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111.
William W. Budd Paul L. Cohen Paul R. Saunders Frederick R. Steiner 《Environmental management》1987,11(5):587-597
King County, Washington is a part of the rapidly growing Pacific Northwest region. This growth has placed pressure on stream corridors. Past studies about regional stream corridors provide a rich source of information for environmental planners and managers. This article draws on existing literature and case studies to provide guidelines for determining optimal stream corridor widths in a watershed located in King County, Washington. 相似文献
112.
/ A predictive model for assessing stand condition as a function of suitability for achieving specified management objectives was originally developed using a data set for only 28 stands. In this study, we evaluate the model using an operational-sized data set composed of currently collected stand inventory data for 238 stands in the Snowy Range of the Medicine Bow National Forest in southern Wyoming. We compared its predictions of old growth suitability to results of a separate special old growth survey. Stands were characterized as profiles of variables derived from stand inventory data, and plotted as points in two-dimensional space where similarity between stands was reflected by the distance between their points. Results suggest the model is useful for classifying stand condition using relatively large sets of data currently collected during routine stand inventories. 相似文献
113.
锌冶炼-氯碱复合污染区昆虫中的重金属 总被引:1,自引:1,他引:0
采集葫芦岛草地中14种昆虫(植食性、杂食性、肉食性)及蚯蚓,测定生物体内汞、镉、铅含量,研究生物体内重金属污染情况.植食性昆虫汞、镉、铅平均含量分别为0.168、 9.19、 12.58 mg·kg-1;杂食性昆虫汞、镉、铅平均含量分别为0.375、 24.43、 17.71 mg·kg-1;肉食性昆虫汞、镉、铅平均含量0.928、 29.78、 18.39 mg·kg-1;蚯蚓平均汞含量为1.923 mg·kg-1,葫芦岛生物体内重金属污染严重.不同种类昆虫对重金属的富集能力差异较大,蜗牛、蜻蜓对汞的富集能力较高;蜘蛛对镉、铅的富集能力较高.昆虫体内重金属含量顺序为汞<铅<镉.汞、镉、铅含量由低到高的顺序均为植食性昆虫<杂食性昆虫<肉食性肉昆虫,杂食性昆虫与肉食性昆虫平均镉、铅含量之间较为接近.昆虫体内镉、铅含量之间极显著相关,而汞与镉、汞与铅含量之间的相关性较差.表明昆虫体内镉铅具有同一来源,而汞的来源较为复杂. 相似文献
114.
115.
采用夜间网捕、无味胶粘、固定捕网等方法对黄花忍冬夜间访花昆虫进行调查,根据对所收集标本分类得出该夜间访花昆虫的基本类群组成主要有夜蛾科占54%、螟蛾科占20%、卷蛾科占20%、豆象科占3%、叶蝉占3%等,其中以螟蛾科和夜蛾科所收集到数量最多,分别是9只和19只.其活动时间分析表明,在夜间19∶00~23∶00时间段内各种类活跃程度较高,对植物的到访较为频繁图1,表2,参12. 相似文献
116.
A Spatially Explicit Resource-Based Approach for Managing Stream Fishes in Riverscapes 总被引:1,自引:0,他引:1
The article describes a riverscape approach based on landscape ecology concepts, which aims at studying the multiscale relationships
between the spatial pattern of stream fish habitat patches and processes depending on fish movements. A review of the literature
shows that few operational methods are available to study this relationship due to multiple methodological and practical challenges
inherent to underwater environments. We illustrated the approach with literature data on a cyprinid species (Barbus barbus) and an actual riverscape of the Seine River, France. We represented the underwater environment of fishes for different discharges
using two-dimensional geographic information system-based maps of the resource habitat patches, defined according to activities
(feeding, resting, and spawning). To quantify spatial patterns at nested levels (resource habitat patch, daily activities
area, subpopulation area), we calculated their composition, configuration, complementation, and connectivity with multiple
spatial analysis methods: patch metrics, moving-window analysis, and least cost modeling. The proximity index allowed us to
evaluate habitat patches of relatively great value, depending on their spatial context, which contributes to the setting of
preservation policies. The methods presented to delimit potential daily activities areas and subpopulation areas showed the
potential gaps in the biological connectivity of the reach. These methods provided some space for action in restoration schemes. 相似文献
117.
