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141.
陕西佛坪国家级自然保护区羚牛的容纳量   总被引:10,自引:0,他引:10  
陕西佛坪国家级自然保护区位于秦岭南坡的中段 ,1998~ 1999年冬季通过分层抽样的方法 ,测定了保护区内羚牛秦岭亚种 (Budorcastaxicolorbedfordi) 10种栖息地类型的单位面积食物资源量和含有的能量 ,估计了越冬区可以利用的总能量。结果表明 ,羚牛越冬区提供的可供羚牛和其它草食动物利用的能量为 (9 877±5 173)× 10 12 J,每只羚牛平均每天需要的能量为 2 6 4 8± 11 88kJ ,整个冬季需要的能量为 4 82 0± 2 16 3× 10 6J ,保护区的羚牛容纳量为 2 0 4 9± 10 37只。考虑到羚牛对空间的需求、保持最佳繁殖状态、其它草食动物种群的需求和保护当地植被等因素 ,建议保护区将羚牛种群的数量控制在 10 0 0只左右.  相似文献   
142.
觅食是获取营养物质和能量的重要途经。对于栖息在四季分明地区的灵长类动物而言,低温以及食物资源相对匮乏的冬季是其生存和生长发育的瓶颈期。本研究以安徽黄山的野生藏酋猴(Macaca thibetana)天湖山群为对象,于2019年11月至2020年1月采用瞬时扫描取样法(Instantaneous scan sampling)采集猴群觅食行为数据,并分析其冬季食物组成及食物中各化学成分含量对取食的影响。结果显示,野生藏酋猴在冬季共取食23科31属34种植物,主要包括壳斗科(Fagaceae, 21.62%)、樟科(Lauraceae, 17.57%)、蔷薇科(Rosaceae, 8.11%)的植物,取食部位以叶片(66.22%)和果实(种子)(24.32%)为主。不同取食部位的水分、总糖、淀粉、脂肪、单宁等成分存在显著差异。其中,叶片的水分含量高于果实(种子)、茎和芽,茎和果实(种子)含有较高的总糖,果实(种子)的淀粉和脂肪含量最高,芽的单宁含量最高。此外,取食植物中的总糖含量高于非取食植物。结果表明,野生藏酋猴适应寒冷冬季与食物匮乏的觅食策略是对植物种类、植物部位及其主要营养成分的综合结...  相似文献   
143.
The research was designed to characterize the phenological behaviour of different apple varieties and to compare different bioclimatic indexes in order to evaluate their adaptability in describing the phenological phases of fruit species. A field study on the requirement for chilling units (winter chilling requirement) and the accumulation of growing degree hours of 15 native apple cultivars was carried out in a fruit-growing area in North West Italy (Cuneo Province, Piedmont). From 1991 to 1993, climatic data were collected at meteorological stations installed in an experimental orchard (Verzuolo, Cuneo). Four methods were compared to determine the winter chilling requirement: Hutchins, Weinberger-Eggert, Utah and North Carolina. The Utah method was applied to determine the time when the chilling units accumulated become effective in meeting the rest requirements. A comparison of the different methods indicated that the Weinberger-Eggert method is the best: as it showed the lowest statistical variability during the 3 years of observations. The growing degree hour requirement (GDH) was estimated by the North Carolina method with two different base temperatures: 4.4°C and 6.1°C. More difficulties were met when the date of rest completion and the beginning of GDH accumulation was determined. The best base temperature for the estimation of GDH is 4.4°C. Phenological and climatic characterizations are two basic tools for giving farmers and agricultural advisors important information about which varieties to choose and which are the best and the most correct cultivation practices to follow. Received: 25 October 2000 / Revised: 6 August 2001 / Accepted: 6 August 2001  相似文献   
144.
