Nouvelles observations cytologiques chez Festuca rubra sensu lato (Poaceae) dans l'Est du Canada

1995 ◽  
Vol 73 (8) ◽  
pp. 1289-1294 ◽  
Author(s):  
Martin Dubé ◽  
Pierre Morisset

Sixty-one chromosome number determinations in Festuca rubra L. from eastern Canada show that hexaploids plants (n = 21) are found in both natural habitats and ruderal places, octoploids rhizomatous plants (n = 28) are mostly found in ruderal places, but also in disturbed natural habitats. Morever, one aneuploid (2n = ca. 48) is found from a natural habitat and intercytotype hybrids are found in ruderal places or disturbed natural habitats. Key words: Festuca rubra, cytotypes, hybrids.

1992 ◽  
Vol 70 (10) ◽  
pp. 1940-1944 ◽  
Author(s):  
Susan G. Aiken ◽  
George Fedak

The presence of B chromosomes is reported in Festuca altaica Trin., where a plant with relatively wide and often flat leaves had a chromosome number of 2n = 4x = 28; an adjacent plant, with conspicuously narrow and tightly rolled leaves, had 2n = 4x = 28 + 2B chromosomes. A first chromosome count of 2n = 42 is reported for Festuca rubra L. ssp. densiuscula (Hackel) Piper, along with observations on the nomenclature and morphology of this west coast subspecies. A first chromosome count for a North American plant of Festuca brevissima Jurtzev is 2n = 14. Collections made in northern Yukon were compared with the type borrowed from Leningrad and with the distribution of this species relative to the other North American diploid Festuca, Festuca aggr. auriculata Drob. A collection of Festuca brachyphylla Schultes from northern Yukon had a chromosome number of 2n = 42, and unusual morphology and phenology were interpreted as the result of a snow patch habitat. A second record for Festuca dasyclada Hackel ex. Beal of a chromosome number of 2n = 28 and justifications for keeping this species in Festuca are presented. Key words: Poaceae, North American, Festuca, chromosomes, morphology, nomenclature.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheng Gong ◽  
Liangtao Li ◽  
Jan C. Axmarcher ◽  
Zhenrong Yu ◽  
Yunhui Liu

AbstractIn the intensively farmed, homogenous agricultural landscape of the North China Plain, family graveyards form distinct cultural landscape features. In addition to their cultural value, these graveyards represent semi-natural habitat islands whose potential roles in biodiversity conservation and ecological functioning has remained poorly understood. In this study, we investigated plant species richness on 199 family graveyards of different ages and sizes. In accordance with biogeography theory, both overall and insect-pollinated plant species richness increased with area and age of graveyards. Even small graveyards show a strong potential for conserving local plant richness, and a mosaic of both large and small family graveyards could play an important role in the conservation of farmland biodiversity and related ecosystem functions. The launch of agri-environmental measures that conserve and create semi-natural habitats, in turn benefitting agricultural biodiversity and ecological functioning, has proven difficult in China due to the shortage of dispensable arable land. Given the great value of family graveyards as semi-natural habitats reflected in our study, we propose to focus preliminary efforts on conserving these landscape features as existing, widespread and culturally important semi-natural habitat islands. This would represent an effective, complementary policy to a subsequent re-establishment of other semi-natural habitats for the conservation of biodiversity and ecological functioning in agricultural landscapes.


1983 ◽  
Vol 31 (5) ◽  
pp. 695 ◽  
Author(s):  
IJ Rooke ◽  
SD Bradshaw ◽  
RA Langworthy

Total body water content (TBW) and TBW turnover were measured by means of tritiated water (HTO) in free-ranging populations of silvereyes, Zosterops lateralis, near Margaret River, W.A. Birds were studied in their natural habitats during spring and summer, and compared with a vineyard population in summer. In the natural habitat TBW content was found to be 77.6% in spring, which was not significantly different from that measured in summer (78.3%). Birds in vineyards in summer, however, were dehydrated, with a TBW content of 69.4%. Calculated rates of water influx for spring, summer and summer vineyards birds were 1.44,2.20 and 0.65 ml g.day-' respectively. These water turnover rates are much higher than those of any other bird yet studied. Dehydration was marked in the vineyard birds, with a significantly lower TBW content and an average net water loss of 0.63 ml day-'. Laboratory studies showed that silvereyes have a low tolerance to sodium loading. Their tolerance is, however, quite adequate for them to drink the most concentrated free water available to them in the field. Ingestion of concentrated sugar solutions of up to 25% did not provoke an osmotic diuresis and thus cannot account for the dehydration and negative water balance of vineyard birds.


