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1.
《Ecological Indicators》2005,5(3):253-266
Benthic macroinvertebrates, macroalgae and phytoplankton constitute the biological quality elements proposed in the Water Framework Directive (WFD, 2000/60/EC) to be used for the classification of the ecological status of a water body. In the context of the preparation for the implementation of WFD, classification schemes for all three elements have been developed and tested for all the European ecoregions. In the present work, the classification schemes, with the corresponding metric tools and the interpretations of the class boundaries according to the normative definitions of WFD, are presented for each biological element in Saronikos Gulf, as case study in the Mediterranean ecoregion. The combination of the three biological elements into an integrated classification for coastal water bodies has been one of the major issues addressed in the context of WFD guidelines. Results are interpreted and validated, through an ecological viewpoint, on the basis of relevant environmental data. Moreover, this work presents a way to combine the EUNIS system to the typology of water bodies in the Mediterranean ecoregion.  相似文献   

2.
Analysis of biogeographic affinities is a key tool to establish and improve the resolution of hierarchical biogeographic systems. We describe patterns of species richness of the marine macroalgal flora across Lusitanian Macaronesia (Azores, Madeira, the Salvage Islands and the Canary Islands), and test (i) whether such differences are related to differences in proximity to the nearest continental shore and size among islands. We also explore biogeographic affinities in the composition of macroalgal assemblages (= presence/absence of each taxon in multivariate datasets) to determine (ii) whether each archipelago is a biogeographic unit within this ecoregion and (iii) whether patterns in assemblage composition are related to proximity (i.e. distances) among islands. Presence/absence matrices were created to test and visualize multivariate affinities among archipelagos. A total of 872 taxa were compiled. Species richness peaked at the Canary Islands and decreased towards the Azores; the pattern matched a progressive increase in distance from the nearest continental shores, matching the classical island biogeography theory. Intra-archipelago differences in species richness were largely related to variations in island size. Biogeographic similarities among archipelagos were hierarchically structured. Madeira and the Salvage Islands constituted one biogeographic unit. Floras from the Azores, Madeira and the Salvage Islands were barely separable from each other, but were different from those at the Canary Islands. Such biogeographic similarities among islands were negatively correlated with the geographical separation (i.e. distances) among them. Proximity to nearby continental shores, in conjunction with large- and meso-scale oceanographic patterns, seems to interact to create patterns in richness and composition of algal assemblages across Lusitanian Macaronesia.  相似文献   

3.
刘星才  徐宗学  张淑荣  徐华山 《生态学报》2012,32(11):3613-3620
指标体系构建是流域水生态分区技术框架中的一项重要内容。目前提出的指标体系尚缺乏一定的科学理论支持,如所选指标的生态尺度与各级分区大小之间的对应关系。生态学研究认为,不同尺度上的生态过程和格局不同。以辽河流域为例,对影响水生态系统的几个大尺度环境要素(降水、地形和植被)的空间尺度特征进行分析,得出了各要素空间变异最为显著的尺度。其中,降水的空间尺度约为75 km,地形要素和指标均大致存在16 km、32 km、64 km和128 km多个景观特征尺度。在界定水生态一、二级分区范围基础上,讨论了各环境要素作为水生态一、二级分区指标的适用性,以期为辽河流域水生态分区指标选取提供一定科学依据,同时希望能为其他流域提供一定参考。  相似文献   

4.
The study of phylogeographical patterns may contribute to a better understanding of factors affecting the dispersal of organisms in ecological and historical times. For intertidal organisms, islands are particularly suitable models allowing the test of predictions related to the efficacy of pelagic larvae dispersal. Here, we study the phylogeographical patterns and gene flow within three groups of species of the genus Patella present in the Macaronesian Islands that have been previously shown to be monophyletic. The genetic variability of around 600 bp of the mitochondrial gene cytochrome c oxidase subunit I was studied by single strand conformation polymorphism and/or sequencing for seven species of limpets. A total of 420 samples were analysed from the Macaronesian archipelagos, North Africa, and Atlantic and Mediterranean shores of the Iberian Peninsula. No clear geographical pattern or temporal congruence was found between the three groups of species, pointing to independent histories and colonization events. However, for the three groups, the split between the Macaronesian and the mainland forms most probably occurred before 3.9 million years ago, predating the establishment of the current circulation patterns. The presence of pelagic larvae in these species is shown to be insufficient to ensure gene flow between continental and Macaronesian populations and between the Macaronesian archipelagos. In the endangered Azorean populations of Patella candei, there is restricted gene flow to Flores and Graciosa.  相似文献   

