Effects of increased drought and selective thinning on growth and resprouting of two coexisting Mediterranean oaks with contrasting leaf habit (Quercus ilex and Quercus cerrioides)

According to the IPCC (2007), the Mediterranean basin is expected to suffer important changes in temperature and precipitation in the next few decades, leading the climate warmer and dryer. Therefore, it is necessary to determine the possible effects of increased drought on species with different structural and physiological traits, to be able to predict possible changes in the structure and composition of Mediterranean forests. Moreover, it will be necessary to assess whether traditional management practices can mitigate the effects of climate change on these forests. The main aim of this study has been to analyze the effects of increased drought on the mortality, growth and resprouting patterns of two co-occurring Mediterranean oak species with contrasting leaf habit (the evergreen Quercus ilex and the winter-deciduous Quercus cerrioides), and to assess the effects of selective thinning on their response to increased drought. Our results show a differential effect of increased drought between species: no differences were observed in the growth of Q. ilex while Q. cerrioides reduced its growth under increased drought conditions. Selective thinning reduced the negative effects of increased drought on tree growth, although this beneficial effect tended to decrease during the experiment. Our results show that increasing aridity in Mediterranean areas can be a constraining factor for deciduous oaks, thus potentially causing their decline in mixed forests and favouring their substitution by the evergreen congeneric species. However, as seen in this study, management can strongly encourage growth both for deciduous and evergreen species, thus reversing the effects of increased water stress on Mediterranean coppices.

Impacte de la variabilitat climàtica ràpida de l'últim període glacial sobre la vegetació del sud-est de Nord Amèrica

Projecte de recerca elaborat a partir d’una estada a UMR-CNRS - Géologie et Océanographie, França, entre 2007 i 2009. Els canvis climàtics ràpids de l���últim període glacial (cicles Dansgaard/Oeschger i Heinrich Stadials-HS), han estat documentats en testimonis marins, de gel i dipòsits continentals, generalment de l���hemisferi nord. Mentre que la majoria dels estudis paleoclimàtics i paleoceanogràfics de l���Atl��ntic Nord sobre l���últim període glacial s’han centrat en la part nord i est, les latituds mitjanes de la part occidental han estat menys estudiades. Particularment, els canvis de la vegetació de l���est de Nord Amèrica durant l���últim glacial es coneixen molt poc degut a la manca de seqüències pol.l��niques llargues en aquesta regió. Només dues seqüències de pol.len del llac Tulane (Florida) mostren canvis de la vegetació significatius i interessants durant l���últim glacial, que suggereixen HS càlids i humits, que contrasta amb el que s’observa a l���altre costat de l���Atl��ntic Nord. El treball realitzat al UMR-CNRS 5805 EPOC, Université Bordeaux 1, EPHE, des del 23 d’abril 2007 al 22 d’abril 2009, gràcies a la beca Beatriu de Pinós, implica una reconstrucció a alta resolució dels canvis de la vegetació a partir de l���anàlisi d’un testimoni marí, localitzat a l���oest de l���Atl��ntic Nord subtropical (MD99-2203, 34º58’N, 75º12’W), durant l���Estadi Isotòpic Marí 3 (MIS 3). Les dades pal.linol��giques del testimoni mostren una alternança entre Picea i Quercus. En general, les associacions pol.l��niques indiquen que les variacions de la vegetació segueixen un patró bosc boreal/temperat durant l���últim glacial. El model d’edat preliminar basat en edats radiomètriques suggereix un augment del bosc temperat acompanyat d’una reducció del boreal entre el H4 i el H3. La comparació amb registres pol.l��nics marins d’alta resolució de la regió est subtropical, a latituds similars, mostren, per primer cop, que els canvis en les formacions forestals associats als canvis climàtics ràpids de l���últim glacial van ser menys intensos al sud-est de Nord Amèrica que a la Península Ibèrica.

Identificação do carbamato de etila durante o armazenamento da cachaça em tonel de carvalho (quercus sp) e recipiente de vidro

The objective of the present study was the identification and quantification of ethyl carbamate (EC), by HPLC-FLD, after different periods of storage in an oak (Quercus sp) barrel and a glass vessel. The concentration of EC in the cachaça samples varied from <LD to 17.46 µg L-1, for the period during which the cachaça was stored in an oak barrel, and <LQ to 18.51 µg L-1 for the cachaça stored in a glass recipient. The storage of the beverage in both the oak barrel and the glass vessel resulted in a significant increase in the concentration of this contaminant.

