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1.
松嫩草原中南部退化羊草草地生态恢复与重建中大型土壤动物群落生态特征 总被引：18，自引：2，他引：16
选取吉林省大安市姜家甸草场清塘羊草草地、三年生人工碱茅草地和一年生人工碱茅草地为研究样地,2002年分7月、8月和10月3次对样地野外采样.共捕获大型土壤动物4 190只,分别隶属3门7纲16目18类.土壤动物群落间个体密度有一定的差异,鞘翅目在各生境中都有较高个体密度分布,显示其是该草原地带大型土壤动物的特征性类群.土壤动物类群和个体数垂直分布表聚程度群落间有较大不同.土壤动物群落生物多样性存在空间分异和明显季节间波动,人为水肥干预可以增加土壤动物群落的生物多样性.DG多样性指数更适合表达不同演替阶段土壤动物群落的差异,大型土壤动物群落生物多样性能够指示退化草地生态系统恢复与重建过程. 相似文献
2.
对川西北红原县3个不同放牧强度(轻度放牧、中度放牧、重度放牧)的亚高山草甸土壤动物群落进行了调查研究,共获得土壤动物1 887个,分别隶属3门7纲15目49类群。不同放牧强度下土壤动物优势类群差异较大。受放牧干扰的亚高山土壤动物群落,其个体数量变化趋势是:重度放牧＞中度放牧＞轻度放牧。中度放牧生境的中小型土壤动物密度最大,大型土壤动物密度最低。3种生境中土壤动物的个体数和类群数均随土层加深而递减,其中中度放牧生境土壤动物表聚性最强。受放牧强度和放牧方式的干扰,中度放牧生境中土壤动物群落种类多样性、均匀性及丰富度均低于其他生境,而优势度高于其他生境。 相似文献
3.
研究了宁夏盐池四墩子人工柠条带边缘与柠条带内部和天然草地间地表甲虫多样性的差异,探讨边缘效应对地表甲虫群落的影响。调查共设9个重复样带,每个样带分别由边缘深入到柠条带内部和草地内部100 m,共设81个样点,利用巴氏罐诱法调查地表甲虫群落组成。共记录地表甲虫56种,隶属于13科,其中步甲科(17种)和拟步甲科(12种)种类最多,拟步甲科、步甲科、金龟科和鳃金龟科的个体数量,分别占总个体数量的41.78%,10.81%,10.54%和10.45%,共同构成研究区域地表甲虫的优势类群。甲虫的个体数量、多样性和均匀度从柠条带、边缘到天然草地逐渐降低,都达到了显著水平。边缘效应强度分析呈现边缘正效应(1.039 6＞1)。 相似文献
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5.
青海湖北岸不同土地利用方式对大型土壤动物群落的影响 总被引：1，自引：0，他引：1
为了解青海湖北岸不同土地利用方式对草地生态系统中土壤动物群落特征的影响,对这一地区不同样地中的大型土壤动物进行了调查。共捕获大型土壤动物657只,隶属3纲9目13个类群,优势类群为鞘翅目幼虫、双翅目幼虫和鞘翅目成虫。研究表明,青海湖北岸草地生态系统中大型土壤动物数量总体稀少,生物多样性较低,推测干旱可能是导致这一现象的主要原因。在果洛藏村样区,弃耕地中大型土壤动物类群极为匮乏,远低于3种原生草地,而补播地的土壤动物个体数显著高于(P<0.05)弃耕地,已与对应的原生草地相当,可见人为耕种对芨芨草原生草地中大型土壤动物群落具有毁灭性的破坏作用,而人工干预措施可以促进土壤动物群落的恢复进程。在烂泥湾样区,18年封育草地和6年封育草地生物量、个体数及多样性指数都无显著差别,而放牧通道内大型土壤动物生物量和个体数都显著低于以上2种封育草地类型(P<0.05),充分体现出放牧通道内植被和土壤条件恶化对大型土壤动物的不利影响。在铁路南河边滩地样区,放牧通道内大型土壤动物生物量、个体数及多样性指数与长期封育草原草甸都无显著差别(P>0.05),可能与这一样区内土壤较湿润有关。 相似文献
6.
