Effects of the anti-fouling herbicide Irgarol 1051 on two life stages of the grass shrimp,Palaemonetes pugio

This study investigated lethal and sublethal effects (glutathione, lipid peroxidation, cholesterol, and acetylcholinesterase) of the anti-fouling herbicide Irgarol 1051 on larval and adult grass shrimp (Palaemonetes pugio). The 96-hour LC50 test for larvae resulted in an estimated LC50 of 1.52 mg/L (95% confidence interval [CI] 1.26–1.85 mg/L). The adult 96-h LC50 was 2.46 mg/L (95% CI = 2.07–2.93 mg/L). Glutathione, lipid peroxidation, cholesterol and acetylcholinesterase levels were not significantly affected in adult grass shrimp by exposure of up to 3.00 mg/L irgarol. Lipid peroxidation and acetylcholinesterase levels in the larvae were significantly higher than controls in the highest irgarol exposures of 1.0 and 2.0 mg/L, respectively. Cholesterol levels were significantly reduced in larvae in all four irgarol concentrations tested while glutathione levels were not significantly affected in larvae. Both lethal and sublethal effects associated with irgarol exposure were only observed at concentrations well above those reported in the environment.     

茅草添加与温度变化对餐厨垃圾厌氧水解产酸的影响简

比较了茅草添加在温度变化条件下对餐厨垃圾厌氧水解过程小分子有机酸产量的影响,提出一种新型餐厨垃圾的资源化方式。研究结果显示,餐厨垃圾在55℃条件下厌氧水解主要产物为乳酸,达到25.7 g/L,其干物质转化率可以达到32.1% （g TS）,而餐厨+茅草处理在同样条件下的乳酸产量为20.1 g/L,干物质转化率为25.1%。温度下降为37℃后继续进行的的厌氧水解,得到的主要产物是乙酸、丙酸和丁酸,餐厨处理和餐厨+茅草处理这两者的峰值分别为6.5、2.8、8.0和6.1 g/L、2.7 g/L和5.9 g/L。结果显示茅草添加可以在一定程度上调节水解产物的比例,而温度变化可以调控小分子有机酸的产量。本研究结果表明,厌氧水解是一种有潜力的小分子有机酸生产与餐厨垃圾资源化处理途径。     

Molecular genetic and behavioral analysis of social organization in the Asian elephant (Elephas maximus)

We report on the genetic evaluation and behavioral study of social organization in the Asian elephant (Elephas maximus). Although Asian elephants and African elephants (Loxodonta africana) were previously thought to have similar social organizations, our results demonstrate a substantial difference in the complexity and structure of Asian elephant social groupings from that described for African savanna elephants. Photographic cataloging of individuals, radio telemetry, and behavioral observations in Ruhuna National Park, Sri Lanka, enabled us to assign associated females and young to four groups with overlapping ranges. Genetic sampling of individuals from the four groups in Ruhuna National Park and three other groups in surrounding areas, conducted through PCR amplification and sequencing of mitochondrial DNA from dung, supported the matriarchal nature of female groups and the lack of inter-group transfer of females. Behaviorally and genetically, the identified social groups were best described as ”family groups”. We did not find any evidence for the existence of social groups of higher complexity than family groups. Received: 25 March 2000 / Received in revised form: 28 March 2000 / Accepted: 1 April 2000     

