青海省旅游客源市场分析研究

青海省旅游资源独特,资源的垄断性高,但旅游业起步晚且发展水平较低,在国际和国内旅游客源市场上占有的份额小。作者运用1990年～1997年旅游统计资料,研究了青海省国内、国际旅游客源市场的数量和地域构成现状,并针对其客源市场发展目标,提出了相应的开发措施。     

城市抗灾力的内涵、度量模型与评估策略

提出城市的抗灾力与城市脆弱性成负相关,与危机弹性成正相关.认为城市内部系统高度相关是城市脆弱性的根源,继而从城市内在系统的相关性出发,给出城市脆弱性定义,并结合危机弹性建立了一套可操作的城市抗灾力度量模型.给出基于度量模型的城市抗灾力\"五步法\"评估策略以及相关的初步防灾策略.提出的度量模型与评估策略可以用于政府及相关部门来评测突发事件对城市产生的影响,从而为有关部门及市政建设规划决策提供依据.     

Male age structure influences females’ mass change during rut in a polygynous ungulate: the reindeer (Rangifer tarandus)

The manipulation of the sex ratio and age structure in many managed ungulate populations calls for a better understanding of their potential consequences on females’ condition and behavior during rut. During 1996–2002, we manipulated the male age structure and male percentage (nine treatments during 7 years) within an experimental herd of semidomestic reindeer (Rangifer tarandus) and investigated their influence on both the body mass change and the behavior of females during rut. On average, the females lost body mass (−0.95±SE 0.18 kg) during rut, which we contend to reflect somatic costs. The females’ losses increased as the percentage of male decreased, but this was certainly ascribed to one treatment with high male percentage (27.7%) as compared to the others (ranging from 3.9 to 12.2%). Female losses were highest for treatments including both young and adult males as compared to only adult or only young males, and higher for treatments including only young compared to only adult males. This is supported by (1) the higher female harassment frequency when females are exposed to only young or a mixture of young and adult males as compared to only adults, (2) the higher female harassment frequency by young males as compared to adults in the mixed treatments, and (3) the reduced females’ feeding activity in treatments including both young and adult males. We conclude that the male age structure during rut will influence the females’ behavior and mass change and may have implications for females’ life history and for population dynamics.     

道路景观生态安全研究

基于道路景观对生态环境的5方面影响,即对生物及生境的影响、对环境的物理影响、对环境的次生影响、对大尺度景观的影响及综合影响,提出保障道路景观生态安全的策略,主要应从道路及其网络规划设计和建设、交通政策、法规的制定与执行、生态工程措施、道路的使用与管理等几个方面加以考虑.笔者认为,要减少和缓解道路对生态环境的影响,环境影响评价是基础、生态道路及其网络建设措施和有效使用管理是手段、制定相关法律法规是依据;同时指出,我国未来应以高速公路的开发建设为契机,在实践中应用并促进道路景观生态安全的研究,带动中国道路建设事业的和谐发展.     

Imperfect chemical female mimicry in males of the ant Cardiocondyla obscurior

Winged and wingless males coexist in the ant Cardiocondyla obscurior. Wingless (“ergatoid”) males never leave their maternal colony and fight remorselessly among each other for the access to emerging females. The peaceful winged males disperse after about 10 days, but beforehand also mate in the nest. In the first 5 days of their life, winged males perform a chemical female mimicry that protects them against attack and even makes them sexually attractive to ergatoid males. When older, the chemical profile of winged males no longer matches that of virgin females; nevertheless, they are still tolerated, which so far has been puzzling. Contrasting this general pattern, we have identified a single aberrant colony in which all winged males were attacked and killed by the ergatoid males. A comparative analysis of the morphology and chemical profile of these untypical attacked winged males and the tolerated males from several normal colonies revealed that normal old males are still performing some chemical mimicry to the virgin queens, though less perfect than in their young ages. The anomalous attacked winged males, on the other hand, had a very different odour to the females. Our study thus exemplifies that the analysis of rare malfunctioning can add valuable insight on functioning under normal conditions and allows the conclusion that older winged males from normal colonies of the ant C. obscurior are guarded through an imperfect chemical female mimicry, still close enough to protect against attacks by the wingless fighters yet dissimilar enough not to elicit their sexual interest.     

