Browsing by Author "Costa, J. C."
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- Acacia saligna (Labill.) H. Wendl in the Sesimbra County: invaded habitats and potential distribution modelingPublication . Gutierres, F.; Gil, A.; Reis, Eusébio; Lobo, A.; Neto, Carlos; Calado, H.; Costa, J. C.The aim of this study is to establish the spatial pattern of colonization and spread of Acacia saligna by predictive modeling, susceptibility evaluation and to perform a cost-effective analysis in two sites of community importance (Fernão Ferro/Lagoa de Albufeira and Arrábida/Espichel) in the Sesimbra County. The main goal is to increase the knowledge on the invasive process and the potential distribution of the Acacia saligna in Sesimbra County, namely in the Natura 2000 sites. The Artificial Neural Networks model was developed in Open Modeller to predict the potential of occurrence of A. saligna, and is assumed to be conditioned by a set of limiting factors that may be known or modeled. The base information includes a dependent variable (present distribution of specie) and several variables considered as conditioning factors (topographic variables, land use, soils characteristics, river and road distance), organized in a Geographical Information System (GIS) database. This is used to perform spatial analysis, which is focused on the relationships between the presence or absence of the specie and the values of the conditioning factors. The results show a high correspondence between higher values of potential of occurrence and soils characteristics and distance to rivers; these factors seem to benefit the specie’ invasion process. According to the conservation value of each cartographic unit, related to natural habitats included in Habitats Directive (92/43/EEC), the coastal habitats (2130, 2250 and 2230) were the most susceptible to invasion by A. saligna. The predicted A. saligna distribution allows for a more efficient concentration and application of resources (human and financial) in the most susceptible areas to invasion, such as the local and national Protected Areas and the Sites of Community Importance, and is useful to test hypotheses about the specie range characteristics, habitats preferences and habitat partitioning
- Annual dune plant communities in the southwest coast of EuropePublication . Costa, J. C.; Neto, Carlos; Martins, M.; Lousã, M.This study presents an updated sintaxonomic review of the annual communities from coastal dunes in the Southwest coast of Europe, specifically in the Iberian Peninsula, including both types: directly influenced by the sea salt spray and not affected by this influence. The floristic segregation of the different plant associations was obtained by statistical agglomerative processes (UPGMA, Unweighted Pair Group Method with Arithmetic Mean) plus principal coordinate analysis (PCoA) and discussed based on the interpretation of phytosociological tables. Three new communities in central western Portugal were found and are described: Pseudorlayo minusculae-Polycarpietum alsinifoli, Cerastio diffusae-Vulpietum fontqueranae and Omphalodo kunzinskyanae-Evacietum ramosissimae.
- Finding the boundary between Eurosiberian and Mediterranean salt marshesPublication . Costa, J. C.; Arsénio, P.; Monteiro-Henriques, T.; Neto, Carlos; Pereira, E.; Almeida, T.; Izco, J.In continental Portugal it is generally recognized that the Ria de Aveiro is the coastal limit between Mediterranean and Eurosiberian regions. Considering salt marshes flora and vegetation communities, the Tagus River estuary seems typically Mediterranean, while the Ria de Aveiro lagoon seems typically Eurosiberian, therefore the boundary between the two regions might be found among the smaller salty areas existing between the two referred wetlands (namely the Óbidos Lagoon, the Tornada and Mondego rivers). Although tide height is a sound explanation for the floristic differences between Eurosiberian and Mediterranean saltmarshes, the fact is that the southwest Portuguese Atlantic salt marshes present Mediterranean climate and flora, despite its greater tide heights if compared to the Mediterranean Basin. Conversely, Mediterranean climate by its own is not enough to explain those florisitc differences, as it exits north of Aveiro. We introduced the importance of sea-surface temperature in order to detail the boundary between the two regions. Despite climate and hydrologic regime being Mediterranean between the Tagus and the Ria de Aveiro, the cold Atlantic waters seem to influence the flora and the vegetation of the present salt marshes. It is proposed to classify as Eurosiberian all salt marshes north of the Tagus Basin.
- A global view on the riparian forests with Salix neotricha and Populus alba in the Iberian Peninsula (Portugal and Spain)Publication . Costa, J. C.; Neto, Carlos; Capelo, J.; Lousã, M.; Rivas-Martínez, S.Forests dominated by Salix neotricha, and Populus alba found along the mesoeutrophic rivers in the Iberian Peninsula, were studied. We discuss the floristic circumscription, chorology, and community segregation based on the available releve´s of all Iberian riparian communities included in Populenion albae. Eleven formerly described communities were analyzed and due to original floristic combination, habitat features, and biogeographic scope, a new willow and poplar forest type is proposed within a well-defined biogeographical unit (Sadensean-Dividing Portuguese Subprovince): Clematido campanifloraeSalicetum neotrichae. This syntaxon is found under a semi-hyperoceanic thermomediterranean to lower mesomediterranean, subhumid to humid bioclimate. Cluster analysis including all Iberian communities of Populenion albae shows a clear floristic segregation within the suballiance and confirms the originality of the new association. Furthermore, chemical characteristics of the water along some of the Portuguese watercourses with Populenion albae were studied and compared to the oligotrophic rivers occupied by Osmundo-Alnion communities. This study suggests that floristic separation between the communities of Populenion and Osmundo-Alnion is accompanied by a differentiation of the water trophic level.
