Community composition and structure had no effect on forest susceptibility to invasion by the emerald ash borer (Coleoptera: Buprestidae)

2015 ◽  
Vol 147 (3) ◽  
pp. 318-328 ◽  
Author(s):  
Annemarie Smith ◽  
Daniel A. Herms ◽  
Robert P. Long ◽  
Kamal J.K. Gandhi

AbstractEmerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a non-native, wood-boring beetle that has caused widespread mortality of ash (Fraxinus Linnaeus (Oleaceae)) in eastern North America. During 2004–2007, we determined whether forest community composition and structure of black (F. nigra Marshall), green (F. pennsylvanica Marshall), and white (F. americana Linnaeus) ash stands influenced their susceptibility to EAB invasion in southeast Michigan, United States of America. There was no relationship between EAB-induced ash decline or percentage mortality and any measure of community composition (tree species diversity, stand/ash density, total basal area, or relative dominance of ash). There was also no relationship between measures of EAB impact (density of EAB signs, ash decline rating, percentage ash mortality, or percentage infested ash) and forest attributes (ash/total stand density, basal area, ash importance, or stand diversity). Decline and mortality of black ash advanced more rapidly than that of white and green ash. Percentage mortality of ash increased from 51% to 93% during 2004–2007. Distance from the epicentre of the invasion was negatively correlated with ash mortality, but this relationship dissipated over time. Stand composition data suggests that ash will be replaced by Quercus Linnaeus (Fagaceae), Acer Linnaeus (Sapindaceae), and Tilia Linnaeus (Malvaceae); such vegetation changes will irreversibly alter the structure and function of these forests.

2019 ◽  
Vol 49 (5) ◽  
pp. 510-520 ◽  
Author(s):  
Molly A. Robinett ◽  
Deborah G. McCullough

Despite catastrophic ash (Fraxinus spp.) mortality observed by the mid-2000s in the epicenter of the emerald ash borer (EAB) (Agrilus planipennis Fairmaire) invasion in southeast Michigan, we noticed numerous live white ash (Fraxinus americana L.) in some forests in this region. In 2015, we inventoried overstory trees and regeneration in 28 white ash sites spanning 11 counties. White ash survival ranged from 0% to 100% of stems. Overall, 75% of 821 white ash trees, ranging from 10.0 to 44.0 cm diameter at breast height, and 66% of the white ash basal area, ranging from 0.3 to 3.5 m2·ha–1, were alive. Nearly all live white ash had signs of previous EAB colonization, but 83% had healthy canopies (≤10% canopy dieback). Green ash trees were recorded in 27 sites, but 92% were killed by EAB. Model selection indicated that variation in white ash survival was related to white ash abundance and distance of sites from the original EAB epicenter but not to green ash related variables or to the distance of sites from the Asian parasitoid release or recovery locations. Regeneration strata were dominated by white ash, suggesting that some white ash populations may persist in post-invasion areas.


2014 ◽  
Vol 44 (7) ◽  
pp. 768-776 ◽  
Author(s):  
Stephen J. Burr ◽  
Deborah G. McCullough

Assessing emerald ash borer (Agrilus planipennis Fairmaire) impacts in North American forests is essential for projecting future species composition of stands invaded by this phloem-feeding pest. We surveyed all species of overstory trees and regeneration in 2010 and 2011 in 24 forested sites with a major component of green ash (Fraxinus pennsylvanica), representing the Core, Crest, and Cusp of the A. planipennis invasion wave across southern Michigan. By 2011, an average of 78.6% ± 0.10%, 44.8% ± 0.11%, and 19.8% ± 0.07% of overstory ash trees representing 87%, 57%, and 14% of the total ash basal area had been killed in Core, Crest, and Cusp sites, respectively. Green ash seedlings, saplings, and recruits were abundant in all sites, but newly germinated ash seedlings were absent in Core sites and scarce in Crest sites. Canopy gaps resulting from current ash decline and mortality increased available photosynthetically active radiation (PAR) and sapling growth in Crest sites, but PAR was low in Core and Cusp sites. Lateral ingrowth of non-ash overstory trees has largely filled canopy gaps in Core sites, and there was little evidence of green ash recruitment into the overstory. Green ash appears unlikely to persist as a dominant species in forests invaded by A. planipennis.