Space requirements by winter sports and accelerating global warming are usually perceived as stressors for mountain meadow plant communities. Cross-country ski track preparation (i.e. grooming), however, might retard effects of climate change and, being limited in space requirements, might increase abiotic heterogeneity. The effect of cross-country ski tracks on meadow vegetation was quantified along a representative ski track that had been operated for 30 years in the Fichtelgebirge, a low mountain range in central Europe. Paired sampling was implemented to assess the effect of skiing operations on snow and soil properties, plant phenology, biomass production and species composition. Additionally, boosted regression tree analyses were used to quantify the relative importance of the cross-country ski track compared to other environmental conditions.The cross-country ski track strongly increased snow density, enhanced soil frost, and retarded snowmelt, thereby delaying flower phenology (by 2.1 days) and the early development stages of plant species on the track. However, biomass, species richness and species composition were unaffected by skiing operations except for one species (Leontodon autumnalis) showing exclusive occurrence on the track while four others showed reduced relative occurrence on the track.While snow and soil properties were influenced by cross-country ski track preparation, natural environmental variability was more influential for species composition and biomass production than the ski track. We therefore conclude that the ski track – without artificial snow – did not negatively affect species composition. By delaying flower phenology, effects of the ski track even counteracted global warming to some degree. Due to their small spatial extent in the landscape, these ski tracks may add to environmental heterogeneity and thus support sustaining diverse species compositions during environmental changes.  相似文献   
145.
We cloned seven microsatellite loci from house wrens (Troglodytes aedon) using a biotin enrichment protocol. Starting with fragments generated using DOP–PCR, fragments containing microsatellite motifs AC and AAC were captured using biotinylated probes and streptavidin coated magnetic particles. Captured fragments were cloned into plasmids; prior to sequencing, the plasmids were screened for microsatellites using a simple PCR approach. Five of the loci showed variation in a sample of nine individuals.  相似文献   
146.
The effects of a combined fungicide and growth regulator treatment on the composition and dry matter digestibility of straw samples of winter wheat cultivars, Beaver, Brigadier, Hussar, Mercia, Riband, Genesis, Hunter, Spark, Cadenza and Flame, were compared. The samples were analysed for nitrogen, ash, fibre fractions and minerals. Nitrogen content of treated samples was reduced compared to the untreated control samples and in contrast the proportion of ash increased for all the treated samples. All samples were analysed by derivative thermogravimetry (DTG) to determine changes in fibre composition. Only six cultivars were analysed by chemical fractionation methods to determine changes in lignin, cellulose and hemicellulose content. The results from the two methods of fibre analysis were broadly similar. K, Ca, Mg and Na concentrations of the treated straw samples were found to be different to the untreated samples. Increase in dry matter digestibility (DMD) of treated straw was observed for all cultivars; the effects on Beaver, Brigadier, Mercia, Riband, Genesis, Hunter and Cadenza were most pronounced, but were less for Hussar, Spark and Flame. The potential impact of these changes in straw quality on organic mushroom compost preparation is briefly discussed.  相似文献   
147.
绿尾虹雉的冬季生态研究   总被引:9,自引:1,他引:8  
绿尾虹雉(Lophophorus lhuysii)属雉科(Phasianidae)虹雉属(Lophophorus),是我国特有珍稀雉类,列为国家一类保护动物。我们于1983年起对绿尾虹雉的生态进行专题研究,现根据对绿尾虹雉的野外考察所得,整理成本文。 野外考察的时间、地点、及路线 我们于1983年4月至1984年7月在四川省宝兴县跷碛公社对绿尾虹雉的生态做了四次考察,前后为期近十个月,其中冬季考察时间为1983年12月至1984年1月。  相似文献   
148.
