Mediterranean Ecoregion Research Articles

Cell biovolume and surface area in phytoplankton of Mediterranean transitional water ecosystems: methodological aspects

1 - A series of experimental researches highlighted the role of morphometric parameters of phytoplankton guilds as descriptors of the ecological status of transitional water ecosystems (TWs). 2 - However, at present, standardized or common methodologies for their use do not exist. In this work, we develop a procedure for the determination of biovolume and surface area in phytoplankton guilds of Mediterranean TWs. 3 - Phytoplankton biovolume and surface area are included among the most studied morphometric descriptors. They can be estimated by associating the algae with similar geometric forms and determining the volume of these by measuring the linear dimensions required for its calculation under the light microscope. 4 - Here, a set of geometric models is suggested for calculating the cell biovolumes and surface area of 235 phytoplankton genera, deriving from the analysis of 869 phytoplankton species, found in transitional water ecosystems of the Mediterranean Ecoregion. The equations were designed to minimize the effort of microscopic measurements. 5 - The similarities and differences between the geometric models here proposed and previously published are discussed.

Climate and landscape drivers of tree decline in a Mediterranean ecoregion

Climate change and anthropogenic land use are increasingly affecting the resilience of natural ecosystems. In Mediterranean ecoregions, forests and woodlands have shown progressive declines in health. This study focuses on the decline of an endemic woodland tree species, Eucalyptus wandoo (wandoo), occurring in the biodiversity hotspot of southwest Western Australia. We determined the change in health of wandoo stands between 2002 and 2008 across its geographic and climatic range, and associated this change in health with non-biotic variables focusing on: (1) fragment metrics; (2) topography; (3) soil characteristics; and (4) climate. Only fragment metrics and climate variables were found to be significantly related to the observed change in health. Stands that were small with high perimeter/area ratios were found to be most sensitive to health declines. Recent increases in autumn temperatures and decreases in annual rainfall were negatively affecting health of wandoo most prominently in the low rainfall zone of its climatic range. Together, these results suggest the onset of range contraction for this ecologically important species, which is likely to be exacerbated by projected future changes in climate. Our results emphasize the importance of establishing monitoring programs to identify changes in health and decline trends early to inform management strategies, particularly in the sensitive Mediterranean ecoregions.

Benthic diatom assemblages and their response to human stress in small-sized volcanic-siliceous streams of central Italy (Mediterranean eco-region)

The river typology ‘volcanic rivers’ represents a unique typology in the Mediterranean eco-region in Europe but its type-specific diatom assemblages are still poorly investigated. The main aims of this study were (i) to analyse the diatom diversity of this river type, (ii) to investigate the relationships between diatom diversity and environmental variables and (iii) to identify the characterizing diatom community structure of different environmental groups. To this end, we selected 13 streams located in central Italy, belonging to a single river type and covering the whole quality range from human impacted sites to those in ‘reference conditions’. Most frequent and abundant diatom species found were Cocconeis placentula var. lineata, Planothidium lanceolatum, Rhoicosphenia abbreviata and Amphora pediculus. Species richness in reference and less impacted sites was not higher than in intermediate and heavily degraded ones, but non-metric multidimensional scaling (N-MDS) analysis revealed a substantial difference among their diatom community structure. The indicator species analysis defined the characteristic species of three environmental groups identified by N-MDS. The findings of this study represent a contribution to the knowledge on diatom communities of Mediterranean volcanic-siliceous rivers and provide information for a data-driven implementation of the Water Framework Directive in Italy for this specific river typology.

