南宁市城区大气微生物污染状况调查与评价

为了解南宁市城区大气微生物的污染状况,本文利用自然沉降法对南宁市城区不同功能区74个监测点进行大气微生物含量调查,并分析评价了南宁市城区大气微生物的污染状况。调查结果表明:南宁市城区大气微生物含量变化范围为1101~29094 cfu/m3,平均值含量高低顺序为交通干线区>工业区>商业区>居民区>文教机关区>休闲广场区>公园旅游区;大气微生物中细菌占79.2%,霉菌占20.8%;在参与评价的74个监测点中,大气微生物总数属于清洁~较清洁级的有60.8%,轻微污染~污染级的有32.8%,中污染占5.4%。     

上海市土壤中人工放射性水平调查及评价

调查了１９８９－１９９０年上海市土壤中及黄浦江水系底泥中，人工放射性核素的含量。调查共设３２个点，结果表明，上海市土壤中的人工放射性核素含量，＾９０Ｓｒ、＾１３７Ｃｓ、总β的比活度均值分别为２、４１±０．７８、３．１４±１．４７、７１７．０±１３５．９Ｂｑ／ｋｇ，属正常本底水平。土壤中人工放射性核素的比活度在全市范围内分布没有明显差别，波动范围不大。土壤中＾１３７Ｃｓ的比活度比＾９０Ｓｒ高，这与土     

重庆市天然气集输系统甲烷泄漏现状调查

利用引进的美国热电子公司 680型便携式碳氢化合物气体分析仪检测重庆市所辖 56个站场天然气集输设备的甲烷泄漏情况 ,分析了“气田 -集输管线 -井站 -设备”的泄漏情况 ,计算出设备的天然气泄漏量及经济损失 ,为生产部门提供了技术支持和服务。     

上海市郊4种地表径流污染负荷调查与评价

地表径流属于非点源污染，地表径流的产生取决于复杂的降雨过程，径流中污染物浓度，径流深度，产流面积是地表径流污染负荷的３大要素，该文对上海郊的４种地表径流进行了调查，并在污染源评价的基础上与市郊非点源污染总量进行了比较。结果表明，上海市郊进入水全的污染负荷，ＣＯＤｃｒ约为６２６３４．７ｔ／ａ，总氮为６２８８．２ｔ／ａ，总磷为１２４４．６ｔ／ａ，此结果说明地表径流是上海市郊仅次于畜禽类尿的重要非点污染     

Past reproductive success affects future habitat selection

Correlational studies have shown that an individual's past reproductive success often increases its breeding site fidelity (i.e., the tendency to return to a previously occupied location), suggesting that individuals use their reproductive experience to assess habitat quality. However, the causality of the relationship between reproductive success and site fidelity is still uncertain. In a field experiment, the effect of mating success on site fidelity was isolated from potential confounding variables in a territorial dragonfly, the eastern amberwing (Perithemis tenera). The experiment controlled for site quality, intrinsic characteristics of males, previous territorial experience at the site, arrival order, and territorial evictions. Males that were prevented from mating were much more likely to change sites the following day than control males that were allowed to mate. This result was not affected by age, the amount of time a male spent on the site, or mortality. These results imply that individuals use their own reproductive success to assess the quality of the habitat. The benefit to an individual of using its reproductive success to determine habitat quality is discussed relative to other sources of information. Received: 31 May 1996 / Accepted: 31 January 1997     

Modelling the response of tree growth to temperature and CO2 elevation as related to the fertility and current temperature sum of a site

A methodology for simulating climate change impacts on tree growth was introduced into a statistical growth and yield model in relation to variations in site fertility and location implemented with current temperature sum. This was based on a procedure in which the relative enhancement in stem volume growth was calculated from short-term runs of a physiological simulation model for Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.) and silver birch (Betula pendula Roth.) stands. These simulations were made for a set of stands with species-specific variations in stand characteristics, location and fertility type first in current climatic conditions and then in different combinations of CO₂ and temperature elevations. Based on these simulations, the relative enhancement of volume growth induced by the climate change (relative scenario effect, RSEv) was calculated and modelled in relation to: (i) CO₂ and temperature elevation, stand density and the competition status of the tree in its stand, and (ii) variations in site fertility type and current temperature sum of a stand. Finally, these transfer functions for RSEv were applied to adapt the stem volume growth in the statistical growth and yield model to reflect the response to climate change.     

