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1.
Abstract

Festuca valesiaca Schleich. ex Gaudin subsp. valesiaca is acknowledged as one of the most characteristic grasses of the continental grasslands and steppes of Eurasia. In Italy, the species was known almost only from the continental valleys of the Alpine chain (with the exception of two small populations at the northernmost edge of the Apennines). Here, we report on the first confirmed finding of F. valesiaca subsp. valesiaca in the surroundings of the Fucino Basin, Central Apennines. This finding expands by c. 400?km southwards the species’ range in Italy. The identity of the species was first ascertained by means of leaf cross-sections and stomata measurements, and then confirmed by chromosome count. Its habitat preferences within the area were found to match well with those described in the literature for C-Europe. After discussing some identification issues and the population’s ecological niche, we present the main biogeographic implications of our finding. By recalling and discussing similar examples, we conclude that during the Holocene forest spread some Apennine “dry valleys” performed as refugia for a number of Pleistocene steppic taxa. The grasslands of these areas may thus be ancient and valuable ecosystems maintained by climate and disturbance throughout the Holocene.  相似文献   

2.
In Central Europe several plant species of dry grasslands are particularly rare. Here I investigate whether habitat requirements, reproduction, and dispersal potential can contribute to the rarity of Astragalus exscapus (Fabaceae) growing in dry grassland habitats in dry regions of Europe. In addition, I question whether historic events might have contributed to the present-day rarity of A. exscapus. To assess habitat requirements of A. exscapus, vegetation composition and soil characteristics were studied in 37 populations in central Germany. Production and dispersal potential of seeds were investigated in 10 populations, and germination and recruitment were assessed in experimental plots in three populations. Vegetation of the habitats included most dry grassland community types occurring in the central German dry region indicating a broad ecological niche of the species within dry subcontinental grasslands. Soil characteristics of the habitats also spanned a wide range. Seed production was moderate. 98% of the seeds sown in the laboratory germinated whereas under natural conditions 20% of the seeds developed seedlings. Half of these seedlings survived for one year but only 4.5% for two years. 90% of the seeds were dispersed less than 50 cm distance indicating a low dispersal potential. I conclude that A. exscapus is mainly limited in dispersal but recruitment limitation might also be important in explaining its rarity. Furthermore, former climate change and postglacial reforestation of the area very likely contribute to the rarity of A. exscapus.  相似文献   

3.
The phylogeography of species associated with European steppes and extrazonal xeric grasslands is poorly understood. This paper summarizes the results of recent studies on the phylogeography and conservation genetics of animals (20 taxa of beetles, butterflies, reptiles and rodents) and flowering plants (18 taxa) of such, "steppic" habitats in Eastern Central Europe. Most species show a similar phylogeographic pattern: relatively high genetic similarity within regional groups of populations and moderate-to-high genetic distinctiveness of populations from currently isolated regions located in the studied area. This distinctiveness of populations suggests a survival here during glacial maxima, including areas north of the Bohemian Massif-Carpathians arc. Steppic species generally do not follow the paradigmatic patterns known for temperate biota (south-north “contraction–expansion”), but to some extent are similar to those of arctic-alpine taxa. There are three main groups of taxa within Eastern Central Europe that differ in their contemporary distribution pattern, which may reflect historical origin and expansion routes. Present diversity patterns of the studied steppic species suggest that they share a unique genetic signature and distinct assemblages exist in each of the now isolated areas rich in steppic habitats. At least some of these areas probably act as present “interglacial refugia” for steppic species. This study strongly supports the need to protect steppic species throughout their entire ranges in the region, as the continuous destruction of steppic habitats in some areas may lead not only to the disappearance of local populations, but also to the extinction of unique evolutionary units.  相似文献   

4.
Abstract

Two new italian stations of Jonopsidium savianum (Caruel) Ball ex Arc. – The authors point out the presence of Jonopsidium savianum (Caruel) Ball ex Arc. in two stations in the mount la Pelosa (Central Apennines). These new stations are characterized by a different climate as regards of those already well-known of mount Calvi, mount Pelato and mount Carvoli in Tuscany. This italian endemism, till now limited to the western Tuscan, had very probably an area of distribution in Central Italy more videly extended than nowadays, but the climatic changes of the post-glacial period may have caused its reduction and the isolation of this species only in very little stations.  相似文献   