Reach and messages of the world's largest ivory burn

Recent increases in ivory poaching have depressed African elephant populations. Successful enforcement has led to ivory stockpiling. Stockpile destruction is becoming increasingly popular, and most destruction has occurred in the last 5 years. Ivory destruction is intended to send a strong message against ivory consumption, both in promoting a taboo on ivory use and catalyzing policy change. However, there has been no effort to establish the distribution and extent of media reporting on ivory destruction events globally. We analyzed media coverage of the largest ivory destruction event in history (Kenya, 30 April 2016) across 11 nation states connected to ivory trade. We used an online‐media crawling tool to search online media outlets and subjected 5 of the largest print newspapers (by circulation) in 5 nations of interest to content analysis. Most online news on the ivory burn came from the United States (81% of 1944 articles), whereas most of the print news articles came from Kenya (61% of 157 articles). Eighty‐six to 97% of all online articles reported the burn as a positive conservation action, whereas 4–50% discussed ivory burning as having a negative impact on elephant conservation. Most articles discussed law enforcement and trade bans as effective for elephant conservation. There was more relative search interest globally in the 2016 Kenyan ivory burn than any other burn in 5 years. Ours is the first attempt to track the reach of media coverage relative to an ivory burn and provides a case study in tracking the effects of a conservation‐marketing event.     

渭北生草果园土壤有机碳矿化及其与土壤酶活性的关系

通过短期(31 d)室内培养法测定苹果园清耕、苹果∕白三叶间作、苹果∕小冠花间作这3种管理模式下土壤有机碳矿化动态和4种土壤酶活性,探讨了渭北果园不同生草条件下土壤有机碳矿化规律及其与土壤酶活性的关系.结果表明,在培养过程中,3种管理模式下土壤有机碳日矿化率均表现出先升高后降低,后期保持低且比较稳定的趋势.培养31 d后,与对照处理土壤有机碳矿化累积量为367 mg·kg-1相比较,白三叶处理最大为590 mg·kg-1、小冠花处理为541 mg·kg-1,并且3个处理在垂直方向上有机碳累积矿化量均随土层深度增加而减小.由一级动力学方程拟合发现,生草果园土壤有机碳矿化碳潜力(Cp)和矿化速率常数(k)值分别为0.252~2.74 g·kg-1和0.019~0.051 d-1,果园生草处理Cp值与对照处理Cp值差异显著,并且土壤蔗糖酶和纤维素酶与土壤有机碳矿化有较高的相关性.     

甘南地区草畜平衡动态评估

过度放牧是导致草原退化和沙化的重要原因之一,草畜平衡管理是保障草原牧区可持续发展的关键。基于多时相遥感和畜牧业统计数据,以甘南地区为研究区,构建逐月草畜平衡动态评估的核算方法,探讨畜牧业生产管理过程中优化时空布局的必要性。主要结论如下：（1）基于产草量—饲草需求量—饲草存量动态关系的逐月核算方法实现了季节性的草畜平衡动态评估;（2）甘南地区的草畜平衡矛盾主要表现为家畜对牧草的稳定需求与天然牧草供给的季节性波动,逐月逐乡镇的饲草缺口核算为精准补饲提供科学依据;（3）州—县—乡尺度的草畜平衡状态表明甘南地区全域草量富富有余但部分县乡超载,揭示了跨行政边界的轮牧措施可以缓解因局地的季节性过载造成的草地退化。     

对二氯苯和镉对草鱼(Ctenopharyngodon idellus)的联合毒性效应研究

以静水法生物测试研究了对二氯苯和镉对草鱼(Ctenopharyngodon idellus)的联合毒性效应,并采用Marking水生毒理联合毒性相加指数法对联合毒性效应进行了评价.结果表明, 对二氯苯和镉对草鱼的单一毒性作用时,24、48、72和96 h对二氯苯对草鱼的LC₅₀分别是10.11、9.04、8.52和7.83 mg/L; 24、48、72和96 h镉对草鱼的LC₅₀分别是40.02、35.05、28.99和24.41 mg/L,因此对二氯苯的毒性大于镉的毒性. 对二氯苯和镉对草鱼种的联合毒性作用,当采用毒性1∶1进行试验时,暴露时间分别为24、48、72、96　h时AI>0,联合作用结果为协同作用,而当采用浓度1∶1进行试验时,表现出暴露时间为24、48、72 h的AI<0,联合作用结果表现为拮抗作用,而暴露时间为96 h时AI>0,联合作用结果则为协同作用,即随着暴露时间的增加,对二氯苯和镉的联合毒性作用从拮抗作用转变为毒性剧增的协同作用.     