5.
Aquatic ecosystems are experiencing increasing disturbance from multiple stressors caused by anthropogenic activities. The potential for multiple stressors to modify each others’ impacts is not well understood. Legislation such as the EU Water Framework Directive (WFD) requires the development of tools to assess human impacts in aquatic systems that incorporate ecological elements, such as macroinvertebrates. Nutrient enrichment and invasive species are major threats to freshwater systems. The invasive zebra mussel Dreissena polymorpha is a conspicuous invader in freshwater aquatic systems in Europe and North America, and has been linked to drastic changes in macroinvertebrate communities and lake ecology. In 31 lake sites varying in nutrient pressure and in the presence or absence of D. polymorpha we tested three ecological quality assessment tools based on macroinvertebrate assemblages (% Sensitive Taxa to Total Phosphorus (TP), TP Score and Indicator Taxa Metric) and two basic ecological metrics. There were highly significant changes in macroinvertebrate diversity, structure, and composition associated with the invasion by D. polymorpha. While the three metrics performed consistently well in non-invaded systems, they lost explanatory power for eutrophication pressure in invaded systems. Our results suggest that metrics may need to be developed separately for invaded and non-invaded systems, and that the interaction between alien species and nutrient enrichment requires further investigation.  相似文献   

6.
Islands offer an interesting framework in which to study the effect of geographical isolation on population genetic differentiation. For plant species with high dispersal abilities, however, oceanic barriers may not represent a factor promoting strong population structure. In this work, we analysed seven nuclear microsatellite loci in Ilex (Aquifoliaceae), a bird‐dispersed plant group, to infer patterns of genetic differentiation among Macaronesian taxa: I. canariensis, I. perado ssp. lopezlilloi, I. perado ssp. platyphylla (Canary Islands) and I. perado ssp. azorica (Azores). In agreement with current taxonomic classification, our results revealed a high genetic differentiation between Ilex lineages (I. canariensis and the I. perado complex), and also supported previous hypotheses that these are the result of independent dispersal events to the islands. In contrast, genetic differentiation between I. perado ssp. azorica and the two subspecies from the Canaries was high, suggesting that taxonomic revision may be necessary. Levels of genetic variation at microsatellite loci in ssp. azorica were, in addition, the lowest reported among Macaronesian bird‐dispersed taxa. Lastly, low genetic differentiation was observed between subspecies occurring on the same island (sspp. platyphylla and lopezlilloi). In summary, our results revealed contrasting patterns between Macaronesian Ilex lineages: I. canariensis displayed moderate population structure across islands, whereas the I. perado complex showed strong differentiation among populations sampled on different islands. Thus, the Macaronesian Ilex taxa show that long‐distance dispersal syndromes (ornithochory) do not always ensure genetic connectivity across large areas in island systems. Plant groups that successfully colonized the islands on multiple occasions may have found barriers to gene flow within certain lineages. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173 , 258–268.  相似文献   

7.
Aim We used a phylogenetic framework to examine island colonization and predictions pertaining to differentiation within Macaronesian Tarphius (Insecta, Coleoptera, Zopheridae), and explain the paucity of endemics in the Azores compared with other Macaronesian archipelagos. Specifically, we test whether low diversity in the Azores could be due to recent colonization (phylogenetic lineage youth), cryptic speciation (distinct phylogenetic entities within species) or the young geological age of the archipelago. Location Macaronesian archipelagos (Azores, Madeira and the Canary Islands), northern Portugal and Morocco. Methods Phylogenetic analyses of mitochondrial and nuclear genes of Tarphius beetles of the Azores, other Macaronesian islands and neighbouring continental areas were used to investigate the origin of island biodiversity and to compare patterns of colonization and differentiation. A comparative nucleotide substitution rate test was used to select the appropriate substitution rate to infer clade divergence times. Results Madeiran and Canarian Tarphius species were found to be more closely related to each other, while Azorean taxa grouped separately. Azorean taxa showed concordance between species and phylogenetic clades, except for species that occur on multiple islands, which segregated by island of origin. Divergence time estimates revealed that Azorean Tarphius are an old group and that the most recent intra‐island speciation event on Santa Maria, the oldest island, occurred between 3.7 and 6.1 Ma. Main conclusions Our phylogenetic approach provides new evidence to understand the impoverishment of Azorean endemics: (1) Tarphius have had a long evolutionary history within the Azores, which does not support the hypothesis of fewer radiation events due to recent colonization; (2) the current taxonomy of Azorean Tarphius does not reflect common ancestry and cryptic speciation is responsible for the underestimation of endemics; (3) intra‐island differentiation in the Azores was found only in the oldest island, supporting the idea that young geological age of the archipelago limits the number of endemics; and (4) the lack of evidence for recent intra‐island diversification in Santa Maria could also explain the paucity of Azorean endemics. Phylogenetic reconstructions of other species‐rich taxa that occur on multiple Macaronesian archipelagos will reveal whether our conclusions are taxon specific, or of a more general nature.  相似文献   

