土壤和沉积物中的聚合有机质对多环芳烃分布和提取的影响

为了研究土壤和沉积物中凝聚型有机碳(碳黑、干酪根)的含量及其对多环芳烃(PAHs)分布和提取的影响,分别用三氟醋酸(TFA)和在375℃下通氧燃烧的方法从珠江三角洲2个污染土壤和5个河口沉积物样品中提取酸非水解有机碳(NHC)和碳黑(BC);用索氏抽提法和不同溶剂的加速溶剂萃取法(包括连续加速萃取法ASESum和标准溶剂萃取法ASESTD)抽提土壤和沉积物中的多环芳烃,并在不同温度梯度(25℃到150℃)下用水为溶剂加速溶剂萃取其水溶态.结果表明,1)NHC是珠江三角洲土壤和沉积物中总有机碳的重要组成部分,NHC碳明显高于BC碳,NHC和BC分别占土壤和沉积物中有机碳的25.6%￣73.8%和4.64%￣17.3%.2)3种有机溶剂(丙酮、甲苯1、甲苯2)连续抽提的PAHs含量是索氏抽提的2.11倍;5种ASE方法(丙酮、甲苯1、甲苯2、ASESum、ASESTD)提取的PAHs含量与NHC含量存在明显的相关性,而且比PAHs含量与BC或无定型有机碳(AOC)含量的相关性更明显.3)在不同温度梯度下水溶态PAHs浓度符合Van’tHoff方程.研究说明除了BC外,非水解有机碳对土壤和沉积物中PAHs的分布和提取具有重要影响.     

双季稻品种根际特征与甲烷排放差异及其关系

为探讨不同水稻品种间甲烷排放差异形成的机制,选取早晚稻各6个品种为供试材料进行大田试验,采用静态暗箱-气相色谱法测定CH4气体.结果表明,早晚稻甲烷排放通量品种间差异显著,全生育甲烷排放通量均值湘早籼24号最高,株两优819最低,相差34. 6%;晚稻种,T优15最高,资优299最低,相差33. 9%.不同双季稻品种间甲烷排放量、单位产量温室效应差异显著.早稻品种的CH4累计排放量介于198. 3～303. 44 kg·hm-2之间,排放量最低是株两优819;单位产量温室效应介于0. 67～1. 40 kg·kg~(-1)之间,陆两优996最低.晚稻品种的CH4累计排放量明显高于早稻,介于291. 93～388. 28kg·hm-2之间,资优299最低;单位产量温室效应介于0. 94～1. 68 kg·kg~(-1)之间,Y两优1号最低.稻田甲烷排放与水稻产量、根冠比、根系孔隙度、土壤溶液Eh值、甲烷浓度、可溶性碳浓度及铵态氮浓度的相关性均达到显著或极显著水平.双季稻品种甲烷排放与水稻根冠比及根孔隙度关系密切,降低早稻品种根系孔隙度或者根冠比可减排甲烷,而晚稻品种则与早稻相反;根际土壤溶液碳氮浓度的降低和Eh值的提高也可减少甲烷的排放.     

广西高镉异常区水田土壤Cd含量特征及生态风险评价

本研究调查了广西高镉异常区水田土壤中重金属Cd的含量水平,评估其对环境的潜在生态风险.通过初步筛查和详细调查两部分,分批次采集高镉异常区土壤样品共912件,测定土壤Cd含量,并运用单因子污染指数法和潜在风险指数法对水田土壤Cd污染程度及潜在风险进行评价.结果表明:①初查中自然土壤、水田土壤和旱地土壤Cd几何均值分别为0. 915、0. 591和0. 593 mg·kg~(-1).②详查中土壤p H为4. 6～8. 7,介于酸性和弱碱性间.若以《土壤环境质量标准》(GB15618-2018)为标准,平果县、天等县、大新县、隆安县和柳城县水田土壤样点Cd超标严重,融水县水田土壤样点无污染;以土壤基线值为评价标准,田东县、柳城县和融水土壤样点中Cd均为无污染状态;田阳县、平果县、天等县、大新县、隆安县和融安县水田土壤Cd处于轻度-中度污染的比例分别为:4. 2%、3. 7%、14. 9%、2. 6%、7. 1%和1. 4%.③9个县市水田土壤中Cd呈现不同级别潜在生态风险.天等县、大新县和隆安县部分水田土壤样点Cd处于高等生态风险,比例为4. 3%、2. 6%、2. 4%;田阳县、平果县、融安县和柳城县水田土壤Cd表现为中-中高等潜在风险;田东县和融水县处于低潜在生态风险.总体上,研究区水田土壤中Cd整体偏高,长此以往可能会对水稻安全种植产生影响,最终对当地居民产生健康威胁,应引起重视.建议开展对研究区土壤镉生物有效性和水稻镉累积状况研究,以便科学合理地评估其生态风险和健康风险.     

