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1.
The author gives a survey of the sea-shore plant communities of Reykjanes peninsula. In all, 5 associations were found, belonging to the alliancesPuccinellion maritimae, Atriplicion litoralis andHonckenyo-Elymion arenarii.  相似文献   

2.
The author gives a survey of fell-field, dwarf shrub-and grass heath-communities of Reykjanes Peninsula. Eight associations were found to belong to this complex; they belong to the alliancesJuncion trifidi Krajina,Loiseleurio-Arctostaphylion Kalliola andNardo-Caricion Bigelowii Nordh. respectively. Their syntaxonomy and ecology are discussed.  相似文献   

3.
In Reykjanes peninsula, mainly in the valley of Krísuvík, in all 6 mire associations were found, belonging to the alliancesEriophorion Scheuchzeri andCaricion canescentis-fuscae. Floristic, ecological and physiognomical differeces between the two alliances are discussed. Most of the associations seem to be restricted in their distribution to Iceland.  相似文献   

4.
In this paper the syntaxonomy and ecology of the following plant communities is discussed:Montic-Cardaminetalia: Montion: Philonoto-Saxifragetum stellaris; Koenigio-Microjuncion: Equiseto palustris-Sedetum villosi, Koenigio-Agrostetum stoloniferae; Litorelletalia: Subularion aquaticae: Subulario-Ranunculetum reptantis; Isoetion lacustris: Ranunculo-Isoetetum lacustris.  相似文献   

5.
The rupicolous vegetation of theAsplenietea trichomanis in the south-western Iberian Peninsula is analysed using the methods of the Zürich-Montpellier School. Phytosociological tables, and biogeographical, ecological and floristic data are given for a number of syntaxa. A phytosociological synopsis of the studied vegetation was made for the entire region. Four new syntaxa are described: theCoincyo logirostri-Dianthetum lusitani, Jasiono marianae-Dianthetum lusitani jasionetosum tomentosae, Digitali thapsi-Dianthetum lusitani conopodietosum ramosi andSedo hirsuti-Polypodietum cambrici polypodietosum interjecti.  相似文献   

6.
We studied degree of variability and relationships among populations belonging to five species of the section Strombocarpa of the family Leguminosae, namelyProsopis ferox, P. torquata, P. pubescens, P. strombulifera andP. reptans, by isozyme electrophoresis. The genetic similarity betweenP. reptans andP. strombulifera is high enough for the two to be considered subspecies or geographic races ofP. strombulifera instead of good taxonomic species. As expected these species cluster withP. pubescens, all belonging to series Strombocarpae. This group is different isoenzymatically from the remaining species,P. torquata andP. ferox. Comparison of our results with those obtained earlier for species of the section Algarobia showed that genetic variability in the section Strombocarpa is lower than in the section Algarobia, while the species divergence is much higher. These results suggest different adaptive strategies between these sections.  相似文献   

7.
Billie L. Turner 《Brittonia》1985,37(1):117-120
Two new species ofSenecio,S. sundbergii andS. neogibsonii, belonging to the sectionPalmatinervii are described, illustrated, and compared to their nearest relatives,S. aschenbornianus andS. lanicaulis.  相似文献   

8.
Ten species ofCarex and one species ofKobresia from Thailand are taxonomically discussed, and some new range extensions into Thailand are noted. Described as new areCarex subinclinata andC. thailandica, both belonging to the sectionIndicae, andC. speciosa ssp.latifolia of the sectionRadicales. Two new combinations proposed areCarex helferi ssp.mapanifolia, andC. speciosa ssp.platyrhina.  相似文献   

9.
This paper reports an ethnobotanical investigation, performed between 1999 and 2002, to determine the wild food plants traditionally used in the province of Madrid (central Spain). One hundred and twenty-three vascular species belonging to 31 families were at one time used as vegetables, wild fruits, in the making of beverages, as seasonings, or as other preparations. Wild vegetables formed the largest group, withScolymus hispanicus, Silene vulgaris, andRumex pulcher the most frequently cooked vegetables, andRorippa nasturtium-aquaticum andMontia fontana the most commonly used in salads. Also common was the consumption of asparagus and several species of climbing plants such asBryonia dioica, Tamus communis, andHumulus lupulus. Ethnobotanical novelties includedSonchus crassifolius, the young sprouts of which were used in salads, and Inula salicina, used to make herbal tea. Some ecological and cultural aspects of the collection of wild plants for food are discussed, as well as the relationships between the food and medicinal uses of some species.  相似文献   