5.
Phytogeographical relations of the Andean dry valleys of Bolivia   总被引:1,自引:0,他引:1  
Aim The objective of this study is to examine the phytogeographical affinities of the Andean dry valleys of Bolivia in order to contribute to a better understanding of the Andean dry flora's distribution, origin and diversity. Particular emphasis is given to the analysis of the floristic connections of this flora with more austral parts of South America. Location The dry valleys of Bolivia are located in the Andes of the southern half of the country, at elevations between 1300 and 3200 m. Methods An extensive floristic list compiled by the author to evaluate plant diversity in these Andean regions was used as the base for this study. To accomplish this, all recorded genera and species were assigned, respectively, to 11 and 12 phytogeographical elements established previously by the author. Two phytogeographical spectra were thus obtained and analysed. Results At the genus level, the Andean dry valleys of Bolivia are clearly dominated by genera that have widespread distributions (cosmoplitan and subtropical genera). Many of these reached the Andes from the lowland region of the Chaco. At species level, Andean elements constitute more than 60% of the species total, most of which are restricted to the central‐southern Andes. This suggests that Chaco‐related and Andean genera had considerable levels of speciation in these valleys. Many genera and more than half the species have their northernmost distribution in the dry valleys of Bolivia, thereby underlining strong relationships with central‐southern South America (mainly Argentina, Paraguay and southern Brazil). The data supports the belief of the existence, in central‐southern Peru, of a floristic disjunction in dry to arid environments that separates a tropical dry flora north of this limit from a dry subtropical/warm temperate flora south of it. Main conclusions The Andean dry valleys of Bolivia are diverse plant communities with high levels of endemism (c. 18% of the species). The species of this region are more related to those present in central‐southern South America than to the flora of northern South America that ranges southwards to Peru. Many of the species have restricted distributions in the dry Andes of Bolivia and Argentina, and many genera of these dry valleys have their northernmost distribution in Bolivia/southern Peru, too. The data point to high levels of speciation also in the central Andes.  相似文献   

6.
Aim Interpretation of fossil pollen assemblages may benefit greatly from comparisons with modern palynological and vegetation analogues. To interpret the full‐ and late‐glacial vegetation in eastern‐central Europe we compared fossil pollen assemblages from this region with modern pollen assemblages from various vegetation types in southern Siberia, which presumably include the closest modern analogues of the last‐glacial vegetation of central Europe. Location Czech and Slovak Republics (fossil pollen assemblages); Western Sayan Mountains, southern Siberia (modern pollen assemblages). Methods Eighty‐eight modern pollen spectra were sampled in 14 vegetation types of Siberian forest, tundra and steppe, and compared with the last‐glacial pollen spectra from seven central European localities using principal components analysis. Results Both full‐ and late‐glacial pollen spectra from the valleys of the Western Carpathians (altitudes 350–610 m) are similar to modern pollen spectra from southern Siberian taiga, hemiboreal forest and dwarf‐birch tundra. The full‐glacial and early late‐glacial pollen spectra from lowland river valleys in the Bohemian Massif (altitudes 185–190 m) also indicate the presence of patches of hemiboreal forest or taiga. Other late‐glacial pollen spectra from the Bohemian Massif suggest an open landscape with steppe or tundra or a mosaic of both, possibly with small patches of hemiboreal forest. Main conclusions Our results are consistent with the hypothesis that during the full glacial and late glacial, the mountain valleys of the north‐western Carpathians supported taiga or hemiboreal forest dominated by Larix, Pinus cembra, Pinus sylvestris and Picea, along with some steppic or tundra formations. Forests tended to be increasingly open or patchy towards the west (Moravian lowlands), gradually passing into the generally treeless landscape of Bohemia, with possible woodland patches in locally favourable sites.  相似文献   

