DEBA - Artigo submetido em Revista Científica Indexada
URI permanente para esta coleção:
Navegar
Entradas recentes
Item Acesso Aberto Impact of Cultivar, Processing and Storage on the Mycobiota of European Chestnut Fruits2022-11-17 - Rodrigues, Paula; Driss, Jihen Oueslati; Laranjo, José Carlos Esteves Gomes; Sampaio, Ana C.Sweet chestnut fruits are popular fruits commercialized as fresh or processed ready-to-eat products. The major post-harvest problems associated with stored chestnut fruits are fungal rots, which cause major losses in fruit quality. The aims of this work were to determine the incidence, abundance and diversity of rots and fungi in three chestnut varieties (Longal, Judia and Martaínha) of Portugal, collected from an industrial plant, and to identify the stages of storage and processing where fungi and rots are more significant. Thirty-three chestnut samples from the three varieties were collected from different stages of industrial processing. Nuts were internally and externally inspected for damage, infestation and infection, and internal fungi were isolated and molecularly identified. The variety Martaínha was identified as the least susceptible to fungal growth, while Longal was the most susceptible. A high diversity of fungi was detected and identified. The dominant fungi were Mucor racemosus, Penicillium spp. (the causal agents of green rots), Ciboria batschiana (black rot) and Botrytis cinerea (gray rot). Gnomoniopsis smithogilvyi, the causal agent of brown rot, was also frequently detected. Sterilization with hydrothermal bath was effective in the elimination or reduction of most of the rot-causing fungi. These results could serve as a baseline for better monitoring fungal development and chestnut decay, and to develop effective management measures to control post-harvest chestnut rots.Item Acesso Aberto Are litterfall and litter decomposition processes indicators of forest regeneration in the neotropics? Insights from a case study in the Brazilian Amazon2018-12 - Silva, Wully Barreto da; Périco, Eduardo; Dalzochio, Marina Schmidt; Santos, Mario Gabriel Santiago Dos; Cajaiba, Reinaldo LucasLitterfall plays an important role in nutrient cycling and maintenance of soil fertility in terrestrial ecosystems. We gauged the effects of anthropogenic impacts on the production, decomposition and seasonality of litterfall in primary and secondary forests within a tropical landscape of the Brazilian Amazon. We hypothesized that leaf litter quantity and quality would differ in line with forest disturbance and that these changes would translate into dissimilar decomposition rates. If proved, these processes could be used as surrogates for indentifying the ecological status of forest habitats. The obtained results have shown that, in the study area litterfall is reduced and litter decomposition is braked in disturbed habitats when compared with primary and recovered secondary forests. Also, within similar climatic conditions, the litter production and decomposition rates begin to stabilize in mature secondary forests. Our results represent a useful contribution to understand the dynamics of the litterfall and litter decomposition processes in the neotropics. Both processes were correlated and sensitive to disturbance gradients and should used as forest recovery indicators in ecological monitoring and ecological restoration studies.Item Acesso Aberto Are Small Dung Beetles (Aphodiinae) useful for monitoring neotropical forests’ ecological status? Lessons from a preliminary case study in the Brazilian Amazon2018 - Cajaiba, Reinaldo Lucas; Périco, Eduardo; Silva, Wully Barreto da; Leote, Pedro; Santos, Mario Gabriel Santiago DosNeotropical forests are extremely diverse ecosystems, listed within the biological hotspots of our planet. However, species from these forests are threatened by diverse anthropogenic activities. Small dung beetles (Scarabaeidae, Aphodiinae) assemblages were studied within different habitats of the Brazilian Amazon. The monitored habitats encompassed the main gradients of disturbance, from pristine to highly anthropogenic situations, with the aim of supporting their use as indicators of neotropical forests’ ecological status. Additionally, seasonal patterns and bait attractiveness were evaluated in the scope of more effective monitoring studies. Our main results demonstrate that the diversity and distribution of small dung beetles along disturbance gradients, represented by the monitored locations, is associated with particular habitats within the forest landscape. Although spatially and temporally restricted, the results of this study highlight the potential of using small dung beetles, due to their sensitivity and habitat specificity, as ecological indicators for assessing the extent of disturbance in neotropical forest landscapes. We also suggest specific techniques and periods to be used in order to increase captures of small dung beetles within the different habitats.Item Acesso Aberto How good are the ecological assumptions and predictions made in the past? Insights from a dynamic modelling approach applied to changing landscapes2018 - Santos, Mario Gabriel Santiago Dos; Silva, Sara; Bastos, Rita; Carvalho, Diogo; Cabral, João Alexandre Ferreira Abel Dos ...Worldwide landscape changes and the uncertainty about its impacts on species abundances, distributions and on ecosystems structure and functioning, have been increasing the value of modelling tools in a very obvious way. Thirteen years ago, the first holistic stochastic dynamic methodology (StDM) application