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1.
贵州省务川汞矿区汞污染的初步研究   总被引:4,自引:1,他引:3  
对贵州省务川汞矿区的大气、地表水和土壤中汞污染的调查表明,务川汞矿区大气汞浓度为7-40000 ng·m-3,超出正常大气汞浓度1-4个数量级.地表水总汞为43-2100 ng·l-1,远高于对照区(15-29 ng·l-1);活性汞、溶解态汞和颗粒态汞含量也显著高于对照区,颗粒态汞是地表水汞迁移的主要方式.土壤总汞含量为1.3-360 mg·kg-1,远高于对照区土壤总汞含量(O.22-0.39 mg·kg-1),土壤剖面汞含量的垂向递减反映了大气汞的沉降是土壤汞的重要来源之一;同一地点不同土地利用类型的土壤,一般为稻田总汞含量高于菜地和玉米地;土壤pH值和有机质影响着土壤中汞的迁移和富集.  相似文献   

2.
研究九龙江河口汞污染情况可为该地区汞污染防治提供科学依据,测定九龙江河口潮间带表层沉积物中总汞含量及不同形态汞的含量,分析了汞的分布特征、赋存形态及生物有效性和潜在生态风险。结果表明:九龙江河口潮间带表层沉积物中总汞含量范围0.112~0.259 mg·kg-1,平均值0.172 mg·kg-1,部分采样点汞含量超过中国海洋沉积物质量第一类标准限值(0.20 mg·kg-1);沉积物中各形态汞平均比例顺序:残渣态(61.8%)可氧化态(27.8%)弱酸溶态(7.8%)可还原态(2.6%),可提取态占有相当的比例,对水体汞污染具有一定贡献。潜在生态风险指数法评价结果可知,该河口区潮间带沉积物中汞污染程度和生态风险程度均为中等~较高水平,需对汞污染进行综合防治。  相似文献   

3.
土壤汞污染对油菜的氧化胁迫效应   总被引:2,自引:0,他引:2  
为了明确土壤汞污染的植物毒性效应,利用盆栽模拟试验研究了汞污染土壤对油菜的氧化损伤.结果表明,低浓度的汞污染轻微促进油菜的生长,汞浓度超过1.0 mg·kg-1就显著抑制植物生长,引起叶片面积变小、失绿变黄甚至枯萎等生理现象.随着汞浓度的增加,丙二醛(MDA)含量增加,当汞的浓度增加到8.0 mg·kg-1时,MDA的含量是对照组的4.17倍.随着汞浓度的增加,超氧化物歧化酶(SOD)活性升高,过氧化物酶(POD),过氧化氢酶(CAT)活性先升高后下降,其中SOD和POD在8.0 mg·kg-1汞处理下,活性达到最大,CAT在0.5 mg·kg-1汞处理下活性最大.土壤汞含量为超过1.0 mg·kg-1时,油菜可食部分汞浓度大于食品安全国家标准《食品中污染物限量》(GB 2762—2012)的规定.油菜吸收的汞主要累积在根部,因此在利用此类植物进行土壤修复时,需要清除植物的地下部,才能实现植物修复的目的.  相似文献   

4.
陕西省潼关采金地区汞污染的初步研究   总被引:5,自引:1,他引:5  
对采金地区水样、沉积物、土壤及部分水藻和苔藓的分析表明 :潼关采金地区已经受到严重的汞污染 .水体总汞浓度最高达 2 5 8 62 μg·l- 1 ,且水样中的汞以颗粒态为主 ,大都占 5 0 %以上 ,而活性汞和溶解态汞的平均浓度分别为 0 1 82± 0 2 4 2 μg·l- 1 和 0 72± 0 79μg·l- 1 ;沉积物中平均汞浓度为 34 98± 2 5 39μg·g- 1 ,最高达 1 1 96μg·g- 1 ;而土壤中汞的浓度最高也只有 1 9 5 0 μg·g- 1 .  相似文献   

5.
在田间条件下,研究添加硫代硫酸铵对黄平大黄油菜(Brassica juncea var.HPDH)富集土壤汞(总汞含量13.7mg·kg-1)及土壤汞形态转化影响。试验设置2个处理,对照小区(无硫代硫酸铵)和处理小区(每公斤土壤加入8 g硫代硫酸铵),硫代硫酸铵溶液在植物收获前7 d添加到土壤。试验结束后,分析植物生物量和组织内汞含量。结果表明,硫代硫酸铵处理小区植物生物量(干重)要略高于对照区。硫代硫酸铵处理小区植物根系和地上部分汞含量分别是对照区的600和250倍。利用连续化学浸提法分析了修复前后土壤汞形态变化特征,发现硫代硫酸铵辅助植物修复后能显著降低土壤有机结合态汞含量,大幅度提高残渣态汞含量,溶解态与可交换态汞含量略有增加,特殊吸附态和铁锰氧化态汞含量无显著变化。  相似文献   

