Agro-Ecosystems最新文献_第4页

Arid-land ecosystems: Structure, functioning and management. Vol. 1 干旱区生态系统:结构、功能和管理。1卷

Agro-Ecosystems Pub Date : 1982-05-01 DOI: 10.1016/0304-3746(82)90020-8

M.H. Andrew

引用次数: 2

Simulation of nitrogen behaviour of soil-plant systems 土壤-植物系统氮素行为的模拟

Agro-Ecosystems Pub Date : 1982-05-01 DOI: 10.1016/0304-3746(82)90017-8

R.J.K. Myers

引用次数: 0

Terrestrial nitrogen cycles 陆地氮循环

Agro-Ecosystems Pub Date : 1982-05-01 DOI: 10.1016/0304-3746(82)90016-6

G. Stanhill

引用次数: 308

Use of the “non-weed” concept in traditional tropical agroecosystems of south-eastern Mexico “非杂草”概念在墨西哥东南部传统热带农业生态系统中的应用

Agro-Ecosystems Pub Date : 1982-05-01 DOI: 10.1016/0304-3746(82)90010-5

J.C. Chacón , S.R. Gliessman

引用次数: 103

Weed-crop competition: A review 杂草作物竞争:综述

Agro-Ecosystems Pub Date : 1982-05-01 DOI: 10.1016/0304-3746(82)90019-1

J. Burdon

引用次数: 0

Population cycles of the small moth-borers of sugar cane, Diatraea spp., and their primary and secondary parasitoids, in Trinidad, West Indies 西印度群岛特立尼达地区甘蔗小蛀虫Diatraea spp.及其初级和次级寄生蜂的种群周期

Agro-Ecosystems Pub Date : 1982-05-01 DOI: 10.1016/0304-3746(82)90011-7

G. Hughes , P.S. Hammond , W.G. Des Vignes

{"title":"Population cycles of the small moth-borers of sugar cane, Diatraea spp., and their primary and secondary parasitoids, in Trinidad, West Indies","authors":"G. Hughes , P.S. Hammond , W.G. Des Vignes","doi":"10.1016/0304-3746(82)90011-7","DOIUrl":"10.1016/0304-3746(82)90011-7","url":null,"abstract":"<div>Population data consisting of counts of larvae of three species of sugar cane moth-borer, Diatraea spp., and assessments of the extent of parasitism by Paratheresia claripalpis and secondary parasitism by Trichopria cubensis, have been analysed. Time-series analysis of the data revealed two regular cycles in population density, one with a period of about four months, the other with a period of about one year.The four month cycle was apparent in all three species of Diatraea, although two species, D. saccharalis and D. impersonatella, were subject to parasitism and one, D. centrella, was not. Analysis of the annual cycle of the Diatraea-Paratheresia-Trichopria interaction indicated that the densities of these populations increased during the rainy season and decreased during the dry season.From the time-series analysis, estimates of time-lags in host-parasitoid interaction responses and in the responses of parasitoid populations' growth rates to changes in their host populations' densities were made. Estimates of parasitoids' generation times could then be derived. These estimates have been compared with independent data collected from direct observations.</div>","PeriodicalId":100066,"journal":{"name":"Agro-Ecosystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1982-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-3746(82)90011-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81914798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Reproduction in an island population of Norway rats, Rattus norvegicus (Berkenhout), treated with an oestrogenic steroid 挪威大鼠，褐家鼠(Berkenhout)的岛屿种群，用雌激素类固醇治疗的生殖