A comparison of macroinvertebrate and diatom responses to anthropogenic stress in small sized volcanic siliceous streams of Central Italy (Mediterranean Ecoregion)

The European Water Framework Directive (WFD 2000/60/CE) requires the use of different biological indicators, supporting physicochemical and hydromorphological elements, in the assessment of the ecological status of rivers: in each member state rivers should be at least in a good condition (or good ecological potential if heavily modified) by 2015, and those failing this criterion should be restored. Given that the need for restoration is primarily based on the results from ecological classifications, precision of these classifications is essential.The present study analyzed the relationships of two different biological communities (diatom and macroinvertebrate) when they are used to characterize a set of sites (from reference sites to human-impacted sites) within a single stream type (Mediterranean small sized volcanic-siliceous streams). In particular, we examine the issue of concordance among these communities and the anthropogenic stressors detected, using both multivariate and multimetric approach.Mantel test based on Bray–Curtis distance showed that assemblage dissimilarity between diatom and macroinvertebrate was weakly correlated, dissuading the use of one taxa group as surrogate of the other. The two biological indicators similarly reflected the overall river integrity, but provided complementary information on the specific stressors. Particularly, in accordance to previous studies, our results show that macroinvertebrate assemblage was influenced by water quality (nutrients enrichment and organic pollution) and habitat degradation. On the other hand, same as for benthos, diatom assemblage was regulated by chemical factors (especially nutrients), while did not show strong responses to morphological degradations.In addition, the ecological status of volcanic streams was evaluated by means of the two Intercalibration Common Metrics Indices (ICMi), based, respectively, on macroinvertebrate and diatom communities. The two ICM indices, developed for the Italian biomonitoring program (sensu WFD), were strongly correlated and provided a final classification mainly related to the water quality (nutrient enrichment and organic pollution). However, both indices were less sensitive to the hydromorphological alterations, highlighting the need for the development of stressor specific indices to achieve a complete evaluation of the anthropogenic stress present in the area. Studies of this kind across different disturbance gradients and focused on a particular river type (e.g. Mediterranean small-size volcanic-siliceous streams), will enable the relative merits of the indicators to become apparent and greatly facilitate their appropriate application.

An invertebrate multimetric index to classify the ecological status of small coastal lagoons in the Mediterranean ecoregion (MIBIIN)

Despite the requirements of the European Water Framework Directive (WFD) to protect water bodies, suitable indices of quality designed specifically to assess coastal lagoons (transitional waters) remain absent. In the present study, we developed a multimetric index of the Balearic Island based on invertebrate communities (MIBIIN) to assess the ecological status of small coastal lagoons (i.e. up to 4-m depth and <2.5 km2), a common ecosystem within the Mediterranean ecoregion. Thirty-four coastal lagoons were sampled on six occasions between 2005 and 2008. A multimetric index for each salinity type of coastal lagoon (oligohaline-MIBIIN, mesohaline-MIBIIN and euhaline-MIBIIN) was developed. The individual metrics, and hence the MIBIINs, fulfilled the normative definitions established by the WFD (abundance, diversity and sensitive : tolerance ratio), responded to gradients of disturbance and discriminated reference from non-reference sites. Common boundary limits for the three MIBIINs were established (high/good = 0.930, good/moderate = 0.730, moderate/poor = 0.500, poor/bad = 0.250). Unlike other metrics used in coastal lagoon evaluation, the MIBIINs were developed exclusively for coastal lagoons, including oligohaline freshwater environments. Although the MIBIIN is yet to be validated with an external dataset, these findings suggest the potential for this new multimetric index to be used in similar systems in the Mediterranean ecoregion.

Cumulative annual dung beetle diversity in Mediterranean seasonal environments

Species diversity assessments should consider the dynamic nature of ecological communities, especially in highly seasonal ecosystems. Here we provide a compre- hensive framework for analysing seasonal changes in species composition, richness and diversity in two local dung beetle (Coleoptera: Scarabaeoidea: Aphodiidae, Geotrupidae, and Scarabaeidae) communities from Wes- tern Tuscany (Italy), in the Mediterranean ecoregion. We test whether, in this highly seasonal region, cumulative annual diversity is an oversimplification of well differen- tiated seasonal communities. Data were obtained through repeated standardised samples collected regularly over an entire year. We clearly identify different summer and winter communities at each site based on species compo- sition and abundance. Seasonal richness and diversity values are different from the cumulative annual values, as a consequence of beta diversity between seasons, and some dung beetle species are identified as idiosyncratic of each particular season. Both ecological (niche partition- ing) and biogeographical factors are suggested as drivers of these temporal variations. Thus, because local inven- tories of fauna that include records over long time periods actually reflect situations where coexistence and interac- tions are unlikely to occur, highly seasonal sites must be viewed as having temporally differentiated communities in order to reach feasible and reliable baselines for local diversity assessments.

