This dissertation thesis deals with ability of secondary crown formation after opening a canopy and secondary crown utilization in landscape architecture. The ability of different taxa of trees to form a secondary crown after opening a canopy is genetically conditioned and influenced by the specific terms of habitat, tree age, physiological state of the individual and the specific characteristics of the individual. As a model plant for this dissertation thesis was chosen a representative of the Quercus L. genus which is very frequently used in landscape architecture. Specifically, Quercus cerris L. taxon was chosen which is grown in forest stands of Lednice-Valtice Cultural Landscape as a monoculture. Field research was conducted in forest stand edges of Forest management unit Židlochovice, namely in forest district Valtice. In this forest district were found suitable sites that meet the condition of chosen evaluation methodology, allowing comparable statistical evaluation. Enough suitable forest stand edges were found that were selected for the experiment. To the topic of secondary crown formation after opening a canopy and practical utilization of secondary crown is paid only little attention in specialized publications and in both basic and applied research. This thesis brings knowledge that can significantly contribute to the development and importance of field Landscape architecture in contemporary society. The thesis brings a lot of new information and relationships that occur during tree crown regeneration when opening a canopy. These findings can be used for example during the regeneration of untended objects of garden art monuments and other objects of landscape architecture. The results may also help in the conversion of forest stands to different objects of landscape architecture both in urban and rural settlements. The results allow modeling the development of woody plant vegetation elements in these objects. It is clear that arbitrary regenerative ability of secondary crown formation and thus the replacement of the primary crown is not sufficient but it is always necessary to respond on this ability of regeneration by various means of tree care measures so that the whole intention reaches the optimal result. The results indicate that primary or secondary woody plant vegetation element opening a canopy is able to regenerate in order to increase its landscaping value or to increase its dendrological potential of the compound vegetation element. Knowledge can also be used for regeneration of trees on the newly created forest stand edges, historical parks or other compound woody plant vegetation elements.

Lors de ce travail de thèse nous avons adopté une approche fonctionnelle de la dynamique forestière méditerranéenne. L'objectif principal est de comprendre comment les réponses fonctionnelles à la disponibilité de la lumière et aux interactions biotiques vont conditionner la régénération des trois principales espèces impliquées dans cette dynamique : Pinus halepensis, Quercus ilex, Quercus pubescens. Une première expérimentation en pots a été menée en conditions contrôlées afin de déterminer progressivement : les différences de stratégies d'acclimations à l'ombre du pin d'Alep et du chêne pubescent, les compromis fonctionnels et les limites ontogéniques et nutritionnelles de ces stratégies, et l'impact de l'allélopathie et de la compétition sur cette réponse à l'ombre. Une expérimentation de terrain a ensuite permis de créer un gradient d'éclaircie dans une pinède de pin d'Alep, pour comprendre les principaux effets positifs et négatifs de la canopée sur les facteurs abiotiques et le développement du chêne pubescent et du chêne vert à différentes échelles de temps. Les résultats obtenus montrent que le pin d'Alep présente une stratégie d'évitement de l'ombre par une forte réponse plastique qui implique des compromis fonctionnels, des coûts nutritionnels élevés, et un temps d'expression limité. Cette stratégie présente un désavantage dans le cas d'une régénération sous canopée. A l'inverse, le chêne pubescent montre une stratégie plus conservatrice grâce à une réponse plastique à l'ombre limitée, mais une forte sensibilité aux interactions plantes-plantes. En conditions naturelles, le chêne pubescent et le chêne vert en régénération présentent des réponses différentes au gradient d'éclaircie de la canopée, le chêne pubescent montrant cette fois ci une moins forte tolérance à l'ombre. Cette thèse permet de mettre en évidence les liens entre limites fonctionnelles de la plasticité phénotypique, tolérance à l'ombre, et réussite d'installation sous couvert forestier. / During this work we studied the Mediterranean forest dynamic through a functional approach. Our main goal consisted to know how functional responses to light availability and biotic interactions determine the regeneration of three main species involved in this dynamic : Pinus halepensis, Quercus ilex and Quercus pubescens.A nursery experiment was set up to determine specific shade acclimatation strategies of the Aleppo pine and the Downy oak, functional tradeoffs and nutritional and ontogenetic limits of these stratgies, and the competitive and allélopathic impact on the shade induced response.Then a field experiment was set up to make a light gradient in an Aleppo pins pinewood in order to know the main positive and negative canopy effects on abiotic factors and oak seedlings development at different scales of time. Results showed that Aleppo pine exhibits a shade avoiding strategy through a strong plastic response involving functional tradeoffs, high nutritional costs, and time-limited expression. This strategy is considered as maladaptive in case of regeneration under unovercome forest canopy. Reversly, the downy oak shows a more conservative strategy through a limited plastic response to shade but a strong vulnerability to plant-plant interactions. In field conditions, Quercus pubescens and Quercus ilex seedlings showed different responses to the canopy cover, with a fewer shade tolerance in Quercus pubescens. This work help to highlight relationships between functional limits of phenotypic plasticity, shade tolerance, and regenerative success in Aleppo pine understory.

