A bioclimatic classification of Chile: woodland communities in the temperate zone

The results of application of a global bioclimatic classification to Chile are presented. A total of 140 weather stations are assigned to bioclimatic belts on the basis of temperature and rainfall regime. In view of these assignements and of phytosociological data, a zonation of Chile into four major bioclimatic regions (Tropical, Mediterranean, Temperate and Boreal) is proposed. For the Temperate region, we discuss the distribution of the various climax forest communities with respect to bioclimatic belt. It is suggested that increased knowledge of the phytosociology of Chile will improve understanding of the climate of the different parts of the country.Nomenclature: Plant nomenclature follows Marticorena et al. (1985) for Chilean species.     

Macroecological patterns of species and genetic diversity in vascular plants of the Mediterranean basin

Aim We address the question of whether broad scale biogeographical structure of species diversity (SD) matches that of genetic diversity (GD) of vascular plants. Location The Mediterranean basin. Methods We normalized vascular plant species richness (SD) estimates per country using the Med‐Checklist taxonomic database. We used a linear regression analysis to correlate normalized country estimates with country longitudinal position. We also compiled published and geo‐referenced within‐population GD data for tree species, which had populations in the Mediterranean. We normalized GD estimates for each population across species. Again, we used a linear regression analysis to correlate GD with population longitudinal position. We then compared the populations’ geographical and bioclimatic trends for GD with Last Glacial Maximum (LGM) palaeo‐climate data and the species current ecological requirements. Results The eastern Mediterranean and the coast of former Yugoslavia had higher SD than other regions. There was no overall spatial structure of SD in the Mediterranean, whereas there was an east–west trend of decreasing GD. This trend for GD tended to covary with an east–west warm/wet–cold/dry trend detected during the LGM. Low elevation xerothermic pine species displayed significantly less GD than higher elevation mesothermic or mountain pine species. Main conclusions We suggest that LGM climate may have significantly shaped the current longitudinal and altitudinal patterns of GD we observed in woody taxa across the Mediterranean, although it did not affect comparable SD patterns. In particular, colder LGM summer temperatures in the western Mediterranean may have reduced population sizes significantly more than in the eastern Mediterranean. As plant species richness and GD did not covary, SD and GD may not be used as surrogates of one another in the Mediterranean basin. As they contain comparatively less GD, conservation priorities in the Mediterranean should focus on hot spots of endemism and Western Mediterranean populations and species.     

Biogeography and history of the Mediterranean bird fauna

With 366 species of breeding birds, the Mediterranean region is a "hot spot" of species diversity. Many biogeographic realms contributed to the establishment of the extant fauna, which makes this region a crossroads for birds, but the two most important realms are the large forest blocks that extend today over Eurasia and the semi-arid belts of the southern and southwestern Palaearctic. The few groups that presumably differentiated within the Mediterranean basin are mostly birds of open habitats and shrublands (e.g. Sylvia spp.), whereas few species evolved in Mediterranean forests dominated by sclerophyllous evergreen tree species. We suggest this results from the history of vegetation belts and their associated faunas during the Pleistocene. On the whole, in contrast to other groups of vertebrates, the bird fauna is fairly homogeneously distributed all over the basin although there are some regional-specific trends in species assemblages, mostly on the basis of habitat selection and biogeographic origin. Many species of eastern and southeastern origin invaded the Mediterranean basin on the northern side of the sea up to the Balkan peninsula and the southern side to the Atlantic coast. The extant biogeographic patterns of the Mediterranean bird fauna are interpreted in the light of the Quaternary history shared by the biotas of the western Palaearctic in relation to the cycle of climatic changes which produced periodic huge spatiotemporal migrations of communities and populations. The severe human impact that started c. 8000-10,000 years ago resulted not so much in species extinctions as in dramatic changes in distributional patterns, complicating the reconstruction of biogeographic scenarios.     

Epiphytic lichen communities in chestnut stands in Central-North Italy

Chestnut forest ecosystems represent an important component of the European Mediterranean basin and the Southern Alps landscape. Despite the good knowledge acquired in the phytosanitary and cultural aspects of chestnut, there is still a lack of data on the relationships between chestnut and epiphytes. We have investigated the changes in frequency of occurrence and species composition of lichen assemblages against the main site characteristics and environmental variables in chestnut woods along a bioclimatic and geographical gradient in Central-North Italy.     

