Costa, A. Maia e
Santos, Carmen; Nelson, Charles Dana; Zhebentyayeva, Tetyana; Machado, Helena; Gomes-Laranjo, José; Costa, Rita Lourenço
Rivaes, Rui; Pinheiro, António N.; Egger, Gregory; Ferreira, Teresa
Le Page, Y.; Vasconcelos, Maria; Palminha, A.; Melo, I.Q.; Pereira, J.M.C.
Carreira, Bruno M.; Segurado, Pedro; Laurila, Anssi; Rebelo, Rui
Rodrigues, Joana; Miranda, Isabel; Furquim, Leonnardo; Gominho, Jorge; Vasconcelos, Manuel; Barradas, Gonçalo; Pereira, Helena; Bianchi-de-Aguiar, Fernando; Ferreira-Dias, Suzana
tJatropha curcas L. is an interesting tropical oil crop for biodiesel production. However, seed conservationuntil oil extraction may be a problem under high temperature and humidity. In this study, Jatropha curcasL. seeds grown in Mozambique and presenting 160 mg/kg of gamma-tocopherol in their oil were storedfor 42 days, in dark, at 35◦C and 75% or 92% relative humidity (RH). Along storage, the oil was extractedand analysed in terms of fatty acid composition, tocopherol content, acidity, initial and final oxidationproducts (monitored by K232 and K270 values, respectively).Jatropha seeds presented an initial water content of 8.4% and an oil content of 45.7%...
Costa-e-Silva, Filipe; Correia, Alexandra C.; Piayda, Arndt; Dubbert, Maren; Rebmann, Corinna; Cuntz, Matthias; Werner, Christiane; David, Jorge Soares; Pereira, João Santos
In seasonally dry climates, such as the Mediterranean, lack of rainfall in the usually wet winter may
originate severe droughts which are a main cause of inter-annual variation in carbon sequestration. Leaf
phenology variability may alter the seasonal pattern of photosynthetic uptake, which in turn is determined
by leaf gas exchange limitations. The current study is based on the monitoring of an extremely dry
winter in an evergreen cork oak woodland under the Mediterranean climate of central Portugal. Results
are focused on net ecosystem CO2 exchange (NEE), phenology and tree growth measurements during two
contrasting years: 2011, a wet year with a typical summer drought pattern...
Oliveira, Vanda; Knapic, Sofia; Pereira, Helena
tThe natural cork stoppers are commercially graded into quality classes according with the homogeneity of theexternal surface. The underlying criteria for this classification are subjective without quantified criteria and standardsdefined by cork industry or consumers. Image analysis was applied to premium, good and standard quality classes tocharacterize the surface of the cork stoppers and stepwise discriminant analysis (SDA) was used to build predictiveclassification models. The final goal is to analyze the contribution of each porosity feature and propose an algorithmfor cork stoppers quality class classification. This study provides the knowledge based on a large sampling to anaccurate grading of natural...
Neiva, Duarte; Fernandes, Luís; Araújo, Solange; Lourenço, Ana; Gominho, Jorge; Simões, Rogério; Pereira, Helena
Eucalypts are among the most important short-rotation hardwoods, planted worldwide for the pulp and
paper industry. Even though the genus comprises over 700 species, only about a dozen species are used for
pulping purposes, therefore, showing the potential for diversification. Six-year-old eucalypt trees from 12
species (Eucalyptus botryoides, Eucalyptus camaldulensis, Eucalyptus globulus, Eucalyptus grandis, Corymbia
maculata, Eucalyptus ovata, Eucalyptus propinqua, Eucalyptus resinifera, Eucalyptus rudis, Eucalyptus saligna,
Eucalyptus sideroxylon, and Eucalyptus viminalis) were analyzed for chemical composition, fiber morphological,
pulping and handsheet paper properties to determine their kraft pulping suitability. The 12 species
showed substantial differences regarding extractives (6.1–18.9%), lignin (21.6–30.8%) and holocellulose
content (55.4–70.1%). The high inter-species variation...