2016 ◽  
Vol 42 (6) ◽  
Author(s):  
Sara Tanis ◽  
Deborah McCullough

Emerald ash borer (EAB) (Agrilus planipennis), first identified near Detroit, Michigan, U.S., in 2002, has killed millions of ash trees (Fraxinus spp.) in 28 states and two Canadian provinces to date. Trunk injections of insecticide products containing emamectin benzoate (EB) (e.g., TREE-ageR) are often used to protect ash trees in landscapes from EAB, but wounds and potential injury resulting from injections are a concern. Researchers examined 507 injection sites on 61 trees and recorded evidence of secondary wounding (e.g., external bark cracks, internal xylem necrosis and pathogen infection). Researchers assessed 233 injection sites on 22 green ash and 24 white ash trees macro-injected with a low or a medium-high rate of EB in 2008 only, or in both 2008 and 2009. Only 12 of 233 injection sites (5%) were associated with external bark cracks and there was no evidence of pathogen infection. On 39 of the 46 trees (85%), new xylem was growing over injection sites. Researchers assessed 274 injection sites on 15 green ash trees injected annually with EB from 2008 to 2013 or injected in 2008 and again in 2011. Bark cracks were associated with four injection sites on three trees, but no evidence of injury was found on the other 12 trees. All 15 trees had new xylem laid over injection sites. Confocal laser scanning and polarizing digital microscopy were used to assess the integrity of discolored xylem tissue removed from the immediate area surrounding 140 injection sites on 61 trees. Researchers found no evidence of decay associated with discoloration.


1983 ◽  
Vol 7 (4) ◽  
pp. 208-212 ◽  
Author(s):  
Robert N. Muller

Abstract An old-growth forest and a 35-year-old, second-growth forest on the Cumberland Plateau were studied to compare species composition and structure. Species composition and total basal area of the two stands did not differ, although total stand density was 19 percent lower and basal area of commercial species was 25 percent higher in the old-growth than in the second-growth stand. Analysis of size-class distributions showed that both stands were best represented by an inverse J-shaped distribution, which best describes old-age stands. The rapid regeneration of the second-growth stand seems to be the result of minimal disturbance to accumulated nutrient pools in the soil. The importance of these accumulated nutrient pools and implications for forest management on the Cumberland Plateau are discussed.


Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 949
Author(s):  
Jordan M. Marshall

Emerald ash borer is an invasive pest in North American forests. Ecological impacts of ash mortality from emerald ash borer are wide-ranging, including shifts in insect communities and wildlife behavior. Additionally, loss of ash from forests may have important implications regarding plant succession. Surveys of overstory, midstory, and understory trees within forests in northeastern Indiana, Lower Peninsula of Michigan, and northwestern Ohio were conducted to quantify the change in forest composition over a 10 year period. Interpolation of ash dominance illustrated inversion of live and dead ash values between 2007 and 2017. Even though more than 83% of overstory live ash basal area was lost across the study area, green ash was the most abundant midstory and understory species representing regeneration. Additionally, loss of ash from many of the sites resulted in compositional changes that were greater than merely the subtraction of ash. Due to the relatively large number of forest types with which ash species are associated, loss of ash will have broad ecological consequences, including on community composition.


Author(s):  
В.Л. Мешкова ◽  
Т.В. Кучерявенко ◽  
Ю.Е. Скрыльник ◽  
О.В. Зинченко ◽  
А.И. Борисенко