Climate and vegetation at the Eurosiberian-Mediterranean boundary in the Iberian Peninsula

Abstract. The Northern Iberian Peninsula is dominated by various types of vegetation from deciduous oak and ash to evergreen oak woodlands. A recent vegetation map of Spain portrays vegetation series which are characterized in terms of their phytogeographic region or bioclimatic (altitudinal) belt. The aim of this paper is to determine whether the areas comprised by both phytogeographic regions (Eurosiberian and Mediterranean) in the study area, as established from the phytogeographic characterization of the vegetation, can be discriminated by climatic variables using multivariate methods, and to compare these with other conventional approaches. In addition, bioclimatic (altitudinal) belts and the main vegetation types were tested for discrimination by climatic variables. Conventional climatic criteria as well as discriminant and principal component analysis were applied to climatic data from 205 meteorological stations for which vegetation information had been taken from the vegetation map. Conventional criteria are good predictors of the phytogeographic division (Mediterranean and Eurosiberian regions) in the study area. Results were improved by multiple discriminant analysis based on climatic data of the dry period of the year (June to September). Both regions in the study area can be predicted with over 95 % accuracy. Using the same multivariate procedure and temperature data the bioclimatic (altitudinal) belts of the study area can be predicted with over 90 % accuracy. The main vegetation groups of the study area can also be predicted with over 80 % accuracy. Ordination analysis supported the results of the discriminant analysis. Empirical models have been generated to predict the phytogeographic- and belt character of any station in the area. The significance of the various periods of the year for discriminating regions and belts is evaluated. The responsiveness to climatic events during the year may be region specific. This study confirms the strong relationship between climate and vegetation in the Northern Iberian Peninsula, particularly regarding the Eurosiberian-Mediterranean boundary.     

Arundo micrantha,a new reed species for Italy,threatened in the freshwater habitat by the congeneric invasive A. donax

Arundo micrantha Lam., a reed species from southern Mediterranean area, has found in Sardinia. Its presence represents the first record for Italy and the third one for western Europe. Investigations on distribution and ecology of the Sardinian population have been carried out, with special focusing on synecology of the species. A. micrantha has found in 40 localities mainly distributed along temporary streams and permanent rivers in the central and southern part of the island. Most of Sardinian populations occurs on alluvial soils in Thermomediterranean bioclimatic context. The autonomy of Sardinian phytocoenoses was characterized with the definition of exclusive floristic taxa, biological and chorological elements, and syndinamic relationships with other assemblages. Comparing the community with other reed beds from the Mediterranean basin, a marked floristic differentiation arose between the phytocoenoses characterized by autochthonous Arundo species and those dominated by the invasive Arundo donax. Finally, management activities are proposed to ensure the conservation of this threatened autochthonous plant community in freshwater habitat.     

The Essential Oils of the Greek Endemic Satureja horvatii ssp. macrophylla in Relation to Bioclimate

The essential oils of the Greek endemic Satureja horvatii subsp. macrophylla collected from 36 areas (among them, 23 are included in twelve sites of the EU network NATURA 2000) belonging to different bioclimatic types were studied. The total essential‐oil content is negatively related to the altitude. The variation of the essential oil composition follows a geographical pattern, which is related to the bioclimatic belts along the taxon's range. Carvacrol dominates in areas with Mediterranean and Submediterranean bioclimate (mainly in the S and C part of the taxon's distribution), linalool or trans‐sabinene hydrate, and/or borneol in the Submediterranean or Temperate Axeric bioclimates (in the N part of distribution), whereas thymol is found as main oil constituent in all three bioclimates.     