10.
11.
The diversity, ecology and biogeography of diatoms in lakes, seepage areas and streams on the Ulu Peninsula, a large ice-free area in the northern part of James Ross Island (Weddell Sea), were studied. A diverse diatom flora of 123 taxa was observed, dominated by several Nitzschia taxa, Psammothidium papilio, Eolimna jamesrossensis, Fragilaria capucina and Fistulifera saprophila. The results from the similarity and diversity analysis suggest James Ross Island to be biogeographically positioned within the Maritime Antarctic region, yet with some affinities with the flora of Continental Antarctica, as shown by the presence of Luticola gaussii and Achnanthes taylorensis. Based on our data, James Ross Island can thus be located close to the boundary of the two main Antarctic biogeographical regions. Diatom communities present in streams and seepage areas could be clearly distinguished from those in lakes, the latter being much more species rich. Based on the multivariate analysis, conductivity and nutrients were selected as the two main environmental factors determining the diatom composition in the Ulu Peninsula lakes. The revised taxonomy of the Antarctic diatom flora induced the construction of a transfer function for water conductivity in the studied lakes that can be applied in further palaeoecological studies.  相似文献   

12.
In the cathedral of León, 36.36% of the sampled surface is covered by up to 39 lichen taxa. Two different communities were found, either on carbonate rocks or on highly nitrified environments. The first is composed of species with crustaceous biotypes, mainly belonging to the generaCaloplaca, Aspicilia andRinodina. The other community is composed of species with foliaceous or lobed crustaceous biotypes of the generaPhyscia, Physconia andPhaeophysica, this latter community being the one producing the higher degree of physical biodeterioration, because of its higher rate of foliaceous species. The species distribution depends directly on nitrophytism, hygrophytism, photophytism and pH index, and to a lesser extent on the variation of the inclination angle, orientation and substratum type.  相似文献   

13.
The murine polycystic kidney disease gene,pcy, is an autosomal recessive trait located on chromosome 9. To determine the genetic locus ofpcy, 222 intraspecific backcross mice were obtained by mating C57BL/6FG-pcy andMus molossinus. Restriction fragment length polymorphism analysis of 70 of the 222 backcross progeny showed thatpcy, dilute coat color (d), and cholecystokinin (Cck) were located in the orderd—pcy—Cck from the centromere. Simple sequence repeat length polymorphism analysis of DNA of all 222 backcross mice was carried out using four markers which were located near the central regions ofd andCck. One and eight recombinations were detected betweenD9Mit24 andpcy and betweenD9Mit16 andpcy, respectively. However, no recombinant was observed amongpcy, D9Mit14, andD9Mit148. These findings strongly suggest thatD9Mit14 andD9Mit148 are located near thepcy gene and are good markers for chromosomal walking to this gene.  相似文献   

14.
Biochemical characteristics and protein electrophoregrams of 22 strains ofEnterobacter agglomerans, Erwinia herbicola, andErwinia milletiae, including the type strains of these species, were found to be very similar. These strains constitute one of the numerous groups within the ‘Erwinia herbicola-Enterobacter agglomerans complex’. Their classification in different genera or species is not supported by the results presented. These strains were isolated from different sources, such as clinical material, plants, or drinking water. It was stressed that further taxonomic studies should include isolates from a wide variety of ecological niches to improve the classification of bacteria belonging to the ‘Erwinia herbicola-Enterobacter agglomerans complex’.  相似文献   