Tüpfel ermöglichen den interzellularen Stoffaustausch im Holzkörper. Im Zuge der Prozessgestaltung in den Bereichen Holzschutz und Zellstoffherstellung sind genauere Kenntnisse über ihren Aufbau von grundlegender Bedeutung. Das anatomische Wissen ermöglicht eine verbesserte Einschätzung der Tränkbarkeit sowie allgemein über die Eindringwege von Flüssigkeiten im Holz. Die Arbeit fasst den aktuellen Wissensstand des Baus der Tüpfel im Laubholz zusammen. Dabei stehen die in Deutschland wichtigsten Laubbaumarten, namentlich die Rot-Buche (Fagus silvatica L.) und Stiel- sowie Traubeneiche (Quercus robur L. und Quercus petraea Liebl.), im Fokus der Untersuchung. Zunächst wird der allgemeine Aufbau der Tüpfel beschrieben und besonders neuere Erkenntnisse mit aufgegriffen. Im Anschluss wird der Wissensstand zur Tüpfelbau der Rot-Buche sowie der Stiel- wie Trauben-Eiche zusammengefasst dargestellt.

Ekträd har en central roll i den biologiska mångfalden, där de utgör både livsrum och födkrok för ett stort antal insekter, lavar, svampar och fåglar under sin långa livstid och därefter i den döda veden. Ek har minskat dramatiskt under de senaste 200 åren, men orsakerna till detta är inte helt klarlagda. I östra Nordamerika har den försämrade föryngringen av ek kopplats till de betydligt färre skogsbränderna och ur detta har den s.k. brand-ek-hypotesen uppstått. Denna säger att branden spelar en viktig roll i ekens föryngring i östra USA och i Nordamerika p.g.a. att eken är bättre anpassad än många andra träd för att klara brand, vilket ger den en konkurrensfördel som gör att den inte bara gynnas av brand, utan också kan vara beroende av den. Jag har studerat hur föryngring av ek påverkats av en naturvårdsbränning som genomförts i Krogölen i Allgunnens naturreservat i sydöstra Sverige. Hypotesen är att brand har en gynnsam effekt på ekföryngring även i Sverige och att brand-ek-hypotesen är tillämpbar också här. Detta kunskapsområde är relevant för naturvården i Sverige när det gäller att planera naturvårdsbränningar i områden med förekomst av ek. Eftersom studien har genomförts som en pilotstudie, där endast ett brandområde studerats, kan inga slutsatser om generella brandfältseffekter dras. Mina resultat talar för att krontäckning har en effekt på tätheten av fröplantor i Krogölen, och att den har större betydelse i brandfältet än i det obrända området, vilket talar emot brand-ek-hypotesen. Effekten av brand och krontäckning förklarar i denna studie 21,8% av variationen i den rottransformerade fröplanttätheten per 12,6 m2. Det går inte att se någon ökning av fröplantor eller rotskott i det brända området jämfört med det obrända. För framtida studier skulle det vara intressant att titta på fröplantors dödlighet i olika livsstadier under varierande ljusförhållanden, effekten av predation i brandfält, hur olika brandintensitet kan inverka på ekens föryngring samt bestående effekter av brand över tid och betydelsen av i vilket utvecklingsstadie branden skett. / Oak trees have a central role in biodiversity, where they serve as both a habitat and a feeding ground for a large number of insects, lichens, fungi and birds during its long life and thereafter in the dead wood. Oak has declined dramatically over the past 200 years, but the reasons for this are not entirely known. In eastern North America, the deteriorating regeneration of oak has been linked to the significantly less forest fires and from this the so-called fire-oak hypothesis have emerged. It states that the fire plays an important role in the regeneration of the oak in the eastern United States and North America due to the oak being better adapted than many other trees to endure fire, which gives it a competitive advantage that makes it not only benefit from fire, but also possibly depend on it. I have studied how the regeneration of oak has been affected by a prescribed fire in Krogölen in the Allgunnen nature reserve in the south-east of Sweden. My hypothesis is that fire has a favorable effect on oak regeneration also in Sweden and that the fire-oak hypothesis is also applicable here. This area of ​​knowledge is relevant for nature conservation in Sweden in planning prescribed fires in oak areas. As the study has been carried out as a pilot study, studying only one burned area compared to a none burned area, no conclusions about general fire effects can be drawn. My results suggest that canopy cover has an effect on the density of seed plants in Krogölen, and that it is more comprehensive in the fire field than in the unburned area, which is not conclusive with the fire-oak hypothesis. The effect of fire and canopy cover in this study explains 21.8% of the variation in the root-transformed seed plant density per 12.6 m2. There is no increase in seed plant density or root sprout density in the burned area compared to the unburned area. For future studies, it would be interesting to look at seed plant mortality in different life stages under varying light conditions, the effect of predation in fire fields, how different fire intensities can affect oak regeneration, lasting effects of fire over time and the significance of the oak developmental stage when the fire occurs.

