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Glenn EP Flessa KW Cohen MJ Nagler PL Rowell K Zamora-Arroyo F 《Environmental management》2007,40(1):1-6
A recent article in Environmental Management by All argued that flood flows in North America’s Colorado River do not reach the Gulf of California because they are captured
and evaporated in Laguna Salada, a below sea-level lakebed near the mouth of the river. We refute this hypothesis by showing
that (1) due to its limited area, the Laguna Salada could have evaporated less than 10% of the flood flows that have occurred
since 1989; (2) low flow volumes preferentially flow to the Gulf rather than Laguna Salada; (3) All’s method for detecting
water surface area in the Laguna Salada appears to be flawed because Landsat Thematic Mapper images of the lakebed show it
to be dry when All’s analyses said it was flooded; (4) direct measurements of salinity at the mouth of the river and in the
Upper Gulf of California during flood flows in 1993 and 1998 confirm that flood waters reach the sea; and (5) stable oxygen
isotope signatures in clam shells and fish otoliths recorded the dilution of seawater with fresh water during the 1993 and
1998 flows. Furthermore, All’s conclusion that freshwater flows do not benefit the ecology of the marine zone is incorrect
because the peer-reviewed literature shows that postlarval larval shrimp populations increase during floods, and the subsequent
year’s shrimp harvest increases. Furthermore, freshwater flows increase the nursery area for Gulf corvina (Cynoscion othonopterus), an important commercial fish that requires estuarine habitats with salinities in the range of 26–38‰ during its natal stages.
Although flood flows are now much diminished compared to the pre-dam era, they are still important to the remnant wetland
and riparian habitats of the Colorado River delta and to organisms in the intertidal and marine zone. Only a small fraction
of the flood flows are evaporated in Laguna Salada. 相似文献
176.
Harald Abele Philipp Wagner Jiri Sonek Markus Hoopmann Sara Brucker Burcu Artunc-Ulkumen Karl Oliver Kagan 《黑龙江环境通报》2015,35(12):1182-1186
177.
ABSTRACT: The hydrologic impacts of livestock grazing schemes on selected plant communities and soils at Fort Stanton, New Mexico, were evaluated. Simulated rainfall was applied to 1 m2plots. On a mesa-top, infiltration rates for a grassland livestock exclosure and a pinyon pine-juniper community closely approximated each other and were significantly greater (P = 0.10) than either a moderate continuous or a heavy continuous treatment in a grassland community. Sediment concentration from the heavy continuous treatment was more than twice that of the other treatments. Infiltration rates on the hillside site were highest in a pinyon pine-juniper community receiving short duration grazing. Infiltration for this treatment was found to be significantly higher (P = 0.10) than that of a short duration grazing treatment, but not from a rest rotation grazing treatment on grassland. The short duration grazing treatment on a grassland had the highest sediment concentration, while the rest rotation grazing on a grassland and the short duration pinyon pine-juniper treatments were found to be similar. In the bottomland site, a fertilized and unfertilized treatment showed no significant difference in infiltration or sediment concentration, although twice as many animals were present on the fertilized treatment. 相似文献
178.
Lying in negotiations can cause negative emotions, so participants may use neutralization strategies to reduce these feelings. We conducted a 2 (ethical versus non‐ethical climate) × 2 (low versus high negative consequences) experiment to examine how individual and situational factors affect the use of three such strategies: minimizing the lie, denigration of the target, and denial. Lying, psychological distress, and self‐perceived moral attributes were measured as non‐manipulated independent variables. One hundred and ninety‐two MBA students participated in a business negotiation in which they were provided with incentives to lie. As predicted, higher distress was associated with greater denial of lies. In addition, climate and consequences interacted to affect minimization and liars engaged in less minimization than did participants who merely concealed information. Climate and moral attributes interacted to affect denigration. We believe these findings support further study of neutralization strategies in the workplace. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
179.
Monitoring of soil chemical properties for pollution assessment generally requires destructive soil sampling and results in spatiotemporal datasets where data from different sampling dates are non co-located. The objective of this study was to assess the spatial distribution of residual pyrite sludge at a reclaimed site, using temporally non co-located data on pH; soil oxidizable fraction (SOF); and EDTA-extractable Fe, Zn, and Cu from six different sampling dates over a period of 2 yr. During this period spatially averaged pH and Zn concentrations ranged, respectively, from 4.4 to 6.6 and from 60 to 140 mg kg(-1), with minimum pH values of below 2.7. The data were merged into a single dataset for each chemical property after applying a normal score (ns) transform. Normal score pH was significantly negatively correlated with the ns metal concentrations. A principal component analysis (PCA) showed that normal score pH, Zn, and Fe were associated with the residual contamination, while ns Cu, SOF, and elevation were related with historic contamination. The spatial dependence between the properties was found to be scale-dependent. The best ns estimates were produced by ordinary kriging with an anisotopic variogram model, for the properties related with Principal Component (PC) I, while those associated with PC II were best estimated using simple kriging with varying local means. A classified ns pH map showed that 33% of the study area reached at least once values of below 4 during the 2-yr period. This part of the area should be excluded to ensure successful revegetation. 相似文献
180.
Hirnforschung am Navigationssystem der Fliegen 总被引:1,自引:0,他引:1
Karl Georg Götz 《Die Naturwissenschaften》1975,62(10):468-475