Assessing lake typologies and indicator fish species for Italian natural lakes using past fish richness and assemblages

In order to establish a fish-based typology of Italian lakes and identify possible reference and indicator fish species for each lake type, we analysed historical data on fish assemblages of all Italian natural lakes >0.5 km2 from the period prior to the major decline in water quality in the 1950s. General linear regression models showed the ecoregion and lake altitude being the best predictors of fish species richness. The number of species was significantly higher in the Alpine than in the Mediterranean ecoregion. Among Alpine lakes, the number of fish species increased significantly with lake volume whilst decreased with altitude. In the Mediterranean lakes, none of the selected parameters was significant. Cluster analysis of fish assemblages (presence/absence) divided the lakes of the Alpine and Mediterranean ecoregions into four and two types, respectively. Pike (Esox lucius), rudd (Scardinius erythrophthalmus) and tench (Tinca tinca) were the main indicator species for the small and mostly shallow lakes in both the Alpine (Type 1) and Mediterranean (Type 6) ecoregions, minnow (Phoxinus phoxinus) for the alpine high altitude lakes (Type 2) and landlocked shad (Alosa fallax lacustris), European whitefish (Coregonus lavaretus) and burbot (Lota lota) for the large and very deep alpine lakes (Type 4). The European whitefish was the only indicator species for the deep Mediterranean lakes (Type 5). These species and associated fish assemblages may be useful indicators in future assessments of the ecological status of Italian lakes according to the European Directives (2000/60/EC and 2008/105/EC).

Macroinvertebrate assemblages at mesohabitat scale in small sized volcanic siliceous streams of Central Italy (Mediterranean Ecoregion)

According to the guidelines of the European Water Framework Directive, assessment of the ecological quality of streams and rivers should be based on type-specific reference conditions. Moreover to support biological indicators an hydromorphological analysis is also requested for each river type. The rationale for including an habitat assessment in biomonitoring study is that a biological community can be influenced by habitat quality just as water chemistry. In the present work benthic macroinvertebrates were analysed in a specific river type of Central Italy (small-sized streams, volcanic-siliceous), to identify taxa assemblages at the mesohabitat scale and to test how common measures of benthic community used in biomonitoring differ between riffles and pools in order to evaluate if differences may influence water quality classification. Macroinvertebrates were collected in 10 selected streams, covering the whole quality range present in the geographic area from ‘reference sites’ to human-impacted sites, along a pool–riffle sequence following a multihabitat sampling protocol. We compared assemblage of macroinvertebrates found in different mesohabitats using principal component analysis (PCA). Similar site grouping was obtained in riffle, pool and abiotic analysis. The measures of diversity and abundance were used as replicates in ANOVA analysis to test differences between pools and riffles within the groups of sites. There were no significant differences in terms of taxa richness and total abundance. When we compared the abundance of each taxon we found significant differences only in the group of reference sites with 18 taxa (about 25%) that showed a significant habitat preference. Our findings support that macroinvertebrates assemblages reflected primarily the environmental conditions and differences at mesohabitat scale are strongly correlated to hydromorphological condition and are maximized in reference sites. However such differences do not influence the ecological status assessment in this typology.

The Bats of Latium : Past and Present

After briefly reviewing past research, the present status of our knowledge on the bats of Latium, Central Italy, one of the richest biodiversity districts of the Central Mediterranean Ecoregion, is outlined, highlighting the contribution of Benedetto Lanza.

