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1.
Phytoplankton samples from twenty-one freshwater localities in the area of Nuuk (Godthåb), West Greenland, have been examined by means of electron microscopy in order to investigate the flora of scale bearing Chrysophyceae. Forty-two taxa of the genera Mallomonas, Synura, Chromophysomonas (Spiniferomonas), Chrysosphaerella and Paraphysomonas have been observed, and thirty-eight of these are illustrated by TEM or SEM micrographs. Thirty-four of the observed taxa, among these all members of the genus Chromophysomonas , are for the first time recorded from Greenland. Chromophysomonas involuta sp.nov. is described. The scale morphology of the Greenlandic specimens is compared with earlier findings from other parts of the world, and the most remarkable features of the chrysophycean flora from the investigated area are discussed.  相似文献   

2.
The agaric flora of the Godhavn region (W Greenland 69°15'–69°30'N) was studied by the authors in 1967, 1970–72, and 1977. 1125 collections were made and 150 taxa were recognized. It was found that the fungus flora varied very much in the different seasons. The authors attempt to join their experience from studies in other arctic and alpine areas. In total, the check–list shows that there is a large degree of similarity between the agaric flora of the Godhavn area and that of the Alps and the Scandinavian mountains, while the similarity with the European lowland flora is less than earlier assumed. A bibliography of the relevant literature is appended.  相似文献   

3.
We analyzed variation in nine non-metric and eight metric variables in the skulls of 132 narwhals (Monodon monoceros) from five localities in Greenland (Inglefield Bredning, Melville Bay, Uummannaq, Disko Bay, and Scoresby Sound) and one in the eastern Canadian Arctic (Eclipse Sound). Metric variables were used to compare the combined Disko Bay and Uummannaq samples with the samples from Inglefield Bredning and Scoresby Sound using three different multivariate techniques for each sex. None of the results were significant. Seven of the non-metric variables were independent of age and sex and were used in comparing samples from the six localities. No differences were found among the four localities in West Greenland, but differences were found in two of the non-metric variables between the combined West Greenland sample and the one from Scoresby Sound. A major shortcoming of the analysis based on metric data was the small sample size from several of the areas, which resulted in low statistical power. Genetic as well as environmental factors could explain the differences detected here between narwhals living along the west and the east coasts of Greenland.  相似文献   

4.
Size, growth and sexual dimorphism of nine skull traits was studied in 300 East Greenland and 391 Svalbard polar bears (Ursus maritimus). Two traits were significantly larger in bears from East Greenland compared to Svalbard bears, and trait size was smaller after 1960 in five traits. For both localities and both age groups (subadult, adult), mean trait size values were higher in males than females (all: P < 0.05). Gompertz growth models showed trait size increasing with age in seven traits. Depending on the trait, males reached 95% asymptotic trait size at age 3–10, females at age 2–6. The females of both localities matured at approximately the same age, whereas the Svalbard males generally matured years later than their East Greenland peers. The differences found in the present study between the two polar bear subpopulations support the notion that East Greenland and Svalbard polar bears probably should be managed as separate units.  相似文献   

5.
Distribution maps of the Greenland Onagraceae and synecological notes are presented. Four species are low–arctic, most often or exclusively growing in the lowland. The northernmost occurrence of the three of them, Epilobium palustre, E. hornemannii and E. lactiflorum is at "hot springs" between 69° and 70° N, while the fourth, Chamaenerion angustifolium , with the same northern limit, does not show this preference. E. anagallidifolium is even growing two degrees of latitude further north, and besides it is not limited to the lowland. E. arcticum has an arctic distribution between 69° and 80° N, while the seventh species, C. latifolium , is circumgreenlandic, being rare only in the most oceanic part of N Greenland. The occurrence of E. alsinifolium in Greenland has been rejected.  相似文献   