In palaeopalynology oaks are rarely identified beyond the generic level. In order to recognize fossil evergreen and deciduous oak pollen, we compiled distinguishing criteria from the literature, most under the SEM, on the living oaks. One of the most significant criteria is the nature of the sculpturing under the SEM. Evergreen oak pollen exhibit at least four kinds of sculpturing, viz. rod-like elements, uniformly fine granules, scabrate-verrucate, and rugulate micromorphology. The first two types of sculpturing are mostly limited to the evergreen oaks and can be used to identify fossil evergreen oak pollen, while the last two types can also be seen in many deciduous oaks. On the other hand, deciduous oak pollen grains have relatively uniform sculpturing, with only two types encountered: scabrate-verrucate and rugulate sculpturing. This sculpturing is mainly present in deciduous oaks, despite its occurrence in some evergreen oaks. An absolute discrimination between evergreen and deciduous oak pollen is thus impossible and would require additional evidence in the form of macrofossils. The diagnostic criteria are applied to a Miocene pollen assemblage from Zhejiang Province, eastern China and demonstrate the high diversity of fossil oaks in the vegetation. The fossil pollen includes three morphotaxa of deciduous origin, two morphotaxa of evergreen habit, and three oaks whose habit is uncertain.

No description available.

Phenotypic plasticity and developmental instability in leaf traits are common in oak species but the role of environmental factors is not well understood. To decipher possible correlations between different leaf traits and effects of the position of leaves within the tree canopy, we quantified the plasticity of three leaf traits of 30 trees of Quercus alba L., Quercus palustris Muench and Quercus velutina Lam. We hypothesized that trees could modify the shape of their leaves for better adaptation to the variable microclimate within the canopy. Our results demonstrated that the south and north outer leaves were significantly smaller, more lobed and denser than those situated in the inner canopy. The order of leaves on the branch accounted for the plasticity of leaf traits in Q. alba only. Plasticity of lobing in Q. alba and Q. velutina depended on the height of the trees. We detected fluctuating asymmetry (FA) in all three species, but the source of variation depended on branch position in Q. velutina only. FA was more pronounced in north-facing leaves. Plasticity of the leaf traits ranged from small to medium. Plasticity of leaf area and leaf mass per area (LMA) depended on the branch position. However, the plasticity of lobation was not affected by the location of a branch within the tree canopy. Quercus alba and Q. palustris had similar plastic responses but the plasticity of Q. velutina was significantly smaller. We concluded that individual plants detect and cope with environmental stress through vegetative organ modification.

This population study of Quercus stellata in the Texas Cross Timbers evaluates that population by observation and sampling of 220 upland forest stands. The Texas Cross Timbers is divided into the East Cross Timbers (ECT) and the West Cross Timbers (WCT) by the Fort Worth Prairie.

