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21.
Phillip N. Price Curtis M. Oldenburg 《International Journal of Greenhouse Gas Control》2009,3(5):658-663
Geologic carbon sequestration is the injection of anthropogenic CO2 into deep geologic formations where the CO2 is intended to remain indefinitely. If successfully implemented, geologic carbon sequestration will have little or no impact on terrestrial ecosystems aside from the mitigation of climate change. However, failure of a geologic carbon sequestration site, such as large-scale leakage of CO2 into a potable groundwater aquifer, could cause impacts that would require costly remediation measures. Governments are attempting to develop regulations for permitting geologic carbon sequestration sites to ensure their safety and effectiveness. At present, these regulations focus largely on decreasing the probability of failure. In this paper we propose that regulations for the siting of early geologic carbon sequestration projects should emphasize limiting the consequences of failure because consequences are easier to quantify than failure probability. 相似文献
22.
在杭州市现有区域环境噪声手工监测点位的基础上,结合地理分布,采用系统聚类法对2012年149个点位的数据样本分类、合并,将149个点位优化到26个,并用T检验法验证数据可靠性。优化前后各城区的点位分布比例相差不大,等效声级绝对误差在1.0 d B(A)内,相对误差不超过±5%。经过2013年和2014年数据验证,确定优化后的点位能体现声环境功能区的代表性。 相似文献
23.
Past reproductive success affects future habitat selection 总被引:4,自引:0,他引:4
Paul V. Switzer 《Behavioral ecology and sociobiology》1997,40(5):307-312
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 相似文献
24.
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. 相似文献
25.
Leo W. Bruinzeel 《Behavioral ecology and sociobiology》2007,61(4):551-556
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. 相似文献
26.
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. 相似文献
27.
28.
29.
Characterization and prediction of highway runoff constituent event mean concentration 总被引:3,自引:0,他引:3
Highway stormwater runoff quality data were collected from throughout California during 2000-2003. Samples were analyzed for conventional pollutants (pH, conductivity, hardness, and temperature); aggregates (TSS, TDS, TOC, DOC); total and dissolved metals (As, Cd, Cr, Cu, Ni, Pb, and Zn); and nutrients (NO(3)-N, TKN, total P, and ortho-P). Storm event and site characteristics for each sampling site were recorded. A statistical summary for chemical characteristics of highway runoff is provided based on statewide urban and non-urban highways. Constituent event mean concentrations (EMCs) were generally higher in urban highways than in non-urban highways. The chemical characteristics of highway runoff in California were compared with national highway runoff chemical characterization data. The results obtained in California were generally similar to those found in other states. The median EMC for Pb measured in studies conducted in previous decades was much higher than the current median Pb EMC in California. The lower Pb EMC in California compared to previous highway runoff monitoring is believed to be due to the elimination of leaded gasoline. An attempt was also made to identify surrogate constituents within a general family of water quality categories using Spearman correlations and selected pairs with Spearman coefficients greater than 0.8. The strongest correlations were observed among parameters associated with dissolved minerals (EC, TDS, and chloride); organic carbon (TOC and DOC); petroleum hydrocarbons (TPH and O & G); and particulate matter (TSS and turbidity). Within the metals category, total iron concentration was highly correlated with most total metal concentrations. The correlations between total and dissolved concentrations were all less than 0.8, even between total and dissolved concentrations of the same metals. Multiple linear regression (MLR) analyses were performed to evaluate the impact of various site and storm event variables on highway runoff constituent EMCs. Parameters found to have significant impacts on highway runoff constituent EMCs include: total event rainfall (TER); cumulative seasonal rainfall (CSR); antecedent dry period (ADP); contributing drainage area (DA); and annual average daily traffic (AADT). Surrounding land use and geographic regions were also determined to have a significant impact on runoff quality. The MLR model was also used to predict constituent EMCs. Model performance determined by comparing predicted and measured values showed good agreement for most constituents. 相似文献
30.
The use of terrestrial ecoregions as a regional-scale screen for selecting representative reference sites for water quality monitoring 总被引:3,自引:0,他引:3
A process has been developed to select watersheds that are representative of terrestrial ecoregions and that are relatively
undisturbed by human activity. Using an existing land classification system at two hierarchical levels of resolution, representative
subsets (ecodistricts) of large-scale ecoregions were selected, on the basis of their physiographic, biological, and climatological
attributes, to represent the ecoregions. This was achieved using a frequency distribution analysis of existing attribute data
and choosing the ecodistrict most closely resembling the most common set of conditions for that ecoregion. Within each ecodistrict,
river basins were selected through a best-judgement evaluation of land use, coupled with an assessment of the size and location
of each river basin, in order to meet the condition of minimal human impact. Preliminary assessment of water quality data
collected from six watersheds selected in this way suggests that the process is effective in targeting regional scale river
basins exhibiting the desired characteristics. 相似文献