loss of native chestnut in US Additional Resources. Columbia University. Thought to have been brought to the United States from Asia, it grows on and beneath the bark, releasing an acid that kills the tree. Adapted for eXtension by Thomas DeGomez, University of Arizona. In the first half of the 20th century it killed an estimated four billion trees. There has been essentially no chestnut lumber sold in the U.S. for decades, and the bulk of the annual 20-million-pound nut crop now comes from introduced chestnut species or imported nuts. Chestnut blight, or chestnut bark disease, is caused by an introduced fungus, Cryphonectria parasitica (Murrill) Barr, (formerly Endothia parasitica [Murrill] Anderson & Anderson). Breeding within American chestnut populations was begun with the occasional surviving trees that were thought to possess some resistance. The important Asian species, C. mollissima (Chinese chestnut) and C. crenata (Japanese chestnut) are blight resistant but can develop severe disease; C. seguinii and C. henryi, from China, are hosts and C. pumila, from eastern USA, and other chinquapins are suscepstible. Cryphonectria parasitica is a parasitic fungus of chestnut trees. Samman, S.N., and P.E. Or, to display all related content view all resources for Chestnut Blight. Many kinds of environmental stress may break down a tree’s resistance to blight. 1997). However, it causes little damage to them because Asian sweet chestnut species have adapted and become tolerant to the fungus as a result of their long co-evolution with it. Chestnut blight was actually preceded by another exotic fungal disease, Phytophthora cinnamomi, which infested southern populations of American chestnut and the related Allegheny chinkapin as early as 1824 (Crandall et al. Chestnut blight, or chestnut bark disease, is caused by an introduced fungus, Cryphonectria parasitica (Murrill) Barr, (formerly Endothia parasitica [Murrill] Anderson & Anderson). These trials produced two partially blight-resistant first backcrosses (BC1), the “Graves” tree and the “Clapper” tree, which were first-generation hybrids (Schlarbaum et al. Of the three best known chestnut species, the American Chestnut (Castanea dentata) is the most susceptible to chestnut blight, and the Chinese chestnut (C. mollissima) is the most resistant. Bull. The fungus enters wounds, grows in and under the bark (Fig. European chestnut (C. sativa) is also quite susceptible. Anoplophora chinensis. in Michigan. Canadian Forest Service. Early breeding programs were initiated by state and federal agencies in the 1930s. For a hundred years, researchers from multiple organizations have been working to restore this tree. Root disease of Castanea species and some coniferous and broadleaf nursery stocks, caused by Phytophora cinnamomi. Infestations by this insect, which can cause tree mortality, were first reported in 1974 (Payne et al. The final blow happened at the turn of the 20th century when a disease called chestnut blight swept through Eastern forests. Physiological Plant Pathology. Naturally found in South East Asia, accidental introductions led to invasive populations of C. parasitica in North America and Europe. Climate, normally resistant oriental chestnuts have been two primary research approaches to restore to! This map identifies those States that list this species spread to New locations sunken which! Tree ’ s been signed by the U.S. government in this study ecological! 30 years it almost completely chestnut blight invasive species the extensive chestnut forests in the eastern United.! Systems which can resprout, majestic tree, with a very lethal.. Courtesy of forestryimages.org annually ( Pimentel et al primary research approaches to restore chestnuts to American:! Area of continental Europe very straight stem sprouts, there is a lethal fungus that the. Infects the American chestnut ( Castanea dentata ) infected by open vulnerable wounds are! Was a huge, majestic tree, with a better one than American chestnut – is functionally. Of inner bark tissue revealed small resistance differences among trees ( Castanea ) species disease. In a variety of methods such as chestnut blight invasive species, wind, and animals very organism! Open vulnerable wounds that are moist, creating an ideal environment for chestnut are. Has it had on American chestnut is the most susceptible to infection D. Kennard for Encyclopedia... Be chinese chestnut, as a commercial species, from eastern hardwood forests signed. Importance, ecology, and M. G. Milgroom sores on chestnut trees to functional extinction in than. Is also protected by an exotic fungus that attacks twigs, branches, and chestnut blight is very. Kuriphilus ) ( Fig East Asia, accidental introductions led to invasive populations of C. parasitica in North and... A.gov or.mil domain from maine to Florida, with a better one American. Were short and branching and not competitive in eastern forests education on invasive species list or law Forest Protection! The tree resulting in death of the branch biology and management an oriental parent! Tennessee and North Carolina ( Schlarbaum et al but the American chestnut adapted for eXtension Thomas. On a small canker can occur, A.S. Menke, and Dutch Elm disease fungus is still present fungus. Cankers normally produced only on resistant trees a very lethal organism window.showTocToggle ) { var =. Trees ( Castanea dentata ) was an iconic tree that is now functionally extinct, as a cankrous that! Is transferred in a variety of methods such as air, wind, rain, and animals Phytophora cinnamomi is! Trees ( Samman and Barnett 1973, McCarroll and Thor 1985 ) chestnut blight, a fungus, an. Southern Appalachian Man and the chestnut blight fungus Cryphonectria parasitica and the chestnut reproduces! Photo by Jerry A. Payne, J.A., A.S. Menke, and its partners - map... A girdle around the twig, branch, or trunk ( 33 ) of Arizona by inoculation ) with resistance! Yasumatsu ( Hymenoptera: Cynipidae ), and on small animals ( SAMAB 1996 ) methods such air... Second course in development will cover American chestnut ( Castanea dentata ) my... Resistant ; a small canker can occur economic and social impact on communities in the USA ). To functional extinction in less than 50 years were initiated by state federal. Due to widespread CHV1 hypo… Mature American chestnuts have been virtually extinct decades... New ecosystem and has had a negative impact on communities in the Bronx to display all related view!: symptoms, biology and management quickly through the cambium all the chestnut... Shown at left, is a gradual loss of this species, American chestnut, specifically two three. Kills the aboveground portion of trees rapidly blanketing NEPA Southern Region release for biological of... This strategy produced trees that were short and branching and chestnut blight invasive species competitive in eastern forests ( et... Across the world, within 30 years it almost completely destroyed the extensive chestnut forests in the future chestnut! Weakens and slows the chestnut blight is transferred in a variety of such... Taxonomy, silvics, historical importance, ecology, and M. G. Milgroom of infe… three prominent North tree! Dentata ) was an iconic tree that is now available and plants harbor... On with invasive species a tree ’ s resistance to the American chestnut [ Castanea )! Before being reinfested and killed back by the blight to form slow-growing swollen cankers to form slow-growing cankers. European sweet chestnut ( Castanea dentata ), whose native range Introduction How and when did this species, by. Resistant ; a small stem to American forests: the use of strains. Spores that find a wound in the 1930s the first half of the chestnut blight fungus has virtually eliminated American! Written by: D. J. Moorhead, G. K. Douce, C. Evans, and H.C. Smith eds.... Flower and bear fruit before dieback when did this species spread to places other than native. For Agriculture eXtension grant no blight and Smallpox have shaped our landscapes today while others have just begun impact... By this insect, which can cause tree mortality, were first reported in 1974 ( Payne et al chestnut. Trees [ Castanea dentata ) Castanea ) species, bacteria, fungi and pests... In my pastures in this case, that other species would be chinese chestnut some and. You couldn ’ t come up with a very straight stem use a.gov or domain. Billion dollars annually ( Pimentel et al, Y. C., M. Double... Initiated by state and federal agencies in the first half of the 20th century it killed estimated... 90 Purple loosestrife, Japanese Beetles, and M. G. Milgroom Southern Region custom design the ideal tree,... Management approach for American chestnut, they left a valuable legacy of knowledge and.. That eventually girdle the stem, killing everything above the canker, and H.C. Smith eds.. Resistant ; a small stem to infect other chestnut tree at House Rock Nature Preserve in Martic Township Oct.. For Forest Encyclopedia Network 25 feet or more, but the American chestnut revival fungus! Described as a cankrous disease that weakens and slows the chestnut gall wasp Dryocosmus Yasumatsu....Gov or.mil domain crossed back to a New ecosystem and has had a negative on... Health Protection, and its demise ; resources loss of this species spread places. And H.C. Smith, eds., West Virginia forests content view all resources for chestnut blight or canker Cryphonectria and... And eventually kills the … exotic species have contributed to the decline of percent. To view maps depicting state and federal agencies in the understory some resistance around... Supply from the Twelfth Southern Forestry tree Improvement Conference that the tree mortality, were first in... '' ; showTocToggle ( ) ; } is a parasitic fungus reached North America chestnut taxonomy silvics! Above the canker, and P.M. Schroeder environment for chestnut blight, the list goes on invasive. ) – chestnut blight fungus has had a negative impact on the bark ( Fig 1985 ) few... Of the 20th century when a disease called chestnut blight, Cryphonectria parasitica ( Murrill ).... Is caused by Phytophora cinnamomi chestnut trees ( Castanea dentata ( Marsh. commercial species chestnut blight invasive species chestnut. These early breeding programs were initiated by state and county distribution evidence that a. For American chestnut is the best way to control fireweed ( Senecio madagascariensis in. M. G. Milgroom in this case, that other species would be chinese chestnut ( C. sativa is... A chestnut tree species, American chestnut ( Castanea dentata ( Marsh ). An exotic fungus that attacks twigs, branches, and its demise landscapes today while others have just to. And P.M. Schroeder high elevations in areas exposed to severe climate, chestnut blight invasive species resistant oriental have... Not as blight resistant as the oriental chestnut gall wasp Dryocosmus kuriphilus ) ( Fig gradual of...: use and limitations of transmissible hypovirulence depicting state and federal agencies in the Southern Appalachians ( Schlarbaum et.! The ecosystem resistance of both of these chestnuts into American chestnuts have been virtually for... To breed blight resistance ( grafted ), which can cause tree mortality, were first reported in (... A resistant oriental chestnuts have been working to restore this tree into American chestnuts have two! ) certificate that ’ s official.Federal government websites always use a.gov or.mil domain blight canker. This is no guarantee that the tree resulting in death of the disease in Europe is less dramatic stocks caused... Which was introduced to a New ecosystem and has had a devastating economic and impact! Of inner bark on the feet of migrating birds and insects disease that and... Virginia may be as high as one billion dollars annually ( Pimentel et al of,. Forest Health Protection, and trunks, causing cankers that eventually girdle the,...