7.
Aim To obtain palaeobotanical evidence enabling evaluation of the viability of the hypothesis that the ‘oriental’ element of the Balkan flora reached south‐east Europe from Turkey prior to the Holocene, probably via the Thracian Plain during a late Quaternary glacial stage but no later than the late Weichselian. Location Ezero wetland, northern Thracian Plain, Bulgaria. Methods We undertook analyses of pollen and microspores, plant macrofossils, wood fragments and molluscs recovered from sediments deposited in the Ezero wetland during the late Weichselian and Weichselian late‐glacial. Sediment chronology was determined using radiocarbon age estimates. Results Six metres of sediments were recovered from the basin, of which the lower 3 m, extending from c. 15,450 cal yr bp to the early Allerød, was analysed. A major hiatus occurred after c. 13,900 cal yr bp , the overlying sediments being of late Holocene age. Palaeobotanical evidence indicates predominantly open vegetation during the Weichselian late‐glacial, although macrofossil remains of woody taxa demonstrate the local presence of patches of wooded steppe and gallery forest. Changes in the composition of the steppe vegetation, and in the nature of the sediments deposited in the basin, indicate changes in climatic conditions, especially in the hydrological regime and in the moisture available to vegetation. After an initially relatively moister phase, the final centuries of the late Weichselian were drier, as was a short interval that may correlate with the Older Dryas. Moister conditions characterize intervals corresponding to the Bølling and Allerød sub‐units of the Weichselian late‐glacial interstadial. Although the pollen evidence is thus consistent with that from previous studies of this period in south‐east Europe and south‐west Asia, indicating predominantly open steppe vegetation, the macrofossil evidence indicates the persistent local presence of woody taxa. The woody taxa recorded include Celtis tournefortii‐type and Juniperus cf. J. excelsa, two taxa today characteristic of the wooded steppes of Anatolia and members of the ‘oriental’ element of the southern Balkan flora, as well as Rosaceae Subfams. Maloideae and Prunoideae, Alnus and Fraxinus. Main conclusions The late Weichselian vegetation of the northern Thracian Plain included patches of wooded steppe that supported members of the ‘oriental’ element of the modern Balkan flora. The presence of such taxa renders viable the hypothesis that they could have reached south‐east Europe from Turkey via the Thracian Plain during glacial times. Such hypotheses in historical biogeography can be evaluated critically using the evidence obtained from plant macrofossil analyses in combination with that from pollen analysis.  相似文献   

8.
The macrobenthos was sampled at 42 stations inDecember 1991 within a shallow eutrophic salt marsh pond, known as Palude della Rosa, located inside the VenetianLagoon, Italy. The benthic assemblages showed adistribution pattern made up of three different zonesreferred to in this paper as `Landward Zone',`Central Zone' and `Seaward Zone'. Thiszonation reflected both the distribution of the greenmacroalga Ulva rigidaAgardh and hydrology ofthe basin. The distribution patterns especially relateto the slow exchange of water due to the meanderingnature of channels surrounding the Palude dellaRosa.  相似文献   

9.
Abstract

Critical notes on the flora of Italy. VI. Final miscellaneous remarks. – The present paper includes a number of changes of rank and nomen-clatural transfers in the genera Jovibarba, Saxifraga, Buglossoides, Stachys, Scabiosa, Helichrysum, Anthemis, Leucanthemopsis, Centaurea, Avenula some of them proposed by other Authors (B. Anzalone, W. Greuter, P. Marchi). Achillea lucana Pign. from the Southern Apennines near Potenza is described as a new species.  相似文献   

10.
Abstract

The long pollen sequences from four volcanic lakes of the Lazio région are presented in order to outline the history of flora and vegetation on the Tyrrhenian side of Central Italy during the last hundred thousand years. The four long pollen records correlate satisfactorily with each other and reflect climatic changes at least at regional scale. Particular attention is paid to the development of arboreal vegetation during the last glacial. The local name “Lazio Complex” is given to the seven main fluctuations of trees of the Pleniglacial (from about 60,000 to about 30,000 years B.P.). The history of Zelkova, Abies, Picea, Fagus, Corylus, Ulmus, Carpinus betulus, Tilia in central Italy is outlined.  相似文献   

11.
Charcoal, the remains of Holocene fires recorded in natural sediments, allows a new approach to the study of forest evolution in the mountains of the Mediterranean region. The area of the Grands Causses and St Guilhem, southern Massif Central (France) played an important role in the preservation of steppic and pre-steppic ecosystems up to the middle Holocene. The present biodiversity developed recently (between 5000–3000 b.p.), which explains the persistence of typical alpine and steppic flora characteristic of these areas. From the middle Holocene on, both fire events in the Eastern areas of the Causse Méjean and grazing have contributed to creating the bald landscape characteristic of this region. Further south the present day forest of Pinus nigra ssp. salzmanni is a recent phenomenon. It was during the Middle Ages that the initial forest of Pinus sylvestris and Pinus nigra ssp. salzmanni, a heritage from the last glaciation, started to change. δ13C measurements were carried out and the results compared with reference material. These show that fire events are closely related to dry periods, implying climatic changes of increasing dryness after the middle Holocene climatic optimum.  相似文献   

12.
Abstract

The Italian distribution of the rare boreal–circumpolar macrolichen Usnea longissima is revised on the basis of a critical re-evaluation of bibliographic and field data. Reported from all Alpine regions of Italy, the species presently survives only in two neighbouring Alpine valleys of Friuli and Veneto. The Friulian population consists of a few thalli on a single tree near the lake of Sauris, while in Veneto scattered populations were observed in nine stands of Val Visdende with ca. 200 colonised trees. The species seems to be locally extinct in Trentino-Alto Adige. Earlier records from Lombardy, Piedmont and Aosta Valley are wrong or at least questionable. Usnea longissima can be considered as critically endangered at the national level. Some recommendations for forest managers are proposed.  相似文献   

13.