6.
This paper presents the first long term (1960–89) data set on both muskox Ovibos moschatus density and weather parameters in north and northeast Greenland The muskoxen appear to have expenenced a 25 yr favourable period from the early 1960 'ies to the mid 1980' ies, in which density increased and reached a maximum level The population minimum around 1960 probably represents a long term minimum, following a long, generally unfavourable period between 1940–60 Variation in the local population trends from the southern parts of the muskox distribution m northeast Greenland to the northeast parts, can be divided into three geographical areas (72°–75°N, 75°–77°30 'N, and north of 79°30' N), where density dependent and density independent factors affecting muskox populations are apparently different Regional population stability does not increase towards the north Two density independent (abiotic) factors seem to be of prime importance in determining the muskox population density and distribution in northeast Greenland 1) the amount of winter precipitation affects the distribution of muskoxen negatively, inducing local migrations, but does not have a direct negative effect on large scale variation in density,11) ablation (i.e melting of the upper snow layer) and concomitant ice crust formation in winter have a highly negative effect on muskox density in the southern range, but not in the northern range The two abiotic factors, which show a considerable variation from north to south, are statistically independent and seem to be triggered by different weather conditions The predictions that follow from a climatic model both with respect to the direct influence of abiotic factors on muskox density and the indirect influence of climatic fluctuation, are not fully supported by the data presented here  相似文献   

7.
Early Holocene plant and animal remains from North-east Greenland   总被引:1,自引:0,他引:1  
Aim The aim of this paper is to describe and interpret early Holocene floras and faunas. Location The floras and faunas come from various localities in North-east Greenland. Methods Sediment samples were wet sieved, and macrofossils picked out and dated by the AMS radiocarbon-dating method. Results Sediments, dated to the first centuries after the last glacial stage came to an abrupt end, contain a macroflora of bryophytes and a few herbs, and we suggest that these plant remains represent a pioneer vegetation entirely without woody plants. The named species of herbs are either confined to the northern parts of Greenland at present, or they become increasingly more important towards the north. Crowberry is the oldest woody plant recovered; it was present at 10.4 cal. ka BP , and it appears to have been common during the early Holocene in East Greenland. Main conclusions We suggest that the majority of the extant flora of vascular plants of East Greenland arrived by long distance dispersal during the Holocene. Some species may also have arrived during the late-glacial, and a few hardy species that are adapted to low summer temperatures may have survived the last glacial stage in nonglaciated areas. Some hardy animals may also have survived, but the majority of the fauna are considered Holocene immigrants. We suggest that migrating birds and storms, perhaps in combination, are under-appreciated dispersal vectors.  相似文献   

8.
Based on a series of collections made in New Zealand it is concluded that Nephroselmis longifilis and Bipedinomonas pyriformis are identical species, for which the correct name is Nephroselmis pyriformis (N. Carter) comb. nov. A detailed examination by light and electron microscopy is given, using material from geographically widely separated areas, including Greenland, the North Sea, a shallow Danish Fiord, Thailand and New Zealand. N. pyriformis is a temperature– and halotolerant species, as shown by its known range of occurrence at temperatures from 2.3°C (West Greenland) to ca. 28°C (Thailand) and at salinities between 3 and 36%o. Features of fine structural interest include details of the scaly covering on the flagellar and cell surfaces, the former very similar to those on the flagella of Tetraselmis cordiformis , a quadriflagellate prasinophyte. Within the cell, the pyrenoid shows an unusual fine structure, being penetrated by a number of membrane–lined pockets, in which the membranes are continuous with thylakoids. N. pyriformis is compared with other members of the genus, and a list of the few known species is included.  相似文献   

9.
P. Compère 《Hydrobiologia》1984,110(1):61-77
The algae contained in some plankton samples from several localities on four wadi in N.E. Sudan were examined. The observed algae amount to 260 taxa, of which the diatoms, representing 50% of the algal flora, are the most numerous. Other large groups are the blue-green algae (17%) and the green algae (24%) among which the desmids (6%) are rather unimportant.  相似文献   

10.
Sequence variation of a 250–bp (base pair) fragment of the mitochondrial cytochrome b gene has been studied using polymerase chain reaction and direct sequencing of 519 Atlantic cod Gadus morhua from Iceland and 78 cod from Greenland. Twenty-four variable nucleotide sites, mostly silent, define 34 haplotypes. The amount of variation is high ( ĥC =0·73, π=0·52 per 100 bp) with five haplotypes at polymorphic frequencies in Iceland and a number of widely dispersed rather rare haplotypes. A tree of genetic relationships among haplotypes has considerable homoplasy yet it is relatively shallow implying a high turnover of variants of the polymorphism. Net nucleotide genetic divergences among localities are nil. Geographic locality overall area, and inshore/offshore comparison explain none of the variation in an AMOVA, all the variation is among individuals and a null hypothesis of non-differentiation of haplotype frequencies among localities or overall areas cannot be rejected. A temporal year-class effect is found. The evolutionary difference between Greenland and Iceland cod is not significant and the percentage of variation accounted for by the Greenland/Iceland difference is half of what a temporal effect within Iceland explains. There is no evidence for considering the cod at Greenland and Iceland to consist of separate evolutionary units and the question of separate management units must address the lack of diagnostic genotypes and evidence for gene flow from clinal variation.  相似文献   

