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The palatability of dominant herbs to the Taiwan field vole (Microtus kikuchii) in alpine meadows in central Taiwan
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The Interactions between Taiwan Vole (Microtus kikuchii) and Alpine Meadow Herbs at the Ho-huan Area: Effects of Nutrition and Abundance of Dominant Herbs
No full text動植物之間交互作用的機制是生態學及演化生物學裡令人著迷的重要議題。尤其是草食動物對植物的擇食現象，深深地影響各生態系的植被多樣性與組成。在全球暖化的陰影之下，了解高山生態系動植物之間交互作用的生態機制尤迫切需要。高山草原植物由於生長速度緩慢，草食動物的擇食對其影響甚鉅，過去的研究顯示小型草食獸的選擇性取食受到植物豐富度及可食度的影響，可食度又受到植物本身營養、次級代謝物及有毒物質含量的影響。在台灣，為冰河孓遺生物的特有種台灣高山田鼠(Microtus kikuchii)是合歡山地區玉山箭竹草原的優勢小型草食獸。為了瞭解台灣高山田鼠對當地高山草原植物的擇食狀況及其生態機制，我測試以下假說:(1) 台灣高山田鼠具有擇食行為(而非機會主義者)：對田鼠而言，不同植物具有不同可食度；(2)化學因子如營養、次級代謝物及有毒物質含量可以解釋可食度的差異：較可食的植物具有較高蛋白質、較低纖維素及多酚類；(3)田鼠的擇食符合兩階段理論：影響可食與否與可食程度者為不同決定因子；(4)田鼠喜食優勢植種：可食度越高的植物也是越優勢的植種；(5)田鼠的分佈受到食物資源的影響：田鼠的分佈與高可食植物的分佈有正相關，與低或不可食植物有負相關。我調查了合歡山區玉山箭竹草原裡的各種動植物(動物限定於小型哺乳動物)分佈及其豐富度，以餵食實驗測量優勢植物的可食度，並以化學分析測量優勢植物各化學因子。結果發現不同植物對台灣高山田鼠具有不同可食度，植物皆未發現有毒且不符合二階段理論，而可食度越高的植物為當地越優勢的植種，其半纖維素含量較高。而食物資源的分佈對台灣高山田鼠的分佈似乎也有影響。此擇食結果顯示台灣高山田鼠在合歡山地區玉山箭竹草原可迅速找到足夠食物並快速獲取熱量，並對當地植被可能具有抑制優勢種生長的效果。Ecological mechanisms explaining how animals and plants interact are fascinating topics in ecology and evolutionary biology. Particularly, selective foraging by herbivores could alter plant species composition and diversity in various ecosystems. Previous studies have suggested that selective foraging by small mammalian herbivores is affected by the differential abundance and palatability of plants. The palatability is in turn influenced by chemical characteristics, like nutrition, secondary compound, and toxin contents, in plants. Under the growing threats of global warming, it is urgent to understand the ecological mechanisms in alpine meadow. In alpine meadow ecosystem vegetation is easily modified by the selective herbivory because of the low growth rates of plants. The endemic Taiwan vole (Microtus kikuchii), a glacial relic species, is the dominant small mammal herbivore in the Yushan cane (Yushania niitakayamensis) grassland in Taiwan. To understand the selective foraging and the involving mechanism, I proposed to test the following hypotheses: (1) Taiwan voles forage selectively (not an opportunist): different plants have different palatability to voles; (2) chemical characteristics, like nutrition, secondary compound, and toxin contents, in plants could account for the differential palatability: palatable plants have higher protein, lower fiber and lower protein-binding phenolics than less palatable ones; (3) food selection by Taiwan voles is a two-step process: the factors accounting for unpalatability and the degrees of palatability are different; (4) Taiwan voles prefer dominant plants: palatable plants have greater cover area than less palatable ones; (5) the distribution of Taiwan voles is influenced by the distribution of food resource: the distribution of voles is positively correlated with that of highly palatable plant species, negatively with less palatable ones. I surveyed the population of small mammals and the plant community in the Yushan cane (Yushania niitakayamensis) grassland in the Ho-huan Mountains to determine the distribution and abundance of different species. I assessed the palatability and chemical characteristics content of dominant plants by feeding trials and chemical analysis in the laboratory. The results showed that different plants had different palatability to voles, and the two-step forage selection process was not supported because no toxin in plants was found. Taiwan voles consumed greater amount of plants with greater cover areas and more hemicellulose contents. Such traits allowed adult voles find food and gain energy quickly. The selective foraging may prevent dominant plant species from over-dominating. The distribution of Taiwan voles also seemed to be affected by the distribution of food.口試委員會審定書誌 ii要 iiibstract ivntroduction - 1 -esearch objectives and hypothesis - 3 -aterials and methods - 5 -tudy area - 5 -mall mammal and vegetation survey - 6 -mall mammal survey - 6 -egetation survey - 6 -eeding trials - 7 -ethods of trials - 7 -utrition analyses - 10 -xtra measurements - 11 -onverting Coverage to Biomass - 11 -ithered Ratio - 11 -irst-Bite Trials - 12 -arts Choice Trial (roots, stems, blades) - 12 -tatistical analyses - 12 -esults - 14 -ield survey - 14 -mall mammals - 14 -egetation composition - 14 -aboratory trials - 15 -alatability trials - 15 -utrition analyses - 16 -xtra measurements - 17 -onverting Coverage to Biomass - 17 -ithered Ratio - 18 -irst-Bite Trials - 18 -arts Choice Trials (roots, stems, blades) - 18 -iscussion - 19 -eference - 24 -igures - 29 -ppendix I - 54 -ppendix II - 61
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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