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1.
凉粉草资源的开发利用   总被引:2,自引:0,他引:2  
本文简介了我国凉粉草(MesonachinensisBenth.)资源的状况,论述了凉粉草的生态生物学特性、栽培技术、化学成分、利用价值和加工方法,还展望了凉粉草的开发利用前景。  相似文献   

2.
本文根据布氏田鼠、达乌达鼠兔、达乌尔黄鼠和草兔在自由生活下的食物组成,分别计算了它们之间的实际营养生态位重叠程度及生态位宽度。还计算了布氏田鼠、达乌尔鼠兔和达乌尔黄鼠间的原始营养生态位重叠程度及宽度。由于栖息地资源可利用性的限制,这3种小哺乳动物的实际营养生态位较原始营养生态位穿。分布空间的重叠可导致布氏田鼠与达乌尔鼠兔间实际营养生态位的较高程度重叠。此结果支持了MacArthur和Wilson(  相似文献   

3.
以小麦族赖草属植物的6个种:赖草(Leymussecalinus)、窄颖赖草(L.angustus)、单小穗赖草(L.aemulans)、多枝赖草(L.multicaulis)、大赖草(L.racemosus)和天山赖草(L.tianshanicus)作试验材料,分别组配成5个种间杂交组合,并与新麦草属(Psathyrostachys)、鹅观草属(Roegneria)以及Thinopyrum属组配成9个属间杂交组合。应用胚胎培养技术,离体培养杂种胚胎,成功地拯救了赖草植物的种间和属间杂种。试验结果表明,杂种胚胎的胚龄、培养基的营养组成以及杂种基因型对离体胚胎的培养有明显影响。  相似文献   

4.
本文报道草兔胃内的四川尖柱线虫,新种Obeliscoides sichuanensis sp.nov.本新种同已知种有明显不同。  相似文献   

5.
赖草属5个种的核型与进化   总被引:15,自引:2,他引:13  
报道了国产赖草属5个种的核型,即大赖草,2n=4x=28=24m(2SAT)+4sm(2SAT);粗穗赖草2n=4x=28=22m(2SAT)+4sm+2st(2SAT);若羌赖草,2n=4x=28=20m(4SAT)+6sm+2st(2SAT);羊草,2n=4x=28=22m(4SAT)+2sm+4st(4SAT);窄颖赖草,2n=4x=28=22m(2SAT)+4sm(2SAT)+2st(2S  相似文献   

6.
蔡联炳   《广西植物》1996,16(3):199-202
报道了禾本科鹅观草属二新种和以礼草属一新种,即稀节鹅观草(Roegnerialaxinodis),缩芒鹅观草(Roegneriacurtiaristata)和沙湾以礼草(Kengyiliashawanensis).  相似文献   

7.
柑桔园生草栽培的生态效应研究   总被引:14,自引:0,他引:14  
柑桔园生草栽培的生态效应研究李国怀章文才刘继红胡德文(华中农业大学园艺系,武汉430070)StudiesofEcologicalEfectsofSodCultureinCitrusOrchard.LiGuohuai,ZhangWencai,LiuJ...  相似文献   

8.
回心草的开发利用严启新张荣平(云南中医学院中药硕士研究生,650200)(昆明医学院药学系,650031)何广新罗天浩(昆明市药检所,650034)(云南中医学院药学系,650200)回心草为真藓科植物大叶藓RhodobryumroseumLimp....  相似文献   

9.
山鹛(Rhopophiluspekinensis)为山西省留鸟和优势种。关于它的繁殖习性在国内只有零星报道。1997—1998年,我们在历山自然保护区对山鹛的繁殖生态作了初步观察。1工作区概况山西历山自然保护区位于中条山东部,地处东经111°51′-...  相似文献   

10.
相山虫草──蝉草王光,朱学玲(安徽省淮北矿务局岱河矿中学235037)蝉草是由一种子囊菌纲(Ascompcetes)、肉座目(Hypcoreales)、虫草属(oordyceps)的真菌寄生于同翅目(Homoptera)、蝉科(Cicadidae)、...  相似文献   