Análisis estructural en un ecosistema multicohortal de Pinus-Quercus en una fracción de la Sierra Madre Oriental [por] Luis Mario Torres Espinosa

Tesis (Maestro en Ciencias Forestales) U.A.N.L.

Identificacao do carbamato de etila durante o armazenamento da cachaca em tonel de carvalho (Quercus sp) e recipiente de vidro

The objective of the present study was the identification and quantification of ethyl carbamate (EC), by HPLC-FLD, after different periods of storage in an oak (Quercus sp) barrel and a glass vessel. The concentration of EC in the cachaça samples varied from <LD to 17.46 µg L-1, for the period during which the cachaça was stored in an oak barrel, and <LQ to 18.51 µg L-1 for the cachaça stored in a glass recipient. The storage of the beverage in both the oak barrel and the glass vessel resulted in a significant increase in the concentration of this contaminant.

Holocene vegetation and fire history of the mountains of Northern Sicily (Italy)

Knowledge about vegetation and fire history of the mountains of Northern Sicily is scanty. We analysed five sites to fill this gap and used terrestrial plant macrofossils to establish robust radiocarbon chronologies. Palynological records from Gorgo Tondo, Gorgo Lungo, Marcato Cixé, Urgo Pietra Giordano and Gorgo Pollicino show that under natural or near natural conditions, deciduous forests (Quercus pubescens, Q. cerris, Fraxinus ornus, Ulmus), that included a substantial portion of evergreen broadleaved species (Q. suber, Q. ilex, Hedera helix), prevailed in the upper meso-mediterranean belt. Mesophilous deciduous and evergreen broadleaved trees (Fagus sylvatica, Ilex aquifolium) dominated in the natural or quasi-natural forests of the oro-mediterranean belt. Forests were repeatedly opened for agricultural purposes. Fire activity was closely associated with farming, providing evidence that burning was a primary land use tool since Neolithic times. Land use and fire activity intensified during the Early Neolithic at 5000 bc, at the onset of the Bronze Age at 2500 bc and at the onset of the Iron Age at 800 bc. Our data and previous studies suggest that the large majority of open land communities in Sicily, from the coastal lowlands to the mountain areas below the thorny-cushion Astragalus belt (ca. 1,800 m a.s.l.), would rapidly develop into forests if land use ceased. Mesophilous Fagus-Ilex forests developed under warm mid Holocene conditions and were resilient to the combined impacts of humans and climate. The past ecology suggests a resilience of these summer-drought adapted communities to climate warming of about 2 °C. Hence, they may be particularly suited to provide heat and drought-adapted Fagus sylvatica ecotypes for maintaining drought-sensitive Central European beech forests under global warming conditions.

Estudio de la selección y desplazamiento de bellotas por roedores bajo diferentes condiciones lumínicas y de microhábitat; implicaciones en el regenerado natural del género Quercus.

Este estudio se centra en la actividad de selección y acopio de bellotas por parte de pequeños roedores, en concreto el ratón de campo (Apodemus sylvaticus), que se ha demostrado como la principal especie dispersora de bellotas en la zona de estudio. La prioridad de este trabajo ha sido estudiar la influencia de ciertos factores ambientales (luminosidad lunar y disponibilidad de refugio para el roedor) en el fenómeno de selección. Se tomaron datos bajo diferentes condiciones de luminosidad lunar (luna llena y luna nueva) y de disponibilidad de refugio (bajo cobertura de matorral y sin cobertura). La zona de estudio se ubicó en el Hayedo de Montejo, Madrid. La razón de la elección de este lugar fue la existencia de estudios genéticos llevados a cabo en él que revelaron largos y curiosos movimientos de semillas, que sólo podían ser fruto de una contribución de la fauna dispersora.

Ecología, tipología, valoración y alternativas silvopascícolas de los Quejigares (Quercus faginea Lamk) de Guadalajara

El quejigo (Quercus faginea Lamk.) es una de las especies arbóreas más características y abundantes en España. El valor ecol��gico de sus masas es muy alto, pero su actual producción económica es muy baja. En el presente trabajo se estudian las características ecol��gicas, silvícolas y pascícolas de los quejigares de Guadalajara para tratar de determinar su forma más adecuada de utilización. En el capítulo 1 se recopila, analiza y resume toda la información existente anteriormente sobre el quejigo en España. En el capítulo 2 se estudia la ecología del quejigo en la provincia de Guadalajara, incluyendo los siguientes temas: - Estudio ecol��gico de los quejigares: clima, suelo, posición topográfica, fauna, acción antrópica, vegetación, etc. - Establecimiento de una tipología forestal para las masas de quejigos. - Cuantificación del desfronde, la biomasa, el efecto fertilizador y la producción del quejigar experimental de Barriopedro. - Estudio de los sistemas de regeneración natural y artificial en el quejigo- - Análisis de la composición específica de un pastizal de quejigar y de las variaciones provocadas en él por claras de distinta intensidad en el estrato arbóreo. II En el capítulo 3 se valora la calidad del arbolado y del pastizal en los quejigares de Guadalajara. En el capítulo 4, y como resultado de los estudios realizados, se concluye analizando las posibilidades de utilización de los quejigares de la provincia: roturación y cultivo agrícola, repoblación forestal, implantación de pastizales, conversión en monte alto, adehesamiento, y mantenimiento del tallar.