- Modelos espacialmente explícitos de análise de dinâmicas locais: o caso da Vegetação Natural Potencial no apoio ao planeamento e ordenamento territorialPublication . Gutierres, F.; Reis, Eusébio; Neto, Carlos; Costa, J. C.A definição da Vegetação Natural Potencial (VNP) reveste-se de grande utilidade no apoio aos processos de decisão no âmbito do ordenamento territorial. Em territórios classificados em que a vegetação apresenta elevada perturbação, como se verifica em algumas áreas dos Sítios da Rede Natura 2000 “Comporta/Galé” e “Estuário do Sado”, a expressão cartográfica da VNP tem a necessidade de se apoiar num conjunto de elementos que vão além das condições da vegetação atual. A modelação preditiva da distribuição das séries de vegetação possibilita a produção de mapas probabilísticos com base na extrapolação das relações entre as variáveis ambientais e as comunidades vegetais. Os resultados obtidos permitiram aferir o modo como os gradientes ecológicos determinam a ocorrência de diversos tipos de séries de vegetação, tal como, a espacialização da VNP para o território em estudo. A expressão cartográfica da VNP a escalas de pormenor assume um papel importante no planeamento e ordenamento do território.
- Phylogenenetic approach of the section Bulbocodii D.C. of Narcissus based on cpDNA: a case of taxonomic inflation?Publication . Fonseca, J. P.; Levy, A.; Henriques, R.; Costa, J. C.; Neto, Carlos; Robalo, J.In this paper, we analyzed the phylogeny of the section Bulbocodii (genus Narcissus; Amarillydaceae) using the matK and trnL-F fragments of cpDNA in order to review the validity of the recognized taxa. Our results indicate that Narcissus obesus should be considered a valid species, and that N. blancoi is a distinct taxon. In addition, seven previously recognized species, N. juressianus, N. subnivalis, N. graellsii, N. conspicuus, N. citrinus, N. nivalis, and N. quintanilhae, should be assigned to na infraspecific rank under N. bulbocodium, as they are not valid species. In addition, we analyzed the distribution of the three morphological characters widely used in the systematics of this section and found that their variation does not agree with the phylogenetic results, rendering these characters limited taxonomical utility. This result suggests that the section Bulbocodii shows high morphological lability, which can explain the proliferation of nominal species.
- Phytosociologic associations and Natura 2000 habitats of Portuguese coastal sand dunesPublication . Neto, Carlos; Costa, J. C.; Honrado, J.; Capelo, J.The portuguese coastline is quite long and the littoral ecosystems are of the outmost importance in the context of the national flora and vegetation. The diversity of vegetation types and the endemicity of their flora justify the attention paid to coastal habitats in the implementation of the Natura 2000 network. In this paper we present a synatoxonomical revision of the phanerophytic, chamaephytic and hemicryptophytic communities occurring in the sandy coastal areas of Portugal, together with their correspondence to the “Natura 2000” natural habitat types. The production of synthetic tables with all available relevés has allowed the segregation of plant community types. We also include maps concerning the distribution of all validated vegetation types occurring in the portuguese sandy coastal areas.
- The application of the habitats directive in PortugalPublication . Costa, J. C.; Monteiro-Henriques, T.; Neto, Carlos; Arsénio, P.; Aguiar, C.A succinct review of the application of the Habitats Directive in Portugal is presented. Since 1971 until 2000 Portugal has defined approximately 8,8% of its territory as national protected areas. With the application of the Habitats Directive nature conservation policies extended to more than 17,4 % of the territory increasing by 98% and the knowledge on vegetation community’s habitats was certainly deepened. Including special protection areas (Birds Directive) the Portuguese territory under one or more conservation status totals 21,5%. Finally, the support given by the Portuguese Phytosociology Association – ALFA in the detailed description of the Directive habitats is divulged, showing the importance, usefulness and efficacy of phytosociologic studies
- The scrubland of limestone-derived decarbonated soils of the western Iberian PeninsulaPublication . Costa, J. C.; Pinto-Gomes, C.; Lopes, M. C.; Neto, Carlos; Monteiro-Henriques, T.; Arsénio, P; Silva, V.; Capelo, J.; Lousã, M.; Rivas-Martínez, S.In the present article, the proposal of a new suballiance, Lavandulo luisieri-Cistenion albidi, is presented, constituted by chamaephytic and nanophanerophytic communities in eroded decarbonated soils derived from limestones (leptosols, chromic luvisols and cambisols) in the dry to lower hyperhumid, thermo-mesomediterranean bioclimatic levels. It is distributed throughout the western Iberian Peninsula in the Coastal Lusitan-Andalusian and Lusitan-Extremadurean biogeographical territories. It is positioned in the Ulici argentei-Cistion ladaniferi, Lavanduletalia stoechadis, Cisto-Lavanduletea. The new associations Anthyllido maurae-Ulicetum jussiaei, Sedo albi-Cistetum crispi and Thymetum congesti are also described. The multivariate analysis confirmed the segregation of this new suballiance, as well as the new associations