五台山草地自然保护区植物中钠元素的含量

通过对五台山草地自然保护区植物中钠元素的的分析，揭示了五台山草地自然保护区植物中的元素的含量特征及钠元素在不同植被垂直带，植物不同科间和不同研听分布特征。     

五台山草地自然保护区不同植物化学元素含量的研究

本文首次对五台山草地自然保护区五个植被垂直带中32种植物的48个样品中N、P、K、Ca、Mg、Mn、Cu、Zn、Co、Cr、Ni、Ph和Cd等13种化学元素的含量进行分析，初步揭示出本区植物中化学元素含量的区域特征以及在不同植被垂直带中草本、阔叶、针叶植物及其不同器官中元素的含量与分布规律．     

五台山草地自然保护区植物中铅元素含量的初探

初步研究了五台山草地自然保护区植物中铅元素含量及分布.结果表明,五台山区植物中铅元素的含量范围为未检出～15.63mg/kg,平均含量为6.54mg/kg;不同植被垂直带中铅含量以常绿针叶林带最低,亚高山草甸带最高;不同科植物中铅含量以莎草科植物最高,松科植物最低,草本、阔叶植物、灌木植物含铅量高于针叶植物.     

五台山草地自然保护区植物中铅元素含量的初探

初步研究了五台山草地自然保护区植物中铅元素含量及分布。结果表明，五台山区植物中铅元素的含量范围为末检出￣１５．６３ｍｇ／ｋｇ，平均含量为６．５４ｍｇ／ｋｇ；不同植被垂直带中铅含量以常绿针叶林带最低，亚高山草甸带最高；不同科植物中铅含量以莎草科植物最高，松科植物最低，草本，阔叶植物，灌木植物含铅量高于针叶植物。     

五台山草地自然保护区植物中钴的含量及分布特征

对五台山草地自然保护区植物中钴的含量及分布特征进行了研究。结果表明：五台山草地自然保护区植物中钴的含量范围为０．０９～０．９５ｍｇ／ｋｇ,平均含量０．５５８ｍｇ／ｋｇ,钴的含量较为丰富,完全能够满足反刍动物的需要,五台山各植被垂直带钴含量的分布特征是随海拔的升高而升高,各植被垂直带和各科植物,特别是豆科植物具有较高的钴含量水平。     

青海湖北岸草地土壤和植物钠、锶、锂矿质元素含量与草地植被特征的关系

选择青海湖北岸退化草地和围栏封育草地为试验样地,通过调查各类型草地及典型植物中钠、锶、锂等矿质元素的含量和植物株高。结果表明：各试验样地退化与封育草地的植被和土壤中钠、锶、锂等矿质元素含量具有差异性。河边滩地、那仁火车站和烂泥湾退化草地植被中钠分别为418.9,370.4和330.3mg/kg,而土壤中则分别为212.8,406.7和593.6mg/kg,锶分别为78.03,239.6和245.3mg/kg,而土壤中则分别为181.9,333.9和187.2mg/kg。退化草地较封育草地植物中钠、锶、锂等均具有蓄积性,且与植物的株高具负相关关系。同一植物种在不同样地钠、锶、锂等矿质元素含量也具有明显的差异性,随着海拔高度增加,同一植物钠元素含量显著降低,而锶、锂元素含量却在增大。     

五台山草地资源保护与资源利用探讨

研究五台山草地生态环境特征及草地资源利用,是对我国北方农牧交错带草地植物合理利用的一种新尝试,对更好地保护草地开发利用资源有着重要意义。对五台山草地资源概况进行了介绍,分析了五台山草地资源保护利用存在的问题,提出了相关建议。     

五台山草地自然保护区草地资源的开发利用

通过总结和分析五台山草地自然保护区植被类型,分布物征及饲用价值,表明亚高山草甸和山地五花草甸是理想的夏季放牧地,为了使草地资源保护与社会经济协调发展,对草地资源的开发利用提出以下建议;（１）加强科学管理,使五台山草地资源能持续利用;持续发展;（２）建立豆科＋禾本科混播人工草地;（３）发展季节性畜牧业;（４）建立畜牧业绿色食品基地;（５）开展草地生态旅游;（６）充分发挥五台山草地自然保护区在教学和科     

五台山草地自然保护区主要豆科植物的地理成分及饲用价值

就五台山草地自然保护区主要豆科植物的地理成分及饲用价值进行了研究。结果表明，五台山草地自然保护区现有豆科植物１０属２７种，属５个分布区２个亚区。大部分在群落为伴生种。这些豆科牧草具有较高的饲用价值和较好的适口性，是本区重要的饲草资源。     

青海湖北岸草地矿物元素特征

为了解青海湖北岸草地中矿物元素特征,在青海湖北岸选择不同草地类型的5个试验样地,采集各样地主要优势种和伴生种植物,通过矿物元素含量分析测试,总结出青海湖北岸草地矿物元素具有特征谱、垂直带状谱、与株高负相关和指示性等4个特征,为草地矿物元素特征以及空间分布格局等研究提供科学依据。     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).     

Heartworm in dogs in Canada in 1986

In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%).

Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.