was published (Ecological Indicators 3(4), 285–303 by Santos and Cabral (2004)) intended for predicting ecological indicators trends in face of realistic scenarios of land use/land cover changes. The application of this StDM framework provided some basis to simulate landscape changes and predict the subsequent response of pertinent ecological indicators. Nevertheless, the results reliability could only be evaluated with subsequent independent information checking. In this work, based on independent data obtained thirteen years after, we compare the simulated land use changes and predicted responses of the selected ecological indicators with the respective real trends. The comparisons made confirmed that the implemented scenario was realistic and the ecological indicators’ response mostly accurate. This allowed for demonstrating the proposed frameworks potential and its use in landscape planning and managing of agro-environmental measures. Our approach also provides a promising and intuitive baseline to support risk assessments for land use changes, derived from ecological models linked with ecological monitoring, crucial to guide decision makers and environmental managers.Item Acesso Aberto Magnesium deficiency in chestnut groves: the influence of soil manganese2010 - Portela, Ester; Pires, Carlos Coelho; Louzada, JoséIn northeastern Portugal, it has been difficult to identify the threshold value of exchangeable magnesium (Mg) below which Mg deficiency occurs in chestnuts (Castanea sativa Mill.), since discrepancies have been observed in some areas, apparently associated with parent material. A regional survey was carried out in chestnut groves established in soils derived from bedrock of several geological formations, some of them rich in manganese (Mn). Leaf sampling and soil analysis were performed in 38 groves. The lowest value of foliar Mg concentration under good growing conditions was 1.8 g kg−1 and the highest value in trees with Mg deficiency symptoms was 1.5 g kg−1 . Under acidic soil conditions higher levels of extractable Mn propitiate Mg deficiency. The soils need to reach higher exchangeable Mg (≥0.34 cmolc kg−1 ) in order to supply Mg. For lower values of extractable Mn, the deficiency appears when exchangeable Mg isItem Acesso Aberto Management of chestnut plantations for a multifunctional land use under Mediterranean conditions: effects on productivity and sustainability2011 - Martins , Afonso; Marques, Guilhermina Miguel Da Silva; Borges, Olga; Portela, Ester; Lousada, José; Raimundo, Fernando Pedro Falcão; Madeira, ManuelChestnut plantations for fruit production in Northern Portugal have been subjected to intensive management system, including soil tillage, mineral fertilization and pruning. Some of these practices have no positive effect on productivity and soil– plant–water relations. Other systems (e.g., no tillage with maintenance of grass cover) have been adopted, aiming a multifunctional land use, exploiting nuts, pasture and edible mushrooms. Thus, an experimental trial was installed to assess the effects of such systems on productivity, sustainability and annual net income, as compared with the conventional system, over a six-year period. The treatments were: conventional soil tillage (CT); no tillage with permanent spontaneous herbaceous vegetation cover (NV); no tillage with permanent rainfed seeded pasture cover (NP); and as NP but with irrigation (NIP). Production of nuts, forage and edible mushrooms were measured and sustainability was assessed by production and diversity of fungal sporocarps. Annual net income was estimated by the difference between the annual gross outputs (market values for nuts, forage and edible commercial mushrooms) and the annual input costs. The greatest nut and edible mushroom production and sporocarp biodiversity were achieved in the NIP and NV and the smallest in the CT treatment. The highest annual gross output was estimated for the NV and NIP treatments, whereas the highest annual net income was obtained for the NV. No tillage with maintenance of spontaneous grass cover showed to be the most favourable management system, as it has increased productivity and biodiversity.Item Acesso Restrito Next-generation sequencing and comparative analysis of Pyrrhocorax pyrrhocorax and Pyrrhocorax graculus (Passeriformes: Corvidae) mitochondrial genomes.2014 - Morinha, Francisco; Clemente, Carla; Cabral, João Alexandre; Lewicka, Magdalena M.; Travassos, Paulo; Carvalho, Diogo; Dávila, José A.; Santos, Mário; Blanco, Guillermo; Bastos, EstelaThe complete mitochondrial genomes of Red-billed Chough (Pyrrhocorax pyrrhocorax) and Yellow-billed Chough (Pyrrhocorax graculus) were sequenced using the Ion Torrent PGM platform. These mitogenomes contain 16,889 bp (Red-billed Chough) and 16,905 bp (Yellowbilled Chough), including 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a control region (D-loop). The gene content, orientation, and structure are similar to a wide range of other vertebrate species and the nucleotide composition is very similar to other Passeriformes. All PCGs start with ATG, except for COX1 that starts with GTG, and four stop codons and one incomplete stop codon are used (TAA, TAG, AGG, AGA, and T-). The size of PCGs is the same in both mitogenomes, except for ND6 that has one codon less in the Yellow-billed Chough. All the tRNAs can fold into a typical cloverleaf secondary structure. These mitogenomic data can be of great value in complementing forthcoming approaches on molecular ecology, comparative and functional genomics.