Phytogeographical data and modern pollen rain of the puna belt in southern Peru (Nevado Coropuna, Western Cordillera)

Aim To improve knowledge of the distribution of species and modern pollen dispersal in the puna vegetation belt (central Andes) for palaeoenvironmental analysis and reconstructions. Location Puna belt, Nevado Coropuna, Western Cordillera, Peru. Methods The vegetation facies and belts of the area were mapped by remote sensing using a March 1998 SPOT4 image. This was complemented by the interpretation of aerial photographs, by field sampling, and by the identification of plants. Data from 1940 to 1994 from the Peruvian meteorological station network were modelled to characterize the relationship between climate and vegetation. Twenty‐four soil‐surface samples were collected in the various vegetation facies identified on the map, and standard palynological techniques were applied to analyse these samples. A principal components analysis was performed on the pollen data set. Results The map shows three bioclimatic belts and seven facies in the puna sensu lato, and identifies the main plants that are characteristic of each bioclimatic area. The pollen results fit the vegetation facies and belts, including the plant species of the distinct facies that are well represented in the pollen assemblages. The mesotropical belt is characterized by the predominance of Asteraceae‐type Ambrosia; the supratropical belt shows significant frequencies of Asteraceae‐type Senecio; the orotropical belt is characterized by high frequencies of Apiaceae and includes Polylepis woodland and peat bogs; and the cryorotropical belt shows significant frequencies of Asteraceae‐type Senecio and Apiaceae. Main conclusions The pollen grains of the plants that grow on the puna sensu lato are generally entomophilous and are therefore not transported far from their plant source. The distinct bioclimatic facies and belts identified by the cartography can thus be well distinguished by their pollen production and deposition. We were therefore able to characterize the relationship between pollen, vegetation and climate that can be used for palaeoenvironmental reconstructions. An altitudinal pollen gradient on the western slopes of the central Andes was revealed by the pollen study, with the succession of Asteraceae‐type Ambrosia (1800–2200 m), Malvaceae (2700–3300 m), Asteraceae‐type Senecio (3500–4100 m) and Apiaceae (above 4600 m).     

Bioclimatic perspectives in the distribution of Quercus ithaburensis Decne. subspecies in Turkey and in the Levant

Aim To define the bioclimatic tolerance ranges of the two Tabor oak subspecies. Prior to this definition, and considering the confusion in the literature regarding the Tabor oak subspecies geography, a reassessment of their present distribution is proposed. Location Turkey and the Levant. Methods The bioclimatic tolerance range of each subspecies was characterized by four parameters: (1) the humidity category (Q₂), (2) the winter variant (m) – the two basic variables used in Emberger's method for the definition of Mediterranean bioclimates, (3) the length of the dry season (LDS) and (4) its severity, expressed by the dry season water deficit (DSWD). The reference to the last two variables in the definition of bioclimatic tolerance ranges of Mediterranean species has so far never been considered. The concept of bioclimatic niche, based on the reference to these four parameters, is proposed and discussed. Results The reassessment of the Tabor oak subspecies distribution shows that their extents of occurrence do not overlap and are significantly distant. The comparison between the characteristics of each subspecies bioclimatic niche has highlighted three major differences: (1) The bioclimatic niche of the subspecies macrolepis is characterized by a great heterogeneity as it includes up to 10 distinct bioclimate types, whereas only four types have been found in the bioclimatic niche of the subspecies ithaburensis. (2) A 10 °C gap has been found between the winter variants of both bioclimatic niches. (3) The third major difference relates to the dry season characteristics: the bioclimatic niche of the subspecies ithaburensis is characterized by an LDS 40–75% longer than it is in the bioclimatic niche of the subspecies macrolepis. Moreover, and surprisingly, although the most arid humidity categories are found in the bioclimatic niche of the subspecies macrolepis, the bioclimatic niche of the subspecies ithaburensis is characterized by a significantly more severe dry season as the DSWD is 36–180% greater than in the bioclimatic niche of the subspecies macrolepis. It is suggested that the duration and the severity of the dry season is a major limiting factor in the spatial distribution of the subspecies macrolepis. Main conclusions The reference to the duration (LDS) and severity (DSWS) of the dry season is essential when defining the bioclimatic niche of Mediterranean species.     

Similarities and dissimilarities,synchronisms and diachronisms in the Holocene vegetation history of the Balearic Islands and Sicily

In some continental and island sites in the western Mediterranean basin, the Holocene vegetation and climate dynamics seem to show the same patterns in time and space. Nevertheless, different synchronous scenarios have been proposed from other south European, North African and Near Eastern pollen records from around the Mediterranean basin. Striking similarities and synchronisms have been found between Sicily and the Balearic Islands. These islands, although under different bioclimatic influences, show similarities in the main trends of vegetation and climate dynamics during the Post-glacial. Lago di Pergusa is the only natural inland lake in Sicily and because of its geographical location, has a good potential sensitivity to the climatic changes of the Mediterranean basin. Likewise, coastal sediments from Minorca and Majorca, the Balearic Islands, have similar peculiarities. The present-day environmental situation, now that most of the natural vegetation in these islands has disappeared, has been brought about either by a climatic trend towards increasing aridity or an increase in human activities. It seems clear that prehistoric human people alone could not have caused all the environmental changes recorded in the last millennia in both places.     