Population frequencies of alternative male phenotypes in tree lizards: geographic variation and common-garden rearing studies

Tree lizards (Urosaurus ornatus) vary in throat fan (dewlap) color. Earlier, we described five dewlap types (Orange, Orange-Blue, Yellow, Yellow-Blue, and Blue), and reported that only males had blue in the dewlap and that presence or absence of a discrete blue patch was correlated with male alternative reproductive phenotypes in a central Arizona population. Here, with a modified scheme characterizing two dewlap elements, background color (orange, yellow, blue) and blue patch occurrence, we assessed: (1) sexual, annual, and geographic variation in the frequencies of dewlap elements; (2) simple habitat correlates; and (3) the effects of laboratory rearing regime on dewlap type. Within a population, frequencies of males and females expressing orange or yellow backgrounds did not differ, suggesting that control of background is similar in the sexes. Within several populations, frequencies of the dewlap elements did not differ across years (and probably generations), indicating that phenotype frequencies are relatively stable. Among five populations frequencies of background colors varied, as did frequencies of male types (blue patch present or absent). Dewlap frequencies did not correlate with habitat (boulders or mesquite trees), although few populations were sampled. In male and female offspring reared from eggs to sexual maturity in a common-garden laboratory study, background color frequencies in both sexes and blue patch frequencies in males differed among offspring from different populations. Offspring frequencies matched respective parental population frequencies. Results suggest that among-population variation in frequencies of the two dewlap elements are mediated by differences in genetics, in maternal effects, or both. Thus, differences in male behavior functionally linked to the blue patch also may be controlled by genetic or maternal effects. Received: 17 January 1997 / Accepted after revision: 30 August 1997     

Male competition in Cardiocondyla ants

The two types of males in the ant genus Cardiocondyla differ remarkably in morphology and behavior. Ergatoid males are wingless fighters whose spermatogenesis continues throughout their entire adult lives and which therefore have an “unlimited” sperm supply. They attempt to kill all eclosing ergatoid rivals and thus to increase their share in copulations with the virgin queens reared in their nests. Winged males, on the other hand, are docile and emigrate from the nests a few days after eclosion, probably to mate with queens from other colonies. By this time, their testes have fully degenerated and all sperm is stored in the seminal vesicles. Before emigration, winged males may mate with virgin queens in their maternal nests, but they are nevertheless rarely attacked by ergatoid males. In the laboratory, the life expectancy of ergatoid males is only slightly higher than that of winged males, but because of the emigration of the latter the difference is likely to be more pronounced in the field. Both male morphs are capable of inseminating more than 35 virgin queens. However, winged males older than 14 days mate less often than ergatoid males of similar age, probably due to sperm depletion in later life. The spermathecae of queens inseminated by ergatoid males contained significantly more sperm than those of queens which mated with winged males. We discuss the evolution of intranidal mating and male polymorphism in ants. Received: 8 August 1997 / Accepted after revision: 6 October 1997     

青岛在山东半岛蓝色经济区建设中的功能定位及发展对策研究

山东半岛蓝色经济区建设已正式上升为国家战略,是国家区域协调发展的重要组成部分。青岛作为山东半岛的龙头城市,综合实力强、地理位置优越、海洋资源丰富、海洋科技领先、海洋经济发达且产业结构较为合理,应借此优势将其建设成为全国蓝色经济发展的先行区、山东半岛蓝色经济区的核心区。在此过程中,青岛要进一步优化蓝色经济的空间布局,并按照“优化提升一产,发展壮大二产,突破发展三产”的思路完善产业结构。为促进山东半岛蓝色经济区快速发展,发挥辐射带动作用,青岛应营造良好的政策环境,突破海洋产业化关键技术,实施项目带动策略,加强半岛城市间的分工协作,并在开发过程中注重生态环境保护,确保蓝色经济可持续发展     

长江中游地区畜牧业生产现状及持续发展策略

长江中游地区年产猪肉１２５．９６万ｔ,鲜鱼７４．１２万ｔ,是我国重要的畜、禽、鱼养殖基地。依生态景观和畜牧业生产特点,可以分为平原湖区和丘陵岗地两种类型的畜牧业生产模式。目前,该地区畜牧业生产尚存在饲料粮严重短缺,畜牧结构不合理,饲料资源利用不充分和畜产品加工业落后等问题。     

长江上游川云贵三省农业自然资源开发方向和对策

川云贵三省农业自然资源丰富,以山地丘陵为主的地貌类型,形成立体性多样农业气候和不同农业区,成为向国内提供丰富的商品农林产品的地区,烟、茶是重要的创汇产品。随着长江流域、沿边省云南和省会城市的开放,通过改造中低产田、冬闲田利用、农业广度开发,加强草场资源的利用和保护等措施,在提高粮食自给水平同时,把本区建成我国烟、油菜、茶叶、瘦肉型猪、半细毛羊、林特产品的商品基地。