Floristic composition patterns of Mediterranean annual non-nitrophilous grasslands in Eastern Portugal

Helianthemetea guttati communities are pioneer spring and early summer ephemeral grasslands, dominated by nonnitrophilous therophytes. In Continental Portugal, these communities have not yet been fully investigated, and thus the objectives of the present study are: (1) to identify community types in therophytic grasslands; (2) to recognize those communities that configure the European priority habitat 6220* (pseudo-steppe with grasses and annuals); (3) to establish environmental gradients underlying their spatial variation; (4) to assess how floristic composition is affected by land use factors. Vegetation sampling using phytosociological methodology was carried out on 80 grasslands. Modified Twinspan classification and canonical correspondence analysis (CCA) was applied for the classification and ordination of releve´s whereas partial CCA (pCCA) and variation partitioning were used to assess the relative influence of individual land use factors. Some 270 species were identified across 11 community types whose floristic patterns were mainly explained by environmental gradients related to altitude and soil type while land use variables could only explain a small part of the floristic variation. Based on biogeography and the determination of diagnostic species, four phytosociological new associations and a new subassociation are proposed: Holco-Brachypodietum distachyi, Holco-Micropyretum tenellae, Micropyro- Anthoxanthetum aristati and Leontodonto-Vulpietum bromoidis vulpietosum membranacea

Dynamics of a Cistus salviifolius L. community after experimental disturbances. Plant cover evolution

Estudou-se, durante 3 anos, a resposta de regeneração da vegetação, após corte, com incorporação, deposição e extracção da biomassa vegetal, numa comunidade arbustiva do sul de Portugal, em sistema de montado. O objectivo principal deste estudo consistiu na caracterização da dinâmica do agroecossistema montado, quando sujeito às tradicionais práticas de maneio, tendo em vista a conservação da diversidade biológica e o seu uso sustentado. O estudo da evolução da flora foi efectuado através de levantamentos florísticos periódicos, em quadrados permanentes, com avaliação das percentagens relativas de cobertura, riquezas específicas e valores de biodiversidade, assim como, as percentagens relativas dos tipos fisionómicos presentes. Observou-se a regeneração da comunidade por processos de autosucessão, tendo os valores mais elevados de riqueza e diversidade específica sido registados dois anos após as intervenções. Quando se estabeleceu a dominância das espécies arbustivas, estes valores diminuíram. Decorridos três anos, verificou-se que já não existiam diferenças significativas, quer em relação à situação inicial, quer entre os diferentes tratamentos

Epigenetic rather than genetic factors may explain phenotipic divergence between coastal populations of diploid and tetraploid Limonium spp. (Plumbaginaceae) in Portugal

Research ArticleBackground: The genus Limonium Miller comprises annual and perennial halophytes that can produce sexual and/or asexual seeds (apomixis). Genetic and epigenetic (DNA methylation) variation patterns were investigated in populations of three phenotypically similar putative sexual diploid species (L. nydeggeri, L. ovalifolium, L. lanceolatum), one sexual tetraploid species (L. vulgare) and two apomict tetraploid species thought to be related (L. dodartii, L. multiflorum). The extent of morphological differentiation between these species was assessed using ten diagnostic morphometric characters. Results: A discriminant analysis using the morphometric variables reliably assigns individuals into their respective species groups. We found that only modest genetic and epigenetic differentiation was revealed between species by Methylation Sensitive Amplification Polymorphism (MSAP). However, whilst there was little separation possible between ploidy levels on the basis of genetic profiles, there was clear and pronounced interploidy discrimination on the basis of epigenetic profiles. Here we investigate the relative contribution of genetic and epigenetic factors in explaining the complex phenotypic variability seen in problematic taxonomic groups such as Limonium that operate both apomixis and sexual modes of reproduction. Conclusions: Our results suggest that epigenetic variation might be one of the drivers of the phenotypic divergence between diploid and tetraploid taxa and discuss that intergenome silencing offers a plausible mechanistic explanation for the observed phenotypic divergence between these microspecies. These results also suggest that epigenetic profiling offer an additional tool to infer ploidy level in stored specimens and that stable epigenetic change may play an important role in apomict evolution and species recognitioninfo:eu-repo/semantics/publishedVersio

Natural and Historical Heritage of the Lisbon Botanical Gardens: An Integrative Approach with Tree Collections

Botanical gardens have long contributed to plant science and have played a leading role in ex situ conservation, namely of threatened tree species. Focusing on the three botanical gardens of Lisbon (i.e., Botanical Garden of Ajuda—JBA, Lisbon Botanical Garden—JBL, and Tropical Botanical Garden—JBT), this study aims to reveal their natural heritage and to understand the historical motivations for their creation. Our results showed that these gardens contain a total of 2551 tree specimens, corresponding to 462 taxa, within 80 plant families. Of these, 85 taxa are found in the three gardens, and more than half of the taxa are hosted in JBL (334 taxa), whereas 230 and 201 taxa were recorded in JBT and JBA, respectively. The motivations for the creation of each garden are reflected in the different geographic origins of the trees they host in their living collections. The Palearctic species are dominant in JBA and JBL, and Tropical trees prevail in JBT. With more than 250 years of history, these gardens hold an invaluable natural and historical heritage, with their living collections providing valuable sources of information for the conservation of threatened plant species, at local and global scalesinfo:eu-repo/semantics/publishedVersio