Intermittent breeding as a cost of site fidelity

Intermittent breeding (skipping a breeding season) can be the result of an adaptive decision by a focal individual, trading current reproductive success in favour of future reproductive success (residual reproductive value hypothesis). In contrast, an individual can also be forced by conspecifics to abandon the familiar breeding site and refrain from breeding due to lack of suitable alternative breeding sites or mates (competition hypothesis). I studied intermittent breeding in the territorial and site-faithful Eurasian oystercatcher Haematopus ostralegus, using a dataset covering 20 years. Intermittent breeding (in total 86 cases) occurred among breeders that formerly bred in high- as well as low-quality territories. The main factor associated with intermittent breeding in high-quality sites was death of a mate, while in low quality sites divorce was the most prominent factor. In 93% of the cases birds were forced to cease breeding due to pressure from conspecifics consistent with the competition hypothesis. There was no association between intermittent breeding and promotion to a territory of better quality. Instead, oystercatchers returned to breeding habitat of similar quality and at a very close distance (median distance 128 m) from the previous breeding location. Breeding absences lasted on average 2.4 years, with a maximum of 9 years, and the quality of the territory obtained after the absence varied with the duration of it. Birds who re-bred in a high-quality territory acquired this on average faster than those that re-bred in a low-quality territory, indicating that birds in high-quality sites are better competitors.     

Sex-specific differences in site fidelity and the cost of dispersal in yellow-headed blackbirds

Male migratory birds tend to be more faithful than females to previous breeding sites, suggesting sex differences in costs or benefits of dispersal. In Illinois, greater site fidelity by male yellow-headed blackbirds (Xanthocephalus xanthocephalus) was associated with reduced reproductive success the following year for dispersers relative to non-dispersers. Dispersing females suffered no reduction in reproductive success the following year. Males that attracted few social mates, and thus had low reproductive success, were more likely to disperse, whereas females dispersed in response to low-patch reproductive success, regardless of their individual performance. Males that dispersed appeared to be successful acquiring territories because none was observed as a floater. The rate of dispersal by males in this low-density population was greater than in more dense populations where dispersing males may be less successful at acquiring territories. Despite success at obtaining territories, males that dispersed acquired territories on the periphery of wetlands where fewer females nested, resulting in lower reproductive success. In the second year after dispersing, however, males moved onto more central territories where they acquired larger harems. Thus, dispersal by males may be a long-term strategy requiring at least 2 years for benefits to be realized. Long-term success was enhanced because dispersing males moved to wetlands on which reproductive success was higher than on the wetlands they left. In addition to demonstrating that both individual and patch reproductive success affect dispersal decisions, these data indicate that when evaluating costs and benefits of dispersal, researchers should use a time frame beyond 1 year.     

沈阳市填埋场填埋气利用途径比较

通过对国外填埋气体的利用情况介绍和国内现有填埋气体利用途径的比较,得出沈阳市填埋气体适于发电的结论。     

泉州市环境放射性水平调查

报道了福建省泉州市环境放射性水平调查方法和结果。调查结果表明 :(1)泉州市原野γ辐射剂量率为 72 .3～ 16 5 .1n Gy/ h,按测点和人口加权均值为 111.5 n Gy/ h和 110 .9n Gy/ h,高于福建省的平均值 (分别为 92 .6 n Gy/ h和87.1n Gy/ h) ,是 UNSCEAR1982年报告中给出的世界陆地γ辐射剂量率按人口加权均值 (5 0 n Gy/ h)的 2 .2 2倍。(2 )泉州市道路γ辐射剂量率测值范围为 6 5 .8～ 14 9.5 n Gy/ h,均值 113.7n Gy/ h,略高于福建省均值 10 6 .4 n Gy/ h。 (3)泉州市建筑物室内天然γ辐射剂量率测值范围为 12 8.9～ 2 86 .3n Gy/ h,按测点和人口加权均值分别为 190 .7n Gy/ h和 188.5 n Gy/h。不同建筑材料建筑物室内天然γ辐射剂量率由高到低的顺序依次为花岗石房 >砖与混凝土房 >煤渣砖房 >砖木、土木房。(4)泉州市天然γ辐射、宇宙和线射天然贯穿辐射所致居民人均年有效剂量当量分别为 1.0 5 m Sv、0 .16 m Sv和1.2 1m Sv,全区集体年有效剂量当量分别为 0 .76× 10 4人· Sv,0 .12× 10 4人·Sv,0 .88× 10 4人· Sv。(5 )土壤中 2 2 6 Ra、2 32 Th、4 0 K含量均值分别为 71.3Bq/ kg、6 8.8Bq/ kg、6 8.8Bq/ kg、94 3.7Bq/ kg。(6 )地下水中2 2 6 Ra、U、Th、Rn浓度均值分别为 31.9m Bq/ L、0 .5