High nuclear genetic diversity, high levels of outcrossing and low differentiation among remnant populations of Quercus petraea at the margin of its range in Ireland

Background and Aims Quercus petraea colonized Ireland after the last glaciation from refugia on mainland Europe. Deforestation. however. beginning in Neolithic times, has resulted in small, scattered forest fragments, now covering less than 12 000 ha. Methods Plastid (three fragments) and microsatellite variation (13 loci) were characterized in seven Irish populations sampled along a north-south gradient. Using Bayesian approaches and Wright's F-statistics, the effects of colonization and fragmentation on the genetic structure and mating patterns of extant oak populations were investigated. Key-Results All Populations possessed cytotypes common to the Iberian Peninsula. Despite the distance from the refugial core and the extensive deforestation in Ireland, nuclear genetic variation was high and comparable to mainland Europe. Low population differentiation was observed within Ireland and populations showed no evidence for isolation by distance. As expected of a marker with an effective Population size of one-quarter relative to the nuclear genome, plastid variation indicated higher differentiation. Individual inbreeding coefficients indicated high levels of outcrossing. Conclusions Consistent with a large effective Population size in the historical migrant gene pool and/or with high gene flow among populations, high within-population diversity and low population differentiation was observred within Ireland. It is proposed that native Q. petraea populations in Ireland share a common phylogeographic history and that the present genetic structure does not reflect founder effects. (C) 2004 Annals of Botany Company.

Aspectos da interacção entre Phytophthora cinnamomi e a doença do decl��nio em Q. suber e Q. rotundifolia

Faculdade de Engenharia de Recursos Naturais, Univ. do Algarve, 2001

Análisis de la dimensión fractal del género Quercus en el sur de Italia

En estudios anteriores propusimos un nuevo método para el estudio del género Quercus (Musarella et al., 2013), baseado en la dimensión fractal (DF). En este trabajo analizamos la DF del género Quercus en el sur de Italia, para ello utilizamos hojas de árboles pertenecientes a Q. robur subsp. brutia, Q. cerris, Q. congesta, Q. crenata, Q. ilex, Q. suber, Q. virginiana. De cada árbol se toman hojas de cada uno de los puntos cardinales para complejiada de la estructura morfol��gica de las hojas. Este análisis extrae información sobre los caracteres fenotípicos de las hojas utilizadas, tales como el número y morfologia de los nervios, ángulos nervios secundarios con principal, contorno de hojas, aspecto reticulado de la hoja etc. En nuestro análisis, no se han detectado diferencias significativas entre la DF en cada una de la orientaciones y la DF global para cada una de las especies. En este trabajo corroboramos estudios anteriores realizados por los autores, en los que se proponía una DF < 1,6 para Quercus esclerófilos y DF entre dos especies sea cero o su cociente sea uno, el grado de parentesco entre las dos especies es del 100%; DFA - DFB = 0; DFA/DFB = 1, la especie Ay B son iguales; por ello cuanto menor es la diferencia o bien cuanto más se acerque el cociente a 1, mayor es la semejanza entre las especies. Si este cociente tiene un valor alejado de 1 como ocurre entre vfvi/vfsu>2, las especies Q. virginiana y Q. suber están muy distantes entre sí. Además, la realización del Test de Rango Múltiple, que es un procedimiento de comparación para determinar cuáles medias son significativamente diferentes unas de otras, confirma los resultados obtenidos de la forma anteriormente expuesta. Conto et al. (2007) ponen de manifiesto el origen hibridógeno de Q. crenata, y según el análisis molecular existe una mayor similitud genética entre Q. crenata y Q. cerris, que entre Q. crenata y Q. suber. Los DF de Q. crenata 1,868; Q. cerris 1,677 y Q. suber 0,932; siendo DFQsu 0,745 y DFQsu = 1,8, lo que significa que existe gran diferencia fenotípica (genética) entre los parentales, se presenta una mayor semejanza entre Q. crenata y Q. cerris que entre Q. crenata y Q. suber, ya que la diferencia DFQcr-DFQce = 0,191 y DFQcr/DFQce = 1,1, por lo que tienen un fuerte grado de semejanza, mientras que DFQcr-DFQsu = 0,936 y DFQcr/DFQsu > 2, lo que pone de manifiesto las fuertes diferencias fenotípicas entre el híbrido y el parental.