Tesis por compendio / [ES] Phytophthora es uno de los géneros fitopatógenos más relevantes y agresivos en la agricultura y silvicultura. Muestreos realizados en la última década han revelado una gran cantidad de interacciones entre especies de Phytophthora y plantas, desconocidas con anterioridad. La introducción de nuevos patógenos de suelo, como Phytophthora en los bosques de Fagaceae, modifica la comunidad microbiana presente en la rizosfera, con importantes consecuencias ambientales y económicas. El género Quercus es uno de los géneros de Fagaceae más extendidos en Europa, y Quercus ilex es la especie dominante en España. El vínculo entre la dispersión de Phytophthora en los ecosistemas naturales y las actividades del ser humano, ha sido previamente estudiado. Numerosos muestreos en viveros y espacios públicos, mostraron la presencia de gran diversidad de especies de Phytophthora que podían suponer una amenaza para la producción y los ecosistemas naturales. En este contexto, se realizó un muestreo de viveros ornamentales y forestales en cuatro comunidades autónomas españolas, centrándose en los posibles síntomas asociados a Phytophthora en diferentes hospedantes e incluyendo muestras de agua de los viveros. Los resultados mostraron 17 filotipos de Phytophthora que afectan a 22 especies vegetales incluidas en 19 géneros. Algunas de estas interacciones se citaron por primera vez en España. Entre los patógenos de suelo aislados en los viveros, se identificó una gran cantidad de formas asexuales tipo Cylindrocarpon en las raíces de hospedantes leñosos. Se caracterizó una colección de aislados mediante estudios morfológicos y moleculares. Se identificaron 12 especies pertenecientes a los géneros Cylindrodendrum, Dactylonectria e Ilyonectria en hospedantes pertenecientes a 15 géneros y otras cuatro nuevas especies se describieron. El estudio demostró la prevalencia de este grupo fúngico asociado con plántulas de diversos hospedantes que muestran síntomas de decaimiento en viveros forestales. Se evaluó la susceptibilidad de Q. ilex a la inoculación con ocho especies de Phytophthora obtenidas de muestreos en viveros. Las especies más agresivas fueron Phytophthora cinnamomi, Phytophthora cryptogea, Phytophthora gonapodyides, Phytophthora plurivora y Phytophthora psychrophila, seguidas de Phytophthora megasperma, mientras que Phytophthora quercina y Phytophthora nicotianae fueron las especies menos agresivas. Los resultados obtenidos en el ensayo de patogenicidad confirmaron que todas las especies de Phytophthora evaluadas podrían representar una amenaza para los encinares. En este contexto, se realizó un estudio para verificar la presencia y / o detección de especies de Phytophthora en dos áreas de España (dehesas del sudoeste y bosque del noreste) utilizando diferentes métodos de aislamiento y detección. El aislamiento directo y el método de trampeo vegetal en muestras obtenidas a partir de encinas con y sin decaimiento, identificaron Phytophthora cambivora, P. cinnamomi, P. gonapodyides, P. megasperma y Phytophthora pseudocryptogea en las dehesas, mientras que, en el bosque del noreste, no se aisló Phytophthora spp. Los análisis estadísticos indicaron que no había una relación significativa entre la frecuencia de aislamiento de las especies de Phytophthora y la expresión de los síntomas de la enfermedad en las encinas de las dehesas. Además, P. quercina se detectó con mayor frecuencia que P. cinnamomi en las dos áreas estudiadas utilizando sondas TaqMan de PCR a tiempo real. Se evaluaron seis masas de Q. ilex ubicadas en tres comunidades autónomas de España mediante “Next Generation Sequencing” (NGS) para tener un mayor conocimiento sobre la diversidad de Phytophthora spp. en los bosques de encinas. Se detectaron 37 filotipos de Phytophthora pertenecientes a los clados 1 al 12, excepto los clados 4, 5 y 11, lo que demuestra una gran diversidad de Phytophthora en los encinares estudiados. Los filotipos más abundantes fueron P. quercina, P. psychrophila, P. cinnamomi y P. plurivora. / [EN] Phytophthora is one of the most relevant and aggressive plant pathogenic genus in agriculture and forestry. Due to the increasing environmental threat of invasive plant pathogens, monitoring new areas in the last decade has revealed a large number of new Phytophthora species-plant host interactions. The introduction of soilborne pathogens, such as Phytophthora in Fagaceae forests modifies the microbial community present in the rhizosphere with relevant environmental and economic consequences. The genus Quercus is one of the most extended Fagaceae genera in Europe, and Q. ilex is the dominant tree in Spain. The link between Phytophthora dispersion in natural ecosystems and human derived activities has been previously