11.
The mountain hare (Lepus timidus) population in southern Norway appears to be in decline. Necropsy and laboratory examinations of 36 hares found dead or diseased during 2007-2009 in Vest- and Aust-Agder counties showed that disease and deaths were attributed to multiple causes, with no specific etiology emerging as a cause for population decline. To investigate whether Borrelia burgdorferi sensu lato (s.l.) infection is associated with mortality in mountain hares, tissues and ticks collected from hares were investigated for infection with the spirochete. Borrelia burgdorferi s.l. DNA was not detected in samples from internal organs, whereas Borrelia afzelii, B. burgdorferi sensu stricto (s.s.), and the not-yet-defined Borrelia sp. SV1 were found in skin samples from hares and in adult and nymphal Ixodes ricinus feeding on hares. Only B. burgdorferi s.s. and Borrelia sp. SV1 were detected in larvae feeding on hares. Our results indicate that disseminated Borrelia infection in hares rarely occurs and, presumably, does not play a central role in the suspected population decline. The results also suggest that the mountain hare to some degree functions as a transmission host for B. burgdorferi s.s. and Borrelia sp. SV1.  相似文献   

12.
Since October 1986 an unusually high mortality has been observed both in wild European brown hares (Lepus europaeus) and in hare farms in Italy. Pathological alterations, including severe hepatosis, nephrosis, congestion and hemorrhages of tracheal mucosa and lungs, and splenic vascular congestion, were observed in 179 of 381 hares necropsied from 1986 to 1988. Jaundice also was seen in 30% of these hares. Histologically, the liver damage was characterized by coagulative necrosis, mainly located around the portal areas, or by degenerative changes. Hyperemia, focal hemorrhages and periportal mononuclear cell infiltration were also present. The epithelium of renal tubules showed the presence of various degrees of vacuolar degeneration and necrosis, and eosinophilic granular hyaline casts or homogenous proteinaceous material were found within the lumen of tubules. Only the adult hares were affected. In wild hare populations night counts revealed a reduction of the number of observed wild hares during the winter period which ranged from 27 to 40%, whereas in hare farms the mortality ranged from 30 to 90%. Bacteriological, parasitological, and toxicological investigations were unable to confirm the primary cause of these deaths. Negative stain electron microscopy and immunoelectronmicroscopy conducted since October 1988 on liver and spleen homogenates from hares with acute hepatosis revealed the presence of viral particles with morphological aspects resembling those of calicivirus, antigenically related to the etiological agent of viral haemorrhagic disease of rabbits.  相似文献   

13.
The number of European brown hares (Lepus europaeus) has been declining throughout much of Europe since the 1960s. Consequently, many studies have focused on analysing habitat selection of European hares in order to improve the suitability of the habitat for this species. Habitat preferences of European hares are known to be affected by hare density, but most studies have been conducted in agricultural areas where hare densities were medium to high. Finding habitat preferences at high densities is difficult as most available habitats are occupied. In addition, in agricultural areas, field size might influence the hares’ habitat selection because it affects the distribution and availability of certain habitat types. However, most studies relate to areas with large field sizes. In this study, we analysed the habitat preferences of European hares in spring and autumn during the activity period, in the early hours of the night, in an agricultural area with low hare density and small average field size using Chesson’s electivity index. Moreover, we focused on the question whether two different habitat classifications varying in their specificity might cause contradictory results regarding European hares’ habitat preferences. Our results show that in this agricultural area with low hare density, European hares avoided several habitat types which were preferred in other study areas with higher hare densities. Therefore, we assume that hare density has an influence on the species’ habitat selection. In contrast, the small average field size of our study area seemed not to have an effect on hare habitat preference. Furthermore, by pooling habitat types into broader groups, substantial information was lost in some categories. Hence, for some categories, e.g. grassland or agricultural crop land, more detail might be needed than for others, such as urban areas, when analysing hares’ habitat selection. In conclusion, our results imply that studies on habitat preferences have to be conducted in areas with low hare density to be able to gain knowledge on the species’ habitat requirement and hereinafter improve the suitability of the habitat for this species.  相似文献   

14.
Across most of their range in Europe, mountain hares are usually restricted to upland areas with poor food quality. In these areas they generally feed on browse species such as heather or twigs and barks of trees. On lowland areas in Europe, with better food quality, the mountain hare is replaced by the brown hare ( Lepus europaeus ) which feeds predominantly on greasses. This khas led some authors to conclude that mountain hares are primarily adapted for browsing. In the absence of brown hares in Ireland, mountain hares are found on a wide variety of habitats including grassland. On grassland, their diet consists almost exclusively of grasses, up to 94% of their annual diet, which is more than has been reported for brown hares on similar habitat. Based on this evidence, and other work, it is proposed that the mountain hare in primarily a grazing animal and competitive exclusion by brown hares may underlie much of their present distribution in Europe.  相似文献   

