排序方式: 共有19条查询结果,搜索用时 15 毫秒
1.
2.
毛乌素沙地南缘生态过渡带植被物种多样性的研究 总被引:3,自引:0,他引:3
对毛乌素沙地南缘生态过渡带流动半流动沙丘、固定半固定沙地、盐化丘间低地和缓坡丘陵梁地4种不同生境的植被物种组成及多样性进行研究。结果表明:随着沙化程度的加重,从缓坡丘陵梁地,经盐化丘间低地、固定半固定沙地到流动半流动沙丘,多年生草本植物逐渐减少,一年生草本植物及沙生灌木、半灌木逐渐增加;物种丰富度指数、多样性指数及均匀度指数均下降。 相似文献
4.
植物物种多样性和土壤生态化学计量比间的关系,是草地植物群落结构维持的关键。高原鼠兔干扰虽被证实能够影响植物物种多样性、土壤有机碳、全氮和全磷的含量,但是否影响高寒草甸植物物种多样性和土壤生态化学计量比间的关系,尚不清楚。本研究以甘南和青海湖流域为对象,采用配对设置样地的方法,分析了高原鼠兔干扰对高寒草甸植物物种多样性和土壤生态化学计量比间关系的影响。结果表明:高原鼠兔干扰显著增加了物种丰富度指数、土壤有机碳、全氮和全磷含量,以及土壤C∶N和C∶P(P<0.05),但没有显著影响物种多样性指数、物种均匀度指数和土壤N∶P。高原鼠兔干扰增加了物种丰富度指数和物种多样性指数与土壤C∶N间的正相关性(P<0.05),减弱了物种丰富度指数与土壤C∶P间的正相关性(P<0.01);物种多样性指数与土壤C∶P间的关系从高原鼠兔未干扰生境的对数关系转变为干扰生境的二次函数关系(P<0.05),而物种丰富度指数与土壤N∶P间的关系从高原鼠兔未干扰生境的不显著相关,改变为干扰生境的显著负相关二次函数(P<0.01);物种多样性指数与土壤N∶P间的关系从未干扰生境的显著正相关二... 相似文献
5.
6.
仔猪腹泻病是养猪生产中较常见的一种疾病,如果诊断不准确,治疗不及时,就会造成仔猪成活率低、僵猪比率大、饲养成本大幅上升,严重影响猪场经济效益。根据本人在猪场的多年工作经验,现将常见的几种仔猪腹泻病的鉴别诊断及防治方法归纳如下,供广大畜牧兽医工作者及养殖户参考借鉴。1仔猪白痢1.1流行特点多发于10~30日龄仔猪,呈地方性流行,季节性不明显,发病率中等,病死率不高。1.2临床症状病猪无呕吐现象,排白色糊状稀粪,发病为急性或亚急性。1.3病理变化小肠卡他性炎症,空肠绒毛无萎缩或有局限性萎缩,结肠内容物呈糊状。1.4病原检查进行细… 相似文献
7.
The relationship between plant species diversity and functional diversity in grassland will change with environmental changes. The plateau pika (Ochotona curzoniae) has an effect on the hydrothermal process of alpine meadow in its nesting area. However,it is not clear whether the disturbance of plateau pika effects the relationship between plant species diversity and functional diversity in alpine meadow. A random stratified and paired design was used to select plots in Luqu county in Gansu Province,and Qilian and Gonghe Counties in Qinghai Province and a field survey was conducted to investigate the effects of plateau pika disturbance on the relationship between plant species diversity and functional diversity of the alpine meadow. It was found that plateau pika disturbance significantly increased the plant species richness index and the species diversity index but did not significantly affect the species evenness index. Plateau pika disturbance significantly increased plant functional richness index (P< 0.05) but had no significant effect on the plant functional evenness index or the functional divergence index. With plateau pika disturbance effects,the relationship between plant functional richness index and species richness index changed from a logarithmic function to a quadratic function,and the relationship between plant functional evenness index and species evenness index changed from non-significant to significantly positive. In addition, positive correlations between functional richness index and species richness index,and functional richness index and species diversity index were significantly decreased,as were negative correlations between functional divergence index and species richness index,and functional divergence index and species diversity index were significantly decreased. The findings of this study provide basic information for understanding the mechanism of species coexistence of plant communities under plateau pika disturbance and help understanding of how plant diversity effects in an alpine meadow ecosystem function under plateau pika disturbance. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved. 相似文献
8.
9.
[目的]探讨日粮中添加硒对滩羊胴体品质的影响,为生产特色滩羊肉提供技术支持。[方法]在滩羊日粮中添加0.35 mg/kg(试验组)和0.30 mg/kg(对照组)硒进行饲养试验,研究富硒日粮对滩羊胴体品质的影响。[结果]试验组滩羊胴体净肉率和肉骨比值较对照组分别提高2%和9.6%;试验组滩羊香味氨基酸、脯氨酸和赖氨酸含量比对照组提高1.2%、3.8%和21%。试验组镁、钙和钾含量较对照组分别提高31.12%、12.76%和24.77%;试验组滩羊体内硒含量比对照组提高10%。[结论]日粮中添加适量的硒能够提高胴体净肉率、肉骨比值以及镁、钙、钾和硒含量。 相似文献
10.
在园林施工中,反季节园林施工不可避免。在园林施工中,有效应用反季节种植技术能够有效提升施工质量,达到反季节施工目标。基于此,对反季节种植技术进行深入分析,并研究该技术在园林施工中有效应用的优势,细化反季节种植技术在园林施工中的实际应用,为园林施工中有效应用反季节种植技术提供重要的参考依据。 相似文献