Agro-Ecosystems Pub Date : 1982-05-01 DOI: 10.1016/0304-3746(82)90015-4

A.B. Lazarus, F.P. Rowe

{"title":"Reproduction in an island population of Norway rats, Rattus norvegicus (Berkenhout), treated with an oestrogenic steroid","authors":"A.B. Lazarus, F.P. Rowe","doi":"10.1016/0304-3746(82)90015-4","DOIUrl":"10.1016/0304-3746(82)90015-4","url":null,"abstract":"<div>A population of Norway rats, Rattus norvegicus (Berkenhout), living on a small island was sampled on four occasions in 1974. Breeding began in the spring and ceased in late autumn. Sub-adult rats (< 150 g) were absent in March but they comprised 45.5% of the sample taken in June; they were even more numerous in September (65.9%) but their numbers were declining by December (36.9%). Pregnant and lactating females were trapped in June and September only.The population was treated with a synthetic oestrogen reproduction inhibitor for 1 week in March 1975. The compound, the 3-cyclopentyl ether of 17α-hexa-1′3′-diynyloestra-1,3,5(10)-trien-17β-ol (BDH 10131), was included at 0.05% in oatmeal bait.Further samples of rats were taken after the treatment, in April, July and September 1975 and in January 1976. Fertility was found to have been impaired; no sub-adult animals were caught and no actively breeding females were found. The capture of fewer individuals at post-treatment (29) than at pre-treatment (143) was a further indication that rat numbers remained low following the treatment.In May 1976, 14 months after the BDH 10131 treatment, both sub-adult and pregnant animals were again present, providing evidence of renewed breeding and of population growth.</div>","PeriodicalId":100066,"journal":{"name":"Agro-Ecosystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1982-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-3746(82)90015-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79289474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Comparison of forest water and energy exchange models 森林水和能量交换模型的比较

Agro-Ecosystems Pub Date : 1982-02-01 DOI: 10.1016/0304-3746(82)90027-0

Gaylord V. Skogerboe

引用次数: 0

Production of organic matter and interference of two grasses at different levels of water supply 两种牧草在不同供水水平下的有机质产量及干扰

Agro-Ecosystems Pub Date : 1982-02-01 DOI: 10.1016/0304-3746(82)90021-X

Susanne Salinger, Reinhard Bornkamm

{"title":"Production of organic matter and interference of two grasses at different levels of water supply","authors":"Susanne Salinger, Reinhard Bornkamm","doi":"10.1016/0304-3746(82)90021-X","DOIUrl":"10.1016/0304-3746(82)90021-X","url":null,"abstract":"<div>Arrhenatherum elatius (L.) Presl. (Oatgrass) and Bromus erectus Huds. (Bromegrass) were grown in pots in pure culture and with (a) root, (b) shoot and (c) root and shoot (total) competition with three levels of irrigation. There was one preliminary harvest of shoots and one final harvest of shoots and roots. Plant height, tiller number, and fresh and dry weight were recorded. The plant material was analyzed for protein and acid soluble nitrogen, for total ash, total lipids, carbon, DNA and RNA.The experiment took place in an unusually dry summer. For this reason both grasses showed nearly the same competitive ability. There was a slight advantage to Arrhenatherum under root and total competition, especially with watering, and a slight advantage for Bromus under shoot competition, with respect to competitive coefficients based on dry matter production. The most distinct effect was the reduction of the root system of Bromus under total competition with watering. The data clearly indicate that water is one of the factors for which Arrhenatherum and Bromus compete.Although there were only small changes in dry matter production, there were clear differences in the chemical composition of the plants. In the main part of the experiment, Arrhenatherum was able to increase its protein content under root and total competition, whereas Bromus showed a similar tendency only under shoot competition. These data confirm the earlier hypothesis that higher protein content of the green parts causes higher growth rate and thus indicates the stronger competitor. Both grasses exhibited an increase of carbon content under competition, whereas DNA and RNA, inversely related to each other, reacted specifically to root and shoot as well as total competition. These findings cannot be explained without further investigation.</div>","PeriodicalId":100066,"journal":{"name":"Agro-Ecosystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1982-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-3746(82)90021-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78684396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Grass — Its production and utilisation 草的生产和利用

Agro-Ecosystems Pub Date : 1982-02-01 DOI: 10.1016/0304-3746(82)90035-X

C.R.W. Spedding

引用次数: 0