Questions

Which major syntaxa of dry grasslands supported by carbonate bedrock occur in the central and southern Balkans? What is their position along major ecological gradients and in the context of phytogeographic patterns of the region?

Location

Central and southern Balkans, including western Bulgaria, northern Greece, Kosovo, Macedonia (FYROM) and Serbia.

Methods

We compiled a matrix of 660 relevés of dry grasslands over lime‐rich bedrock, previously classified in the Festuco‐Brometea. We applied clustering techniques to classify separately synoptic and relevé data, and applied NMDS with passive projection of indicator values, climatic data and biogeographic geo‐elements onto ordination diagrams to assist interpretation of the syntaxonomic patterns. We constructed elevation distribution profiles for alliances and classes of grasslands of several grassland classes from a broader study area to elucidate the relationship of the elevational sorting of the syntaxa in relation to latitude.

Results

The analysis revealed six major vegetation types, classified into four orders: (1) Stipo pulcherrimae‐Festucetalia pallentis, incl. (sub)montane rocky steppic grasslands of the Saturejion montanae of central Balkans, and the Koelerio‐Festucion dalmaticae – submontane rocky grasslands of southern Serbia and Kosovo; (2) Astragalo onobrychidis‐Potentilletalia represented by the Saturejo‐Thymion (low‐elevation steppic grasslands of southern Balkans); (3) Festucetalia valesiacae represented by grasslands on deep soil and low elevation of northern Greece, and finally (4) high‐elevation rocky grasslands of southern Balkans, classified as a new alliance – Diantho haematocalycis‐Festucion hirtovaginatae, that might belong to a new, yet undescribed, syntaxonomic order. Ordination suggests that the major differentiation of the high‐rank syntaxa follows north–south geographic and low–high elevation gradients.

Conclusions

Because of the transitional biogeographic position of the studied region, as well as considerable large elevation span across latitudes, the diversity of vegetation types is high. The indication a putative new dry grassland order, the mid‐high altitudes of the southern Balkans points to a need to re‐assess the Balkan vegetation occupying the community niche between the low‐elevation dry grasslands (Festuco‐Brometea) and those typical of high elevations (Elyno‐Seslerietea and Daphno‐Festucetea), seeking parallels to patterns described from the western Alps, Pyrenees, and Apennines. This syntaxonomic unit is poised to expand the concept of the Festuco hystricis‐Ononidetea striatae to the Balkans.
  相似文献   

14.
The Anatolian Biogeographical Region is unique in the Palearctic realm, with high plant and butterfly species richness and populations of globally threatened birds, mammals and herptiles (amphibians and reptiles). It is a place of diverse land-use practices, dating back to the earliest farming practices in the world. Among 10,930 species of vascular plants, birds, butterflies, mammals and herptiles distributed in Turkey, we identified 1130 living predominantly in steppic environments and being classified either as threatened, near-threatened or data deficient at the national level, if not globally. A total of 28 effective protected areas were present in the region, covering 1.5 % of the 391,597 km2 land area. Only 16.2 % of the threatened and near-threatened species (n = 809) were distributed within the protected area network, ranging from 94.1 % for birds to as low as 12.9 % for vascular plants. The total area of steppe and steppe forest vegetation has been reduced by at least 44 % of its former extent due to diverse habitat destructive activities. The most significant threats arise from unsustainable agricultural activities including overgrazing, conversion to croplands and afforestation. To maintain steppe diversity, we propose a “to-do list”, including mainstreaming biodiversity, effective implementation of Turkey’s Rangeland Act, conducting effective environmental impact assessments, establishing an effective site network for steppe biodiversity conservation and filling gaps in scientific knowledge.  相似文献   

15.
Parastenocaris lorenzae n.sp. is described from rhithrostygal of the Sangro river (Abruzzo, Central Italy). Parastenocaris glacialis Noodt, 1952 is for the first time recorded from Italy. The presence of borealpine elements in ground waters of Central Apennines is briefly discussed.Contribution to the knowledge of the groundwater fauna in central Research supported by grants from M.P.I. (40%) and C.N.R. (Gruppo and southern Italy: XLIV. Nazionale di Biologia Naturalistica).  相似文献   