Caldeira, Ilda; Anjos, Ofélia; Belchior, A. Pedro; Canas, Sara
The production of wine brandies requires their stage in wooden barrels, for a minimum period of time, a process called ageing or maturation. Due
to the high cost of this process, alternative technologies are being studied in order to accelerate the ageing process, such as the use of wood
fragments inside of stainless steel tanks. The present work evaluates the influence of different ageing technologies on the sensory profile of the
brandy. A brandy was aged, during two years, in 650 L wooden barrels and in 3000 L stainless steel tanks. Both had Limousin oak (Quercus
robur) and Portuguese chestnut staves (Castanea sativa). The...
Fernandes, Cláudia; Gaspar, Maria João; Pires, Jani; Alves, Ana; Simões, Rita; Rodrigues, José Carlos; Silva, Maria Emília; Carvalho, Ana; Brito, José Eduardo; Lousada, José Luís
Paulo, Joana A.; Tomé, Margarida
Miranda, Isabel; Sousa, Vicelina; Ferreira, Joana; Pereira, Helena
Jongen, Marjan; Hellmann, Christine; Unger, Stephan
To date, the implications of the predicted greater intra-annual variability and
extremes in precipitation on ecosystem functioning have received little attention.
This study presents results on leaf-level physiological responses of five species
covering the functional groups grasses, forbs, and legumes in the
understorey of a Mediterranean oak woodland, with increasing precipitation
variability, without altering total annual precipitation inputs. Although extending
the dry period between precipitation events from 3 to 6 weeks led to
increased soil moisture deficit, overall treatment effects on photosynthetic performance
were not observed in the studied species. This resilience to prolonged
water stress was explained by different physiological and morphological strategies
to withstand periods below the wilting...
Oliveira, Sofia L.J.; Campagnolo, Manuel L.; Price, Owen F.; Edwards, Andrew C.; Russel-Smith, Jeremy; Pereira, J.M.C.
Ferreira, Liliana; Constantino, Miguel F.; Borges, José G.; Garcia-Gonzalo, Jordi
Fundamental Research - Forest Management
Paulo, Joana Amaral; Palma, J.H.N.; Gomes, Alberto Azevedo; Faias, Sónia Pacheco; Tomé, José; Tomé, Margarida
Site productivity, assessed through site index, was modelled using partial least
squares regression as a function of soil and climatic variables. Two alternative models were
developed: a full model, considering all available explanatory variables, and a reduced
model, considering only variables that can be obtained without digging a soil pit. The
reduced model was used for mapping the site index distribution in Portugal, on the basis of
existing digital cartography available for the whole country. The developed models indicate
the importance of water availability and soil water holding capacity for site index
value distribution. Site index was related to climate, namely evaporation and frost, and soil
Amaral, S.D.; Franco, A.; Ferreira, M.T.
Angling competitions are a popular leisure activity in reservoirs of
Southern Portugal. These competitions can gather more than 100 anglers
aiming to catch the maximum fish weight. Groundbaiting and catch-andrelease
angling are two common practices for anglers in competition. In
this study, the loads of nutrients from commercial groundbait powders
used in angling competitions in the Maranhão reservoir and the possible
balance out of those nutrients through a moderate biomanipulation of the
fish biomass caught in competitions were analysed. In order to achieve
this aim, chemical analyses to groundbait powders most purchased by
Portuguese anglers and to fish species most captured in competitions
were made. Mass balances on inputs and...
Enes, Teresa Duque; Fonseca, Teresa Fidalgo
Aim of the study: The objective of this paper is to investigate the use of Biomass Conversion and Expansion Factors
(BCEFs) in maritime pine (Pinus pinaster Ait.) stands subjected to thinning.
Area of the study: The study area refers to different ecosystems of maritime pine stands in Northern Portugal.
Material and methods: The study is supported by time data series and cross sectional data collected in permanent
plots established in the North of Portugal. An assessment of BCEF values for the aboveground compartments and for
total was completed for each studied stand. Identification of key variables affecting the value of the BCEFs in time