11.
12.
Forty-three taxa of Synurophyceae were identified by means of transmission electron microscopy of samples from ten different localities in southeastern Louisiana, USA, on the southern portion of the Atlantic Coastal Plain Province of North America. Samples were collected during a one month period when water temperatures ranged from 15.5–24.5"C. Sample pH values ranged from 4.4–7.2. Notable scale morphology variation was described for some taxa. The flora included three warm water taxa but was dominated by temperate and cosmopolitan taxa. Mallomonas prora and Synura australiensis are reported for the first time from North America. Comparisons with related studies from New World subtropical regions in Florida, USA, and Argentina were made, and significant North American range expansions were noted. The large number of aquatic habitats, 7–8 consecutive months at temperatures (6–20°C) best suited for development of synurophycean populations, and proximity to major bird migrations routes are postulated as explanations for the large number of reported species.  相似文献   

13.
Diet selection by vertebrate herbivores in the high arctic of Greenland   总被引:1,自引:0,他引:1  
Microhistological analysis of fecal droppings indicates that graminoids (sedges, grasses, and rushes) and the only willow present, Salix arctica , are primary food items of the muskox Ovibos moschatus , arctic hare Lepus arcticus , and collared lemming Dicrostonyx groenlandicus in northern Greenland (79°-83°N). Plant biomass available during the peak growing season varied with vegetation types from < 2 g m−2 in polar barrens to 34 g m−2 in sedge fens. The clustered distribution of vegetation minimizes competition among vertebrate herbivores.  相似文献   

14.
Baited traps were deployed in the coastal areas of Svalbard (0–175 m), Franz Josef Land (15 and 20 m), Northeast Greenland (6 and 20 m) and Ellesmere Island (2–145 m). The samples were dominated by Lysianassidae (Amphipoda). In the most extensively sampled locality (Hornsund, Svalbard), differences between the necrophagic fauna of the outer and inner basins were observed. Clear depth separations of closely related species of the Anonyx and Onisimus genera were found between 0 and 175 m in Hornsund. Anonyx nugax and Onisimus edwardsi were the only species found in all of the examined localities. Accepted: 14 January 2000  相似文献   

15.
The bacterial flora of samples taken from a subterranean saline well was enriched (1) by periodic salinity increase and (2) by periodic salinity decrease, both at 25° and 35°C. During the enrichment process, bacterial flora, including halotolerant, marine, moderately and extremely halophilic bacteria, were enumerated. Results were similar at both temperatures. Marine bacteria and moderately halophilic microorganisms were the most favoured groups, predominating between 3 and 30% (w/v) salt content; extremely halophilic bacteria also appeared when salinity reached 30% (w/v) and halotolerant bacteria were poorly represented. The taxonomic distribution of 125 selected strains, chosen at random from counting media, was essentially similar to those from other hypersaline environments.  相似文献   

16.
A new species of Mallomonas, M. nuussuaqensis was found to be common in samples collected from waterbodies on Nuussuaq/Nûgssuaq (70N-71N, West Greenland). The species has very compact silica scales with a thick broad marginal rim and a very thick and broad hood, which often occupies more than two thirds of the shield.  相似文献   

17.
The incidence of histamine- or tyramine-producing lactic acid bacteria was examined in several products of vacuum-packed sugar-salted fish (salmon, halibut, mackerel). No histamine-producing isolates were observed, whereas the majority of tyramine-producing isolates were identified as Carnobacterium spp. These organisms were shown to be important members of the microbial flora during storage of vacuum-packed sugar-salted salmon at 5°C. The amount of tyramine produced was reduced by lowering the temperature from 9°C to 4°C for all of five strains of carnobacteria or lactobacilli. The majority of tyramine was produced during the exponential growth phase for Carnobacterium piscicola N 5 and Lactobacillus viridescens N 69. The ability of these bacteria to produce tyramine may be used as an index of microbial quality/acceptability of stored vacuum-packed sugar-salted fish.  相似文献   

