Use of Empirically Derived Source-Destination Models to Map Regional Conservation Corridors

Abstract:  The ability of populations to be connected across large landscapes via dispersal is critical to long-term viability for many species. One means to mitigate population isolation is the protection of movement corridors among habitat patches. Nevertheless, the utility of small, narrow, linear features as habitat corridors has been hotly debated. Here, we argue that analysis of movement across continuously resistant landscapes allows a shift to a broader consideration of how landscape patterns influence connectivity at scales relevant to conservation. We further argue that this change in scale and definition of the connectivity problem improves one's ability to find solutions and may help resolve long-standing disputes regarding scale and definition of movement corridors and their importance to population connectivity. We used a new method that combines empirically derived landscape-resistance maps and least-cost path analysis between multiple source and destination locations to assess habitat isolation and identify corridors and barriers to organism movement. Specifically, we used a genetically based landscape resistance model for American black bears ( Ursus americanus ) to identify major movement corridors and barriers to population connectivity between Yellowstone National Park and the Canadian border. Even though western Montana and northern Idaho contain abundant public lands and the largest wilderness areas in the contiguous United States, moving from the Canadian border to Yellowstone Park along those paths indicated by modeled gene flow required bears to cross at least 6 potential barriers. Our methods are generic and can be applied to virtually any species for which reliable maps of landscape resistance can be developed.     

不同水分处理下农田黑土水分特征

采用田间定位试验,利用中子仪原位监测土壤储水量的方法,研究3个水分处理下农田土壤水分特征.结果表明:受长期不同水分处理的影响,适宜水分处理0-110 cm土壤储水量最高,其次为自然降水处理,分别比干旱处理增加了23.4%和12.9%;在大豆生育期内,各水分处理土壤储水量的季节性变化均呈"减小-增加-减小-增加"的趋势,与大豆生育期内降雨分布密切相关;各处理大豆耗水量表现为适宜水分处理>自然降水处理>干旱处理,其值分别为459.4、420.3、326.4 mm;不同时段大豆耗水量表现为在无控水影响的时期(2008-05-01-2008-06-15)大豆耗水量处理间差异较小,而在控水时期差异较明显;从进水量与耗水量的比值可以看出,黑土调节土壤水分的能力较强;干旱处理、自然降水处理和适宜水分处理水分利用效率分别为3.9、4.8和5.4 kg·hm-2·mm-1,表明一般年份灌溉能够提高水分利用效率.     

Contribution of black carbon to nonlinearity of sorption and desorption of acetochlor on sediment

In order to investigate the contribution of various black carbon (BC) contents to nonlinearity of sorption and desorption isotherms for acetochlor on sediment, equilibrium sorption and desorption isotherms were determined to measure sorption and desorption of acetochlor in sediment amended with various amounts of BC. In this paper, two types of BC referred to as BC400 and BC500 were prepared at 400°C and 500°C, respectively. Higher preparation temperature facilitated the formation of micropores on BC to enhance its sorption capacity. Increase of the BC content obviously increased the sorption amount and reduced the desorption amount for acetochlor. When the BC500 contents in total organic carbon (TOC) increased from 0 to 60%, Freundlich sorption coefficient (K _f) increased from 4.07 to 35.74, and desorption hysteresis became gradually obvious.When the content of BC in TOC was lower than 23%, the sorption isotherm had a significant linear correlation (p = 50.05). In case of desorption, a significant nonlinear change could be observed when the content of BC was up to 13%. Increase of BC content in the sediment would result in shifting the sorption-desorption isotherms from linearity to nonlinearity, which indicated that contribution of BC to nonlinear adsorption fraction became gradually remarkable.     

微库仑法测定新疆棉浆粕企业废水中可吸附有机卤素AOX

建立微库仑滴定法测定水质中可吸附有机卤素AOX的方法,考察3种活性炭柱对于空白的影响。实验结果表明,AOX的检出限为2.19μg/L,相对标准偏差为2.80%,纯水中高、中、低加标回收率在92.5%~107%,新疆棉浆粕企业废水中加标回收率为96.0%~101%。实验室空白也只有新购开封的耶拿原装活性炭小柱能满足标准要求的空白值(<30μg/L)。     