为了解沙漠化对沙质草地土壤大型动物群落的影响,2008和2009年在科尔沁沙地研究了沙质草地沙漠化过程中土壤动物类群丰富度、多样性和个体密度的变化及其机制。结果表明,随着草地沙漠化的发展,土壤大型动物类群丰富度、Shannon-Wiener多样性指数和个体密度明显下降,均匀度和优势度趋于增加,其中轻度和严重沙漠化阶段变化幅度最大;土壤动物群落组成不断变化,相似性降低,群落由多优势类群向单一优势类群,甚至无明显优势类群转化,致使群落发生逆行演替;沙漠化对草地土壤植食性动物影响相对较大,对杂食性和捕食性动物影响相对较小,导致群落功能群结构明显改变;草地沙漠化过程中,土壤动物群落的变化主要源于植被退化和土壤环境的恶化,特别是植被盖度和凋落物产量的下降以及土壤质地、有机质和养分状况的恶化,土壤温度、水分和pH的影响未达到显著水平。 相似文献
7.
以宁夏盐池国家级草原资源生态监测站为依托,选择荒漠草原典型冰草植被类型的封育(5年)与未封育样地对地面节肢动物、植物以及土壤性质进行了调查,同时分析了地面节肢动物对封育后植物和土壤变化的响应。结果表明,封育对地表植被和土壤性质均产生了明显的影响,尤其是植物个体数、高度和盖度以及生物量封育样地显著高于未封育样地(P<0.05)。调查样地共捕获地面节肢动物7目26科28个类群;封育围栏内外共有的优势类群为拟步甲科琵甲属,共有的常见类群有13个类群,共有类群数占总类群数的50%。并且,地面节肢动物对封育亦产生了积极的响应,动物群落个体数、类群数和多样性封育样地均高于未封育样地,但均没有达到显著水平(P>0.05),说明荒漠草原短期封育(5年)对地表植被和地面节肢动物具有不同的生态效应。相关分析表明,地面节肢动物类群数和Shannon指数均与土壤容重呈显著负相关(P<0.05),而优势度指数与土壤容重呈显著正相关(P<0.05)。表明土壤容重是地面节肢动物群落结构封育内外差异的主要影响因素,而且不同地面节肢动物类群对封育内外生境的选择性而表现出不同的响应特征。 相似文献
8.
疏勒河上游冻土区大型土壤动物群落调查 总被引：1，自引：0，他引：1
为了掌握疏勒河上游冻土生态系统中土壤动物的群落特征,于2010 年6-7月对这一地区不同生境中的大型土壤动物进行了调查。共捕获大型土壤动物453头,隶属3纲9目13个类群,优势类群为鞘翅目幼虫、双翅目幼虫和鞘翅目成虫。与我国西北高原地区的土壤动物群落相比,疏勒河上游地区的土壤动物数量稀少、生物多样性较低,推测极端干旱可能是导致这一现象的主要原因。尽管不同植被类型间的大型土壤动物物种组成方面有较大差别,但其生物量和多样性与植被定量指标之间无显著相关关系（P>0.05）。季节冻土和多年冻土之间,土壤动物生物量、个体数和Shannon Wiener多样性指数都无显著差异（P>0.05）,而过渡类型冻土中的土壤动物生物量和个体数却显著大于其他2种冻土类型（P<0.05）。 相似文献
9.
利用样方统计法,对内蒙古高原东南缘森林草原过渡地带森林、森林草甸、草甸草原和草原4种不同土地利用类型大型土壤动物群落结构进行了研究。共采集大型土壤动物2 394只,隶属于3门8纲22目（类）。由森林向草原过渡过程中,大型土壤动物群落组成变化较大,土壤动物个体数量和类群数呈递减趋势。统计分析表明,大型土壤动物类群数和密度-类群指数（DG）在不同土地利用类型之间存在显著差异（P＜0.05）;森林带大型土壤动物个体数量显著大于森林草甸、草原和草甸草原（P＜0.05）,多样性指数（H′）显著大于草原带,均匀度指数（J）在4个土地利用类型之间无显著差异（P>0.05）。森林具有最高的大型土壤动物个体数量、类群数、H′值和DG值,其次是森林草甸,草原带最低。 相似文献
10.