Compassionate versus consequentialist conservation

Ethical treatment of wildlife and consideration of animal welfare have become important themes in conservation, but ethical perspectives on how best to protect wild animals and promote their welfare are diverse. There are advantages to the consequentialist harms ethical framework applied in managing wild herbivores for conservation purposes. To minimize harms while achieving conservation goals, we argue that overabundant wild herbivores should in many cases be managed through consumptive in situ killing. Advantages of this policy are that the negative welfare states imposed on animals last only a short time; remaining animals are not deprived of positive welfare states (e.g., linked to rearing offspring); poor welfare states of animals in overabundant populations are avoided (e.g., starvation); negative welfare impacts on heterospecifics through resource depletion (i.e., competition) are prevented; harvesting meat reduces the number of (agricultural) animals raised to supply meat; and minimal costs maximize funding for other wildlife management and conservation priorities. Alternative ethical approaches to our consequentialist framework include deontology (containing animal rights) and virtue ethics, some of which underpin compassionate conservation. These alternative ethical approaches emphasize the importance of avoiding intentional killing of animals but, if no population reduction occurs, are likely to impose considerable unintentional harms on overabundant wildlife and indirectly harm heterospecifics through ineffective population reduction. If nonlethal control is used, it is likely that overabundant animals would be deprived of positive welfare states and economic costs would be prohibitive. We encourage conservation stakeholders to consider animal-welfare consequentialism as an ethical approach to minimize harms to the animals under their care as well as other animals that policies may affect while at the same time pursuing conservation goals.     

Perspectives of farmers and tourists on agricultural abandonment in east Lesvos,Greece

Regional Environmental Change - Multi-stakeholder perceptions of landscape changes are increasingly recognized as essential inputs to discussions on future landscape developments, particularly when...     

Effects of age and sex ratios on offspring recruitment rates in translocated black rhinoceros

Success of animal translocations depends on improving postrelease demographic rates toward establishment and subsequent growth of released populations. Short‐term metrics for evaluating translocation success and its drivers, like postrelease survival and fecundity, are unlikely to represent longer‐term outcomes. We used information theory to investigate 25 years of data on black rhinoceros (Diceros bicornis) translocations. We used the offspring recruitment rate (ORR) of translocated females—a metric integrating survival, fecundity, and offspring recruitment at sexual maturity—to detect determinants of success. Our unambiguously best model (AICω = 0.986) predicted that ORR increases with female age at release as a function of lower postrelease adult rhinoceros sex ratio (males:females). Delay of first postrelease reproduction and failure of some females to recruit any calves to sexual maturity most influenced the pattern of ORRs, and the leading causes of recruitment failure were postrelease female death (23% of all females) and failure to calve (24% of surviving females). We recommend translocating older females (≥6 years old) because they do not exhibit the reproductive delay and low ORRs of juveniles (<4 years old) or the higher rates of recruitment failure of juveniles and young adults (4–5.9 years old). Where translocation of juveniles is necessary, they should be released into female‐biased populations, where they have higher ORRs. Our study offers the unique advantage of a long‐term analysis across a large number of replicate populations—a science‐by‐management experiment as a proxy for a manipulative experiment, and a rare opportunity, particularly for a large, critically endangered taxon such as the black rhinoceros. Our findings differ from previous recommendations, reinforce the importance of long‐term data sets and comprehensive metrics of translocation success, and suggest attention be shifted from ecological to social constraints on population growth and species recovery, particularly when translocating species with polygynous breeding systems.     

Influence of temperature and salinity on the trace element incorporation into statoliths of the common cuttlefish (<Emphasis Type="Italic">Sepia officinalis</Emphasis>)

The use of statolith chemistry to trace migration pathways and distinguish populations of cephalopods is based on the assumption that the elemental composition of statoliths is influenced by physicochemical properties of the ambient environment. However, such influences have not been investigated experimentally up until now. This study presents the first microchemical analyses of cephalopod statoliths obtained from laboratory experiments under different controlled temperature and salinity conditions. Our results show that statolith chemical composition is strongly related to both salinity and temperature in ambient waters. The Ba/Ca ratio is negatively related to temperature and shows no relation to salinity. The I/Ca ratio is positively related to temperature and negatively to salinity. No Sr/Ca relation was found to either salinity or temperature, suggesting that the well-established proxy strontium is not as useful in cephalopod statoliths as in other biomineralized aragonites. Microanalysis of trace elements, however, shows an enormous potential for field studies on distribution, migration and stock separation of cephalopods. Furthermore, Synchrotron X-ray Fluorescence Analysis is introduced as a promising novel method for statolith analysis, providing a spatial resolution of typically 10–15 μm combined with detection limits down to 0.5 ppm.     

Recovery of gold from computer circuit board scrap using aqua regia.

Computer circuit board scrap was first treated with one part concentrated nitric acid and two parts water at 70 degrees C for 1 h. This step dissolved the base metals, thereby liberating the chips from the boards. After solid-liquid separation, the chips, intermixed with some metallic flakes and tin oxide precipitate, were mechanically crushed to liberate the base and precious metals contained within the protective plastic or ceramic chip cases. The base metals in this crushed product were dissolved by leaching again with the same type of nitric acid-water solution. The remaining solid constituents, crushed chips and resin, plus solid particles of gold, were leached with aqua regia at various times and temperatures. Gold was precipitated from the leachate with ferrous sulphate.     

关于长江中游沿江产业带建设的构想

长江中游沿江地区具有特殊的战略地位，其产业带建设又面临上海浦东开发和三峡工程建设两大契机。必须扩大对外开放，建设开放型产业带；加快改革步伐，建立社会主义市场经济体系；以资源优化配置，促进长江产业带整体效益的提高；必须协调资源、环境与产业带建设的关系，加强基础产业，调整加工制造业，合理布局生产，实现持续发展。