Geographic range size and extinction risk assessment in nomadic species

Geographic range size is often conceptualized as a fixed attribute of a species and treated as such for the purposes of quantification of extinction risk; species occupying smaller geographic ranges are assumed to have a higher risk of extinction, all else being equal. However many species are mobile, and their movements range from relatively predictable to‐and‐fro migrations to complex irregular movements shown by nomadic species. These movements can lead to substantial temporary expansion and contraction of geographic ranges, potentially to levels which may pose an extinction risk. By linking occurrence data with environmental conditions at the time of observations of nomadic species, we modeled the dynamic distributions of 43 arid‐zone nomadic bird species across the Australian continent for each month over 11 years and calculated minimum range size and extent of fluctuation in geographic range size from these models. There was enormous variability in predicted spatial distribution over time; 10 species varied in estimated geographic range size by more than an order of magnitude, and 2 species varied by >2 orders of magnitude. During times of poor environmental conditions, several species not currently classified as globally threatened contracted their ranges to very small areas, despite their normally large geographic range size. This finding raises questions about the adequacy of conventional assessments of extinction risk based on static geographic range size (e.g., IUCN Red Listing). Climate change is predicted to affect the pattern of resource fluctuations across much of the southern hemisphere, where nomadism is the dominant form of animal movement, so it is critical we begin to understand the consequences of this for accurate threat assessment of nomadic species. Our approach provides a tool for discovering spatial dynamics in highly mobile species and can be used to unlock valuable information for improved extinction risk assessment and conservation planning.     

Effect of Macroalgal Expansion and Marine Protected Areas on Coral Recovery Following a Climatic Disturbance

Disturbance plays an important role in structuring marine ecosystems, and there is a need to understand how conservation practices, such as the designation of Marine Protected Areas (MPAs), facilitate postdisturbance recovery. We evaluated the association of MPAs, herbivorous fish biomass, substrate type, postdisturbance coral cover, and change in macroalgal cover with coral recovery on the fringing reefs of the inner Seychelle islands, where coral mortality after a 1998 bleaching event was extensive. We visually estimated benthic cover and fish biomass at 9 sites in MPAs where fishing is banned and at 12 sites where fishing is permitted in 1994, 2005, 2008, and 2011. We used analysis of variance to examine spatial and temporal variations in coral cover and generalized additive models to identify relations between coral recovery and the aforementioned factors that may promote recovery. Coral recovery occurred on all substrate types, but it was highly variable among sites and times. Between 2005 and 2011 the increase in coral cover averaged 1%/year across 21 sites, and the maximum increase was 4%/year. However, mean coral cover across the study area (14%) remained at half of 1994 levels (28%). Sites within MPAs had faster rates of coral recovery than sites in fished areas only where cover of macroalgae was low and had not increased over time. In MPAs where macroalgae cover expanded since 1998 there was no recovery. Where coral was recovering on granite reefs there was a shift in relative prevalence of colony life‐form from branching to encrusting species. This simplification of reef structure may affect associated reef fauna even if predisturbance levels of coral cover are attained. Efecto de la Expansión de Macroalgas y Áreas Marinas Protegidas sobre la Recuperación de Coral Después de una Perturbación Climática     

四环素在光催化剂TiO2上的吸附研究

选取四环素作为代表抗生素,考察了溶液的pH值、离子强度(二价阳离子Ca2+和Mg2+)、腐殖酸3种环境因子对四环素在光催化剂二氧化钛(TiO2)上吸附的影响.结果表明,在3个不同pH(pH 3、6和9)条件下的吸附等温线均符合Langmuir吸附等温方程,拟合的相关系数R2均大于0.999; 四环素在TiO2上的吸附量在pH 2—9范围内逐渐增大,在pH值高于9后显著减小.四环素在TiO2上的吸附量明显受到离子强度和腐殖酸的影响.本文对吸附机理及影响机制进行了讨论.     

2007年火电行业温室气体排放量估算

为了解我国火电行业温室气体排放情况,参考《IPCC国家温室气体排放清单指南》中固定源燃烧温室气体排放量计算方法学部门方法的相关内容,利用实测的温室气体排放因子以及2007年火电行业活动水平数据,计算火电行业温室气体排放量. 排放因子测算及排放量计算过程均遵循IPCC关于温室气体排放计算的质量保证和质量控制内容. 结果表明,2007年我国火电行业CO₂与N₂O排放量分别为2.81×109和1.56×105 t.同时使用参考方法,利用国家级能源统计数据直接计算火电行业CO₂排放量.将部门方法与参考方法计算结果进行比对发现,原煤、原油和天然气燃烧温室气体排放量2种方法的相对偏差分别为7.5%,98.8%和1.6%,除原油外,原煤和天然气燃烧CO₂排放量与参考方法相差并不大.      

水质对UV/H_2O_2降解2,4-二氯酚的影响

研究了UV/H2O2工艺对2,4-二氯酚(2,4-DCP)的去除效果和水中阴离子、腐殖酸对该工艺降解2,4-DCP的影响。结果表明:UV/H2O2工艺可以有效的去除水中2,4-DCP,光降解过程符合一级反应动力学模型;在H2O2投加量为8mg/L,1个30W低压汞灯照射下,2,4-DCP在蒸馏水和自来水中光降解速率常数分别为0.0232/min和0.0162/min;NO3-、Cl-、HCO3-对2,4-DCP光降解有抑制作用;当3种离子浓度为0.5mmol/L、10mmol/L、20mmol/L时,对2,4-DCP光降解的抑制程度为HCO3->NO3->Cl-;随着离子浓度增大,抑制作用增强;自来水中的光降解速率常数低于蒸馏水中的光降解速率常数是由于水中多种离子影响的结果;腐殖酸在低浓度时,促进光降解反应的进行,在高浓度时,2,4-DCP的光降解氧化受到抑制。     

焙烧温度对CeO_2(ZrO_2)/TiO_2选择性催化脱硝性能的影响

采用溶胶-凝胶法并以不同温度焙烧制备一系列CeO_2(ZrO_2)/TiO_2(CZT)催化剂,考察了CZT催化剂固相结构、酸量、比表面积等性能与催化活性的关系。采用XRD、BET、NH3-TPD、H2-TPR以及XPS等表征技术对催化剂进行表征。结果表明:焙烧温度为450℃时CZT催化剂具有最高的催化活性,其在240~400℃的温度窗口内活性均高于90%,且具有较好的抗水和抗硫中毒能力。随着焙烧温度的提高,催化剂表面的Ce和Zr原子进入体相晶格且Ce0.5Zr0.5O2向Ce0.75Zr0.25O2转变,导致催化剂的储释氧能力和氧化还原性能降低。另外,锐钛矿和金红石型TiO_2晶粒尺寸的增加,催化剂的有效比表面积和总酸量降低,因此CZT催化活性随着焙烧温度的提高而有所降低。换言之,大的比表面积、良好的氧化还原性能、表面Ce4+的富集以及酸性位的增多均有利于NH3-SCR活性的提高。     

蚕豆根尖细胞微核对金属冶炼厂排污水的监测

以蒸馏水、自来水和矿泉水处理为阴性对照,以不同浓度的NaN3、HgCl2、Pb2++Zn2++Cd2+复合处理为阳性对照。用蚕豆根尖细胞微核法对重金属冶炼厂排污水、污染源附近湖水进行检测评价。结果表明,重金属冶炼厂排污水、污染源附近湖水的水样均使蚕豆根尖细胞微核率增加;蚕豆根尖细胞微核监测与化学检测基本一致,将重金属冶炼厂排污水、污染源附近湖水分为三种程度,重污染、中度污染和轻污染。