8.
Islands are often considered to be natural laboratories where repeated ‘evolutionary experiments’ have taken place. Consequently, islands have been key model systems in our understanding of evolutionary theory. The greater white‐toothed shrew (Crocidura russula) is of interest as it has invaded French Atlantic islands within the last few thousand years and is considered to be morphologically and genetically stable in this area. In this article, we study the shape of the mandible of the greater white‐toothed shrew on four islands and compare it with that of individuals from populations on the mainland to quantify the effects of insularity. The degree of insularity (i.e. island size and distance to the continent) is thought to be linked to differences in ecological characteristics of islands compared with the mainland. We used geometric morphometric analyses to quantify differences in size and shape between populations and employed a simple biomechanical model to evaluate the potential effects of shape differences on bite force. Specimens from island populations are different from continental populations in shape and mechanical potential of the mandible. Among islands, the mandible shows various shapes that are correlated with both the distance from the coast and island area. The shape differences are located on different parts of the mandible, suggesting different ecological constraints on each island. Moreover, these shapes are linked to the ‘mechanical potential’, which is markedly different between islands. Mechanical potential has been suggested to evolve in response to prey size and or mechanical properties. In conclusion, our results show that, in spite of the relatively recent colonization of the Atlantic Islands, the mandible of C. russula possesses a distinct shape. Moreover, the shape differs among islands and is probably linked to the consumption of different prey. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.  相似文献   

9.
The Madeiran endemic Echium nervosum W.T. Aiton is illustrated based on plants grown at the Royal Botanic Gardens, Kew. Its ecology; phylogenetic and taxonomic placement, and conservation status are discussed. Twenty‐nine species of Echium are endemic to the Macaronesian Islands and they represent one of the most spectacular and best known examples of adaptive radiation on oceanic islands.  相似文献   

10.
Aims Several bird‐pollinated or ornithophilous flowers are present on the Macaronesian archipelagos, the Canary Islands and Madeira, but absent from nearby NW Africa and Europe. In Macaronesia, no specialist nectar‐feeding birds are found, but several generalist passerine bird species visit flowers for nectar. Two hypotheses attempt to explain the origin and evolution of ornithophily in the Macaronesian flora. According to ‘the island de novo hypothesis’, bird‐flowers evolved from mainland insect‐pollinated ancestors after island colonization. Alternatively, ancestors of the ornithophilous Macaronesian plant species evolved bird‐flowers before reaching the islands (‘the relict hypothesis’). In this study we first compile information of Macaronesian bird–flower interactions from the literature and our own field observations. Secondly, we discuss the two hypotheses of origin of ornithophily in the light of evidence from recent molecular plant phylogenies, palaeontology, historical biogeography of the African avifauna and flora, and present‐day ecological patterns. Location Madeira and Canary Islands. Results At least eleven endemic Macaronesian plant species from six genera have typical ornithophilous floral traits. These genera are: Canarina and Musschia (Campanulaceae), Isoplexis (Scrophulariaceae), Echium (Boraginaceae), Lotus (Fabaceae) and Lavatera (Malvaceae). These lineages have clear affinities to the Mediterranean region, except for Canarina whose closest relatives grow in East African mountains. Six generalist passerine bird species of Sylvia, Phylloscopus (Sylviidae), Serinus (Fringillidae) and Parus (Paridae) visit this flora for nectar. Main conclusion We suggest that the origin and evolution of ornithophilous traits in these plant species took place mostly in mainland areas prior to island colonization. In Canarina and Lavatera, it is well supported that ornithophily is a relict condition, which originated in mainland areas possibly in association with specialist nectar‐feeding birds. For the remaining plant species except Echium wildpretii bird floral traits probably also are a relict condition. These species may be derived from ancestors, which were visited by specialist nectar‐feeding birds during geological periods when the Mediterranean and the Ethiopian vegetation were intermingled in mainland Africa. Probably, these mainland ancestors went extinct due to severe climatic fluctuations, while their Macaronesian descendants survived in ‘refuge’ on the islands. Finally, the island de novo hypothesis may explain the evolution of a mixed bird/insect‐pollination system in the neo‐endemic red‐flowered Echium wildpretii.  相似文献   