1992 ◽  
Vol 72 (2) ◽  
pp. 473-475
Author(s):  
K. M. Ho ◽  
T. M. Choo ◽  
R. A. Martin

AC Burman is a six-rowed spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Canada Barley Breeding Group, Agriculture Canada and is adapted to Eastern Canada. It was selected from a Leger/Bruce/2/2*Leger cross. AC Burman has high yield, good test weight and is moderately resistant to loose smut (Ustilago nuda (Jens.) Rostr.).Key words: Hordeum vulgare L., six-rowed barley, feed barley, high yield


1998 ◽  
Vol 78 (2) ◽  
pp. 217-222 ◽  
Author(s):  
M. J. Edney ◽  
T. M. Choo ◽  
D. Kong ◽  
T. Ferguson ◽  
K. M. Ho ◽  
...  

Kernel colour is an important marketing trait for both malting and feed barleys. Therefore a study was initiated to investigate the kernel colour of 75 Canadian barley (Hordeum vulgare L.) cultivars at three locations (Charlottetown, Ottawa and Bentley) across Canada in 1991 and 1992. Kernel colour was measured by an Instrumar Colormet Spectrocolorimeter. Kernel colour was found to be brighter at the two locations in eastern Canada (Charlottetown and Ottawa) than at the location in western Canada (Bentley). Two-row cultivars on average were more discoloured than six-row cultivars; eastern two-row were more discoloured than western two-row. Covered barleys were less discoloured than hulless barleys in five of the six environments, but covered barleys at Bentley in 1992 were more discoloured than hulless barleys. Kernel discolouration appeared to be associated with susceptibility to net blotch for six-row cultivars. More studies are needed on kernel discolouration of barley. Key words: Barley, Hordeum vulgare, kernel colour


1983 ◽  
Vol 40 (3) ◽  
pp. 267-271 ◽  
Author(s):  
Paul Brodie ◽  
Brian Beck

The increase in population size of the grey seal (Halichoerus grypus) off eastern Canada over the past 20 yr may be attributed to a decrease in shark stocks, their supposed predators. Reduction of the shark population is presumed to have resulted from a directed longline fishery and, of greater significance, from a change in the fishery for swordfish (Xiphias gladius) from selective harpooning to pelagic longlining, which has produced a large bycatch of sharks. The resulting enhanced survival of grey seals is reflected in greater infestation of commercially important fish species by the codworm (Phocanema decipiens).Key words: grey seals, harbour seals, sharks, swordfish, codworm, predation, fisheries


2019 ◽  
Vol 77 ◽  
pp. 1-18
Author(s):  
Julien Carlier ◽  
James Moran

Across Europe, Greenways upcycle disused railway infrastructure into non-motorised public infrastructure, often with limited consideration to potential ecological synergies. Pre-development, disused transport corridors become relatively undisturbed and potentially host diverse semi-natural habitats. The study objectives were 1) to produce a highly detailed and accurate dataset using remote sensing with rapid assessment techniques for ground truthing and 2) subsequently examine habitat diversity existing along a proposed Greenway. A 7000 ha study corridor was based on a disused railway proposed as a transfrontier Greenway connecting the Republic of Ireland and the United Kingdom. The study applied a rapid-assessment virtual validation techniquealongside remote sensing and accuracy assessment. Inter-relationship between seminatural habitat diversity and land-use intensification was examined. Remote sensing accuracies of 89% and 99% for a real and linear habitat classification were obtained. Degrees of land-use intensification were observed throughout the corridor, highlighting the importance of maintaining and enhancing remaining semi-natural habitat that exists along the proposed Greenway route. Through understanding the landscape matrix composition and semi-natural habitat diversity, European Greenwayscan achieve multi-functionality for ecosystem conservation, forming integral components of Green Infrastructure.


