物种多样性
- 与 物种多样性 相关的网络例句 [注:此内容来源于网络,仅供参考]
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Laboratory experiments were carried out to study the survival and development of the Harmonia axyridis feeding on Chaito phorus popleti on high insect-resisitance hybrid poplar 741(Pb29) and medium insect-resisitance hybrid poplar 741(Pbl7).The API 741 poplar was used as control.The mortality and development during immature period,adult,baby mass.eclosion and sex ratio of H. axyridis were measured.The results showed that:to contrast The API 741, Chaito phorus popleti on Pbl7 and Pb29 has no significantly impacts on eclosion,pupation, ecdysis,mortality of immature period and pupa stage;Although every development stage of ladybeetles were not affected to ,the pupal duration of ladybeetles was lowered than the control;The body mass,eclosion and sex ratio have no significant difference.
通过利用节肢动物群落及各个亚群落的物种丰富度、个体数、均匀度和优势集中性对多样性指数进行通径分析,表明了高抗Pb29和CK节肢动物群落及各个亚群落多样性指数与均匀度和优势集中性的相关系数最高,与其物种个体数关系最为不密切:对各组分进行通径分析均表明的多样性提高是建立在降低优势集中性和增加均匀度指数的基础上的,而且以优势集中性的直接作用效果较为显著。
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Vegetation ecotype tend to be xerophyte and even hyper-xerophyte and finally replaced by annual plant. Community structure and species diversity also decrease as the ecological environment worsen, In this process, the height, coverage and biomass decreases by 56.6%、 80.8% and 74.2% respectively compared to steppe, and the indices of species richness, diversity and evenness decrease by 76.4%、 56.7% and 32.0%, but β diversity indices increase by 14.6 times, especially the decease of species gregariousness and the breadth and overlay of species Niche shows that grassland tend to be more sandy and vegetation retrogression succession take place.
其中,植被生态型逐渐由中旱生向旱生、超旱生过渡,并最终被一年生植被替代;群落结构及多样性呈明显递减规律,到严重沙化阶段,草群高度、盖度、生物量与典型草原相比,下降幅度分别达到56.6%、80.8%和74.2%;物种丰富度、多样性及均匀性分别降低76.4%、56.7%和32.0%;而群落β多样性增长14.6倍,特别是多年生物种群聚度降低和生态位宽度、生态位重叠值的下降,表明草地沙化,植被发生逆行演替。
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Major results were summarized as follows:(1) A total of 58 tree species from 53 genera in 36 families among which 8 species were Rosaceae, 5 species were Liliaceae, 5 species were Eriaceae, 3 species were Ranunculaceae, 3 species were Compositae, 2 species were Cupressaceae, 2 species were Caprifoliaceae, 2 species were Umblliferae, and other 28 tree species were only one receptively. These were recorded in the 8 plots of the A. georgei var. smithii forest;(2) Number of families, genera, species and Margalef index correlated negatively with altitude (P.05), with a peak at 3600 m.(3) Shannon-Wiener index correlated negatively with altitude (P.01), and maintained stable at the altitudes between 3700~4100 m, evenness with altitudes, however, this trend was insignificant.(4) Jaccard index increased sharply with increasing altitude at the altitudes between 3600~4100 m, and was lower between different vegetation types at the altitudes between 4100~4200. Cody index β(subscript c decreased with an increasing altitude, but there were 2 troughs between 4000~4100 m and 4200~4300 m.(5) Maximum tree height H(subscript max and HH(subscript max=37 mcorrelated negatively with altitude (P.05); but basal area and BA BA(subscript max=5.3m^2 correlated with altitudes, however, this trend was insignificant.
结果表明:(1)在调查的8个急尖长苞冷杉林样地内共有植物58种,分属于36科53属,其中植物较多的科有蔷薇科8种、百合科5种、杜鹃花科5种、毛茛科3种、菊科3种、柏科2种、忍冬科2种、伞形科2种,其余的28科各只有1个种;(2)物种科、属、种数、Margalef指数D(下标 M与海拔存在显著的负相关性(P.05),在分布急尖长苞冷杉最低海拔3600m处出现物种丰富度的最大值;(3)多样性指数与海拔之间有极显著的负相关性(P.01),并且在3700~4100m之间多样性指数保持稳定;均匀度指数与海拔梯度之间存在负相关性,但不显著;(4)Jaccard指数C(下标 j在海拔3600~4100m随海拔的升高而升高,在生境过渡带的4100~4200m之间Jaccard指数C(下标 j较低;Cody指数β(下标 c随海拔的升高呈下降的趋势,但在4000~4100m和4200~4300m 海拔区间出现2个低谷;(5)最大树高H(下标 max和最大胸径DBH(下标 max与海拔之间存在显著负相关性(P.05);胸高断面积之和和立木密度与海拔之间存在负相关性,但不显著。
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Through individual species-area relationship analysis and Monte Carlo simulation, the species-area patterns from individual view were estimated; as such, every woody species was distinguished as a diversity accumulator, repeller, or neutral species. These species specific characteristics then were treated as implication for the strength of competitive interactions in the study site.
藉由个体物种面积关系分析与蒙地卡罗模拟,我检测个体观点之物种面积关系,并由此将所有树种区分为多样性累积者、多样性排斥者以及多样性中性者三类,再以这些物种特徵来推论种间竞争作用的重要性。
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Endangered Abies yuanbaoshanensis will probably have been extinct,so it very necessary to studying its genetic diversity with a proper way in order to save this key group of biological diversity in China.In the present study,AFLP(amplified fragment length polymorphism) markers was used to examine population of Abies yuanbaoshanensis in order to understand the level of population genetic variation and genetic structure.
