The potential to encode sex,age, and individual identity in the alarm calls of three species of Marmotinae

In addition to encoding referential information and information about the sender’s motivation, mammalian alarm calls may encode information about other attributes of the sender, providing the potential for recognition among kin, mates, and neighbors. Here, we examined 96 speckled ground squirrels (Spermophilus suslicus), 100 yellow ground squirrels (Spermophilus fulvus) and 85 yellow-bellied marmots (Marmota flaviventris) to determine whether their alarm calls differed between species in their ability to encode information about the caller’s sex, age, and identity. Alarm calls were elicited by approaching individually identified animals in live-traps. We assume this experimental design modeled a naturally occurring predatory event, when receivers should acquire information about attributes of a caller from a single bout of alarm calls. In each species, variation that allows identification of the caller’s identity was greater than variation allowing identification of age or sex. We discuss these results in relation to each species’ biology and sociality.     

Sediment and phosphorus transport in irrigation furrows

Sediment and phosphorus (P) in agricultural runoff can impair water quality in streams, lakes, and rivers. We studied the factors affecting P transfer and transport in irrigated furrows in six freshly tilled fallow fields, 110 to 180 m long with 0.007 to 0.012 m m-1 slopes without the interference of raindrops or sheet flow that occur during natural or simulated rain. The soil on all fields was Portneuf silt loam (coarse-silty, mixed, superactive, mesic Durinodic Xeric Haplocalcids). Flow rate, sediment concentration, and P concentrations were monitored at four, equally spaced locations in each furrow. Flow rate decreased with distance down the furrow as water infiltrated. Sediment concentration varied with distance and time with no set pattern. Total P concentrations related directly to sediment concentrations (r2=0.75) because typically >90% of the transported P was particulate P, emphasizing the need to control erosion to reduce P loss. Dissolved reactive phosphorus (DRP) concentrations decreased with time at a specific furrow site but increased with distance down the furrow as contact time with soil and suspended sediment increased. The DRP concentration correlated better with sediment concentration than extractable furrow soil P concentration. However, suspended sediment concentration tended to not affect DRP concentration later in the irrigation (>2 h). These results indicate that the effects of soil P can be overshadowed by differences in flow hydraulics, suspended sediment loads, and non-equilibrium conditions.     

蜀南竹海的生态环境问题及其综合整治

蜀南竹海开发旅游获得一定经济效益的同时 ,也给环境和资源带来若干弊端。本文提出 ,以生态学有关理论作为指导 ,重新构思竹海旅游发展基本框架 ,拟定适宜竹海生境和资源的旅游项目 ,对竹海生态保护采取相应的措施 ,使之生态平衡良性循环 ,实现旅游业的可持续发展。     

蜀南竹海的生态环境的问题及其综合整治

蜀南竹海开发旅游获得一定经济效益的同时,也给环境和资源带来若干弊端。本文提出：以生态学有关理论作为指导,重新构思竹海旅游发展基本框架,拟定适宜竹海生境和资源的旅游项目,对竹海保护采取相应的措施,使之生态环境良性循环,实现旅游业的可持续发展。     

川西生态旅游区山地灾害防治对策刍议

川西九寨沟风景为世界级的生态旅游胜地,但该区山地灾害频繁。本文提出对山地灾害防治及管理的主要措施。     

The impact of disasters on small business disaster planning: a case study

A major flood in 1997 forced the evacuation of Grand Forks, North Dakota and caused damage of USD 1 billion. Despite this recent disaster there is only marginal evidence of an increase in disaster recovery planning by businesses that experienced the flood. This finding is consistent with the results of other business-related disaster research. Statistical tests of survey results from 2003 indicate that there is a significantly higher rate of disaster recovery planning in businesses started since the 1997 flood than in businesses started before the flood and still in business. Such an outcome indicates a need for public policy actions emphasizing the importance of disaster planning. Improved disaster planning is an aid to business recovery and the results demonstrate the need for more widespread efforts to improve disaster recovery planning on the part of smaller businesses, even in areas that have recently experienced disasters.     

