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81.
生态环境与汾河水库输沙量的灰色关联分析和预测 总被引:2,自引:0,他引:2
汾河水库1960年开始拦洪,设计总库容量为7.2×10~7m~3。它担负着太原市的防洪、工业用水和1.0×10~5ha 的农田灌溉。水库上游包括宁武、静乐、岚县、娄烦四县,总流域面积为5268km~2。年平均降水量450—500mm,其中汛期降水占全年降水量的70—80%。建库前,多年平均输沙量达2.105×10~7m~3,年侵蚀模数 相似文献
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84.
Lúcio Bertoldo Costa Marcelo Augusto Boechat Morandi Sara Marie Stricker 《Biocontrol Science and Technology》2016,26(12):1736-1749
There is a lack of information comparing UV-B radiation conidial sensitivity of the biocontrol agent Clonostachys rosea (Cr) and its target pathogen, Botrytis cinerea (Bc). We investigated the interactions in vitro and on strawberry leaf discs between previously selected Cr and Bc strains tolerant to UV-B radiation. Strawberry leaf discs inoculated with Bc, Cr, or combinations of both fungi were exposed to UV-B doses (2.9, 5.9, and 8.9?kJ?m?2). Incidence and sporulation of both fungi were evaluated, and the Area Under Incidence Progress Curve (AUIPC) and Area Under Sporulation Progress Curve (AUSPC) were calculated. AUIPC and AUSPC of Cr on leaf discs were negatively correlated to increased UV-B. When inoculated alone on leaf discs, Bc was not affected by UV-B, but when inoculated with Cr the incidence and sporulation of Bc were positively correlated to UV-B radiation dose. In the absence of UV-B, Cr reduced incidence and sporulation of Bc. However, the ability of Cr to control Bc was reduced by 20% to 50% with increasing UV-B radiation. Increasing the applied concentration of Cr conidia 10-fold partially overcame the deleterious effects of UV-B on the ability of the biocontrol agent to reduce Bc sporulation in strawberry leaves. The selection of antagonists must fulfil many requirements; besides being active against the specific targeted plant pathogens, they must be cost-effective and have ecological characteristics suitable for the desired use conditions. We suggest that UV-B exposure must be taken into account during the development of bio-fungicides based on Cr. 相似文献
85.
A. W. Mansfield 《Marine Mammal Science》1991,7(1):44-49
The ages of 82 grey seals of known age from 1 to 10 yr were determined from growth layer groups in the cementum, readily seen in longitudinal sections 150 μm thick viewed under transmitted light. The sample of teeth was read five times in a series of blind replicates.
With only one reading, an accuracy of 84% was achieved. This increased to 93% on the basis of three readings but improved only marginally to 94% when all five readings were considered. Accuracy was best in the middle range of ages (3–6 yr) which are the critical years for estimating age-specific reproductive rates in population models. 相似文献
With only one reading, an accuracy of 84% was achieved. This increased to 93% on the basis of three readings but improved only marginally to 94% when all five readings were considered. Accuracy was best in the middle range of ages (3–6 yr) which are the critical years for estimating age-specific reproductive rates in population models. 相似文献
86.
Courtney C. Irvine Seth G. Cherry Brent R. Patterson 《The Journal of wildlife management》2022,86(2):e22163
Characteristics of spatio-temporal clusters of locations from global positioning system (GPS)-collars have been used to distinguish kill sites of various predators. We deployed GPS collars on 9 grey wolves (Canis lupus) in the southwest area of Prince Albert National Park in central Saskatchewan, Canada, and used a GPS location clustering algorithm to identify kill sites of ungulate and other large-bodied prey during winter, December 2013–March 2017. We used logistic regression in a model-selection framework to determine if spatio-temporal and habitat characteristics of grey wolf GPS clusters could be used to reliably identify sites where wolves had killed prey. Global positioning system clusters were more likely to be wolf kill sites when they had a higher number of location fixes, did not begin within 300 m and 30 days of a previous cluster, did not begin within 1 km and 4 days of a previous cluster, began in the evening, had a high percentage of fixes occurring during the day, occurred farther from open habitat, and had both a high number of location fixes and a high percentage of fixes occurring during the day. Our results highlight the limits of using spatio-temporal clusters with a fix rate of 1/hour to discriminate wolf kill sites in systems dominated by deer (Odocoileus spp.) because of the associated short handling time with these prey. 相似文献
87.