18.
Knowledge of the occurrence, distribution and diversity of pathogens of insects and arachnids (entomopathogens) in the Arctic is very limited. Climate change is expected to affect Arctic terrestrial arthropod communities and therefore also host–pathogen interactions, given that entomopathogens are present. We conducted a survey of fungal entomopathogens in soil samples collected at four localities in Greenland; two at low Arctic sites (Ritenbenk and Disko Island) and two at sites in the high Arctic (Zackenberg and Danmarkshavn). Fungi were isolated from soil samples using larvae of the insect species Galleria mellonella (Lepidoptera) and Tenebrio molitor (Coleoptera) as baits providing evidence that the fungal isolates were indeed entomopathogenic. Five fungal species (Ascomycota; Hypocreales) were found: Isaria fumosorosea Wize, Isaria farinosa (Holmsk.) Fr., Beauveria bassiana (Bals.) Vuill., Beauveria pseudobassiana Rehner and Humber and Tolypocladium inflatum W. Gams (syn.?=?T. niveum). I. farinosa was found at all four localities, while I. fumosorosea was detected in single samples at each of three localities including both high Arctic sites. Only the locality on Disko Island revealed B. bassiana, whereas B. pseudobassiana was isolated at the three other sites. T. inflatum was only found on Disko Island and only isolated with T. molitor as a bait insect. The results document that fungal entomopathogens are widely distributed in the soil environment in Greenland. Entomopathogens should therefore be included in future studies of arthropod ecology in the Arctic.  相似文献   

19.
In this paper we report on the distributions of immunoglobulin allotypes among 564 olive baboons collected at six localities in Kenya. The sample localities and sizes are 1) Lake Magadi, N = 107; 2) Nanyuki, N = 77; 3) Lake Baringo, N = 55; 4) Mosiro, N = 132; 5) Isiolo, N = 36; 6) Gilgil, N = 157. Gm allotypes 1, 10, 13, 15, and 17 are polymorphic among these samples. Gm(11) and Km(3) were present in all samples, and Gm(2,3,5,6,14,16,21,24,26) and Km(1) were absent from all samples. The proportions of individuals positive for polymorphic allotypes varied substantially between different local samples, as did the arrays and estimated frequencies of haplotypes. Allotype frequencies in local samples do not appear to be simply related to either geographic location or habitat characteristics of the localities. Our data suggest that much of the geographic variability in Kenya olive baboon populations occurs between populations separated by small geographic distances.  相似文献   

20.
Anopheles gambiae Giles s.s. and Anopheles arabiensis Patton (Diptera: Culicidae) are major vectors of malaria in Nigeria. We used 1115 bp of the mitochondrial COI gene to assess their population genetic structures based on samples from across Nigeria (n = 199). The mtDNA neighbour-joining tree, based on F(ST) estimates, separated An. gambiae M and S forms, except that samples of An. gambiae M from Calabar clustered with all the An. gambiae S form. Anopheles arabiensis and An. gambiae could be combined into a single star-shaped, parsimonious haplotype network, and shared three haplotypes. Haplotype diversity values were high in An. arabiensis and An. gambiae S, and intermediate in An. gambiae M; all nucleotide diversities were relatively low. Taken together, patterns of haplotype diversity, the star-like genealogy of haplotypes, five of seven significant neutrality tests, and the violation of the isolation-by-distance model indicate population expansion in An. arabiensis and An. gambiae S, but the signal was weak in An. gambiae M. Selection is supported as an important factor shaping genetic structure in An. gambiae in Nigeria. There were two geographical subdivisions in An. arabiensis: one included all southern localities and all but two central localities; the other included all northern and two central localities. Re-analysing an earlier microsatellite dataset of An. arabiensis using a Bayesian method determined that there were two distinctive clusters, northern and southern, that were fairly congruent with the mtDNA subdivisions. There was a trend towards decreasing genetic diversity in An. arabiensis from the northern savannah to the southern rainforest that corroborated previous data from microsatellites and polytene chromosomes.  相似文献   

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