首先,物种的遗传多样性是长期进化的结果,是其生存和发展的前提,对遗传多样性进行研究可以为分析濒危物种或种群的进化潜力和未来命运提供重要资料;其次,遗传多样性是保护生物学研究的核心之一,不了解种内遗传变异大小、时空分布及其与环境条件的关系,就无法采用科学有效的措施来挽救濒于灭绝的物种、保护受到威胁的物种,对珍惜濒危物种制定合理的保护方针和策略,有赖于对物种遗传多样性的认识。
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The result showed that:(1) There were a higher density of Ostreidae and Balanidae and a lower biodiversity in the cay sampling section of Daxie Island.(2) No significant difference was found in the macrozoobenthos community among the tide plat sampling section in Daxie Island.(3) There was a lower macrozoobenthos species number, biodiversity, and a higher density of Sternaspis scutata and Capitella capitata than those in the sea area beside Daxie Island. Moreover, a significant difference was found in the macrozoobenthos community between the sea area of Daxie Island and the adjacent islands.
结果发现:(1)大榭岛岩相潮间带断面牡蛎科和藤壶科等科的物种栖息密度较高,生物多样性较低;(2)泥沙相潮间带底栖动物状况与其他海岛差别不显著;(3)大榭岛近岸海域底栖动物种数少于其他海岛近岸海域,且前者不倒翁虫和小头虫等多毛类物种栖息密度较高,生物多样性较低,群落结构与其他区域相差较大;(4)环境质量的生物评价结果显示,大榭岛近岸海域扰动程度高于其他海岛近岸海域。
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Prattii- Ailanthus altissima deciduous broad-leaved forest community and Cerasus trichostorna-Cerasus dielsiana-Acer caudatum deciduous broadleaved forest community , had lower total richness and Shannon-Wiener index .
3人工林群落与次生林群落相比,人工林群落具有较低的物种丰富度指数和Shannon-Wiener多样性指数以及较高的优势度指数,次生林具有较高的物种丰富度指数和Shannon-Wiener多样性指数以及较低的优势度指数。
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Farm. In the past (until app. 25 years ago) pistachiodiversity was maintained high in the field through a number of cultivation practices, s.a. use of male varieties derived from seed, use of wild Pistacia species to boost pollination and hence the fruit setting, use of natural populations of wild Pistacia (P. atlantica) as rootstock due to their well known resistance to stony and calcareous soils.
最近在农场栽培无花果技术的改变更加导致作物的多样性减少。25年前,无花果多样性通过多种栽培保持在很高的水平(源于种子的雄性物种采用,野生开心果物种改善授粉的采用,自然野生开心果作为根茎的采用——因为他们已知很好的抵抗多石和石灰性土壤的能力,等等
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At the same time, the biomass of species-rich community was more sensitive to the change of environmental conditions, while communities with fewer species had a little change in biomass.2 There were a total of 87 vascular plant belonging to 27 families and 68 genus in the six communities. Most species had a narrow distribution and a lower local abundance, while few species had a wider range and higher local abundance, and this distribution trends varied in different communities. The endemics were positive correlation to y diversity.
物种丰富的群落生物量对环境条件的变化敏感,较过去显著降低,而种类构成简单的群落则变化不大。2在6种植物群落中共出现27科68属87种高等维管植物,大多数物种具有狭窄的分布范围和较小的局域多度,而少数种具有较广的分布范围和较大的局域多度,并且这种分布趋势在不同的群落类型中又有所不同,γ多样性高的群落中特有种的数量增加;而γ多样性低的群落中稀有种数量相对较少。
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The results showed that the species richness,the speciesdiversity and its biomass of understorey vegetation decreased with the stand age in-creasing.There was the most significant negative-linear relationship between thiskind of changes and age.It is possible that the certain shading condition may benefit to understorey growing better.The richness,diversity index and biomass of thevegetation in eucalypt plantation decreased with CPR increasing,however,after ro-tating by watermelon one rotation,the richness,the diversity index and biomass ofunderstorey in CP stand increased,this result will provide the possibility of therestoration and reestablishment of vegetation in eucalypt plantations.The nutrientstorage of understorey decreased in accord with the productivity decreased withCPR increasing,this is the result which the stand enviroment became worse and thestand stratum competed with the vegetation for the water and fertility of soil.
结果表明,随着年龄的增长,桉树林下植被物种丰富度降低,多样性减少,生物量下降,这种变化趋势与年龄存在极显著的负线性关系;随着造林密度的增加物种丰富度降低,多样性也下降,但林下植被生物量尚有增加,可能是一定程度的庇荫有利于桉树林下植被的生长;随连栽代次的增加,桉树林下植被丰富度降低,多样性指数下降,生物量减少;但在轮作一茬西瓜后的林地,物种丰富度提高,多样性指数升高,生物量增加,为桉树林下植被的恢复与重建提供了可能性;随连栽代次增加,林下植被养分总量逐代下降,与生产力下降一致,这是林分环境恶化后上层乔木和林下植被对水肥竞争的结果。
- 推荐网络例句
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In the United States, chronic alcoholism and hepatitis C are the most common ones.
在美国,慢性酒精中毒,肝炎是最常见的。
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If you have any questions, you can contact me anytime.
如果有任何问题,你可以随时联系我。
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Very pretty, but the airport looks more fascinating The other party wisecracked.
很漂亮,不过停机坪更迷人。那人俏皮地答道。