Ferreira, Joana P.A.; Miranda, Isabel; Sousa, Vicelina B.; Pereira, Helena
The bark from Quercus faginea mature trees from two sites was chemically characterized for the first time. The barks showed the
following composition: ash 14.6%, total extractives 13.2%, suberin 2.9% and lignin 28.2%. The polysaccharides were composed
mainly of glucose and xylose (50.3% and 35.1% of all monosaccharides respectively) with 4.8% of uronic acids. The suberin
composition was: ω-hydroxyacids 46.3% of total compounds, ɑ,ω-alkanoic diacids 22.3%, alkanoic acids 5.9%, alkanols 6.7% and
aromatics 6.9% (ferulic acid 4.0%). Polar extracts (ethanol-water) had a high phenolic content of 630.3 mg of gallic acid equivalents
(GAE)/g of extract, condensed tannins 220.7 mg of catechin equivalents (CE)/g extract, and...
Yáñez-Serrano, A.M.; Fasbender, L.; Kreuzwieser, J.; Dubbert, D.; Haberstroh, S.; Lobo-do-Vale, R.; Caldeira, M.C.; Werner, C.
Mediterranean vegetation emits a wide range of biogenic volatile organic compounds (BVOCs) among
which isoprenoids present quantitatively the most important compound class. Here, we investigated
the isoprenoid emission from two Mediterranean Cistaceae shrubs, Halimium halimifolium and Cistus
ladanifer, under controlled and natural conditions, respectively. For the first time, diurnal emission
patterns of the diterpene kaurene were detected in real-time by Proton-Transfer-Reaction-Timeof-
Flight-Mass-Spectrometer. Kaurene emissions were strongly variable among H. halimifolium
plants, ranging from 0.01 ± 0.003 to 0.06 ± 0.01 nmol m−2 s−1 in low and high emitting individuals,
respectively. They were in the same order of magnitude as monoterpene (0.01 ± 0.01 to 0.11 ± 0.04
Knapic, Sofia; Grahn, Thomas; Lundqvist, Sven-Olof; Pereira, Helena
Romão, Filipe; Santos, José M.; Katopodis, Christos; Pinheiro, António N.; Branco, Paulo
Most fishway studies are conducted during the reproductive period, yet uncertainty
remains on whether results may be biased if the same studies were performed outside of the
migration season. The present study assessed fish passage performance of a potamodromous cyprinid,
the Iberian barbel (Luciobarbus bocagei), in an experimental full-scale vertical slot fishway during
spring (reproductive season) and early-autumn (non-reproductive season). Results revealed that
no significant differences were detected on passage performance metrics, except for entry efficiency.
However, differences between seasons were noted in the plasma lactate concentration (higher in
early-autumn), used as a proxy for muscular fatigue after the fishway navigation. This suggests that,
for potamodromous cyprinids, the...
Ochs, Konstantin; Rivaes, Rui P.; Ferreira, Teresa; Egger, Gregory
Hayes, Daniel S.; Brandle, Julia M.; Seliger, Carina; Zeiringer, Bernhard; Ferreira, Teresa; Schmutz, Stefan
Abstraction, diversion, and storage of flow alter rivers worldwide. In this context,minimumflow regulations are applied
to mitigate adverse impacts and to protect affected river reaches from environmental deterioration. Mostly,
however, only selected instreamcriteria are considered, neglecting the floodplain as an indispensable part of the fluvial
ecosystem. Based on essential functions and processes of unimpaired temperate floodplain rivers, we identify
fundamental principles towhich we must adhere to determine truly ecologically-relevant environmental flows. Literature
reveals that the natural flow regime and its seasonal components are primary drivers for functions and processes
of abiotic and biotic elements such as morphology, water quality, floodplain, groundwater, riparian
vegetation, fish, macroinvertebrates, and amphibians,...