The anterior nasal spine (ANS) is considered by some to be a unique characteristic of modern humans; however, it has been reported to occur in chimpanzees. Among human populations, ANS size correlates with facial prognathism and timing of premaxillary-maxillary sutural fusion, which may have implications for models of midfacial growth. To investigate these questions, skulls from 55 chimpanzees (Pan troglodytes) (29 male, 26 female), ranging in age from infants to adults, were examined. None of the 55 specimens examined had a true ANS, but a number of specimens exhibited raised anterior nasal prominences or tubercles (ANT) on the nasal surface of the premaxilla. Female specimens had significantly (P less than .05) more ANTs and more extensive fusion of both the palatal and facial components of the suture than did the male specimens. Results from the present study document the presence of an ANT in a sample of chimpanzee crania and are consonant with associations predicted by a septal-traction model of midfacial growth.  相似文献   
149.
A systematic analysis of space utilization in the home enclosures of four adult and three juvenile social groups of chimpanzees (Pan troglodytes) was conducted at the Primate Foundation of Arizona. The locations of all members of each group (excluding nursing infants) were recorded several times per week over a 3-month period. Adult chimpanzees were observed significantly more often in small vs large cages, on upper vs lower levels, and near cage perimeters vs cage centers. Analyses of sex differences in adults revealed that adult females are largely responsible for these space use patterns; adult males show only a significantly higher usage of perimeter areas. Individual differences were found in the habitual use of certain enclosure sites. Juveniles show no spatial patterns with regard to the above parameters but appear to evenly use all available space. Both adults and juveniles were observed to be in contact with mesh barriers more often than with solid walls. These findings suggest important elements that should be incorporated into the caging design of captive chimpanzee facilities.  相似文献   
150.
The euchromatic regions of chimpanzee (Pan troglodytes) genome share approximately 98% sequence similarity with the human (Homo sapiens), while the heterochromatic regions display considerable divergence. Positive heterochromatic regions revealed by the CBG-technique are confined to pericentromeric areas in humans, while in chimpanzees, these regions are pericentromeric, telomeric, and intercalary. When human chromosomes are digested with restriction endonuclease AluI and stained by Giemsa (AluI/Giemsa), positive heterochromatin is detected only in the pericentromeric regions, while in chimpanzee, telomeric, pericentromeric, and in some chromosomes both telomeric and centromeric, regions are positive. The DA/DAPI technique further revealed extensive cytochemical heterogeneity of heterochromatin in both species. Nevertheless, the fluorescence in situ hybridization technique (FISH) using a centromeric alpha satellite cocktail probe revealed that both primates share similar pericentromeric alpha satellite DNA sequences. Furthermore, cross-hybridization experiments using chromosomes of gorilla (Gorilla gorilla) and orangutan (Pongo pygmaeus) suggest that the alphoid repeats of human and great apes are highly conserved, implying that these repeat families were present in their common ancestor. Nevertheless, the orangutan's chromosome 9 did not cross-hybridize with human probe. The euchromatic regions of chimpanzee (Pan troglodytes) genome share approximately 98% sequence similarity with the human (Homo sapiens), while the heterochromatic regions display considerable divergence. Positive heterochromatic regions revealed by the CBG-technique are confined to pericentromeric areas in humans, while in chimpanzees, these regions are pericentromeric, telomeric, and intercalary. When human chromosomes are digested with restriction endonuclease AluI and stained by Giemsa (AluI/Giemsa), positive heterochromatin is detected only in the pericentromeric regions, while in chimpanzee, telomeric, pericentromeric, and in some chromosomes both telomeric and centromeric, regions are positive. The DA/DAPI technique further revealed extensive cytochemical heterogeneity of heterochromatin in both species. Nevertheless, the fluorescence in situ hybridization technique (FISH) using a centromeric alpha satellite cocktail probe revealed that both primates share similar pericentromeric alpha satellite DNA sequences. Furthermore, cross-hybridization experiments using chromosomes of gorilla (Gorilla gorilla) and orangutan (Pongo pygmaeus) suggest that the alphoid repeats of human and great apes are highly conserved, implying that these repeat families were present in their common ancestor. Nevertheless, the orangutan's chromosome 9 did not cross-hybridize with human probe. © 1995 Wiley-Liss, Inc.  相似文献   
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