Browsing by Author "Almeida, Maria Helena"
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- Characterization of the international network FAIR 202 of provenance and progeny trials of cork oak on multiple sites for further use on forest sustainable management and conservation of genetic resourcesPublication . Varela, Maria Carolina; Tessier, Charles; Ladier, Jean; Dettori, Sandro; Filigheddu, Maria Rosaria; Almeida, Maria Helena; Patrício, Maria Sameiro; Sampaio, TeresaThe international network of provenance and progeny trials was established in 1998 in France, Italy, Portugal, Spain and Tunisia under the EU Commission financed concerted action FAIR 202 benefiting from homogeneous plant raising and standardize experimental design. The trials include 34 provenances that are being characterised using quantitative genetics and molecular genetics to study survival, growth, morphological and physiological traits in relation with geographical origin. France 2008– Provenance were assess using survival, growth (height) and vigour parameters. Provenance PT 23 and PT+ES 25 had the lowest survival rate respectively 79,2% and 77,8% while ES 8, ES 7, MA 31 and PT 19 had 94,4%. In 2008 the mean height at Les Maures was 48.73 cm and the form keeps plagiotropic. Italy- Sardinia, Grighine, 2010 The average mortality was 7%, ranging from 13-14% at the provenance IT LA-VT; IT SI-CT; MO I-1 and 0-2% for FRII, ES 3-V, ES F-PAR, PT IV-03, TU I; TU II. Mean height and trunk DBH over cork were respectively 273cm and 5.1cm. MO I-2, TU II, ES 4-CR are above mean on height (302-309 cm), and the Italian provenances are under mean (237-249cm). The maximum DBH was reached by MO I-2 (6 cm) followed by ES-4 CR and MO III-2 (5.8 cm) and the minimum is at IT PU-BR (3.8 cm), followed by the other Italian provenances (4-4.6cm) and PT V-01 (4.5 cm). Portugal Results from field trials show significant differences among populations on survival, growth and adaptive traits (phenology, water use efficiency - WUE). Mogadouro trial, 2011 -provenance variation was assessed using growth, vigour and survival. The bud burst as adaptive characteristic was observed during 2011-2013. The Moroccan provenances show good adaptive characteristics in terms of growth, vigour and stem form. There was no significant differences (p<0.05) in provenances bud burst. The mean height is not correlated with survival. Italian provenances present lower height but higher survival. The overall mortality is around 26%. The highest growth is being observed in the Moroccan provenances and French ones showed lowest survival. Results from field trials at Italy (continent), Spain and Tunisia are also referred. Genotype by environment interaction (G x E) is discussed. Due to the large variability of responses between cork oak provenances we emphasise the importance to use these results when considering the seed origin aiming for large scale planting programs for adaptation, cork quality, pest and diseases susceptibility and for conservation of genetic resources, Progeny trials provide key information for genetic improvement programmes on estimates of breeding values on economic characteristics such as cork quality and an approach on inbreeding problems. Perspectives Used in synergy the results from provenance and progeny trials are likely to provide insights for balancing the conflicting objectives such as maximising selection intensity while maintaining variation. Taking into consideration that the cork from the second striping made 3-4 years after the first gives information about the quality liable to be used on selection for afforestation guide lines we enhance the need of concerted criteria on debarking season and procedures. The results from these trials will contribute to the knowledge on genetic variation and are a privileged living material to study climate change effects and adaptation to biotic and abiotic factors and for sustainable management of this long living species.