碳素纤维泛氧化塘治理高寒地河水的试验研究

采用碳素纤维生态草填料和间歇曝气强化的泛氧化塘对长春新凯河河水展开了异位式治理的试验研究,考察了单一的填料强化和"间歇曝气+填料强化泛氧化塘"对污染物的年度去除效果。试验过程中发现COD、NH4+-N、TP的去除效果受温度的影响比较明显,四季平均去除率分别为16.85%~34.19%、13.6%~53.14%、9.22%~26.08%;NH4+-N去除率同时受DO的影响也很明显,夏季间歇曝气可提高NH4+-N去除率27%左右。全年监测结果表明:曝气强化作用在夏季最为明显,在停留时间为36 h、曝气时间为18 h/d、曝气量为0.4 m3/min时,碳素纤维曝气泛氧化塘对COD、NH4+-N、TP的平均去除率分别为34.19%、53.14%、26.08%,这表明采用碳素纤维曝气泛氧化塘对受污染河水的治理是可行的。     

植草沟控制道路径流污染效果的现场实验研究

在合肥市滨湖新区建造了2条不同形式的植草沟,在实际降雨条件下监测2种植草沟的进、出水流量与水质,考察其对道路径流的水质净化和污染负荷控制效果.结果表明,植草输送沟(设施Ⅰ)与干植草沟(设施Ⅱ)均能有效去除径流中的TSS、COD、Pb、Cu、Cd、Zn等污染物,设施Ⅰ对TSS及COD的去除率中值分别为67.1%、46.7%,设施Ⅱ对TSS及COD的去除率中值分别为78.6%、58.6%,设施Ⅱ出水中Pb、Cu、Zn这3种重金属离子浓度均可达到地表水Ⅴ类水的要求;2种植草沟在部分降雨事件出水中均存在氮、磷物质的释放现象;2种植草沟对TP的去除受进水浓度的影响,去除效果随进水浓度的增加而逐渐提高,设施Ⅰ和设施Ⅱ对TP的平均去除率分别为14.7%和45.4%;设施Ⅱ对TSS、COD、TP、TN、NH+4-N、NO-3-N的负荷控制效果优于设施Ⅰ;在土壤渗透性能差、地面坡度小的地区,使用干植草沟可以取得较好的水质控制及污染负荷削减效果.     

Effect of petroleum on decomposition of shrub–grass litters in soil in Northern Shaanxi of China

The impacts of petroleum contamination on the litter decomposition of shrub–grass land would directly influence nutrient cycling, and the stability and function of ecosystem. Ten common shrub and grass species from Yujiaping oil deposits were studied. Litters from these species were placed into litterbags and buried in petroleum-contaminated soil with 3 levels of contamination (slight, moderate and serious pollution with petroleum concentrations of 15, 30 and 45 g/kg, respectively). A decomposition experiment was then conducted in the lab to investigate the impacts of petroleum contamination on litter decomposition rates. Slight pollution did not inhibit the decomposition of any litters and significantly promoted the litter decomposition of Hippophae rhamnoides, Caragana korshinskii, Amorpha fruticosa, Ziziphus jujuba var. spinosa, Periploca sepium, Medicago sativa and Bothriochloa ischaemum. Moderate pollution significantly inhibited litter decomposition of M. sativa, Coronilla varia, Artemisia vestita and Trrifolium repens and significantly promoted the litter decomposition of C. korshinskii, Z. jujuba var. spinosa and P. sepium. Serious pollution significantly inhibited the litter decomposition of H. rhamnoides, A. fruticosa, B. ischaemum and A. vestita and significantly promoted the litter decomposition of Z. jujuba var. spinosa, P. sepium and M. sativa. In addition, the impacts of petroleum contamination did not exhibit a uniform increase or decrease as petroleum concentration increased. Inhibitory effects of petroleum on litter decomposition may hinder the substance cycling and result in the degradation of plant communities in contaminated areas.