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61.
张学全 《内蒙古林业调查设计》2013,36(3):96-99
古林箐自然保护区位于北回归线以南,哀牢山南端以东的滇东南高原向东南半岛延伸的结合部,南亚热带与热带的过渡地带。在这特殊的自然地理条件下,成为我国三大生物多样性中心之一的滇东南—桂西北的核心部位,区内有发育完整,保存完好的森林生态系统和丰富的生物资源。但在管理中存在许多方面问题,据此提出保护措施。 相似文献
62.
63.
为探明东北地区常见野生葱属植物耐旱能力,筛选野生葱属植物耐旱种质资源,本研究以野韭(Allium ramosum L.)、山韭(Allium senescens L.)和蒙古韭(Allium mongolicum Regel)3种葱属植物为材料,采用不同浓度的PEG-6000模拟干旱胁迫,分析其种子萌发期渗透调节物质及酶活性的影响,并结合主成分分析和隶属函数分析比较抗旱性。结果表明:干旱胁迫下,3种葱属植物种子萌发期相对电导率显著升高(P<0.05),丙二醛、脯氨酸、可溶性糖、可溶性蛋白含量及超氧化物歧化酶、过氧化氢酶、过氧化物酶、多酚氧化酶活性均呈现先上升后下降的趋势。3种植物相比,山韭相对电导率最低,渗透调节物质积累量最高,酶活性变化明显。主成分分析表明,4种酶活性之间显示出强相关性。隶属函数分析得出3种植物种子的抗旱性由高到低依次为:山韭 > 野韭 > 蒙古韭。 相似文献
64.
以黄河兰州段分布最广泛的芦苇-假苇拂子茅群落和酸模叶蓼-灰绿藜群落为研究对象,研究2个群落的植物物种组成和多样性特征。结果表明:芦苇群落有植物22种,隶属于13科20属,酸模叶蓼群落有植物24种,隶属于11科22属,2个群落的共种有10种,相似性系数为43.48%,菊科、禾本科、藜科、蓼科是该植物区系的优势科。物种多样性的分析说明2个群落的Pielou指数(J)波动比较小,Simpson指数(D)和Shannon-Wiener指数(H)均波动都比较大,并且H指数与J指数存在明显的正比例关系,而与D指数呈显著的反比例关系。方差分析表现出两群落S,H,D和J指数的差异并不明显,说明组成两群落的物种有一定的相似性和连续性,也存在着差异。 相似文献
65.
Nelmarie Saayman Craig Morris Hannes Botha 《African Journal of Range and Forage Science》2016,33(4):225-233
The Succulent Karoo, one of two arid biodiversity hotspots in the world, is known for its high plant species richness, but little is known about the influence of topography and how it mediates the potentially deleterious effects of grazing. Changes in vegetation species composition, cover and species diversity were examined along piosphere gradients on northerly slopes, bottomlands and low-lying plains on 45 farms. Landscapes differed in the plant speciesand life-form composition, species richness and cover, with the more species-rich, heterogeneous grassy northerly slopes distinct from the plains and bottomlands, which were dominated by Pteronia pallens, Psilocaulon junceum and Drosanthenum spp. with more annual and ephemeral species. Overall, species richness declined linearly with decreasing rangeland condition. A weak grazing effect was detected only on the north-facing slopes, where shrubs and grass decreased with intense grazing. Years of overgrazing have resulted in the widespread dominance of P. pallens, especially on the plains and bottomlands, rendering them insensitive to grazing. The current condition of the northern slopes should be maintained and managed such that palatable species can spread to more degraded areas of the landscape. 相似文献
66.
U.S. state fish and wildlife agencies have responded to perceived ecological and social threats posed by mute swans by implementing population control strategies. In Michigan, some stakeholder groups have vocally opposed particular control activities. To better understand and characterize key aspects of the underlying media dialogue about mute swan management in Michigan, one factor in the development of public perceptions about wildlife issues, we conducted a qualitative content analysis of Michigan-specific online news articles. Results revealed tensions between stakeholder groups about management priorities were rooted in differing ideas about healthy social and ecological systems, appropriate wildlife behavior, and the acceptability of lethal control (i.e., shooting living birds). Characterizing which stakeholder groups aligned with particular arguments might allow managers to tailor and direct messaging to specific audiences. 相似文献
67.