11.
Feral cats Felis catus Linnaeus, 1758 have contributed to the extinction of numerous native species on islands, which are clearly sources of global biodiversity. We studied the diet of this introduced predator in the Madeira and Cape Verde archipelagos, which harbour important colonies of endangered seabirds in the high mountain habitats, and compared the results with those obtained in the same habitat in the Canary Islands, Macaronesian archipelago. On Madeira, 461 prey were identified from 143 scat groups. Mammals, overall mice, constituted the basic diet appearing in 95% of cat scats. On Fogo (Cape Verde), 657 prey items were obtained from 145 scats, and mammals were also the most important prey, reaching a frequency of occurrence of 88%. Although introduced mammals were the main prey category on all Macaronesian islands, we observed variation in feral cat diet among these islands. Birds were more frequently consumed on Madeira, lizards on Tenerife (Canaries) and invertebrates on Fogo. No specific differences were observed in relation to La Palma. We suggest that the diet composition on these islands varies according to the respective availability of the different prey types.  相似文献   

12.
Genetic variation at 17 isozyme loci was used to assess divergence among the four genera comprising subtribe Chrysantheminae (Anthemideae: Asteraceae). The Macaronesian endemic genus Argyranthemum is supported as monophyletic and is about equally divergent at isozyme loci from the other three genera of the Chrysantheminae, Chrysanthemum, Heteranthemis, and Ismelia. Chrysanthemum is native to the Mediterranean whereas Heteranthemis occurs in southern Iberia and Morocco, and Ismelia is endemic to Morocco. The genera Chrysanthemum and Ismelia have a genetic identity of 0.9283, which is comparable to values often seen for congeneric species and indicates that they should be treated as one genus. The isozyme data indicate that three lines consisting of Argyranthemum, Chrysanthemum-Ismelia, and Heteranthemis radiated rapidly from a common ancestor. Divergence times estimated from isozyme data suggest that the initial radiation of the three lines occurred 2.5–3.0 mya. If this is so, then Argyranthemum or its ancestor arrived in Macaronesia after all the islands except La Palma and El Hierro were formed. The evolutionary history of the subtribe is discussed in relation to the climatic and geological events that took place in the Western Mediterranean between the Tertiary and Quaternary, i.e., the first Northern Hemisphere glaciation and desertification of the Sahara region. The high mean genetic identities between species of Argyranthemum suggest that it might have subsequently undergone a second more recent radiation in the Macaronesian Islands. Also, the high mean identity (0.860) between populations in Chrysanthemum and Ismelia suggest that these continental genera might be in the early stages of secondary speciation.  相似文献   

13.
In most cases the negative impacts of climate change to aquatic ecosystems cannot be mitigated by measures in the river basin management. Ignoring climate change by the Water Framework Directive may have strong implications for the typology and quality assessment systems used for water bodies. As a result of climate change, water bodies, especially those located near the type boundaries may change their type. Compared to typology characteristics, water quality parameters are even more labile and may be easily affected by climate change. The paper exemplifies that the anticipated deterioration of water quality within the time frame relevant for WFD implementation may be large enough to endanger the fulfillment of the set water quality objectives. The review of the river basin characterization every six years, as required by the WFD, might also include re-evaluation of reference conditions according to the changes observed at pristine reference sites. As a consequence, the restoration targets (i.e., the good ecological status) would also need to be evaluated periodically.  相似文献   

14.
Pollinators play an important role in the reproduction of zoophilous plants. A shift in pollinators has often been observed for oceanic island plants, probably because of the differences in fauna. In this study, we obtained data on pollinator shifts from insects to birds in Orobanche boninsimae (Orobanchaceae), a holoparasitic plant species endemic to the Bonin (Ogasawara) Islands, oceanic islands in the Pacific. We observed pollination and measured seed viability in O. boninsimae and its continental sister species O. coerulescens. We found that two passerine birds, the Japanese white-eye (Zosterops japonicus) and bulbul (Hypsipetes amaurotis squameiceps), visited the flowers and sucked the nectar of O. boninsimae, while only insects visited those of O. coerulescens. Viable seeds were produced under pollinator-excluded treatments in the two Orobanche species, indicating that the seeds were produced by automatic self-pollination and/or apomixis. These results suggest that O. boninsimae may be pollinated by birds and can produce seeds by automatic self-pollination/apomixis. This is the first record of visitation of the genus Orobanche by birds. Studies of pollination systems in native plants on the Bonin Islands are few compared to those on other oceanic islands, and O. boninsimae may provide a valuable example of pollinator shifts in the Bonin Islands.  相似文献   