15.
Abstract. A phytosociological survey of the tundra vegetation of the Kola Peninsula, Russia according to the Braun-Blanquet approach is presented. The areas examined comprise the treeless zones along the shores of the White Sea and the Barents Sea as well as mountain areas above the timberline. Plant communities were assigned to five alliances: Loiseleurio-Diapension on dry, wind-swept habitats on summits and wind-eroded sites in the lowland; Phyllodoco-Vaccinion myrtilli on well-drained soils with intermediate snow cover and moisture status, mostly in the lowlands and lower belts of mountain tundra; Nardo-Caricion bigelowii comprising early snowbed and Salicion herbaceae late snowbed communities; Adenostylion alliariae comprising mesophilous tall-herb communities along mountain springs and in wind-protected and well-drained sites near the sea shore. A DCA-ordination showed that two major gradients determine the varation in tundra vegetation, altitude and topography, which are connected to variation in snow cover. The syntaxa described are well-differentiated, although they form a syntaxonomical continuum.  相似文献   

16.
Freshwater mollusc communities readily respond to various human-induced stressors, and thus are appropriate models for studying the effects of such stressors on the structure and dynamics of stream macroinvertebrate communities. This paper examined the distribution of freshwater molluscs in 35 stream reaches of 18 small coastal basins in the south-western Iberian Peninsula. Using several multivariate techniques, I showed that mollusc distribution mainly responded to gradients in drainage area, water availability, pollution and salinity. Upstream and downstream communities were clearly differentiated, with the former dominated by freshwater species (Bithynia tentaculata, Galba truncatula, Radix balthica, Ancylus fluviatilis and Planorbarius metidjensis) and the latter by species typical of brackish waters (Peringia ulvae and Myosotella myosotis). There was a clear decrease in species richness from upper to lower reaches. The conservation of mollusc communities of these small basins requires a deeper understanding of their ecological requirements, effective control of urban discharges and an analysis of their interaction with invasive species.  相似文献   

17.
An introduction is presented to a taxonomic evaluation of rich cultivated and herbarium material of the genusTaraxacum from the Caucasus. Sources of the material, a survey of localities, and a preliminary account of the sections and species groups ofTaraxacum described from the Caucasus are given. The introduction is followed by a monograph ofT. sect.Porphyrantha, a section shown (contrary to the original conception and some literature data) to be endemic to the Caucasus. Six new species are described belonging to the section divided in two subsections, subsect.Porphyrantha and subsect.Haemantha, viz.T. pseudoporphyranthum, T. vepallidum, T. haemanthum, T. ignivomum, T. exstinctum andT. deminutum. Lectotypes are selected forT. porphyranthum Boiss. andT. pseudoroseum ?i?kin.  相似文献   

18.
John T. Mickel 《Brittonia》1985,37(3):261-278
Thirteen taxa of the fern genusElaphoglossum reproduce vegetatively by a bud borne at the retuse apex of the sterile frond. These and six of their nonproliferous close relatives, all of tropical America, are discussed and described. All but one belong to various species groups in the closely allied sectionsSetosa andUndulata, the remaining one belonging to sectionLepidoglossa. Fourteen of the taxa are new:E. boryanum var.eutecnum, E. cardioglossum, E. entecnum, E. exsertipes, E. herpestes, E. inciens, E. nanoglossum, E. omissum, E. phoras, E. phyllitidis, E. plumosum f. maternum, E. pseudoboryanum, E. rufum, andE. wardiae.  相似文献   

19.
Morphological comparisons are made from the study of 64 specimens belonging to the following species:Squalus acanihias, S. blainvillei, S. megalops andS. acutirostris. The results suggest conspecificity betweenS. acutipinnis andS. megalops. The differences betweenS. blainvillei andS. megalops in the E-Atlantic are stressed. The Indo-Pacific species calledS. blainvillei by Chen et al. (1979) is regarded in this paper as probably an undescribed species. Some consideration on the status of several nominal species and the species grouping withinSqualus are also made.  相似文献   

20.
T. Rivnay  D. Gerling 《BioControl》1987,32(5):463-475
Fifteen aphelinidae species, belonging to the generaEncarsia Foerter andEretmocerus Haldeman, are recorded as new whiteflies parasitoids from Israel. Three new species are described and recorded for the first time from Israel. A key to the Israeli species is given.  相似文献   

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