为了解广西生态茶园与普通茶园节肢动物群落结构特点及其稳定性,本文采用Shannon-Wiener多样性指数(H′)、群落物种优势度指数(D)、丰富度指数(J)、物种均匀度指数(E)等分析了茶园节肢动物群落的多样性结构,应用群落相似度指数对生态茶园和普通茶园节肢动物的群落相似性进行了分析,用灰色关联度方法综合分析多样性指数与优势度、均匀度等6个特征参数间关系的密切程度。结果表明,在广西茶园节肢动物共34种,其中害虫(螨)17种,优势种群是:小贯小绿叶蝉Empoasca onukii Matsuda、茶蓟马Scirtothrips dorsalis Hood、蚜虫、白粉虱Trialeurodes vaporariorum Westwood;天敌8种,优势种群是:棕管巢蛛Clubiona japonicola Boeset Str.、八斑球腹蛛Theridion octomaculatum Boes. et Str.、异色瓢虫Harmonia axyridis(Pallas);中性昆虫9种,优势种群是:蚊虫、蚁类。多样性指数、群落均匀度指数与物种优势度在生态茶园比普通茶园高。生态茶园的群落稳定性比普通茶园的强。不同茶园间的群落相似性指数q在0.444~0.9355之间,群落间相似性关系在中等不相似与极度相似之间。与多样性指数密切相关的前3位群落特征参数依次是群落物种优势度、益害物种的个体数比、丰富度,其中关系最密切的特征参数是群落物种优势度。研究结果为茶园害虫的综合防控提供了理论依据。 相似文献
88.
The ABC transporter BcatrB from Botrytis cinerea exports camalexin and is a virulence factor on Arabidopsis thaliana 总被引:1,自引:0,他引:1
Francesca L. Stefanato Eliane Abou-Mansour Antony Buchala Matthias Kretschmer reas Mosbach Matthias Hahn Christian G. Bochet Jean-Pierre Métraux Henk-jan Schoonbeek 《The Plant journal : for cell and molecular biology》2009,58(3):499-510
Arabidopsis thaliana is known to produce the phytoalexin camalexin in response to abiotic and biotic stress. Here we studied the mechanisms of tolerance to camalexin in the fungus Botrytis cinerea , a necrotrophic pathogen of A. thaliana . Exposure of B. cinerea to camalexin induces expression of BcatrB , an ABC transporter that functions in the efflux of fungitoxic compounds. B. cinerea inoculated on wild-type A. thaliana plants yields smaller lesions than on camalexin-deficient A. thaliana mutants. A B. cinerea strain lacking functional BcatrB is more sensitive to camalexin in vitro and less virulent on wild-type plants, but is still fully virulent on camalexin-deficient mutants. Pre-treatment of A. thaliana with UV-C leads to increased camalexin accumulation and substantial resistance to B. cinerea. UV-C-induced resistance was not seen in the camalexin-deficient mutants cyp79B2/B3 , cyp71A13 , pad3 or pad2 , and was strongly reduced in ups1 . Here we demonstrate that an ABC transporter is a virulence factor that increases tolerance of the pathogen towards a phytoalexin, and the complete restoration of virulence on host plants lacking this phytoalexin. 相似文献
89.
Nicolas Giret Franck Péron Lenka Tichotová Michel Kreutzer Dalila Bovet 《Behavioural processes》2010,85(2):90-877
Some African grey parrots (Psittacus erithacus), the most famous being Pepperberg's parrot Alex, are able to imitate human speech and produce labels referentially. In this study, the aim was to teach ten African grey parrots from two laboratories to label items. Training three parrots from the first laboratory for several months with the Model/Rival method, developed by Pepperberg, in which two humans interact in front of the subject to demonstrate the use of a label, led to disappointing results. Similarly, seven parrots from the second laboratory, having been trained with several variants of Model/Rival attained little success. After the informal observation of the efficiency of other methods (i.e. learning to imitate labels either spontaneously or with specific learning methods and use of these labels referentially), four different teaching methods were tested with two birds: the Model/Rival; Repetition/Association which consisted of repeating a label and presenting the item only when the parrot produced the label; Intuitive in which the experimenter handled an item and repeated its name in front of the subject; Diffusion in which labels with either variable or flat intonation were played back daily to parrots. One bird learned three labels, one of which was used referentially, with the Repetition/Association method. He learned one label non-referentially with the Model/Rival but no labels were acquired using the other methods. The second bird did not learn any labels. This study demonstrates that different methods can be efficient to teach labels referentially and it suggests that rearing conditions and interindividual variability are important features when assessing learning ability of African grey parrots. 相似文献