15.
Species of the genus Meladema (Dytiscidae, Colymbetinae) are some of the largest macroinvertebrates in the western Palearctic region, being top predators in fishless streams. Two of the three described species, Meladema imbricata (Wollaston, 1871) and Meladema lanio (Fabricius, 1775) are Macaronesian endemics from the Canary Islands and Madeira, respectively, while the third, Meladema coriacea Laporte, 1835, is widely distributed from Morocco and the Iberian Peninsula to Turkey, including the Canary Islands. Previous phylogenetic analysis using only mitochondrial markers revealed the existence of two cryptic lineages within M. coriacea, one restricted to Corsica and the other including the rest of sampled populations. We reconstruct here the evolutionary history of the species of Meladema using a more comprehensive sampling covering its whole geographical range, adding nuclear markers and Bayesian molecular dating. Using environmental niche modelling, we test for possible differences in climatic preferences among lineages and reconstruct their ancestral climatic niche. Our results strongly supported the existence of four monophyletic lineages represented by the three recognized species plus a fourth cryptic lineage with populations of M. coriacea from the Tyrrhenian islands (Corsica, Sardinia and Montecristo). This pattern is not likely to be the result of mitochondrial artefacts due to Wolbachia infection, as all 11 tested individuals were negative for this parasite. Dating analysis placed the origin of Meladema in the Middle Miocene although diversification among extant Meladema lineages started in the early Pleistocene and took place in a relatively short time period. Phylogeographic analysis inferred a continental origin of Meladema, with an independent colonization of the Macaronesian and Mediterranean islands. From the south‐western Mediterranean region, the continental M. coriacea expanded its range up to Bulgaria and Turkey in the northern basin and to Tunisia in the southern. Results of niche modelling showed that seasonality is the critical factor in shaping the current distribution of Meladema. Island lineages (M. imbricata, M. lanio and the Tyrrhenian lineage of M. coriacea) occur in sites with low seasonality, within the range of the reconstructed ancestral climatic niche of the genus. On the contrary, continental M. coriacea expanded its range to localities outside the ancestral climatic range of the genus, with a higher seasonality and aridity.  相似文献   

16.
The swallowtail butterfly Papilio machaon Linnaeus, 1758 is widely distributed in the Holarctic region, including all of the main islands of Japan, as well as Sakhalin, and on other smaller islands south to Yakushima Island. The Japanese population is situated at the margin of the Eurasian distribution range of this species. It is morphologically different from other populations and has been classified as the subspecies hippocrates C. & R. Felder, 1864. The population of the Japanese Islands is considered to be genetically distinct from the continental populations in relation to the geographical history of the Japanese Islands. Therefore, we examined a part of the ND5 gene sequence of the mitochondrial DNA for P. machaon individuals of various localities in Japan and some nearby countries, and found 68 haplotypes in 400 individuals from the Japanese Islands and Sakhalin. A DNA polymorphism analysis revealed that the genetic structure of the Hokkaido population was significantly different from that of the southern populations on the main Japanese islands. These results imply that P. machaon expanded its range from the Amur region of Russia southward through Sakhalin to the Japanese Islands, and that the Tsugaru Strait between Hokkaido and Honshu may have subsequently limited their gene flow as a geographical barrier.  相似文献   