Multilocus approach reveals an incipient differentiation process in the Stone-curlew, <Emphasis Type="Italic">Burhinus oedicnemus</Emphasis> around the Mediterranean basin

The Stone-curlew Burhinus oedicnemus, a steppe bird species, is mainly distributed in the Mediterranean and Macaronesian regions, which are considered hotspots of biodiversity with priority for animal and plant species richness conservation. In this study, we investigated the genetic diversity of the Stone-curlew in the Mediterranean basin and in the Canary Islands by applying a multilocus approach. We analysed mitochondrial and nuclear markers in order to evaluate the genetic structure and the congruence between morphological subspecies and geographic samples. We found a significant level of genetic differentiation between Mediterranean and Canary Island populations with all markers. Both in the Mediterranean basin and in the Canary Islands, we found a significant level of genetic diversity with nuclear markers only. We identified seven population groups, including insular populations. The four subspecies described for the Western Palaearctic were confirmed with some changes in distribution range. In spite of habitat fragmentation and negative population trend, the Stone-curlew showed a significant level of genetic diversity and gene flow among continental populations. However, islands constitute important reservoirs of genetic diversity and a potential for the evolution of the species.     

Mollusques septentrionaux en Mediterranée occidentale: Datation par le C

In the Western Mediterranean, heaps of shells lying in the upper part of the continental slope between 90 and 340 m include boreal species which do not occur at present in this basin. The most common are Arctica arctica, Chlamys septemradiata, Modiolus modiolus. This malacological fauna seems to have been living when the sea-level was 80 m lower than at present.     

The role of bioclimatic origin,residence time and habitat context in shaping non-native plant distributions along an altitudinal gradient

An important factor influencing whether or not a non-native plant species becomes invasive is the climate in the area of introduction. To become naturalised in the new range, a species must either be climatically pre-adapted (climate matching), have a high phenotypic plasticity, or be able to adapt genetically, which in the latter case may take many generations. Furthermore, patterns of successful establishment across species might vary with habitat context. To address the interaction of these factors on non-native species richness, we recorded the presence of non-native annual plant species along an altitudinal gradient on Tenerife (Canary Islands, Spain). We compared the distributions of species differing in bioclimatic origin (Mediterranean and temperate) and time since introduction (old and recent introductions), and compared richness patterns of these groups in anthropogenic and natural habitats. Non-native species richness increased strongly from lowlands to mid-altitudes, but dropped sharply at the transition from anthropogenic to natural habitats, and thereafter declined with altitude in the natural habitat. This pattern indicates that the altitude effects reflected changes in both climate and habitat context. Mediterranean and temperate species were distributed similarly along the altitudinal gradient, and we found no effect of bioclimatic origin on species distributions. As almost all species present at the highest sites also occurred in the lowlands, we conclude that most species were introduced to lowland sites and were therefore pre-adapted to those climatic conditions (lowland introduction filter). The altitudinal ranges of species tended to increase with time since introduction, and the species reaching the highest altitudes were mostly old introductions. This effect of time was more pronounced among Mediterranean than temperate species. Thus, while climatic pre-adaptation is important for establishment along this altitudinal gradient, species tend to extend their altitudinal range with time.     