Mota, Graciene S.; Sartori, Caroline J.; Miranda, Isabel; Quilhó, Teresa; Mori, Fábio Akira; Pereira, Helena
The bark of Anadenanthera peregrina (L.) Speg and Anadenanthera colubrina (Vell.) Brenan
were characterized in relation to anatomical and chemical features. The barks were
similar and included a thin conducting phloem, a largely dilated and sclerified non-conducting
phloem, and a rhyridome with periderms with thin phellem interspersed by cortical tissues.
Only small differences between species were observed that cannot be used alone for
taxonomic purposes. The summative chemical composition of A. peregrina and A. colubrina
was respectively: 8.2% and 7.7% ash; 28.8% and 29.3% extractives; 2.4% and 2.6%
suberin; and 18.9% lignin. The monosaccharide composition showed the predominance of
glucose (on average 82% of total neutral sugars) and...
Vieira, Joana; Matos, Paula; Mexia, Teresa; Silva, Patrícia; Lopes, Nuno; Freitas, Catarina; Correia, Otília; Santos-Reis, Margarida; Branquinho, Cristina; Pinho, Pedro
The growing human population concentrated in urban areas lead to the increase of road traffic and artificial
areas, consequently enhancing air pollution and urban heat island effects, among others. These environmental
changes affect citizen's health, causing a high number of premature deaths, with considerable social and economic
costs. Nature-based solutions are essential to ameliorate those impacts in urban areas. While the mere
presence of urban green spaces is pointed as an overarching solution, the relative importance of specific vegetation
structure, composition and management to improve the ecosystem services of air purification and climate
regulation are overlooked. This avoids the establishment of optimized planning and management procedures...
Sousa, Vicelina B.; Louzada, José Luís; Pereira, Helena
Ring width and wood density variation were studied from pith-to-bark and along the stem
in two naturally regenerated stands of Quercus faginea Lam. in Portugal. Ring width was significantly
different between sites, in both heartwood and sapwood rings, ranging from 1.83 mm to 2.52 mm and
from 0.77 mm to 2.11 mm, respectively. Wood density was significantly different between sites only
in the heartwood, i.e., 914 kg m??3 and 1037 kg m??3. Site effects were the main source of variation for
ring width and wood density within the heartwood as well as for sapwood ring width, while the
between-tree effects explained more the density variation within...
Andrade, Tafnes da S.; Cunha, John E. de B.L.; Galvão, Carlos de O.; Rufino, Iana A.A.
Several spectral indices have been used to estimate droughts, however, these indicators only give evidence of a dry spell leaving out its impacts on significant economic activities performed in a given region. In this context, livestock breeding in one of the most important activities to analyze in the Brazilian semiarid region. The aim of this study was to evaluate the relationship between the drought indices, obtained through remote sensory devices, and annual milk production (2004 – 2014), identifying the most affected cities by the drought and were considered the most vulnerable and in need of special attention during dry periods....
Pereira, Allan A.; Pereira, José Miguel Cardoso; Libonati, Renata; Oom, Duarte; Setzer, Alberto W.; Morelli, Fabiano; Machado-Silva, Fausto; Carvalho, Luís Marcelo Tavares de
We used the Visible Infrared Imaging Radiometer Suite (VIIRS) active fire data (375 m
spatial resolution) to automatically extract multispectral samples and train a One-Class Support Vector
Machine for burned area mapping, and applied the resulting classification algorithm to 300-m spatial
resolution imagery from the Project for On-Board Autonomy-Vegetation (PROBA-V). The active fire
data were screened to prevent extraction of unrepresentative burned area samples and combined with
surface reflectance bi-weekly composites to produce burned area maps. The procedure was applied
over the Brazilian Cerrado savanna, validated with reference maps obtained from Landsat images and
compared with the Collection 6 Moderate Resolution Imaging Spectrometer (MODIS) Burned Area
Dolan, Katelyn A.; Hurtt, George C.; Flanagan, Steve A.; Fisk, Justin P.; Sahajpal, Ritvik; Huang, Chengquan; Le Page, Yannick; Dubayah, Ralph; Masek, Jeffrey G.