超声辅助乳化液相微萃取分析绿茶饮料和番茄汁中有机磷农药残留

农药施用于田间,必然会残留于环境中。农药残留的分析方法多种多样。为探究灵敏度高、重现性好的样品前处理方法,建立了超声辅助乳化液相微萃取,结合气相色谱和火焰光度检测器测定绿茶饮料和番茄汁中5种有机磷农药的方法,对萃取条件进行了优化,如萃取溶剂种类和体积、超声频率和时间、盐效应。在优化后的萃取条件下,5种有机磷农药实现良好分离,空白添加实验结果表明在0.1~10μg·L-1之间,线性相关系数在0.9985~0.9994之间,检测限在0.005~0.020μg·L-1之间,相对标准偏差(n=5)在4.3%~9.4%之间。在绿茶饮料和番茄汁实际样本检测中,目标分析物含量均低于检出限。样本添加回收试验的回收率均大于88.5%,相对标准偏差(n=3)在2.2%~9.8%之间,结果表明该方法用于液体样本中农药残留检测真实可靠。     

多酚原位固化茶渣对水中Cr（Ⅵ）的吸附

通过甲醛与茶渣中多酚类组分的反应制备了多酚原位固化茶渣吸附材料,并将其用于对水中Cr（Ⅵ）的吸附。表征结果显示：茶渣多酚的原位固化提高了其热稳定性,同时对茶渣粒料起到了修补增强作用。固化茶渣对Cr（Ⅵ）的吸附量随溶液pH的减小而增大。在吸附温度303 K、初始Cr（Ⅵ）质量浓度60 mg/L、吸附剂投加量1.0 g/L、吸附时间300 min、溶液pH为2的条件下,固化茶渣对Cr（Ⅵ）的吸附量为56.56 mg/g,去除率达94.3%。固化茶渣对Cr（Ⅵ）的吸附符合Langmuir等温吸附模型和准二级动力学方程,吸附是一个自发的、吸热过程,303,318,333 K下的Langmuir饱和吸附量分别为83.26,107.64,129.20 mg/g。     

Dissipation of carbofuran and carbaryl on Oolong tea during tea bushes,manufacturing and roasting processes

Carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranol-N-methylcarbamate) and carbaryl (1-naphthyl-N-methylcarbamate) are insecticides widely used in tea plantations. The objective of the present study was to evaluate the dissipation of carbofuran and carbaryl during the growth periods of Oolong tea, processing and roasting. Analysis of the residual insecticides was carried out using high-pressure liquid chromatography with a post-column fluorescence detector. Results showed that in the tea field carbofuran dissipated faster then carbaryl. Manufacturing processes of Oolong tea further reduced the carbofuran and carbaryl contents. The persistence of carbofuran and carbaryl was decreased with increasing roasting temperature. From the results, we conclude that the presence of carbofuran and carbaryl in tea can be reduced by proper field management, manufacturing and roasting processes.     

酸析-活性炭纤维吸附预处理精制棉黑液

采用酸析-活性炭纤维吸附工艺去除精制棉黑液中的有机物,先用酸析法去除木质素,再用活性炭纤维吸附黑液中的剩余有机物。采用紫外-可见(UV-vis)吸收光谱、傅立叶转换红外吸收光谱(FTIR)和明亮发光菌水质急性毒性法等手段分析处理前后的精制棉黑液。研究表明,黑液中主要有机成分为愈创基(G-)和羟苯基(H-)木质素。在pH为2.0,活性炭纤维用量为90 g/L,温度为40°C,吸附时间为5 h的条件下,COD去除率可以达到85%。活性炭纤维对酸析后精制棉黑液的吸附热力学符合Redlich-Peterson经验吸附模型,吸附动力学符合伪二级动力学模型,吸附为吸热过程。酸析-吸附过程使精制棉黑液急性毒性去除率达到95%以上,为后续生物法处理提供了有利条件。     

2011年重庆地区灰霾污染特征初步研究

本文结合2011年重庆区域灰霾统计结果表明,灰霾污染状况已逐步由重度和严重灰霾向轻中度灰霾污染过渡,污染程度得到好转。灰霾／非灰霾对比发现颗粒物PM2.5污染浓度较高,超标率较大,占颗粒物污染较大比重,且对能见度影响显著。2011年BC／PM2.5平均比值为18％左右,且比值时间序列变化趋势与全年灰霾污染总体发生趋势相符。     

屯绿陈茶有效成分提取及茶多酚提纯工艺研究

探讨了从陈茶中提取有效成分和茶多酚的提纯工艺。采用不同物料比、浸提温度、浸提时间的正交实验,通过热水煮提从茶叶中获取水溶性物质。结果表明,当料液比为1：20、90℃、120min时,测得的水提取物固化物量最多可达31％;茶叶水提物固化物、水配比为13：400时与乙酸乙酯萃取茶多酚的得率达23％,茶多糖从总量中提取的得率达2．5％。屯绿陈茶有效成分保留效果良好,具有较好的综合利用价值。