- Characterization of the international network FAIR 202 of provenance and progeny trials of cork oak on multiple sites for further use on forest sustainable management and conservation of genetic resources.Publication . Varela, Maria Carolina; Tessier, Charles; Ladier, Jean; Dettori, Sandro; Filigheddu, Maria Rosaria; Bellarosa, Rosanna; Vessella, Federico; Almeida, Maria Helena; Sampaio, Teresa; Patrício, Maria SameiroThe international network of provenance and progeny trials was established in 1998 benefiting from homogeneous plant raising and standardize experimental design. The trials include 34 provenances that are being characterised by several teams. France 2008. Provenance PT 23 and PT+ES 25 had the lowest survival rate. In 2008 the mean height was 48.73 cm and the form keeps plagiotropic. Italy- Sardinia, 2010 - The average mortality was 7%. Mean height and trunk DBH over cork were respectively 273 and 5.1 cm. MO I-2, TU II, ES 4-CR are above mean on height (302-309 cm), and the Italian provenances are under mean (237-249cm). Italy- Roccarespampani, Lazio- The mortality is about 45% and it is the only plantation site where the French provenance FR3 has a growth above mean. Portugal. Results show significant differences among populations on survival and growth. The Moroccan provenances show good adaptive characteristics in terms of growth, vigour and stem form. Italian provenances present lower height but higher survival. The overall mortality is around 26%. The highest growth is being observed in the Moroccan provenances and French ones showed lowest survival. Provenances and plantation sites are characterised for rainfall regime. The provenances Morocco MA27 and Tunisia TU33 that are from sites of high rainfall are among the best on growth at sites of considerable more xerothermic climate. If persistent at older age these results indicate that fast adaptation of cork oak populations to cope with climate changes leading to drier and warmer conditions seems possible.
- O contributo da origem e das práticas silvícolas na sustentabilidade dos montados de sobroPublication . Almeida, Maria Helena; Nunes, Ana Margarida; Correia, António H.; Patrício, Maria Sameiro; Carvalho, Maria Augusta; Varela, Maria Carolina; Monteiro, Maria do LoretoConsiderando que, num contexto global de exigência crescente das sociedades e de implementação de políticas de gestão sustentável dos recursos naturais, cabe às entidades e agentes ligados ao sector participar de uma forma activa numa adequada aplicação e inovação das práticas existentes, os autores pretendem dar um contributo para o melhoramento dos montados de sobro e para a obtenção de um maior rendimento em cortiça. Nesse sentido entendem que os esforços desenvolvidos para a identificação de populações de sobreiro mais adaptadas devem ser completados com a aplicação de práticas silvícolas que conduzam a um maior rendimento em cortiça. Assim, foram implementados cortes de formação nas primeiras idades em ensaios genéticos de sobreiro existentes no nosso País, pertencentes a uma rede internacional, que cobrem no seu conjunto toda a área de distribuição da espécie, com o objectivo de obter fustes direitos e cilíndricos em pelo menos 3 a 4 m do tronco, contribuindo de uma forma efectiva e directa para uma maior valorização da prancha de cortiça e consequentemente proporcionar uma mais-valia no rendimento do proprietário florestal. A variação observada quer ao nível das populações quer das descendências nestes ensaios é indicativo que não é indiferente a escolha da população a utilizar nas acções de repovoamento, assim como na implementação de um programa de melhoramento, apontando também para a necessidade de seleccionar os indivíduos dentro das populações. A experiência adquirida relativamente à poda de formação aconselha que esta operação seja efectuada num período de crescimento activo das plantas para garantir uma cicatrização rápida dos tecidos e uma menor rebentação nas zonas dos cortes.