Checklist da Flora de Portugal Continental, Açores e Madeira

Em Novembro de 2007 realizou-se uma reunião entre a Direcção da ALFA e Instituto da Conservação da Natureza e da Biodiversidade (ICNB). Ficou então decidido que a ALFA tomaria a seu cargo a elaboração da Checklist da Flora de Portugal (Continental, Açores e Madeira). Após quase 3 anos de trabalho, a ALFA apresentou publicamente a Checklist durante os VIII Encontros Internacionais de Fitossociologia – ALFA, que decorreram em Lisboa entre 13 e 16 de Setembro de 2010. A ALFA disponibiliza agora a todos os interessados a Checklist da Flora de Portugal (Continental, Açores e Madeira). Através da página http://www3.uma.pt/alfa/checklist_flora_pt/output_db.php podem ainda ser enviados comentários, sugestões ou correcções. A Checklist da Flora de Portugal (Continental, Açores e Madeira) foi formalmente adoptada pelo ICNB e será parte integrante do inventário da biodiversidade prevendo-se a sua integração no futuro Sistema de Informação do Património Natural (SIPNAT,www.icn.pt/sipnat)

A methodological approach to potential vegetation modeling using GIS techniques and phytosociological expert-knowledge: application to mainland Portugal

An attempt to obtain a consistent spatial model of natural potential vegetation (NPV) for the mainland Portuguese territory is reported. Spatial modeling procedures performed in a Geographic Information System (GIS) environment, aimed to operationalize phytosociological expert-knowledge about the putative distribution of potential zona1 forest communities dominam in the Portuguese continental territories. The paradigm for NPV assumed was that of RIVAS-MARTINE(1Z9 76) and RIVAS-MARTINEeZt al. (1999), which presupposes, for a given territory, a univocal correspondence between a uniform combination of bioclimatic stage and lithology' gi ven a biogeographical context, and a unique successional sequence leading to a single climax community (i. e. a vegetation series (VS)). Information issued from both literature and a team of phytosociologists possessing detailed knowledge about Portuguese vegetation, namely about forests and its seria1 vegetation, was acknowledged as a starting point for the construction of such a habitat-vegetation correspondence model. First, a bioclimatic map concerning the "Worldwide Bioclimatic Classification System" (WBCS) of RIVAS-MARTINE(1Z9 81 -2004), obtained by multivariate grostatistical interpolation issuing from the work of MESQUITA(2 005), was set. Severa1 partia1 matrices, one for each biogeographical Province, combined such habitat statements to VS. Initial incoherence due to vagueness of statements led to an important amount of both superimposition of VS and habitat gaps in the matrices. Further rearrangement of the table according to known field distribution of VS by experts allowed setting an approximate univocal correspondence VS-habitat. Finally, an intersection of bioclimatic, lithology and biogeographic maps yielded over a thousand habitat combinations to be associated each to a single VS through implementation of the matrices as a set of rules. Again, inconsistencies were solved likewise, but this time by direct observation of the map by experts. Keeping of phytosociological consistency and fidelity to information on actual vegetation field distribution was always mandatory during the proces

Climate change and outdoor regional living plant collections: an example from mainland Portugal

Original PaperClimate change threatens not only plant species occurring naturally, but also impacts on regional living plant collections, which play an important role in ex situ conservation strategies. In the last few years, several global circulation models have been used to predict different global climate change scenarios. Due to their coarse resolutions, and while more detailed regional approaches are not available, downscaling techniques have been proposed, as a very simple first approach to increase detail. We analysed seven sites on mainland Portugal with potential for species conservation (four botanic gardens and three universities), in the light of downscaled climate change scenarios, using an environmental envelope approach and a predefined bioclimatic neighbourhood for each site. Thresholds for the bioclimatic neighbourhood were based on Rivas-Martı´nez’s Bioclimatic Classification of the Earth. For each site, the expected geographical shift of its original bioclimatic neighbourhood (1950–2000) was mapped for 2020, 2050 and 2080. Analysing those shifts enabled us to delineate knowledge-transfer paths between sites, according to the analysed scenarios. We concluded that, according to the Intergovernmental Panel on Climate Change A2 scenario, all considered sites will be outside the predefined bioclimatic neighbourhood by 2080, while according to the B2 scenario all of them will be inside that neighbourhood, although sometimes marginally so. Therefore, the implementation of global sustainability measures as considered in the B2 scenario family can be of great importance in order to delay significantly the impacts of climate change, giving extra time for the adaptation of the outdoor regional living plant collectionsinfo:eu-repo/semantics/publishedVersio

Habitat specificity of a threatened and endemic cliff-dwelling halophyte

Research ArticleCoastal areas and other saline environments are major contributors to regional and global biodiversity patterns. In these environments, rapidly changing gradients require highly specialized plants like halophytes. In European coastal cliff-tops, rocky and sandy seashores, and saltmarshes, typical halophytes from the genus Limonium are commonly found. Among them, the aneuploid tetraploid (2n ¼ 4x ¼ 35, 36, 37) Limonium multiflorum, endemic to the west coast of Portugal, is an interesting case study for investigating the ecology and conservation of a halophyte agamospermic species. Although it is listed in the IUCN red list of threatened species, information on its population size or rarity, as well as its ecology, in some respects is still unknown. Field surveys in the largest known population were performed (Raso cape, Portugal) in order to determine habitat requirements and conservation status. A total of 88 quadrats were monitored, 43 of which contained at least one L. multiflorum individual. For each sampled quadrat, four abiotic and four biotic variables as well as two spatially derived variables were recorded. Principal component analysis and cluster analysis showed narrow habitat specificity for this species which appeared to be intolerant to competition with invasive alien plants. We conclude that in situ conservation in a local ‘hotspot’ of this rare and vulnerable species emerges as a priority in order to ensure that biodiversity is not los