Disturbances, both natural and anthropogenic, are critical determinants of forest structure, function,
and distribution. The vulnerability of forests to potential changes in disturbance rates remains largely
unknown. Here, we developed a framework for quantifying and mapping the vulnerability of forests
to changes in disturbance rates. By comparing recent estimates of observed forest disturbance rates
over a sample of contiguous US forests to modeled rates of disturbance resulting in forest loss, a novel
index of vulnerability, Disturbance Distance, was produced. Sample results indicate that 20% of
current US forestland could be lost if disturbance rates were to double, with southwestern forests
showing highest vulnerability. Under a future climate...
Rivaes, Rui; Boavida, Isabel; Santos, José M.; Pinheiro, António N.; Ferreira, Maria Teresa
Environmental flows remain biased toward the
traditional biological group of fish species. Consequently,
these flows ignore the inter-annual flow variability that rules
species with longer lifecycles and therefore disregard the
long-term perspective of the riverine ecosystem. We analyzed
the importance of considering riparian requirements
for the long-term efficiency of environmental flows. For
that analysis, we modeled the riparian vegetation development
for a decade facing different environmental flows
in two case studies. Next, we assessed the corresponding
fish habitat availability of three common fish species in
each of the resulting riparian landscape scenarios. Modeling
results demonstrated that the environmental flows disregarding
riparian vegetation requirements promoted riparian
degradation, particularly vegetation encroachment. Such circumstance
altered the hydraulic characteristics...
Teichert, Nils; Lepage, Mario; Sagouis, Alban; Borja, Angel; Chust, Guillem; Ferreira, Maria Teresa; Pasquaud, Stéphanie; Schinegger, Rafaela; Segurado, Pedro; Argillier, Christine
The impact of species loss on ecosystems functioning depends on the amount of trait similarity
between species, i.e. functional redundancy, but it is also influenced by the order in which species are
lost. Here we investigated redundancy and sensitivity patterns across fish assemblages in lakes, rivers
and estuaries. Several scenarios of species extinction were simulated to determine whether the loss of
vulnerable species (with high propensity of extinction when facing threats) causes a greater functional
alteration than random extinction. Our results indicate that the functional redundancy tended to
increase with species richness in lakes and rivers, but not in estuaries. We demonstrated that i) in the
Usié, Ana; Simões, Fernanda; Barbosa, Pedro; Meireles, Brígida; Chaves, Inês; Gonçalves, Sónia; Folgado, André; Almeida, Maria Helena; Matos, José; Ramos, António M.
Cork oaks show a high capacity of bud sprouting as a response to injury, which is important
for species survival when dealing with external factors, such as drought or fires. The characterization
of the cork oak transcriptome involved in the different stages of bud sprouting is essential to
understanding the mechanisms involved in these processes. In this study, the transcriptional profile
of different stages of bud sprouting, namely (1) dormant bud and (2) bud swollen, vs. (3) red bud and
(4) open bud, was analyzed in trees growing under natural conditions. The transcriptome analysis
indicated the involvement of genes related with energy production (linking the TCA...
Le Page, Yannick; Morton, Douglas; Hartin, Corinne; Bond-Lamberty, Ben; Pereira, José Miguel Cardoso; Hurtt, George; Asrar, Ghassem
Tropical forests have been a permanent feature of the Amazon basin for at least 55 million years,
yet climate change and land use threaten the forest’s future over the next century. Understory forest fires, which
are common under the current climate in frontier forests, may accelerate Amazon forest losses from climatedriven
dieback and deforestation. Far from land use frontiers, scarce fire ignitions and high moisture levels
preclude significant burning, yet projected climate and land use changes may increase fire activity in these
remote regions. Here, we used a fire model specifically parameterized for Amazon understory fires to examine the
interactions between anthropogenic activities and climate under...
Rivaes, Rui; Pinheiro, António N.; Egger, Gregory; Ferreira, Teresa
Costa, A. Maia e
Santos, Carmen; Nelson, Charles Dana; Zhebentyayeva, Tetyana; Machado, Helena; Gomes-Laranjo, José; Costa, Rita Lourenço
Le Page, Y.; Vasconcelos, Maria; Palminha, A.; Melo, I.Q.; Pereira, J.M.C.