- O contributo da origem e das práticas silvícolas na sustentabilidade dos montados de sobroPublication . Almeida, Maria Helena; Nunes, Ana Margarida; Correia, António H.; Patrício, Maria Sameiro; Carvalho, Maria Augusta; Varela, Maria Carolina; Monteiro, Maria do LoretoConsiderando que, num contexto global de exigência crescente das sociedades e de implementação de políticas de gestão sustentável dos recursos naturais, cabe às entidades e agentes ligados ao sector participar de uma forma activa numa adequada aplicação e inovação das práticas existentes, os autores pretendem dar um contributo para o melhoramento dos montados de sobro e para a obtenção de um maior rendimento em cortiça. Nesse sentido entendem que os esforços desenvolvidos para a identificação de populações de sobreiro mais adaptadas devem ser completados com a aplicação de práticas silvícolas que conduzam a um maior rendimento em cortiça. Assim, foram implementados cortes de formação nas primeiras idades em ensaios genéticos de sobreiro existentes no nosso País, pertencentes a uma rede internacional, que cobrem no seu conjunto toda a área de distribuição da espécie, com o objectivo de obter fustes direitos e cilíndricos em pelo menos 3 a 4 m do tronco, contribuindo de uma forma efectiva e directa para uma maior valorização da prancha de cortiça e consequentemente proporcionar uma mais-valia no rendimento do proprietário florestal. A variação observada quer ao nível das populações quer das descendências nestes ensaios é indicativo que não é indiferente a escolha da população a utilizar nas acções de repovoamento, assim como na implementação de um programa de melhoramento, apontando também para a necessidade de seleccionar os indivíduos dentro das populações. A experiência adquirida relativamente à poda de formação aconselha que esta operação seja efectuada num período de crescimento activo das plantas para garantir uma cicatrização rápida dos tecidos e uma menor rebentação nas zonas dos cortes.
- Efeito da intervenção cultural na caracterização morfológica de diferentes proveniências de Quercus suberPublication . Patrício, Maria Sameiro; Nunes, Luís; Almeida, Maria HelenaO sobreiro (Quercus suber L.) é uma espécie muito importante nas áreas de influência mediterrânea por razões económicas, ecológicas e ambientais. É uma espécie com elevado potencial de expansão considerando os cenários das alterações climáticas. Apesar da sua importância, a adaptação da espécie às condições ambientais está pouco estudada. Com o objetivo de compreender o determinismo genético dos traços adaptativos da espécie e estudar padrões de variação adaptativa, assumindo que existe diferenciação genética nos traços fenológicos encontrados nas populações de sobreiro, estabeleceu-se um ensaio em Mogadouro - Trás-os-Montes com 34 proveniências oriundas da bacia do Mediterrâneo onde a espécie tem a sua distribuição natural. Considerando que não só a adaptação, mas também a melhoria da qualidade do material reprodutivo em termos de forma e da cortiça produzida, são importantes, e que a melhoria da forma pode ser induzida artificialmente através da técnica de assentamento de cortes de formação, neste trabalho testou-se a influência das podas de formação na melhoria da forma das proveniências. A caracterização morfológica das proveniências foi efetuada com recurso à avaliação de características qualitativas do fuste, inclinação e dominância da árvore individual, utilizando uma escala de 1 (pior característica) a 6 valores (melhor característica), antes dos cortes e cinco anos depois da aplicação dos mesmos. As podas de formação parecem não ter efeito ou ter um efeito muito reduzido no escalonamento das proveniências que anteriormente revelavam já as piores características morfológicas como o grupo das italianas e o das francesas e algumas proveniências dos grupos de portuguesas e espanholas. As proveniências marroquinas revelam boas características adaptativas que são potenciadas pelos cortes de formação.