DEADWOOD IN FOREST STANDS CLOSE TO OLD-GROWTHNESS UNDER MEDITERRANEAN CONDITIONS IN THE ITALIAN PENINSULA

Considering that indicators of old-growth features can vary across the European ecoregions, this paper provides some results to identify the distinctive traits of old-growth forests in the Mediterranean ecoregion. Deadwood occurrence as indicator of naturalness is investigated in some remote forest areas that have developed in absence of anthropogenic disturbance over the past few decades. Eleven study sites across the Italian peninsula were selected and records of deadwood were carried out in 1-ha size plots. Deadwood volume, deadwood types and decay stages were inventoried in the selected sites. The amounts of deadwood indicate a large variability among the investigated forest stands: the total volume ranged between 2 and 143 m3ha-1, with an average of 60 m3ha-1. Lying deadwood is the most abundant component of deadwood in the investigated forests, due to the natural mortality occurring in the stands in relation to the processes established in the last decades. On the contrary, stumps are the less represented type of deadwood in almost all the study areas. All the decay classes are present in each study site. The amount of deadwood in Southern Europe, even if lower than that reported for North and Central European countries, could have a different meaning due to the faster decay occurring in Mediterranean forest ecosystems. For this reason, old-growth features and the characteristics of each indicator should be framed and referred to well-defined climatic andbiogeographic contexts. Distinctively, under the conditions here investigated, three main deadwood features prove to characterize forest stands close to old-growthness: a ratio of dead to living wood not lower than 10%; lying deadwood much more abundant than the standing one; large range of deadwood size and decay classes across all the deadwood components.

Global assessment of nitrogen deposition effects on terrestrial plant diversity: a synthesis

Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to tropical forests. Current thinking on the mechanisms of N deposition effects on plant diversity, the global distribution of G200 ecoregions, and current and future (2030) estimates of atmospheric N-deposition rates are then used to identify the risks to plant diversity in all major ecosystem types now and in the future. This synthesis paper clearly shows that N accumulation is the main driver of changes to species composition across the whole range of different ecosystem types by driving the competitive interactions that lead to composition change and/or making conditions unfavorable for some species. Other effects such as direct toxicity of nitrogen gases and aerosols, long-term negative effects of increased ammonium and ammonia availability, soil-mediated effects of acidification, and secondary stress and disturbance are more ecosystem- and site-specific and often play a supporting role. N deposition effects in mediterranean ecosystems have now been identified, leading to a first estimate of an effect threshold. Importantly, ecosystems thought of as not N limited, such as tropical and subtropical systems, may be more vulnerable in the regeneration phase, in situations where heterogeneity in N availability is reduced by atmospheric N deposition, on sandy soils, or in montane areas. Critical loads are effect thresholds for N deposition, and the critical load concept has helped European governments make progress toward reducing N loads on sensitive ecosystems. More needs to be done in Europe and North America, especially for the more sensitive ecosystem types, including several ecosystems of high conservation importance. The results of this assessment show that the vulnerable regions outside Europe and North America which have not received enough attention are ecoregions in eastern and southern Asia (China, India), an important part of the mediterranean ecoregion (California, southern Europe), and in the coming decades several subtropical and tropical parts of Latin America and Africa. Reductions in plant diversity by increased atmospheric N deposition may be more widespread than first thought, and more targeted studies are required in low background areas, especially in the G200 ecoregions.