Defining phytoclimatic units in Galicia,Spain, by means of multivariate methods

Abstract. Floristic and climate data from 150 plots in 25 sites in Galicia, Spain, were analysed to test the hypothesis that climate is the major factor governing the distribution of woody plant species. TWINSPAN classification, Detrended Correspondence Analysis and Canonical Correspondence Analysis were applied in successive stages of the data analysis to describe vegetational variation in relation to climatic gradients. Six groups of species were defined, two clearly oceanic (Maritime and Cool Maritime), one mediterranean maritime, and three mediterranean (Cold Mediterranean, Cool Mediterranean and Temperate Mediterranean). An aridity gradient was revealed as the primary factor regulating the distribution of the species considered. This main gradient reflects the transition between the Eurosiberian and Mediterranean bio-geographic regions. The gradient can be characterized by means of the Vernet bioclimatic index. A value ≥ 4 for this index can be taken to define the mediterranean zone in our study area. The mean minimum temperature in the coldest month was the second most influential climatic variable. Partial ordination analysis revealed that the residual variation was insignificant and that the observed variation in vegetation can be fully accounted for by climatic variables.     

Comparing the Response of Birds and Butterflies to Vegetation-Based Mountain Ecotones Using Boundary Detection Approaches

Mountains provide an opportunity to examine changes in biodiversity across environmental gradients and areas of transition (ecotones). Mountain ecotones separate vegetation belts. Here, we aimed to examine whether transition areas for birds and butterflies spatially correspond with ecotones between three previously described altitudinal vegetation belts on Mt. Hermon, northern Israel. These include the Mediterranean Maquis, xero-montane open forest and Tragacanthic mountain steppe vegetation belts. We sampled the abundance of bird and butterfly species in 34 sampling locations along an elevational gradient between 500 and 2200 m. We applied wombling, a boundary-detection technique, which detects rapid changes in a continuous variable, in order to locate the transition areas for bird and butterfly communities and compare the location of these areas with the location of vegetation belts as described in earlier studies of Mt. Hermon. We found some correspondence between the areas of transition of both bird and butterfly communities and the ecotones between vegetation belts. For birds and butterflies, important transitions occurred at the lower vegetation ecotone between Mediterranean maquis and the xero-montane open forest vegetation belts, and between the xero-montane open forest and the mountain steppe Tragacanthic belts. While patterns of species turnover with elevation were similar for birds and butterflies, the change in species richness and diversity with elevation differed substantially between the two taxa. Birds and butterflies responded quite similarly to the elevational gradient and to the shift between vegetation belts in terms of species turnover rates. While the mechanisms generating these patterns may differ, the resulting areas of peak turnover in species show correspondence among three different taxa (plants, birds and butterflies).     

The speciation history and systematics of Carthamus (Asteraceae) with special emphasis on Turkish species by integrating phylogenetic and Ecological Niche Modelling data

To discuss the classification and possible scenarios for the speciation of Carthamus species in Turkey, 143 species occurrence data from Turkey used in Ecological Niche Modelling (ENM), ITS sequences of 23 available species gathered from the GenBank and current distribution information were used. The ENM was carried out by using MAXENT software. Among the 19 bioclimatic variables used in ENM, precipitation of coldest quarter (25 %), mean temperature of driest quarter (19 %) and annual precipitation (17 %) parameters have the highest percent contribution to the resulting prediction pattern, respectively. Bayesian-based phylogenetic analysis with divergence time estimation was implemented to obtain phylogenetic history of Carthamus species. Statistical dispersal–vicariance analysis and Bayesian binary MCMC analysis were also used to discuss biogeographical inferences. An identification key for Turkish Carthamus species that is in accordance with phylogenies was given. Ancestral area reconstruction analyses pointed out that the Western Asia region was the ancestral area for Carthamus species and in the Pliocene/Pleistocene period they started to diversify. Also ENM results clearly indicate that especially Anatolian species used Aegean and Mediterranean coastal part of Anatolia as potential refugia.     

Microsatellite Analysis of Olive Fly Populations in the Mediterranean Indicates a Westward Expansion of the Species

Bactrocera oleae is the major insect pest of the olive fruit. Twelve microsatellite loci isolated from the genome of this insect were used in a Mediterranean-wide population analysis. These loci were highly polymorphic with a mean number of alleles per locus of 10.42 and a mean effective number of alleles of 2.76. The analysis was performed on a sample of 671 flies collected from nineteen locations around the European part of the Mediterranean basin. Despite the high level of gene flow across the Mediterranean, results support the notion of a differentiation of three subpopulations: one of the Iberian Peninsula, one of Greece and Italy and one of Cyprus. In addition, the gradual decrease of heterozygosity from the Eastern to the Western part of the Mediterranean indicates a westward expansion of the species.     