17.
Aim The aim of this paper is to identify the patterns in the morphological differentiation in Canary Island mice, based on fossil and modern samples. In order to achieve this, the mouse species present on the archipelago were first compared with a set of continental mice. The differences between the continental and Canary Island samples, and among the Canary Island samples, provide insights into the processes of colonization and the subsequent insular evolution. Location Canary archipelago. Methods An outline analysis based on Fourier transformation was used to quantify shape differences between lower molars. Together with the fossil and modern Canary Island samples, a reference set of genotyped continental populations of the commensal Mus musculus and the wild Mus spretus was used for comparison. Results The morphometric analysis showed that all the mouse specimens from the Canary Islands and Cape Verde belonged to Mus musculus domesticus. Lower molars of extant mice from La Gomera, El Hierro, Gran Canaria, Tenerife, and to a lesser degree from Lanzarote, were similar to those of genotyped M. m. domesticus from the continent, while teeth of extant mice from Fuerteventura were more divergent. Fossil mice from Fuerteventura were very similar to the extant representatives on this island, and similar to the fossil mice on the nearby islands of Lobos and La Graciosa. Main conclusions The mouse present on the Canary archipelago has been identified as the house mouse M. m. domesticus. Based on the shape of the lower molar, the Canary Island mice are divergent from the continental ones, but the degree of divergence varies with the geography of the archipelago. Overall, populations from eastern islands are more divergent from the continental mice than populations from western ones. Fossil populations indicate that this situation was established several centuries ago. Two main factors may have contributed to this pattern: the appearance of different types of environment on the islands since the successful settlement of the mouse, and/or the number of subsequent introductions of continental individuals via shipping.  相似文献   

18.
Sideritis L. (Lamiaceae) comprises approximately 150 species of annuals and perennials distributed chiefly in the Mediterranean region. The majority of the species belong to the continental subgenus Sideritis which is divided into two perennial (Sideritis and Empedoclea) and two annual (Hesiodia and Burgsdorfia) sections. Twenty-three species are woody perennials endemic to the Macaronesian archipelagos of Madeira and the Canary Islands. In an effort to determine the continental origin of the insular group, we constructed independent phylogenies comprising sequence data from both chloroplast and nuclear markers. Sampling included 7 island taxa drawn from the Macaronesian subgenus Marrubiastrum and 25 continental taxa representing all four sections of subgenus Sideritis. Subgenus Marrubiastrum and the two continental perennial sections form well-supported monophyletic groups in both individual and combined analyses. The annual sections are not monophyletic in any analysis; further sampling of annual taxa is needed to resolve these relationships. All analyses identified Sideritis cossoniana, an annual species from Morocco, as the closest continental relative of the Macaronesian group. This contrasts with the hypothesis of earlier workers who suggested that the insular taxa were most closely related to eastern Mediterranean species of the genus. The phylogenies also demonstrate a distinct increase in woodiness among the Macaronesian species relative to their continental congeners, providing further support for the secondary nature of woodiness in island plants.  相似文献   

19.
In order to emphasize the importance of vegetation mapping for nature conservation purposes a case study in Terceira island (Azores) is presented, in which the importance of the natural vegetation of the eastern slope of Santa Bárbara volcano (which is part of the Site of Community Importance of Santa Bárbara–Pico Alto) is evaluated through the elaboration of its vegetation map. Fourteen (14) different natural vegetation types were identified: grasslands (1 type), peat bogs (2 types), scrubs (2), forests (5), successional vegetation (3) and vegetation of rocky slopes (1). All communities are protected under the Habitat and Species Directive (EC/92/43) and most of them are endemic to the Azores Islands. This fact, together with the significant number of Azorean endemic taxa (18), Macaronesian endemic taxa (5) and species protected under the Habitat and Species Directive (7), gives this area an important conservation value that justifies future protection actions. Vegetation mapping is an important tool for the characterization, evaluation and implementation of managing plans of natural areas of the Azores islands. The use of a floristic-based classification, supported by multivariate analysis and structural data, is an efficient methodology for the construction of these maps. The data collected comprise an important set of information about the distribution and abundance of natural vegetation types and endemic and rare species. This information was not available until now and is indispensable for the elaboration of management plans of Special Zones for Conservation that will be part of the NATURA 2000 network.  相似文献   

20.
Despite improvements in wastewater treatment systems, the impact of anthropogenic nutrient sources remains a key issue for the management of European lakes. The Water Framework Directive (WFD) provides a mechanism through which progress can be made on this issue. The Directive requires a classification of the ecological status of phytoplankton, which includes an assessment of taxonomic composition. In this paper, we present a composition metric, the plankton trophic index, that was developed in the WISER EU FP7 project and demonstrate how it has been used to compare national phytoplankton classification systems in Northern and Central Europe. The metric was derived from summer phytoplankton data summarised by genus from 1,795 lakes, covering 20 European countries. We show that it is significantly related to total phosphorus concentrations, but that it is also sensitive to alkalinity, lake size and climatic variables. Through the use of country-specific reference values for the index, we demonstrate that it is significantly related to other national phytoplankton assessment systems and illustrate for a single European (intercalibration) lake type how it was used to intercalibrate WFD boundaries from different countries.  相似文献   

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