Intercomparison, interpretation, and assessment of spring phenology in North America estimated from remote sensing for 1982–2006

AbstractShifts in the timing of spring phenology are a central feature of global change research. Long‐term observations of plant phenology have been used to track vegetation responses to climate variability but are often limited to particular species and locations and may not represent synoptic patterns. Satellite remote sensing is instead used for continental to global monitoring. Although numerous methods exist to extract phenological timing, in particular start‐of‐spring (SOS), from time series of reflectance data, a comprehensive intercomparison and interpretation of SOS methods has not been conducted. Here, we assess 10 SOS methods for North America between 1982 and 2006. The techniques include consistent inputs from the 8 km Global Inventory Modeling and Mapping Studies Advanced Very High Resolution Radiometer NDVIg dataset, independent data for snow cover, soil thaw, lake ice dynamics, spring streamflow timing, over 16 000 individual measurements of ground‐based phenology, and two temperature‐driven models of spring phenology. Compared with an ensemble of the 10 SOS methods, we found that individual methods differed in average day‐of‐year estimates by ±60 days and in standard deviation by ±20 days. The ability of the satellite methods to retrieve SOS estimates was highest in northern latitudes and lowest in arid, tropical, and Mediterranean ecoregions. The ordinal rank of SOS methods varied geographically, as did the relationships between SOS estimates and the cryospheric/hydrologic metrics. Compared with ground observations, SOS estimates were more related to the first leaf and first flowers expanding phenological stages. We found no evidence for time trends in spring arrival from ground‐ or model‐based data; using an ensemble estimate from two methods that were more closely related to ground observations than other methods, SOS trends could be detected for only 12% of North America and were divided between trends towards both earlier and later spring.

Freshwater diatom and macroinvertebrate diversity of coastal permanent ponds along a gradient of human impact in a Mediterranean eco-region

Mediterranean coastal areas are characterised by heavily transformed landscapes and an ever-increasing number of ponds are subjected to strong alterations. Although benthic diatoms and macroinvertebrates are widely used as indicators in freshwater ecosystems, little is still known about the diatom communities of lowland freshwater ponds in the Mediterranean region, and, furthermore, there are few macroinvertebrate-based methods to assess their ecological quality, especially in Italy. This article undertakes an analysis of benthic diatom and macroinvertebrate communities of permanent freshwater ponds, selected along a gradient of anthropogenic pressures, to identify community indicators (taxa and/or metrics) useful to evaluate the effect of human impacts. A series of 21 ponds were sampled along Tyrrhenian coast in central Italy. Five of these ponds, in a good conservations status and surrounded by woodland were selected as ‘reference sites’ for macroinvertebrates and epipelic diatoms. The remaining sixteen ponds were located in an agricultural landscape subject to different levels of human impact. The total number of macroinvertebrate taxa found in each pond was significantly higher in reference sites than in both the intermediate and heavily degraded ones, whereas the diatom species richness did not result in a good community variable to evaluate the pond ecological quality. The analysis revealed a substantial difference among the compositions of diatom communities between reference ponds and degraded ponds. The former were characterised by the presence of several species belonging to genera, such as Pinnularia sp., Eunotia sp., Stauroneis sp., Neidium sp., all of which were mostly absent from degraded ponds. Furthermore, the taxonomic richnesses of some macroinvetebrate groups (Odonata, Ephemeroptera, Trichoptera, Coleoptera), and taxa composition attributes of macroinvertebrate communities (total abundance, percentages of top three dominant taxa, percentages of Pleidae, Ancylidae, Hirudinea, Hydracarina) significantly correlated with variables linked with anthropogenic pressures. The results of the investigation suggested that diatoms tended more to reflect water chemistry through changes in community structure, whereas invertebrates responded to physical habitat changes primarily through changes in taxonomic richness. The methodologies developed for the analysis of freshwater benthic diatom and macroinvertebrate communities may have a considerable potential as a tool for assessing the ecological status of this type of water body, complying with the European Union Water Framework Directive 2000/60/EC.