studied. Numerous sampling in nurseries and public spaces revealed a great diversity of Phytophthora species that compromised production and threated natural ecosystems. In this context, sampling ornamental and forest nurseries in four Spanish regions was carried out focusing on possible symptoms associated to Phytophthora on different hosts and including water samples from the nurseries. The results showed 17 Phytophthora phylotypes affecting 22 plant species included in 19 plant genera and some of them reported for the first time in Spain. Among the soilborne pathogens isolated in the nurseries, a large number of Cylindrocarpon-like asexual morphs were identified from the roots of woody hosts. A collection of Cylindrocarpon-like isolates recovered from Spanish nurseries was characterised by morphological and molecular studies. Twelve species belonging to the genera Cylindrodendrum, Dactylonectria and Ilyonectria were identified from damaged roots of 15 different host genera and other four species were newly described. The study demonstrated the prevalence of this fungal group associated with seedlings of diverse hosts showing decline symptoms in forest nurseries in Spain. The susceptibility of Quercus ilex to the inoculation with eight Phytophthora species obtained from nurseries was evaluated. The most aggressive species were Phytophthora cinnamomi, Phytophthora cryptogea, Phytophthora gonapodyides, Phytophthora plurivora and Phytophthora psychrophila followed by Phytophthora megasperma, while Phytophthora quercina and Phytophthora nicotianae were the least aggressive species. Results obtained in the pathogenicity test confirmed that all Phytophthora species tested could represent a threat to holm oak ecosystems. In this context, a study to verify the presence and/or detection of Phytophthora species was conducted in two holm oak areas of Spain (southwestern dehesas and northeastern woodland) using different isolation and detection methods. Direct isolation and baiting methods in declining and non-declining holm oak trees revealed Phytophthora cambivora, P. cinnamomi, P. gonapodyides, P. megasperma, and Phytophthora pseudocryptogea in the dehesas, while in the northeastern woodland, no Phytophthora spp. were recovered. Statistical analyses indicated that there was not a significant relationship between the Phytophthora spp. isolation frequency and the disease expression of the holm oak stands in the dehesas. Phytophthora quercina and P. cinnamomi TaqMan real-time PCR probes showed that P. quercina was detected in a higher frequency than P. cinnamomi in both studied areas. A better understanding of the Phytophthora spp. diversity in holm oak forests was assessed using Next Generation Sequencing (NGS) in six Q. ilex stands located in three regions in Spain. Thirty-seven Phytophthora phylotypes belonging to clades 1 to 12, except for clades 4, 5 and 11, were detected in this study, demonstrating a high diversity of Phytophthora species in holm oak Spanish forests. The most abundant phylotypes were P. quercina, P. psychrophila, P. cinnamomi and P. plurivora. In summary, this Thesis demonstrated a high diversity of Phytophthora and Cylindrocarpon-like species in Spanish nurseries, reporting new pathogen-plant host in / [CA] Phytophthora és un dels gèneres fitopatògens més rellevants i agressius en l'agricultura i la silvicultura. Mostrejos realitzats en l'última dècada han revelat una gran quantitat d'interaccions desconegudes fins ara entre espècies de Phytophthora i plantes. La introducció de nous patògens del sòl, com Phytophthora en els boscos de Fagaceae, modifica la comunitat microbiana present en la rizosfera, amb importants conseqüències ambientals i econòmiques. El gènere Quercus és un dels gèneres de Fagaceae més estesos a Europa, i Quercus ilex és l'espècie dominant a Espanya. El vincle entre la dispersió de Phytophthora en els ecosistemes naturals i les activitats de l'ésser humà, ja ha sigut estudiat prèviament. Nombrosos mostrejos en vivers i espais públics, van mostrar la presència d'una gran diversitat d'espècies de Phytophthora que podien suposar una amenaça per a la producció i els ecosistemes naturals. En aquest context, es va realitzar un mostreig de vivers ornamentals i forestals en quatre comunitats autònomes espanyoles, centrant-se en els possibles símptomes associats a Phytophthora en diferents hostes i incloent mostres d'aigua dels vivers. Els resultats van mostrar 17 filotipus de Phytophthora que afecten 22 espècies vegetals incloses en 19 gèneres. Algunes d'aquestes 'interaccions es van citar per primera vegada a Espanya. Entre els patògens del sòl aïllats en els vivers, es va identificar una gran quantitat de formes asexuals tipus Cylindrocarpon en les arrels de plantes llenyoses. Es