Allergenic profile of Quercus rotundifolia pollen in Alentejo, Portugal

Background and Aim: Grasses and olive are the most relevant allergenic species in the Alentejo region. However, aggravation of allergic symptoms has been reported in the early spring, before grass and olive pollen seasons. Quercus pollen is the most abundant pollen type in the early spring in Alentejo, nonetheless its allergen profile has not yet been evaluated. The aim of this work was to characterize the allergen profile of pollen from Quercus rotundifolia among the most representative species showing pollination in April, prior to the main pollen season in Alentejo. Methods: Pollen from Quercus rotundifolia, Olea europaea and Dactylis glomerata was extracted with ammonium bicarbonate buffer, lyophilized and stored at -80ºC until analysis. Extract from Quercus ilex pollen was kindly offered by Bial. Protein content was determined by the Bradford method. SDS-PAGE followed by western blot, using allergic patient sera (obtained from the Hospital do Espírito Santo de Évora – HESE), were performed to evaluate the allergen profile of the pollen. Sensitization and cross-reactivity was assessed by solid phase immunoblot. Results: Most of the patient evidenced sensitization to pollen extracts of Q. rotundifolia. Protein profile of Q. rotundifolia has shown several bands in the Mr 10-90 kDa, mostly overlapping with Q. ilex. Western blot have shown several immunoreactive bands. Immunoreactive bands were also observed in the protein profile according to the pI in the range 4.0-6.1. Cross-reactivity between Q. rotundifolia with O. europaea and D. glomerata was found. Conclusion: These results evidenced allergens found in Q. rotundifolia pollen. It also shows that protein profile of Q. rotundifolia and Q. ilex are mostly alike suggesting that similarities in allergen profile are expected. Moreover, cross–reactivity between Q. rotundifolia and highly allergenic species such as O. europaea and D. glomerata was found which probably contributes to the aggravation of pollinosis in the early spring. Acknowledgments: This work was supported by FEDER through the “Programa Operacional Fatores de Competitividade – COMPETE” (Strategic projects of ICAAM and ICT 2013-2015). We also aknowledge Bial-Aristegui for supplying pollen and extract samples of Q. ilex.

Perfil em alergénios do pólen de Quercus rotundifólia

Background and Aim: Grasses and olive are the most relevant allergenic species in the Alentejo region. However, aggravation of allergic symptoms has been reported in the early spring, before grass and olive pollen seasons. Quercus pollen is the most abundant pollen type in the early spring in Alentejo, nonetheless its allergen profile has not yet been evaluated. The aim of this work was to characterize the allergen profile of pollen from Quercus rotundifolia the most representative species showing pollination in April, prior to the main pollen season in Alentejo. Methods: Pollen from Quercus rotundifolia, Olea europaea and Dactylis glomerata was extracted with ammonium bicarbonate buffer, lyophilized and stored at -80ºC until analysis. Extract from Quercus ilex pollen was kindly offered by Bial. Protein content was determined by the Bradford method. SDS-PAGE followed by western blot, using allergic patient sera (obtained from the Hospital do Espírito Santo de Évora – HESE), were performed to evaluate the allergen profile of the pollen. Results: Protein profile of Q. rotundifolia has shown several bands in the Mr 10-90 kDa, mostly overlapping with Q. ilex. Western blot have shown several immunoreactive bands. Protein profile according to the pI showed immunoreactive bands in the pI range 4.0-6.1. Cross-reactivity of Q. rotundifolia with O. europaea and D. glomerata was found. Conclusion: These results evidenced allergens found in Q. rotundifolia pollen. It also shows that protein profile of Q. rotundifolia and Q. ilex are mostly alike suggesting that similarities in allergen profile are expected. Moreover, cross–reactivity between Q. rotundifolia and highly allergenic species such as O. europaea and D. glomerata was found which probably contributes for aggravation of pollinosis in the early spring. Acknowledgments: This work was supported by “FEDER - Programa Operacional Factores de Competitividade – COMPETE”. A special acknowledgment to our colleague Prof. Rui Brandão, deceased, for his dedication to the present work, to the implantation and development of Aerobiology in the University of Évora. We have the honour of dedicating this work to the memory of Prof. Rui Brandão.