Development of a typology for transitional waters in the Mediterranean ecoregion: The case of the islands

The European Water Framework Directive (WFD, 60EC, 2000) requires that a typology be developed at national and European level for the differentiation of ecologically distinct types within water categories. Although common typological descriptors have been defined for stream, lake and coastal areas, a typology for transitional waters has not yet been defined, and its implementation by the European countries is still under development. A set of 30 coastal lagoons from the Balearic archipelago were selected to act as case studies for the application of the WFD in the Mediterranean ecoregion. Within these systems, and according to normative definitions, we studied both biological (i.e., invertebrate and phytoplankton communities) and physico-chemical quality elements. Our objective is to propose an adequate typology for small Mediterranean coastal lagoons and to establish those criteria that, based on human pressures in the neighbouring perimeters, may allow the establishment of type-specific reference conditions. The salinity range was the only factor that enables to differentiate, in a first phase of application, ecologically relevant typologies in the studied Mediterranean islands. Other descriptors, such as tidal range and geographic localisation of the studied area had scarce relevance. The analysis of the data suggests a three-level typology for the Mediterranean coastal lagoons: oligohaline (up to 5 of salinity); mesohaline (6–26) and euhaline (>26). A total of 6 out of the 30 studied lagoons fulfil the reference criteria, covering the three salinity types proposed. The invertebrate communities showed a consistent agreement with the proposed typology, while the phytoplankton did not. Moreover, the inherent variation in the biological communities across salinity types was higher than that obtained when a subtypology based on the annual salinity range of each lagoon was applied. These results support the need for further research on the ecology of small coastal lagoons, focused on the applied aspects addressing scientific and technical implementation of WFD at the national and European levels.

A conceptual model for assessing risks in a Mediterranean Natura 2000 Network site

Every year millions of tons of chemical products are disposed to the environment as a result of human activities, with deleterious consequences to biodiversity. In Europe the biodiversity policy basis for action is provided by the Birds and the Habitats Directives. According to these directives a network of protected areas is being built across EU countries encompassing the Natura 2000 Network. But the management plans of these protected areas do not require an ecotoxicological assessment of chemicals used within its limits. As for risk assessment protocols described in EC pieces of legislation and technical guidance documents, they are generic guidelines that not take into consideration regional particularities, e.g. the Mediterranean ecoregion specificities, and its local ecological values. Herewith we present a conceptual model for the assessment of risks posed by agriculture to bird species of conservationist concern from Natura 2000 Network sites; an example is set in a cereal steppe of the Iberian Peninsula. Hazards identified are related to the utilization of herbicides, disposal of sewage sludge to be used as fertilizer, and the input of veterinary pharmaceuticals that can be found in livestock dung and urine. This innovative model, to be used in high tier risk assessment, takes into account the biotic parameters of the protected bird species: great bustard ( Otis tarda), lesser kestrel ( Falco naumanni), and montagu's harrier ( Circus pygargus). The transfer of chemicals is considered to occur mainly through a realistic trophic chain scenario according to the different feeding behaviour among different species and even within the same species when having different feeding habits (e.g. adults and juveniles). Moreover, the probabilistic approach is proposed in order to perform a transparent risk assessment and clearer risk communication.

Benthic macrophytes as a tool for delineating, monitoring and assessing ecological status: The case of Slovenian coastal waters

Benthic macrophytes from 51 sites in the upper infralittoral zone along the Slovenian rocky coast were sampled (randomly stratified) in order to (1) confirm water body (WB) boundaries, (2) select sampling points for a surveillance monitoring programme, and (3) assess preliminary Ecological Status Classes (ESC) within the European Water Framework Directive (WFD). Coverage data of macrophytes were analyzed by using cluster analysis, Simper analysis and the Ecological Evaluation Index (EEI). The vegetation was rather homogenously classified into two Cystoseiretum crinitae subassociations: Halopithetosum incurvae, and Cystoseiretosum compressae, and into Cystoseiretum barbatae association. Seven monitoring sites at a kilometer scale were selected in two significant sized WBs following the mixing zone principle and the EEI successional model. The preliminary assessment of the ESC with the EEI was in agreement with existing human pressures in the area. In view of the present results, benthic macrophytes and EEI could be valuable tools for the implementation of the WFD within the Mediterranean eco-region.