- Efeito da intervenção cultural na caracterização morfológica de diferentes proveniências de Quercus suberPublication . Patrício, Maria Sameiro; Nunes, Luís; Almeida, Maria HelenaO sobreiro (Quercus suber L.) é uma espécie muito importante nas áreas de influência mediterrânica por razões económicas, ecológicas e ambientais. É uma espécie com elevado potencial de expansão considerando os cenários das alterações climáticas. A área de sobreiro em Trás-os-Montes é de 8800 ha sendo uma espécie importante a considerar nas estratégias de silvicultura adaptativa em resposta às alterações climáticas. Apesar da sua importância a adaptação da espécie às condições ambientais está pouco estudada. Com o objetivo de compreender o determinismo genético dos traços adaptativos da espécie e estudar padrões de variação adaptativa, assumindo que existe diferenciação genética nos traços fenológicos encontrados nas populações de sobreiro, estabeleceu-se um ensaio em Mogadouro - Trás-os-Montes com 34 proveniências oriundas da bacia do Mediterrâneo onde a espécie tem a sua distribuição natural. Considerando que não só a adaptação, mas também a melhoria da qualidade do material reprodutivo em termos de forma e da cortiça produzida, são importantes, e que a melhoria da forma pode ser induzida artificialmente através da técnica de assentamento de cortes de formação, neste trabalho testou-se a influência das podas de formação na melhoria da forma das proveniências. A caracterização morfológica das proveniências foi efetuada com recurso à avaliação de características qualitativas do fuste, inclinação e dominância da árvore individual, utilizando uma escala de 1 (pior característica) a 6 valores (melhor característica), antes dos cortes e 4 anos depois da aplicação dos mesmos. As podas de formação parecem não ter efeito ou ter um efeito muito reduzido no escalonamento da evolução das proveniências que anteriormente revelavam já as piores características morfológicas como o grupo das italianas e o das francesas e algumas proveniências dos grupos de portuguesas e espanholas. As proveniências africanas parecem revelar boas características adaptativas que são potenciadas pelos cortes de formação.
- Évaluation préliminaire des essais de provenances de chêne-liège et perspectives de recherchePublication . Varela, Maria Carolina; Almeida, Maria Helena; Sampaio, Teresa; Patrício, Maria Sameiro; Dettori, Sandro; Filigheddu, Maria Rosaria; Sirca, C.; Belarosa, R.; Vessella, Federico; Simeone, M.; Iglesias, S.; Aranda, Ismael; Khouja, M.; Khaldi, A.Le réseau international des essais de provenance et de descendance de chêne-liège (établie dans le cadre du projet Action Concertée FAIR CT 95-202 “European network for the evaluation of genetic resources of cork oak for appropriate use in breeding and gene conservation strategies” financé par l’Union Européenne) constitue un matériel vivant unique pour la recherche, qu’elle soit appliquée, ou fondamental, sur l’espèce. Les essais génétiques ont été réalisés sur une base méthodologique harmonisée au niveau des plants utilisés (tous les plants ont été élevées dans une même pépinière au Portugal) et sur terrain un même dispositif expérimental a été suivi. En 1997/98, 13 essais de provenances ont été établis. Ceux ayant réussi sont situés en Espagne (2), France (1), Italie (3), Portugal (3) et Tunisie (1). Concernent les essais de descendances il existe 4 des 5 initiales - Espagne (1), Portugal (2) et Tunisie (1). Dans ce travail nous présentons quelques résultats du comportement des provenances à travers des caractéristiques adaptatifs tels que la survie, l’efficacité d’utilisation de l’eau et des études de génomique. Nous avons procédé à la comparaison de chaque provenance dans les essais - niveau horizontal- et à la comparaison de chaque provenance entre les essais - niveau vertical afin de discuter la plasticité phénotypique et l’interaction génotype X environnement. Les données disponibles pour hauteur en 2006 montre des différences de comportement entre provenances et entre les essais. Par exemple, les provenances du Maroc montre une croissance supérieure dans l’essai plus au Sud au Portugal et aussi dans un essai en Espagne. Pour l’essai de Sardaigne les meilleures provenances sont de Tunisie et d’Espagne. A la fin on discute sur les avantages des essais comme matériel vivant dénominateur commun pour une recherche avancée, multidisciplinaire, synergétique, transnational et concertée. Les perspectives pour la recherche sur les grands thèmes tels que la gestion durable du chêne-liège, notamment la sélection, amélioration génétique, adaptation aux changements globaux, fluxes génétiques, problèmes phytosanitaires, qualité du liège en liaison avec la respective génomique sont adressées.