16.
A new species, Ranunculus giordanoi, belonging to the R. auricomus complex is described from Latium, central Apennines (Italy). It grows in damp meadows on Monti della Laga (National Park of Gran Sasso and Monti della Laga), the largest sandstone massif of central Italy. The new species differs from the closely related R. silanus, endemic to Sila (Calabria, southern Apennines), by leaf aperture, shape of the basal leaves, entire or sometimes deeply lobed cauline leaves, gynoclinium without intervallum and longer carpellophores.  相似文献   

17.
Abstract

Flora of Popoli's gorges (Central Italy). — The results of floristic research developed from 1967 to 1969 at the Popoli's gorges (province of Pescara, in Abruzzo, Central Italy) are reported. Short accounts on the geographic position, on the geology and climate of the gorges are given, together with the floristic index of 696 entities, 4 of which are new for Abruzzo. For each species the biological and the phytogeographical categories are indicated; and for the whole of the flora the biological spectrum. This shows that this flora is a submediterranean one, with altitude influences. Critical remarks are developed about the taxonomy and distribution in the region of Abruzzo of several species wich looked particularly significant to the author.  相似文献   

18.
A palynological study was carried out on four Italian Miocene‐Pliocene sections ranging in age from uppermost Tortonian to Zanclean located on the Adriatic side of the North‐Central Apennines. The study documents the Mediterranean isolation, the salinity crisis (s.s), the “lago‐mare”; event and the re‐establishment of open‐marine conditions in the Mediterranean at the beginning of the Pliocene. From a climatic point of view, a transition from subtropical/warm‐temperate conditions during the Messinian to warm‐temperate/temperate conditions during the Zanclean is recorded. The presence of a lower thermic level, with respect to the Messinian, the re‐establishment of open‐marine conditions and the uplift of the Apennines were major factors controlling paleoenvironmental variations during the Zanclean. The latter is also characterized by cyclic temperature oscillations. Correlations with coeval sections in the Mediterranean area confirm the existence of latitudinal climatic gradients within the studied area.  相似文献   

19.
The Robertsonian fusion is a common chromosomal mutation among mammal species and is especially prevalent in the West European house mouse, Mus musculus domesticus. More than 40 races of the house mouse exist in Europe, including the famous “tobacco mouse” (Poschiavo race) of Val Poschiavo, Switzerland. Documented here is the discovery of an extreme case of karyotypic variation in the neighboring Upper Valtellina, Italy. In a 20-km stretch of the valley, 32 karyotypes were observed, including five chromosomal races and 27 hybrid types. One previously unknown race is reported, the “Mid Valtellina” race, with a diploid number of 2n = 24 and the Robertsonian fusions Rb(1.3), Rb(4.6), Rb(5.15), Rb(7.18), Rb(8.12), Rb(9.14), Rb(11.13), and Rb(16.17). The Poschiavo race (2n = 26), Upper Valtellina race (2n = 24), Lower Valtellina race (2n = 22) and all-acrocentric race (2n = 40) were also present. The races form a patchy distribution, which we term a “mottled hybrid zone.” Geographical position, isolation, extinction, recolonization, and selection against hybrids are all believed to be instrumental in the origin and evolution of this complex system. Previous studies of house mice from Upper Valtellina indicated that two of the races in the valley (the Upper Valtellina and Poschiavo races) may have speciated in the village of Migiondo. We discuss the possibility that there may have been a reinforcement event in this village.  相似文献   

20.
Thick successions of Cretaceous carbonates in the southern Apennines of Italy are of great economic interest since they host important aquifers and huge hydrocarbon accumulations. The reservoir of the Val d’Agri and Tempa Rossa oilfields (in the subsurface of Basilicata) consists of Upper Cretaceous rudist-rich limestones passing downward into mid-Cretaceous dolomitized limestones of restricted platform facies. Upper Albian-Lower Cenomanian dolomitized carbonates exposed in the Sorrento Peninsula and in the Cilento Promontory, part of the Apennine Carbonate Platform, represent a good surface analogue for the lower part of the reservoir. They are composed of meter-thick beds of stratabound dolomite and shallowing-upward cycles of restricted platform limestones capped by silicified evaporites and marly levels. Field relations, petrography, and geochemistry implicate the reflux of penesaline waters as the most probable dolomitization process. High-frequency climatic variability between dry and wet phases can explain the formation of evaporites, which are coeval with karstic bauxites in other sectors of the southern Apennines. The dolomitized carbonates of the Sorrento Peninsula pass laterally into dolomitized breccias, which were the result of local tectonic collapse of the platform. This is further evidence of mid-Cretaceous syn-sedimentary tectonics that in other areas of the Adria passive margin contributed to the formation of intraplatform basins where source rocks accumulated.  相似文献   

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