va caracteritzar una col·lecció d'aïllats mitjançant estudis morfològics i moleculars. Es van identificar 12 espècies pertanyents als gèneres Cylindrodendrum, Dactylonectria i Ilyonectria en hostes pertanyents a 15 gèneres i altres quatre noves espècies es van descriure. L'estudi va demostrar la prevalença d'aquest grup fúngic associat amb plàntules de diversos hostes que mostren símptomes de decaïment en vivers forestals espanyols. Es va avaluar la susceptibilitat de Q. ilex a la inoculació amb huit espècies de Phytophthora obtingudes de mostrejos en vivers. Les espècies més agressives van ser Phytophthora cinnamomi, Phytophthora cryptogea, Phytophthora gonapodyides, Phytophthora plurivora i Phytophthora psychrophila, seguides de Phytophthora megasperma, mentre que Phytophthora quercina i Phytophthora nicotianae van ser les espècies menys agressives. Els resultats obtinguts en l'assaig de patogenicitat van confirmar que totes les espècies de Phytophthora avaluades podrien representar una amenaça per als ecosistemes d'alzines. En aquest context, es va realitzar un estudi per a verificar la presència i / o detecció d'espècies de Phytophthora en dues àrees d'Espanya (deveses del sud-oest i bosc del nord-est) utilitzant diferents mètodes d'aïllament i detecció. L'aïllament directe i el mètode de parany vegetal en mostres obtingudes a partir d'alzines, amb i sense decaïment, van identificar Phytophthora cambivora, P. cinnamomi, P. gonapodyides, P. megasperma i Phytophthora pseudocryptogea en les deveses, mentre que, en el bosc del nord-est, no es va aïllar Phytophthora spp. Les anàlisis estadístiques van indicar que no hi havia una relació significativa entre la freqüència d'aïllament de les espècies de Phytophthora i l'expressió dels símptomes de la malaltia en les alzines en les deveses. A més, P. quercina es va detectar amb major freqüència que P. cinnamomi en les dues àrees estudiades utilitzant sondes TaqMan de PCR a temps real. Es van avaluar sis masses de Q. ilex situades en tres comunitats autònomes d'Espanya mitjançant "Next Generation Sequencing" (NGS) per a tindre un major coneixement sobre la diversitat de Phytophthora spp. en els boscos d'alzines. Es van detectar 37 filotipus de Phytophthora pertanyents als clades 1 al 12, excepte els clades 4, 5 i 11, la qual cosa demostra una gran diversitat d'espècies de Phytophthora en els alzinars estudiats. Els filotipus més abundants van ser P. quercina, P. psychrophila, P. cinnamomi i P. plurivora. / Mora Sala, B. (2020). Detection and identification of Phytophthora spp. in woody plant nurseries and holm oak forests [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/153808 / TESIS / Compendio

The ecology, species distribution, and population structure of Armillaria was investigated in the forests of Massachusetts. From 64 plots at 16 sites, 640 isolates of Armillaria were collected from six forest types (northern hardwoods, mixed oak, pitch pine, white pine, white pine/mixed oak, and eastern hemlock). Armillaria gallica proved to be the most abundant species, making up 316/640 (52%) of all isolations. This was followed by A. solidipes (219/640; 34%), A. mellea (46/640; 7%), A. calvescens (36/640; 6%), A. gemina (16/640; 3%), and A. sinapina (7/640; 1%). Armillaria gallica was routinely encountered causing significant decay of the lower bole on living hardwood hosts, especially oaks. The population structure of 153 isolates of A. gallica collected from mixed oak forests was investigated using amplified fragment length polymorphisms (AFLPs). From a total sampling area of 4.51 ha, 38 AFLP genotypes were discovered, yielding a figure of eight genets per hectare with the average A. gallica genet occupying 0.13 ha. When the effects of hydrolyzable tannins on in vitro growth were compared between A. calvescens and A. gallica, it was A. gallica that appeared better at oxidizing and metabolizing commercial tannins (tannic acid and gallic acid) along with black oak root bark extracts. This was determined through measurements of colony area and dry biomass, and suggests that A. gallica may be a better adapted pathogen of oak. In order to more accurately distinguish between isolates of A. calvescens and A. gallica, a three-gene phylogeny was reconstructed, using partial sequences of the elongation factor 1-alpha (tef1), RNA polymerase II (rpb2) and nuclear large subunit (nLSU) genes. After comparing 12 isolates each of A. calvescens and A. gallica that originated from across northeastern North America, only the tef1 gene could accurately distinguish these two species. Five single nucleotide polymorphisms were present between the two species and maximum likelihood and maximum parsimony methods grouped A. calvescens and A. gallica into monophyletic clades.