- Genetic variation of cork oak a tool for improving regeneration of cork oak woodlandsPublication . Almeida, Maria Helena; Aranda, Ismael; Chambel, Maria Regina; Silva, F. Costa e; Dettori, Sandro; Faria, Carla Maria Gomes Marques; Filigheddu, Maria Rosaria; Fernández, Elena; Khaldi, Abedelhamid; Patrício, Maria Sameiro; Perez, Felipe; Ramirez-Valiente, José Alberto; Rodrigues, Ana; Sampaio, Teresa; Varela, CarolinaThe European Academies' Science Advisory Council (2017) reports that the Mediterranean forest is already being affected by climate change (IPCC, 2014) and cork oak woodlands are particularly vulnerable to high-end climate scenarios that go above the Paris Agreement 2° C increase in temperature. Since longer, more frequent, and more intense drought periods are expected, stress caused by the expansion of arid and semi-arid climate will affect the species distribution. Consequently, not only established stands may be prone to tree mortality, but also the current reforestation effort may be jeopardized by low survival rates attributed to the use of unsuitable genetic material. It is expected that, through genetic adaptation and/or phenotypic plasticity, cork oak populations may have developed significant differences in fitness and the traits related to it. In this context, provenance and progeny trials are the best resource of material to assess the variability between and within populations from seed sources sampled in a wide range of locations (stands) covering the geographical distribution of the species. Profiting from the multi-locality provenance and progeny trials belonging to a Network, established in 1998, in the initiative frame of FAIR I CT 0202 for the evaluation of genetic resources of cork oak for appropriate use in breeding and gene conservation strategies”, where 35 cork oak populations covering all the natural distribution area are represented. The provenance trials that where set up in different countries are entering now the age of first debarking and this should allow to have first data about the influence of genetics on production by different site qualities. INCREDIBLE project should document this knowledge
- Geographic variation in cork oak and its implications for expected impacts of climate changePublication . Rodrigues, Ana; Sampaio, Teresa; Silva, João Costa e; Patrício, Maria Sameiro; Silva, Filipe Costa e; Faria, Carla Maria Gomes Marques; Correia, António H.; Varela, Carolina; Pereira, João Santos; Almeida, Maria HelenaCork oak (Quercus suber L.) is a protected tree species in Portugal, being also the source of raw material for the cork industry, a major player in Portuguese economy (representing 3% of GDP in 2010). The future climatic scenarios for Portugal point to an increase in average summer temperatures from 0.3 to 0.7ºC between 2016 and 2035, and up to 4.6ºC until 2100. In addition, precipitation estimates suggest a reduction of annual rainfall from 20 to 40%, especially in southern Portugal. Water stress will, therefore, be a leading constraint to primary production. The combined effects of drought and high temperatures will lead to decreases in carbon assimilation and increases in tree mortality, and consequently current reforestation efforts will need to account for these expected adverse outcomes through the sustainable use of suitable genetic material. There are several reasons that can be highlighted to emphasize the need for an efficient management of cork oak genetic resources in Portugal, namely: i) to avoid cork import, and thus to increase cork production to meet the industry demands; ii) to overcome a generally poor area of natural regeneration, which does not help to ensure an in situ conservation of genetic resources; iii) to deploy adapted genetic material for afforestation/reforestation; and iv) to develop a gene resources conservation program, as cork oak is a vital component of agro-silvopastoral systems in the Mediterranean region. Given the broad native range of the species, involving significant environmental and geographic gradients, a high level of genetic variation can be expected. It is possible that disruptive selection has caused a large differentiation in adaptive traits among populations, namely in the ability to tolerate different environmental stress events (e.g. drought and frost) and to cope with pests and diseases. Between 1998 and 2011, we have collected data involving survival, growth, phenology and water-use efficiency traits from five common-garden provenance trials (including family structure in two of the trials), that were established in Portugal under a concerted action launched by the EUFORGEN’s network. These multi-site field experiments are based on up to 35 tested provenances covering the entire natural distribution of cork oak, and results obtained from the genetic evaluation of the trials have indicated significant differences among populations for all the measured traits at all observed ages. Four of the tested provenances (Alpujarras – Haza de Lino, Puglia – Lucci - S. Teresa, Landes - Soustons, Rif Occidental – Ain Rami) were then chosen according to their contrasting field performance for growth, phenology and water-use efficiency (WUE), and were further evaluated under controlled-environment conditions where drought stress was induced. In this context, the main drivers of drought adaptation appeared to be early stomatal closure and root investment, which also showed significant differences among the selected provenances. The responses to drought over time also varied among these studied populations, and seemed to be related to their differences in growth rhythm. The Ain Rami population seemed to be most prone population to endure drought conditions. Facing a water deficit scenario this population, with highest growth, showed a higher investment on roots compared to the Haza de Lino population, that even under optimal hydration status, had lower biomass values, more reduced transpiration area (smallest size, with lowest Specific Leaf Area), leading to a lower water consumption. This population showed a delay in onset of stress when compared to other populations, only revealed no stomatal limitations with high stress levels. Furthermore, Ain Rami showed higher WUE under drought conditions both in the field trials and under controlled conditions, but average WUE in wet conditions. The results from the field and controlled-environment experiments were consistent in that geographic origin had an important influence on the performance of fitness surrogates and functional traits, and thus providing a strong indication that seed origin must be considered in cork oak reforestation programs.
