Long-term reactions of plants and macroinvertebrates to extreme floods in floodplain grasslands

Extreme summertime flood events are expected to become more frequent in European rivers due to climate change. In temperate areas, where winter floods are common, extreme floods occurring in summer, a period of high physiological activity, may seriously impact floodplain ecosystems. Here we report on the effects of the 2002 extreme summer flood on flora and fauna of the riverine grasslands of the Middle Elbe (Germany), comparing pre- and post-flooding data collected by identical methods. Plants, mollusks, and carabid beetles differed considerably in their response in terms of abundance and diversity. Plants and mollusks, displaying morphological and behavioral adaptations to flooding, showed higher survival rates than the carabid beetles, the adaptation strategies of which were mainly linked to life history. Our results illustrate the complexity of responses of floodplain organisms to extreme flood events. They demonstrate that the efficiency of resistance and resilience strategies is widely dependent on the mode of adaptation.     

Pigment allocation to eggs decreases plasma antioxidants in a songbird

Although evidence is accumulating on the adaptive function of female ornamentation, very little is known about maternal allocation decisions involving sexual signaling and other reproductive functions. Blue egg coloration has been suggested as a sexually selected signal of female quality to males, and some recent studies are in accordance with this hypothesis. Blue eggshell coloration results from the deposition of biliverdin pigment by laying females, which is a potent antioxidant. Thus, egg pigmentation should be costly in terms of antioxidants, an assumption of the signaling hypothesis that has not been tested yet. We induced increased reproductive effort in a set of female pied flycatchers Ficedula hypoleuca through nest removal and measured egg pigmentation and plasma antioxidant levels in relation with a control group. Experimental females showed a negative association between egg color and plasma antioxidant levels, while there was no relationship for control birds. This supports that egg pigmentation is costly in terms of general antioxidant defenses and suggests a tradeoff between the allocations to both traits. Furthermore, experimental females with more colorful eggs raised more fledglings, especially when breeding early. Controls did not show a relationship between egg color and reproductive success. Females laying more colorful eggs could have shifted their allocation decisions towards current reproduction, at the expense of their own antioxidant defenses. Our results highlight that blue egg coloration is a life-history trait, subject to tradeoffs with other attributes, and seems to be especially informative under harsh breeding conditions.     

Development and Application of Critical,Target and Monitoring Loads for the Management of Acid Deposition in Alberta,Canada

The Alberta, Canada acid deposition management framework, based upon the application of critical, target and monitoring loads, is described. This framework is the culmination of four years work by stakeholders brought together within Alberta's Clean Air Strategic Alliance (CASA). The elements of the framework include scientific aspects of measurement, model estimation, and monitoring of acid deposition, assessment of receptor sensitivity, and management processes to reduce emissions and deposition (should reductions become necessary). All loads are applied to grid cells measuring 1°latitude × 1° longitude, with each cell being categorized as sensitive, moderately sensitive or of low sensitivity on the basis of the sensitivities of the soil and water systems within the cell. Critical loads have been set at 0.25, 0.50 and 1.00 keq H⁺ ha^-1 yr^-1 for grid cells that are categorized as sensitive, moderately sensitive, and of low sensitivity, respectively. Target loads, the environmental management objectives, have been set at 0.22, 0.45, and 0.90 keq H⁺ ha^-1 yr^-1, and monitoring loads, a new concept in acid deposition management, have been set at 0.17, 0.35 and 0.70 keq H⁺ ha^-1 yr^-1 for the three sensitivity classes. When model prediction indicates that deposition may be exceeding the monitoring load, deposition monitoring and receptor sensitivity studies are to be initiated to confirm the deposition model prediction, and to ensure that the sensitivity of the recipient systems is understood. In this manner, management actions that occur in the event of a target load exceedance will be based upon receptor sensitivity and deposition data rather than upon model prediction alone. A process for stakeholder involvement in the evaluation of the framework and its application in long-term, long-range management of emissions and deposition is also included within the framework.     

CASA DEL AGUA: WATER CONSERVATION DEMONSTRATION HOUSE 1986 THROUGH 19981

ABSTRACT: Casa del Agua (Casa) in suburban Tucson, Arizona, was designed as a residential water conservation facility for applied research, demonstration of operational results, and transfer of technology to the general public. Starting in 1983, an existing residence was located, modified and retrofitted to acquire operational data on residential water use. Modifications included retrofitting existing landscapes and enlarging the rooftop to collect and harvest rainwater; separating blackwater and graywater lines; installing meters, low‐water‐use appliances and fixtures, and underground storage tanks for rainwater and graywater; and creating a public information center. Over the 13‐plus years of actual operation, both the interior and exterior water use research results indicate large reductions in water use can be effected using water‐saving devices andlor harvesting and reusing rainwater and graywater. Casa achieved over a 24 percent reduction in total water use and a 47 percent reduction in municipal water used compared to the typical Tucson residence. Overall water used was comprised of harvested rainwater (10 percent), recycled graywater (20 percent), and municipal water (70 percent). Casa's Information Center was visited by approximately 13,000 people from September 1985 through April 1999 and the research has been featured in local, national, and international media.     

Characteristics of Composition B particles from blow-in-place detonations

We sampled residues from high-order and low-order blow-in-place detonations of mortars and projectiles filled with Composition B (Comp B), a TNT and RDX mixture. Our goals were to (1) characterize the types of explosive particles, (2) estimate the explosive 'footprint' for different munitions, and (3) estimate the mass of Comp B remaining after each detonation. The aerial deposition of Comp B particles helps estimate how large of an area is contaminated by a low-order detonation and how best to sample residue resulting from different rounds. We found that the high-order detonations deposited microgram to milligram quantities whereas the low-order detonations deposited gram quantities of Comp B. For the high-order detonations the concentration of Comp B in the residue decreased as a function of distance from the blast. The low-order tests scattered centimeter-sized chunks and millimeter-sized or smaller particles of Comp B. The chunks were randomly scattered whereas the number of millimeter-sized particles decreased with distance from the detonation. For both high- and low-order detonations we found that the smaller munitions deposited less Comp B than the larger munitions and deposited it closer to the detonation point.     

Identity and distribution of residues of energetic compounds at army live-fire training ranges

Environmental investigations have been conducted at 23 military firing ranges in the United States and Canada. The specific training facilities most frequently evaluated were hand grenade, antitank rocket, and artillery ranges. Energetic compounds (explosives and propellants) were determined and linked to the type of munition used and the major mechanisms of deposition.