在内蒙古乌拉特荒漠草原退化红砂灌丛林地内,引入柠条灌丛已成为一种重要的生态恢复措施。关于人工种植柠条灌丛对天然红砂灌丛林地地面节肢动物群落结构及其多样性分布的影响研究,是该区域生物多样性保育和退化生态系统恢复过程研究的重要科学问题。本研究以红砂和柠条灌丛作为研究对象,以灌丛间裸露地为对照。于2018年春季（5月）、夏季（8月）和秋季（10月）,利用陷阱诱捕法,调查柠条和红砂灌丛微生境内地面节肢动物的群落结构分布及其与环境因子间的关系。结果显示：1）试验调查期间,共捕获地面节肢动物560只,隶属于10目23科。其中,优势类群有拟步甲科和蚁科,其个体数分别占总个体数的41.07%和22.14%;常见类群有10类,其个体数共占总个体数的32.68%;稀有类群有11类,其个体数共占总个体数的4.11%。2）地面节肢动物的群落组成在红砂灌丛、柠条灌丛和裸露地微生境内存在较大差异,狼蛛科和管巢蛛科仅在柠条灌丛微生境内存在,蜉金龟科和木伪蝎科仅在裸露地微生境内存在。3）地面节肢动物的个体数、类群数、Shannon-Wiener指数和Simpson指数在红砂灌丛、柠条灌丛和裸露地微生境间均无显著差异（P>0.05）。4）红砂灌丛、柠条灌丛和裸露地微生境间的Jaccard相似性指数均处于较高水平,为0.65~0.71,属于高度相似。5）冗余对应分析（RDA）和偏RDA结果表明,土壤pH是影响地面节肢动物个体数分布的主要环境因子。研究表明,在乌拉特荒漠草原红砂灌丛林地内种植柠条灌丛,虽然会对地面节肢动物的群落组成产生一定的影响,但对其个体数、类群数和多样性分布的影响较小,说明种植柠条灌丛对地面节肢动物多样性恢复乃至生物多样性恢复均存在局限性。 相似文献
11.
Rassnick KM Gieger TL Williams LE Ruslander DM Northrup NC Kristal O Myers NC Moore AS 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2001,15(3):196-199
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks. 相似文献
12.
Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects 总被引：1，自引：0，他引：1
Johansson AM Gardner SY Levine JF Papich MG LaFevers DH Fuquay LR Reagan VH Atkins CE 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2003,17(6):887-895
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses. 相似文献
13.
Waruiru RM Thamsborg SM Nansen P Kyvsgaard NC Bogh HO Munyua WK Gathuma JM 《Tropical animal health and production》2001,33(3):173-187
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round. 相似文献
14.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host. 相似文献
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Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ 
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下载免费PDF全文 S. Pashaei T. Ghoorchi A. Yamchi 《Journal of animal physiology and animal nutrition》2016,100(2):211-216
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed. 相似文献
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Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb
albumin
- ALT
alanine aminotransferase
- AST
aspartate aminotransferase
- BUN
blood urea nitrogen
- Chol
cholesterol
- Glob
globulin
- -GT
-glutamyl transpeptidase
- IP
inorganic phosphorus
- TP
total protein 相似文献
18.
A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance
in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological
status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples
of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected
for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of
the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered,
coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the
gland cisterns and teat cisterns.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L3) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L3 developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone. 相似文献
20.
Acute phase proteins in dogs naturally infected with the Giant Kidney Worm (Dioctophyme renale) 下载免费PDF全文
下载免费PDF全文 Elizabeth M. S. Schmidt Mads Kjelgaard‐Hansen Funmilola Thomas Asta Tvarijonaviciute José J. Cerón P. David Eckersall 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2016,45(4):657-664