2012 ◽  
Vol 10 (4) ◽  
pp. 75-96
Author(s):  
Piotr Matyjasiak

The aim of this paper is (i) to review the method of valorization of natural resources as applied in the environmental impact assessment, and (ii) to develop recommendations on how valorization expertise should be prepared in order to be comprehensive and transparent. Valorization is the proper time to carry out identi>cation of the possible negative environmental impacts and damages of a planned project. It is recommended to perform valorization due to the state (numbers) and functions (quality) of natural resources. This approach is related to the concept of environmental damage, which is defined as a measurable adverse change in a natural resource or measurable impairment of a natural resource service (which means the functions performed by a natural resource for the benefit of another natural resource or the public). Valorization of natural resources should include an assessment of potential environmental damage, including an impact on the local biodiversity, the ecological connectivity, the N2000 network, and the legally protected areas. The valorization of natural resources should be performed at the following thematic levels focusing on the role of the area under consideration due to: (1) the implementation of the objectives of protection of Nature 2000 network and its overall coherence, (2) the implementation of the objectives of protection of legally protected areas other than N2000, (3) the maintenance of the ecological connectivity in a context other than the coherence of Nature 2000 network, (4) the maintenance of species and natural habitats with favorable conservation status, (5) the conservation of species and natural habitat types that are not legally protected.


Author(s):  
Vladimir Grigor'ev ◽  
Dan Chuong Fam Thi ◽  
Rustam Nizamov ◽  
Igor' Grigor'ev

Aquaculture is one of the most promising and dynamically developing types of agricultural production, especially in countries with warm climates. The research was carried out to analyze the current situation in aquaculture in Vietnam to clarify the existing problems and prospects of this industry. When collecting materials, we used statistical data from the Government of the Socialist Republic of Vietnam, as well as information from representatives of the Institute of Economics and Business of the Vietnam National University (Hanoi). In the Socialist Republic of Vietnam, aquaculture is well developed and continues to actively expand, annually increasing the production of products that are in significant demand on the world market. One of the most important problems of the industry is the threat to natural biodiversity, primarily due to the reduction of the natural habitats of the inhabitants of rivers and mangroves. An equally important problem is the strong dependence of the production of products, primarily shrimp, on foreign markets, which today is objective and insurmountable. Due to the use of chemicals and antibiotics in aquaculture, especially in natural conditions, environmental degradation is possible. Among the promising areas for the development of the industry is the convergence of natural ecosystems and agriculture, a good example of which is the cultivation of shrimp in mangroves without destroying the forest cover. It is possible to switch to aquaculture as an adaptation to changes in the ecological situation, primarily to the salinization of river deltas. As a result of a decrease in the profitability of fishing in the natural habitat of fish and shrimps, an increase in their populations in natural conditions is possible


2021 ◽  
Vol 12 ◽  
Author(s):  
Zhaoying Zeng ◽  
Dan Mou ◽  
Li Luo ◽  
Wenlin Zhong ◽  
Lin Duan ◽  
...  

Cordyceps cicadae is an entomogenous fungus with important uses in traditional Chinese medicine. However, its wild resources have not met consumers’ demand due to excessive harvesting practices. Artificial cultivation is therefore an important alternative, but research on cultivating C. cicadae in natural habitats has not been reported. In this study, we aimed to explore the viability of cultivating C. cicadae in a natural habitat, in the soil of Pinus massoniana forest. We assessed and compared the yield, metabolite contents and bacterial community composition of C. cicadae grown in the Antheraea pernyi pupae at different growth stages, and under different cultivation conditions, in the soil of a natural habitat and in sterile glass bottles. Our results showed that cultivating C. cicadae in a natural habitat is feasible, with up to 95% of pupae producing C. cicadae fruiting bodies. The content of nitrogen compounds (amino acids) in C. cicadae cultivated in a natural habitat was significantly higher than in glass bottles, while the yield and carbon compound (mannitol and polysaccharide) and nucleoside (cordycepin and adenosine) contents were lower. Different bacterial genera were enriched in C. cicadae at different growth stages and cultivation environments, and these bacterial genera were closely related to metabolites contents during growth. This study demonstrated the viability of a novel cultivation method of C. cicadae, which could be used as an alternative to wild stocks of this fungus. These findings provided new insights into the growth mechanism of C. cicadae and its interaction with soil microorganisms.


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