Целью исследования является выявление особенностей распространения ясеневой изумрудной узкотелой златки (ЯИУЗ) в насаждениях Луганской обл. в первый год после ее обнаружения. Обследованы насаждения с наличием в составе ясеня обыкновенного (Fraxinus excelsior L.) и ясеня зелёного, или пенсильванского (Fraxinus pennsylvanica Marsh.), в лесном фонде трёх государственных лесоохотничьих предприятий (Старобельского, Белокуракинского и Сватовского), расположенных к западу от пунктов первого обнаружения ЯИУЗ в Луганской области. Установлено, что ясеневая изумрудная узкотелая златка присутствует практически во всех насаждениях с наличием в составе ясеня зелёного, что составляет 11,1% покрытой лесом площади. В течение 2020 г. ЯИУЗ распространилась на расстояние 32-52 км от первой точки обнаружения. Самая южная точка ее выявления - в районе с. Меловатка, самая западная - в районе с. Донцовка. Учитывая тенденцию распространения ЯИУЗ в юго-западном направлении, можно ожидать ее проникновения в Харьковскую и Донецкую области. Ясеневая изумрудная узкотелая златка заселяет в основном ясень зелёный, а у ясеня обыкновенного - поросль, деревья в насаждениях с низкой полнотой, на опушках и по периметру небольших по площади урочищ или лесополос. Средняя плотность личинок ЯИУЗ (±S.E.) в заселенных ветвях ясеня зелёного и ясеня обыкновенного достоверно не отличается (0,6±0,07 и 0,7±0,09 шт./дм2 соответственно). Однако доля образцов ясеня зелёного с наличием жизнеспособных личинок ЯИУЗ (91,4±3,12%; n = 45) была достоверно более высокой, чем ветвей ясеня обыкновенного (76,1±6,29%; n = 82). Вылетных отверстий ЯИУЗ в деревьях ясеня обыкновенного не обнаружено, а дополнительное питание её имаго отмечено только на листве деревьев ясеня зелёного. Наличие поселений ЯИУЗ в деревьях I-II категорий санитарного состояния свидетельствует о высокой агрессивности насекомого. Вопросы динамики состояния заселенных деревьев и выживания личинок ясеневой изумрудной узкотелой златки предстоит исследовать в дальнейшем, особенно относительно ясеня обыкновенного, который присутствует в насаждениях региона на 36,9% покрытой лесом площади. The goal of the research was to reveal the features of the spread of the emerald ash borer (EAB) in the stands of the Luhansk region during the first year after its detection. The stands with the presence of the common ash (Fraxinus excelsior) and the green ash (F. pennsylvanica) in the forest fund of Starobelskoe, Belokurakinskoe, and Svatovskoe Forest and Hunting Enterprises, located to the west of the points of the first detection of EAB in the Luhansk region, were examined. The EAB was found in almost all stands with the presence of green ash in the composition, which comprises 11.1% of the forested area. During 2020, the EAB spread over a distance of 32-52 km from the first detection point. The southernmost point where it was registered is near Melovatka, and the westernmost - is near Dontsovka. Taking into account the tendency of EAB to spread in the southwestern direction, we can expect its invasion to the Kharkiv and Donetsk regions. EAB inhabits mainly green ash, and in common ash it prefers sprouts, trees in the stands with low relative stocking density, and trees at the edges and along the perimeter of small forests or forest belts. The mean density (±S.E.) of EAB larvae in populated branches does not differ significantly for green ash and common ash (0.6±0.07 and 0.7±0.09 larvae/dm2, respectively). However, the proportion of EABcolonized branches of green ash (91.4±3.12%; n = 45) is significantly higher than that of common ash (76.1±6.29%; n = 82). The exit holes of EAB in the trees of common ash were not found. Maturation feeding of EAB was registered only in the trees of green ash. The presence of EAB galleries and larvae in the trees of the 1st and the 2nd categories of health condition (healthy-looking and weakened trees according to the Sanitary Rules in the Forests of Ukraine) indicates the aggressiveness of EAB. The dynamics of the health condition of EAB colonized trees, as well as the survival of its larvae are to be investigated further, especially for the common ash, which proportion in the stands of the region is about 36.9% of forest-covered area.


2014 ◽  
Vol 12 (3) ◽  
pp. 286-297 ◽  
Author(s):  
Constance E. Hausman ◽  
Michelle M. Bertke ◽  
John F. Jaeger ◽  
Oscar J. Rocha