Faunistic data and biogeography of terrestrial isopods from Tunisian wetlands

In Tunisia, while wetlands are considered as remarkable habitats for their faunal and floral diversity, few studies on the biogeography and the diversity of terrestrial isopods were performed. To fill this gap, we carried out a field study in the supralittoral zone of 146 Tunisian wetlands belonging to eight types (lagoon, river, lake, sebkha, dam, hill reservoir, beach and chott) and to five bioclimatic zones (humid, subhumid, semi‐arid, arid and Saharan). Field work was carried out in spring 2010. Terrestrial isopods were collected in the morning by hand search each time with the same sampling effort. During the study, 22 species of terrestrial isopods belonging to nine families were collected. Porcellio variabilis, Porcellio laevis, Chaetophiloscia elongata and Armadillidium pelagicum are the most common species identified. From the northern to the southern regions, a gradual decrease in species richness has been shown. The identified species belonged to different biogeographical categories: Mediterranean, Mediterranean‐Atlantic, North Africa with circum‐Sicilian islands, semi‐arid and Saharan species. Some of these species are endemic to Tunisia (Porcellio dominici) or to North Africa (Armadillidium sulcatum, Armadillidium tunisiense, Porcellio marginenotatus and P. variabilis). Terrestrial isopod species differ according to wetland type and bioclimatic zone.     

Climatic determinism in phytogeographic regionalization: A test from the Irano-Turanian region,SW and Central Asia

This study investigates the role of climate in determining phytogeographic regions, focusing particularly on the Irano-Turanian floristic region in SW and Central Asia. A set of simple climatic variables and bioclimatic indices were used to prepare climate-space scatter plots and climate diagrams. The climate data were also subjected to multivariate analyses (PCA and Regression tree) in order to develop a bioclimatic characterization of the Irano-Turanian region in comparison with the adjacent Mediterranean, Saharo-Sindian, Euro-Siberian, and Central-Asiatic regions. Phytogeographic regions of SW and Central Asia display distinct bioclimatic spaces with small overlaps. The Irano-Turanian region is differentiated from surrounding regions by continentality, winter temperature, and precipitation seasonality. Continentality is the most important bioclimatic factor in differentiating it from the Mediterranean and Saharo-Sindian regions and is responsible for floristic differences among sub-regions of the Irano-Turanian region. In our case study, the Irano-Turanian region is a nearly independent bioclimatic unit, distinct from its surrounding regions. Hence, it is suggested that the term “Irano-Turanian bioclimate” be used to describe the climate of most of the continental Middle East and Central Asia. Among different sub-regions, the west-central part of this floristic region (“IT2 sub-region”) is a major center of speciation and endemism. Our case study demonstrates that climate is a primary determinant of phytogeographic regionalization. Although modern climate and topography are strong control parameters on the floristic composition and geographical delimitation of the Irano-Turanian region, the complex paleogeographic and paleoclimatic history of SW Asia has also influenced the Tertiary and Quaternary evolution of the Irano-Turanian flora, with additional impacts by the long-lasting historic and present land-use in this region. Many Irano-Turanian montane species are threatened by global warming, and particular conservation measures are needed to protect the Irano-Turanian flora in all sub-regions.     

Variability of lichen diversity in a climatically heterogeneous area (Liguria,NW Italy)

Abstract:The influence of environmental variables on epiphytic lichens in Liguria (NW Italy) was examined using two complementary approaches. Firstly, the variability of lichen vegetation in relation to environmental variables was investigated. Secondly, the variability of Lichen Biodiversity (LB) counts, used in biomonitoring studies, was analysed in relation to bioclimatic areas. Geomorphology strongly affects lichen vegetation. The coastal mountain ridge and the Tyrrhenian-Po valley watershed limit the distribution range of three different communities: a Parmelion community with a high frequency of coastal suboceanic species, a Parmelion community rich in oak wood species and the Parmelietum acetabuli association, situated beyond the Po Valley watershed. Substantial differences in the distribution of lichen communities related to a climatic gradient (from humid Mediterranean to dry sub-Mediterranean regions) are not matched by corresponding statistically significant differences in LB counts. More accurate studies are necessary to define homogeneous bioclimatic areas, in which LB values can be compared for biomonitoring purposes.