Metlholo Andries Phukuntsi Helene Brettschneider Desiré L Dalton Teresa Kearney Jacqueline Badenhorst Antoinette Kotze 《African Zoology》2016,51(1):69-76
DNA barcoding has been proposed as a method for species identification. However, this method has been criticised for its over-reliance on a single mitochondrial gene. In this study, four mitochondrial gene regions and one nuclear gene region were used to investigate their different abilities to identify tissue associated with museum specimens of Aethomys chrysophilus, Aethomys ineptus and Micaelamys namaquensis. Aethomys chrysophilus and the more recently elevated A. ineptus are indistinguishable on morphological grounds; however, their ranges are largely parapatric with only one syntopic locality currently known. All of the mitochondrial gene regions were able to separate M. namaquensis from A. chrysophilus and A. ineptus, but they varied in their abilities to resolve differences between A. chrysophilus and A. ineptus. The sequence results identified a specimen from KwaZulu-Natal that was misclassified and should have been identified as A. ineptus. Seven specimens that had not been reclassified following the elevation of A. ineptus to species level were identified as A. ineptus. Individuals of A. chrysophilus from Malawi could not be classified as either A. chrysophilus or A. ineptus, and may be a hybrid or a new, distinct species. This study indicates that DNA barcoding may be used to separate M. namaquensis from A. chrysophilus and A. ineptus, and although it was not able to separate A. chrysophilus and A. ineptus, it did indicate specimens from Malawi may be a new cryptic species. 相似文献
68.
Son Truong NGUYEN Masaharu MOTOKAWA Tatsuo OSHIDA Hideki ENDO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(2):187-198
Southeast Asia is a region of high biodiversity, containing species of plants and animals that are yet to be
discovered. In this region, bats of the subfamily Kerivoulinae are widespread and diverse with six species
recorded in Vietnam. However, the taxonomy of the Kerivoulinae in Asia is complicated. In our study, we used
diagnostic characters and multivariate analysis to determine morphological differences between the genera
Kerivoula and Phoniscus. We showed that the two genera are distinguishable
by the size of second upper incisors, the shape of skull, nasal sinus, canines, second upper and lower
premolars. In addition, the two genera can be osteometrically separated by measurements of the braincase
height, interorbital width and shape of anterior palatal emargination. Our data clearly revealed the
morphological variations in the skull shape of Kerivoula hardwickii in Vietnam. This suggests
a possible separation into three morphotypes, representing cryptic species supported by statistical
differences with wide variation in skull shape, size and teeth. These results demonstrated Kerivoula
hardwickii can be separated three subspecies, and the result will serve as the basis for the future
assessment and classification of this group in Southeast Asia. 相似文献
69.
70.
The effects of short-term nutrient additions (NPKμ, 10 g·m- 2) and disturbances on the species diversity, functional traits, soil properties, and community assembly mechanisms of the herbaceous community in the Urat desert steppe were examined. A mixed linear model, principal component analysis, and null model methods were utilized and both disturbance and interaction treatments were found to significantly reduce species richness and β diversity. Short-term nutrient additions significantly reduced soil pH but increased soil electrical conductivity. Six functional traits of the dominant species (i.e. Stipa glareosa, Peganum harmala, Salsola collina, Corispermum mongolicum) and six community-weighted mean significant changes under the disturbance and nutrient addition treatments were identified. The disturbance and nutrient additions promoted the transformation of the dominant species in the community from conservative strategies to acquisitive strategies. The results of the two null models revealed that community assembly under the control tended to be a stochastic process, while the disturbance and interaction treatments tended to be deterministic processes, and that of the nutrient addition treatments tended to be weaker deterministic processes. Plant communities in the desert steppe responded and adapted to the nutrient additions and disturbances through changes in the dominant species and their crucial functional traits. © 2023 Chinese Academy of Sciences. All rights reserved. 相似文献