Invasive competitor and native seed predators contribute to rarity of the narrow endemic Astragalus sinuatus Piper

The conservation of rare plant species hinges on our ability to identify the underlying mechanisms that limit rare plant populations. Theory on rarity suggests that both predispersal seed predation and competition can be important mechanisms influencing abundance and/or distribution of rare plant populations. Yet few studies have tested these interactions, and those that have evaluated each mechanism independently. Astragalus sinuatus Piper (Whited's milkvetch) is a narrow endemic plant species restricted to eight populations within a 10-km2 area in eastern Washington. We used experimental and observational methods to test the effects of native insect predispersal seed predators and an invasive grass (Bromus tectorum L. [cheatgrass]) on seed set and population density of A. sinuatus. We quantified per capita seed production and pod predation rates across four sites and among four years. Seed predation rates were high across four sites (66-82%) and all years (65-82%). Experimental reduction of predispersal seed predators significantly increased per capita seed set of A. sinuatus (164-345%) at two experimental sites. Concurrently, two seed addition experiments demonstrated the effect of seed loss and presence of B. tectorum on seedling recruitment and establishment of A. sinuatus over four growing seasons. In the first seed addition experiment, we found no difference in recruitment and establishment between low (40) and high (120) seed addition levels. In the second addition experiment (one level of addition; 40 seeds), we found that recruitment and survivorship increased 200% in plots where B. tectorum was removed compared to plots where B. tectorum was present. Thus, seed addition had no impact in the presence of B. tectorum; conversely, in the absence of B. tectorum, seed addition was highly effective at increasing population numbers. Results suggest that, in areas where B. tectorum is present, recruitment is site limited, and it is seed limited when B. tectorum is absent. We recommend that managers reduce B. tectorum in an effort to increase population growth of A. sinuatus; in areas where B. tectorum is absent, short-term reduction of insect predators should be considered as a strategy to increase population growth of this rare species.     

Advancing effects analysis for integrated, large-scale wildfire risk assessment

In this article, we describe the design and development of a quantitative, geospatial risk assessment tool intended to facilitate monitoring trends in wildfire risk over time and to provide information useful in prioritizing fuels treatments and mitigation measures. The research effort is designed to develop, from a strategic view, a first approximation of how both fire likelihood and intensity influence risk to social, economic, and ecological values at regional and national scales. Three main components are required to generate wildfire risk outputs: (1) burn probability maps generated from wildfire simulations, (2) spatially identified highly valued resources (HVRs), and (3) response functions that describe the effects of fire (beneficial or detrimental) on the HVR. Analyzing fire effects has to date presented a major challenge to integrated risk assessments, due to a limited understanding of the type and magnitude of changes wrought by wildfire to ecological and other nonmarket values. This work advances wildfire effects analysis, recognizing knowledge uncertainty and appropriately managing it through the use of an expert systems approach. Specifically, this work entailed consultation with 10 fire and fuels program management officials from federal agencies with fire management responsibilities in order to define quantitative resource response relationships as a function of fire intensity. Here, we demonstrate a proof-of-concept application of the wildland fire risk assessment tool, using the state of Oregon as a case study.     

Photocatalytic remediation of methylene blue and antibacterial activity study using Schiff base-Cu complexes

This work describes the design of novel Cu(II) complexes and their application in the photocatalytic degradation of methylene blue (MB). The same photocatalyst exhibits antibacterial activity against Escherichia coli (gram-negative) and Bacillus circulans (gram-positive). The characterisation of the photocatalysts has been done by several up-to-date physical methods. The rationale behind the photocatalysts’ beneficial intervention is discussed in this study. Statistical analysis of the degradation of MB is done using a one-way ANOVA, and the significance of means is determined by a multiple comparison test using Turkey HSD. Also, the degradation of MB follows pseudo first-order kinetics with high correlation coefficient values (R²?>?0.95), making them useful as simple and low-cost organic dye degradation agents.

     

络合萃取法处理模拟金刚烷胺制药废水

采用络合萃取法处理模拟金刚烷胺制药废水,比较了苯、CCl4和P204等11种萃取剂对水溶液中金刚烷胺的萃取效果,考察了溶液初始pH值、稀释剂的类型、萃取剂与稀释剂的配比和油/水比等因素对萃取效率的影响,并对萃取液进行了反萃取分离研究.结果表明,在水溶液中金刚烷胺浓度为1000 mg·L-1,溶液初始pH值为8.0~10.0,油/水比为1∶1的条件下,采用P204与正辛醇体积比3∶2的复配萃取剂进行萃取分离,金刚烷胺萃取率可以达到99.0%以上,当金刚烷胺浓度增加至10.0 g·L-1时,萃取率仍可以保持在97.0%以上;以2.0 mol·L-1的HCl溶液为反萃取剂,按照油/水比为1∶1可将51.1%的金刚烷胺从萃取剂中反萃分离.     

Agricultural application of life cycle iNdeX (LInX) for effective decision making

Mechanisms for evaluating system sustainability should allow for the consideration of three main parameters: social, economic and environmental. While, there are methods for comparing processes, projects or systems on the basis of environmental impact or cost, few incorporate all three parameters into the decision process. Life cycle index (LInX) is an indexing system that is meant to simplify the decision making process by incorporating a life cycle based approach with components of sustainability and safety. Although LInX was designed for large industrial systems, this paper presents the application on a small anaerobic digestion (AD) unit on a dairy farm in Clymer, New York. An AD unit can be used to generate electricity from the combustion of biogas produced from organic waste. From the analysis, the AD unit performed well on environmental and cost parameters, but not as well on risk and social parameters. However, the AD unit performed similar to natural gas and biomass-based production. One recommendation for the method is that consideration be given to modifying parameters and weightings to suit agriculture and location specific needs.