15.
The progressive decline in the hare population across Europe has been associated with the occurrence of European brown hare syndrome (EBHS), a highly contagious disease considered endemic in all European countries. This study aimed to evaluate the in-field temporal dynamics of European brown hare syndrome virus (EBHSV) infection in wild European brown hares (Lepus europaeus) and to test the influence of population density on EBHS seroprevalence. A total of 512 blood samples were collected from free ranging hares captured for restocking in seven different areas of the province of Brescia (Northern Italy) during seven consecutive years (2006–2013) and tested using a competitive ELISA. A generalized linear mixed model estimated the yearly effects of population density on EBHS prevalence. Of the 512 tested, 344 (67.2 %) tested positive for EBHSV antibodies, with the annual seroprevalence ranging from 94.3 to 35.8 %. The prevalence was 3.303 times higher in areas with a density of over 15 hares/km2 and declined over the years. The results indicate the ongoing transmission of the virus in the tested brown hare population. Since the eradication of EBHS in a wild population is not feasible, a strategy aimed at promoting the endemic stability of the virus through density-dependent mechanisms could be applied; however, this seems more difficult in practice than in theory and would most likely require a very high density of brown hares.  相似文献   

16.
In many areas, the management of overexploited populations of brown hare (Lepus europaeus) is based on annual restocking. While in some cases exotic hares are introduced, in some others hares are captured locally within protected areas and subsequently released into hunting grounds. We evaluated the genetic effects of this management regime in an Italian province where the brown hare population has recovered in the last few decades, by sequencing the hypervariable domain 1 of the mitochondrial control region and by genotyping eight autosomal microsatellites in hares sampled in both hunting and non-hunting areas. Both nuclear (H e?=?0.68 and H o?=?0.65) and mitochondrial variability (h?=?0.853 and π?=?0.012) were in line with other European populations. When comparing our data with mitochondrial sequences retrieved from GenBank, out of the 21 detected haplotypes, 14 were private to our study area. While 4.6 % of the individuals were found to carry haplotypes attributable to past introductions, 41.5 % grouped within a well-supported lineage, previously identified with a presumed native Italian taxon, L. e. meridiei. Despite the detectable geographic partitioning of mitochondrial haplotypes across the province, no genetic structure resulted from microsatellites analysis, indicating that no reproductive barriers exist among hares carrying different mitochondrial lineages. In conclusion, the local management seems to have contributed to the recovery of the species and to a full admixture of nuclear genes in the province. However, neither the extensive translocations nor the possible introductions of exotic heads seem to have completely undermined the local mitochondrial lineages.  相似文献   

17.
Abstract: The fecal pellet-plot method has been used extensively for snowshoe hare (Lepus americanus) population studies across the species' range, but potential biases associated with the technique have not been addressed adequately. We studied hare pellet-plots in northern Idaho to quantify pellet decomposition rates across environmental gradients, and conducted feeding trials on captive hares to assess the role of diet on pellet production rates. We found that across our study area pellet numbers tended to be higher on plots with high vegetative cover, which likely was a reflection of hare habitat choice rather than lesser pellet decomposition in such habitat. A pellet decomposition experiment indicated that pellet persistence was negatively related to moisture level, and that pellets produced by hares during summer decomposed more quickly than those from winter. We found that only 19% of fecal pellets collected from plots located across northern Idaho were produced by hares during winter. There was a correlation between pellet numbers from plots that were pre-cleared 1 year earlier and estimated numbers of hares on 6 study areas. A similar correlation was lacking for pellet counts from uncleared plots, implying that hare population estimation via pellet-plot counts should involve plot pre-clearing. In captive studies, juvenile hares produced slightly fewer pellets per day per gram of food ingested than adults, but pellet production was similar across diets comprised of 10 different browse species. We conclude that for our study area the fecal pellet-plot method may be subject to notable pellet decomposition bias, and therefore recommend that use of the method elsewhere across the species' range be preceded by assessment of both the pellet-hare density relationship and pellet decomposition rates across habitats.  相似文献   