Multi-scale landscape factors influencing stream water quality in the state of Oregon

Enterococci bacteria are used to indicate the presence of human and/or animal fecal materials in surface water. In addition to human influences on the quality of surface water, a cattle grazing is a widespread and persistent ecological stressor in the Western United States. Cattle may affect surface water quality directly by depositing nutrients and bacteria, and indirectly by damaging stream banks or removing vegetation cover, which may lead to increased sediment loads. This study used the State of Oregon surface water data to determine the likelihood of animal pathogen presence using enterococci and analyzed the spatial distribution and relationship of biotic (enterococci) and abiotic (nitrogen and phosphorous) surface water constituents to landscape metrics and others (e.g. human use, percent riparian cover, natural covers, grazing, etc.). We used a grazing potential index (GPI) based on proximity to water, land ownership and forage availability. Mean and variability of GPI, forage availability, stream density and length, and landscape metrics were related to enterococci and many forms of nitrogen and phosphorous in standard and logistic regression models. The GPI did not have a significant role in the models, but forage related variables had significant contribution. Urban land use within stream reach was the main driving factor when exceeding the threshold (> or =35 cfu/100 ml), agriculture was the driving force in elevating enterococci in sites where enterococci concentration was <35 cfu/100 ml. Landscape metrics related to amount of agriculture, wetlands and urban all contributed to increasing nutrients in surface water but at different scales. The probability of having sites with concentrations of enterococci above the threshold was much lower in areas of natural land cover and much higher in areas with higher urban land use within 60 m of stream. A 1% increase in natural land cover was associated with a 12% decrease in the predicted odds of having a site exceeding the threshold. Opposite to natural land cover, a one unit change in each of manmade barren and urban land use led to an increase of the likelihood of exceeding the threshold by 73%, and 11%, respectively. Change in urban land use had a higher influence on the likelihood of a site exceeding the threshold than that of natural land cover.     

Improving environmental risk management through historical impact assessments

A historical contaminant impact assessment was conducted at 48 heavy manufacturing facilities located in 20 different states for a U.S.-based company. The facilities evaluated were industrial manufacturing sites that operated for as long as 100 yr and used several types of hazardous substances, including solvents and degreasers, oils and other petroleum products, paints and pigments, and heavy metals. The purpose of conducting the impact assessment was to provide direction and guidance on future environmental objectives and pollution prevention initiatives. The impact assessment involved examining historical investigative and remediation costs since 1985, types of contaminants, subsurface geology, hydrology, and regulatory requirements. The results reveled that 85% of the historical environmental costs were associated with hexavalent chromium and chlorinated solvents. Other contaminants, such as oils and other petroleum products and other heavy metals, were far more commonly detected but only accounted for the remaining 15% of costs. The results also indicated that the costs are also strongly associated with the type of geologic environment to which the chemicals were released. As a result of these findings, an aggressive pollution prevention program has been initiated to eliminate the use of those contaminants that are especially expensive to remediate and to develop stronger and more effective engineering controls at facilities located in sensitive ecological areas.     

Rapid screening of 90Sr activity in water and milk samples using Cherenkov radiation

A method for screening 90Sr in milk samples is proposed. This method is based on a liquid scintillation technique taking advantage of Cherenkov radiation, which is produced in a liquid medium and then detected by the photomultipliers of a Liquid Scintillation Counter (LSC). Twenty millilitres of water and milk samples spiked with various concentrations of 90Sr/90Y in equilibrium were added in plastic vials and then were measured with an LSC (TriCarb 3170 TR/SL). The derived efficiencies were 49% for water samples and 14% for milk samples. The detection limit was 470 mBq L(-1)(90)Sr for water, without any pretreatment. Milk contains potassium, which also produces Cherenkov radiation due to the presence of 40K. For this reason, the interference of 40K in the measurements of 90Sr in milk samples was also investigated. The detection limit for milk was 1.7 Bq L(-1)90Sr.