为科学评估河流修复效果,研究修复河流中底栖动物物种多样性和生态功能恢复特征,以浙江省浦江县浦阳江干流为研究对象,分别对2个近自然河段、2个城区修复河段和3个郊区修复河段在修复后1,3,4和5年的水质和底栖动物恢复状况进行调查研究.采用广义最小二乘法(GLS)模型探索底栖动物物种多样性(总物种丰富度、EPT丰富度和Sha... 相似文献
118.
Wayland M Headley JV Peru KM Crosley R Brownlee BG 《Environmental monitoring and assessment》2008,136(1-3):167-182
An immense volume of tailings and tailings water is accumulating in tailings ponds located on mine leases in the oil sands
area of Alberta, Canada. Oil sands mining companies have proposed to use tailings- and tailings water-amended lakes and wetlands
as part of their mine remediation plans. Polycyclic aromatic hydrocarbons (PAHs) are substances of concern in oil sands tailings
and tailings water. In this study, we determined concentrations of PAHs in sediments, insect larvae and adult insects collected
in or adjacent to three groups of wetlands: experimental wetlands to which tailings or tailings water had been purposely added,
oil sands wetlands that were located on the mine leases but which had not been experimentally manipulated and reference wetlands
located near the mine leases. Alkylated PAHs dominated the PAH profile in all types of samples in the three categories of
wetlands. Median and maximum PAH concentrations, especially alkylated PAH concentrations, tended to be higher in sediments
and insect larvae in experimental wetlands than in the other types of wetlands. Such was not the case for adult insects, which
contained higher than expected levels of PAHs in the three types of ponds. Overlap in PAH concentrations in larvae among pond
types suggests that any increase in PAH levels resulting from the addition of tailings and tailings water to wetlands would
be modest. Biota-sediment accumulation factors were higher for alkylated PAHs than for their parent counterparts and were
lower in experimental wetlands than in oil sands and reference wetlands. Research is needed to examine factors that affect
the bioavailability of PAHs in oil sands tailings- or tailings water-amended wetlands. 相似文献
119.
采用微波消解-电感耦合等离子体质谱法测定水系沉积物中12种元素,通过优化试验相关条件消除质谱干扰和非质谱干扰对测定的影响,使方法在0μg/L~200μg/L范围内线性良好,当取样质量为0.25 g,定容体积为50 m L时,各元素的方法检出限为0.002 mg/kg~0.05 mg/kg。用该方法测定沉积物标准物质,6次测定结果均在标准值范围内,RSD为1.3%~6.1%,实际样品的加标回收率为83.0%~97.0%。 相似文献
120.
The effects of timber harvesting on stream water quality and efficiency of alternate streamside management zones were evaluated
in Pockwock Lake and Five Mile Lake watersheds in central Nova Scotia, Canada. The streamside management zone (SMZ) included
a 20 m no cut, 20 m select cut and a 30 m select cut buffer strips along the stream. Water quality of eight streams, six in
harvested and two in not-harvested watersheds were monitored for two years before and two years after the harvesting of timber.
Nonparametric statistical tests on stream water quality showed that there was significant change in the concentration of potassium
in six streams, manganese in five streams, zinc in two streams and total nitrogen in one stream after timber harvesting. There
was no significant change in the quality of water in two streams used as control sites in the neighboring watersheds of similar
size and hydrological characteristics. The results show that forest management practices were most favorable in streams maintained
with 30 m select cut followed by 20 m no cut and 20 m select cut SMZ. The streamside zone width and treatment of select cut
or no cut in the zone played an important role in filtering or retaining the minerals in surface water runoff. In buffer zones
of similar width, the buffer zone with no cut or forested buffer was relatively more effective at protecting stream water
quality than select cut SMZ. The vegetation in the zone may have decreased the flow velocity and increased residence time
and thus increased filtration and retention of minerals in the riparian soil. 相似文献