The USA is experiencing a prolific invasion of the wood-boring emerald ash borer,Agrilus planipennis. Native to Asia, this beetle completes its life cycle on ash trees and results in nearly complete mortality of all infested trees. In the present study, we examined the levels of genetic diversity and differentiation among eight populations ofFraxinus pennsylvanica(green ash) using five polymorphic microsatellite loci. Genetic information was used to design guidelines for the establishment of a seed collection sampling strategy to conserve the genetic diversity of ash trees. We found high levels of genetic diversity, as indicated by the allelic richness, both across the populations (16.4 ± 5.18 alleles per locus) and within them (8.03 ± 1.21 alleles per locus). The expected and observed heterozygosity was also high (0.805 ± 0.38 and 0.908 ± 0.04, respectively), and there was moderate genetic differentiation among the populations (FST= 0.083) with members of these eight populations grouped into three distinct clusters. We examined the relationship between the number of individuals sampled and the number of alleles captured in a random sample taken from a population of 10,000 individuals. Only sample sizes of 100 individuals captured most of the alleles (average = 78.74 alleles), but only seven of 50 samples effectively captured all the 82 alleles. Smaller samples did not capture all alleles. A probabilistic model was used to determine an optimal sampling strategy, and it was concluded that a collection of 200 seeds from each of five mother trees would have the highest likelihood of capturing all alleles in a population.


2011 ◽  
Vol 28 (2) ◽  
pp. 79-83 ◽  
Author(s):  
Toby R. Petrice ◽  
Robert A. Haack

Abstract Efforts to eradicate or slow the spread of emerald ash borer (EAB) (Agrilus planipennis Fairmaire [Coleoptera: Buprestidae]) include cutting infested and nearby uninfested ash (Fraxinus spp.) trees. However, ash trees readily sprout after they have been cut, providing potential host material for EAB. In 2004–2005, we conducted studies to determine how different cutting times (midspring, late spring, and late summer), different cutting heights (0–5, 10–15, and 20–25 cm above the ground), and triclopyr (44% active ingredient) stump treatment of green ash (Fraxinus pennsylvanica Marsh.) trees affected subsequent stump sprouting and colonization by EAB. We also cut white ash (Fraxinus americana L.) and black ash (Fraxinus nigra Marsh.) trees 20–25 cm above the ground in late spring. Some stumps of each ash species tested sprouted and were colonized by EAB. All green ash stumps treated with triclopyr died and were not colonized by EAB. Stump sprouting was significantly lower for stumps cut in late spring compared with stumps cut in midspring or late summer. Stump sprouting did not vary significantly among cutting heights. None of the green ash stumps cut in midspring or cut 0–5 cm above the ground were colonized by EAB; however, the frequency of stump colonization by EAB did not vary significantly among cutting times or cutting heights.


Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 691
Author(s):  
Mark G. Volkovitsh ◽  
Andrzej O. Bieńkowski ◽  
Marina J. Orlova-Bienkowskaja

Emerald ash borer (EAB), Agrilus planipennis, native to East Asia, is an invasive pest of ash in North America and European Russia. This quarantine species is a threat to ash trees all over Europe. Survey in ten provinces of European Russia in 2019–2020 showed that EAB had spread faster and farther than was previously thought. The new infested sites were first detected in St. Petersburg (110–120 km from the EU border: Estonia, Finland) and Astrakhan Province (50 km from the Kazakhstan border). The current range of EAB in Europe includes Luhansk Province of Ukraine and 18 provinces of Russia: Astrakhan, Belgorod, Bryansk, Kaluga, Kursk, Lipetsk, Moscow, Orel, Ryazan, Smolensk, St. Petersburg, Tambov, Tula, Tver, Vladimir, Volgograd, Voronezh, and Yaroslavl. Within these, only seven quarantine phytosanitary zones in five provinces are declared by the National Plant Protection Organization of Russia. EAB was not found in the regions along the Middle Volga: Mari El, Chuvash and Tatarstan republics, Nizhny Novgorod, Samara and Saratov provinces. The infested sites in St. Petersburg and in the Lower Volga basin are range enclaves separated from the core invasion range by 470 and 370 km, correspondingly. It is possible that new enclaves can appear in the cities of Eastern Europe and Kazakhstan far from the current known range. All previously known infestations in European Russia were in green ash (Fraxinus pennsylvanica), which was introduced from North America, and individual trees of European ash (F. excelsior). A first confirmed case of mass decline of several thousand of EAB-infested European ash trees in Moscow province is provided. Therefore, there is no more doubt that under certain conditions EAB can seriously damage native ash trees in European forests.


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