An intercalibration of classification metrics of benthic macroinvertebrates in coastal and transitional ecosystems of the Eastern Mediterranean ecoregion (Greece)

Three coastal and three lagoonal sites located in Greece (Eastern Mediterranean) were selected to test and intercalibrate classification methods developed for benthic invertebrates ecological quality assessments. These methods were developed for the purposes of the European Water Framework Directive which is a European legislation adopted for the protection and improvement of the coastal and transitional waters. However, through testing these methods, this work addresses in general the issue of determining and comparing the ecological status of the coastal and transitional macrobenthic communities in Eastern Mediterranean ecosystems. Among methods tested were the biotic indices AMBI and BENTIX, the multivariate method M-AMBI and the biomass size structure index ISD in lagoonal sites only. ISD index is a rather new method developed especially for transitional ecosystems and in this contribution its performance is intercalibrated with the other benthic classification metrics. Comparison and intercalibration of the indices results in assessing the ecological quality status (EQS) are presented graphically and statistically performing the Kappa analysis. Results of the comparison and the indices’ performance are evaluated based on the knowledge of the sites’ environmental condition and baseline studies. Based on an extended dataset of coastal and transitional ecosystems benthic invertebrates, an evaluation of each index performance and effectiveness is attempted through an insight and comparative analysis of each methods’ structure and design. Results showed that in these Eastern Mediterranean coastal sites the BENTIX index seems to give a more biologically relevant classification and gives a higher confidence level regarding the classification compared to the other indices. In the coastal areas AMBI showed a tendency for the “good” class classification, while the factorial M-AMBI gave more consistent results with the BENTIX. In the lagoonal sites the biotic indices tested were not proved efficient enough and the biomass based ISD index proved more appropriate for these ecosystems. AMBI showed the highest agreement with the ISD which is due to the better performance of this index in the slightly and moderately polluted lagoons, compared to the other indices. However, AMBI failed to classify the polluted lagoon, in which case the BENTIX gave a more relevant classification.

Biovolume determination of phytoplankton guilds in transitional water ecosystems of Mediterranean Ecoregion

1 - Conceptually, morphometric measurements of phytoplankton guilds seem to have major advantages as descriptors of the ecological status of transitional water ecosystems (TW) with respect to classical taxonomic descriptors. However, at present, standardized or common methodologies for the use of morphometric descriptors do not exist. 2 - This paper aims to provide a starting point for the activation of standardized methods for the determination of morphometric descriptors of phytoplankton as a quality element in TW in accordance with the new directive of WFD 2000/60/EU. 3 - Phytoplankton biovolume is one of the most studied morphometric descriptors. It can be estimated by associating the algae with similar geometric forms and determining the volume of these by measuring the linear dimensions required for its calculation under the microscope. However, the lack of a standardized set of geometric forms and equations for calculating biovolume causes difficulties and produces data that are not comparable. 4 - A set of geometric models is suggested here for calculating the cell biovolumes of 201 phytoplankton genera found in transitional water ecosystems of Mediterranean Ecoregion. The equations were designed to minimize the effort of microscopic measurements. The main methodological problems, and the similarities and differences between our own and previously published proposals are discussed.

Conserving Biodiversity Efficiently: What to Do, Where, and When

Conservation priority-setting schemes have not yet combined geographic priorities with a framework that can guide the allocation of funds among alternate conservation actions that address specific threats. We develop such a framework, and apply it to 17 of the world's 39 Mediterranean ecoregions. This framework offers an improvement over approaches that only focus on land purchase or species richness and do not account for threats. We discover that one could protect many more plant and vertebrate species by investing in a sequence of conservation actions targeted towards specific threats, such as invasive species control, land acquisition, and off-reserve management, than by relying solely on acquiring land for protected areas. Applying this new framework will ensure investment in actions that provide the most cost-effective outcomes for biodiversity conservation. This will help to minimise the misallocation of scarce conservation resources.

A synthesis of the biological quality elements for the implementation of the European Water Framework Directive in the Mediterranean ecoregion: The case of Saronikos Gulf

Abstract 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.