- Geographic variation in phenology behavior and response to drought of cork oak populations is crucial to cope with climate changePublication . Rodrigues, Ana Paula; Sampaio, Teresa; Silva, J. Costa e; Patrício, Maria Sameiro; Pereira, João Santos; Almeida, Maria HelenaCork oak is widely distributed in the Western Mediterranean region, spanning a range of different environmental conditions, and frequently dominating open woodlands of high conservation and socioeconomic value. Cork oak woodlands spread-out for over 715000 ha in Portugal, covering 21% of the national forested area and 30% of the world’s cork producing area. Cork oak is well adapted to the seasonal drought of Mediterranean climate, following several decades of warming- up and frequent drought years. However, since the 70's, maximum and minimum temperatures have risen in Portugal about 0.5 ºC each decade, corresponding to twice the average world temperature increment. In addition, since longer, more frequent, and more intense drought periods are expected, stress caused by the expansion of arid and semi-arid climate throughout the country will affect the species distribution. Consequently, not only established stands may be prone to tree mortality, but also the current reforestation effort may be jeopardized by low survival rates attributed to the use of unsuitable genetic material. It is expected that, through genetic adaptation and/or phenotypic plasticity, cork oak populations may have developed significant differences in fitness and the traits related to it. In this context, provenance trials are the best resource of material to assess the variability between and within populations from seed sources sampled in a wide range of locations (stands) covering the geographical distribution of the species. This will enable to assess the levels and patterns of genetic variation for growth and traits determining adaptation to a specific environment, hence providing crucial information to select appropriate seed sources for planting, as well as to develop sustainable breeding and gene conservation programs. In 1998, multi-site provenance trials were established at three locations in Portugal, as a part of the “European Network for the Evaluation of Genetic Resources of Cork Oak for Appropriate Use in Breeding and Gene Conservation Strategies”. Results from these field trials at 7 years from planting pointed out that seed origin must be considered in reforestation programs, since survival, growth and adaptive traits (phenology, water use efficiency - wue) showed significant differences among populations. Responses to drought (a major limitation to cork oak regeneration) of four contrasting populations, selected according to their field performance for growth, phenology and wue, were further studied under controlled-environment conditions where drought stress was induced. In addition, morphological (total height, root/shoot biomass), physiological (wue, water potential, relative water content and gas exchange) and biochemical (maximum quantum yield of PSII) traits were assessed in 6-month seedlings produced from acorns collected in the stands representing the four contrasting provenances. Results from the controlled experiment provided an indication that drought adaptation was mainly related to early stomatal closure and root investment, with these traits showing significant differences between the studied populations. We have also observed significant differences in growth rhythm, as well as dissimilar temporal drought responses, in the populations under study. In conclusion, both field trials and controlled environment showed consistent results and indicated an important influence of geographic origin on growth performance and wue.