18.
From 1997-99 European brown hare (Lepus europaeus) population densities were estimated by spotlight surveys within different areas in Schleswig-Holstein, Germany. These areas showed a wide variation in local hare population densities. In addition, red fox (Vulpes vulpes) densities were estimated in 1997 by surveys of fox dens and litters. Sera of 321 hares (shot between 1998-2000) from four study areas were examined for antibodies against European brown hare syndrome virus (EBHSV) by enzyme linked immunosorbent assay (ELISA), Yersinia spp. (n = 299) and Francisella tularensis (n = 299) by western blotting, Brucella spp. by Rose Bengal test, and Toxoplasma gondii by Sabin-Feldman test (n = 318). Tissue samples comprising lung, liver, spleen, kidney, heart, and adrenal glands were collected for histopathology. Liver (n = 201) and spleen (n = 201) samples were processed for the detection of T. gondii-antigen in tissue sections and 321 liver and spleen samples were investigated for EBHSV-antigen by ELISA. Furthermore, 116 hares were examined macro- and microscopically for lungworms. Significant negative correlations between hare and fox densities were found in spring and autumn 1997. Antibodies against EBHSV were detected in 92 of 321 (29%), against Yersinia spp. in 163 of 299 (55%), and against T. gondii in 147 of 318 (46%) hares. We evaluated the potential influence of origin and hunting season on exposure rates of hares using logistic regression analysis. A strong association between hare densities and exposure rates was observed for various agents. One hundred and eight of 201 (57%) hares were positive for T. gondii-antigen. All sera were negative for antibodies against Brucella spp. and F. tularensis and all lung samples were negative for lungworms. In conclusion, variation in red fox densities may have an impact on the hare populations examined and the infectious diseases we studied seem to play a subordinate role in the dynamics of European brown hare populations from Schleswig-Holstein.  相似文献   

19.
We evaluated patterns of occurrence and non-occurrence for Canada lynx (Lynx canadensis) across a 16,530-km2 study area in Maine to provide a better understanding of lynx habitat selection and habitat ecology on commercially managed forestlands in the Acadian Forest. Because of the influence of forest structure on lynx habitat selection and abundance of their primary prey, the snowshoe hare (Lepus americanus), and to improve our ability to build robust models, we used habitat information derived from a time series of Landsat satellite imagery spanning the period 1973–2004. We defined and mapped 10 forest types based on forest harvest history, time since harvest, and current forest condition. We compared a suite of models to evaluate relative influences of forest composition, habitat patch configuration, and hare density on habitat selection by lynx at the landscape scale. Occupied areas had greater average hare densities and percentage of mature conifer. Average hare density in occupied areas (0.74 hares/ha) was greater than in unoccupied areas (0.62 hares/ha), but was less than previous research has suggested may be necessary to support lynx populations in the southern portion of the species' range. No occupied areas occurred where average hare density was <0.5 hares/ha. Average hare density at the landscape-scale was strongly influenced by amount of high-quality hare habitat (i.e., conifer or mixedwood regenerating forest, 15–35 yr post-harvest). Edge density between mature conifer and high-quality hare habitat was substantially greater in occupied areas compared to unoccupied areas. Juxtaposition of those 2 forest types may provide edge habitat where lynx experience easier travel and improved access to prey in landscapes with extensive areas of high-quality hare habitat where travel and access may be somewhat limited by high understory stem density. Probability of occurrence declined nonlinearly with changes in hare density and percent mature conifer forest in the landscape; thus, suitability of currently occupied landscapes could change markedly with future changes in landscape-level hare densities and changing habitat associated with forest management. Where lynx conservation is a priority, we recommend that managers focus on creating and maintaining a minimum of 27% high-quality hare habitat within 100-km2 areas to promote landscape-scale hare densities >0.5 hares/ha. © The Wildlife Society, 2013  相似文献   

20.
Snowshoe hares (Lepus americanus) undergo 8- to 11-year population cycles caused by direct and/or interactive effects of overwinter food shortage and predation. However, the demographic significance of food shortage during cyclic population lows remains unclear. I evaluated the importance of overwinter food limitation to the demography (numbers, age and sex ratios) of low-density hare populations during two winters in Manitoba. Also, I examined whether the hypothesized differences in demography of fed and unfed hare populations could be explained by altered movement patterns or social dynamics. Bimonthly live-trapping revealed that food failed to have a direct long-term effect on the number, or change in number, of hares estimated to be on the three supplemented areas, relative to three control areas. Modest numerical responses to supplementation tended to be short-term (i.e., restricted to winter) and related to pre-supplementation densities, with the study area characterized by the highest hare density displaying the strongest and most consistent response to added food. During winter the percentage of females was remarkably variable among study areas and time periods, but added food may have augmented slightly the proportion of females captured in traps. There tended to be slightly more juveniles on supplemented areas during winter periods, and this effect was strongest during the first winter (1991–1992). I found that immigration rates and percentage of hares that were considered to be transient animals were similar on supplemented and control areas, and that spatial distribution of radio-collared animals on versus off of study areas also was similar. Because the overall effect of food on hare populations was small and short-lived, and could be explained largely by small increases in survival and reproduction, I conclude that the study population was not subject to overwinter food limitation. Received: 22 February 1998 / Accepted: 12 February 1999  相似文献   

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