6.
葫芦岛市有色冶金-化工区土壤与植物汞污染   总被引:2,自引:1,他引:1  
通过对有色冶金-化工区土壤汞、植物汞空间特征的分析,确定不同源对土壤、植物的影响。土壤表层汞含量以锌冶炼厂和氯碱厂及其附近为中心,向外围辐散降低,呈双中心分布,其含量为0.055~14.575mg·kg-1,平均值为1.435mg·kg-1;植物叶汞含量为柳树(Salix)>榆树(Ulmus)>槐树(Sophora)>丁香(Cytisus)>杨树(Populus)>松树(Pinus)>柏树(Cyparissus),其汞含量为0.029~2.700mg·kg-1,平均为0.182mg·kg-1。植物汞的空间分布特征是以锌冶炼厂及其附近为中心,表明大气沉降作用对植物汞的含量有显著的影响,锌冶炼厂是植物汞含量的主要来源,有色冶金-化工区是我国汞污染最重的地区之一,其生态风险应引起重视。  相似文献   

7.
阳朔铅锌矿是广西境内一个较大型的铅锌老矿山。对阳朔铅锌周边耕作区、居民区土壤和白菜(Brassica rapa L.Chinensis Group)汞含量分布及污染进行调查和研究,可以为汞污染防治与修复提供科学依据。在铅锌矿下游耕作区、对照耕作区分别采集土壤样各66、38个,白菜样各35、20个;居民区采集土壤样17个。全部土壤和白菜样品采用MDS-2003F型压力自控密闭微波溶样系统进行消解,并用原子荧光测汞仪进行分析测定。结果表明,阳朔铅锌矿下游耕作区土壤汞质量分数为(0.567 4±0.268 3)mg·kg-1,对照耕作区土壤汞质量分数为(0.147 1±0.039 5)mg·kg-1,居民区土壤汞质量分数为(0.188 0±0.097 2)mg·kg-1,分别为中国一些地区土壤汞的自然含量(0.071 mg·kg-1)的7.99、2.07、2.65倍。在铅锌矿下游耕作区土壤汞含量随着远离矿区方向依次降低。阳朔铅锌矿下游耕作区白菜根汞平均质量分数为27 600 ng·kg-1,茎汞平均质量分数为7 100 ng·kg-1,叶汞平均质量分数为19 300 ng·kg-1;对照耕作区白菜根汞平均质量分数为12 500 ng·kg-1,茎汞平均质量分数为4 800 ng·kg-1,叶汞平均质量分数为10 000 ng·kg-1,白菜汞含量分布特征与土壤汞含量分布相似。白菜植株各部位汞含量与土壤有效态(水溶态、交换态)汞含量显著相关,且根汞与之相关性最为显著,白菜植株不同部位汞含量表现为:根叶茎,上述特点表明土壤汞是白菜汞的主要来源。所采土样中有61.2%的土壤样汞含量超过了中国《土壤环境质量标准(GB 15618─2008)》二级标准的最低限值(0.2 mg·kg-1)。铅锌矿下游耕作区土壤汞污染最为严重,中等-严重污染以上占53.0%,中等污染占36.4%;居民区次之,中等污染占35.3%;对照耕作区污染最轻,均在中等污染以下。阳朔铅锌矿耕作区白菜植株各部位汞平均含量均未超过国家相关标准,这表明尽管耕作区土壤总汞严重超标,但由于土壤中有效态汞并不高,土壤汞污染并未对白菜汞含量造成显著影响。  相似文献   

8.
松花江沉积物中总汞及汞形态的演化   总被引:1,自引:0,他引:1  
为进一步掌握松花江汞污染的动态,通过2005年的样品采集与分析,结合有关历史数据,研究了松花江表层沉积物中汞的分布与变化.结果表明,在切断汞的主要污染源之后,第二松花江和松花江干流沉积物中汞含量均呈明显下降趋势;松花江18个断面沉积物中总汞质量含量较低,平均为0.172 mg·kg-1,除哈达湾、哨口和白旗江段外,大部分江段已处于背景水平.各江段沉积物中汞的形态分布差别较大,第二松花江沉积物中汞以过氧化氢溶态和王水溶态为主,而干流江段则以酸溶态和过氧化氢溶态为主;与20世纪80年代相比,除了王水溶态汞以外,2005年哈达湾、哨口和白旗3个代表性断面酸溶态、碱溶态及过氧化氢溶态汞含量均大幅下降.说明经过多年的环境治理以及水体的自然净化作用,松花江的汞污染已经得到了有效控制.  相似文献   

9.
贵州万山汞矿地区耐汞野生植物研究   总被引:3,自引:0,他引:3  
在贵州万山地区废弃汞矿堆和矿山附近,受长期高剂量汞暴露的影响经过的自然选择,该地区出现了一些能耐受汞毒性的生态型植物。对汞耐受及汞富集植物的筛选对于汞污染土壤的植物修复具有一定的现实意义。通过对万山梅子溪地区汞污染土壤及汞耐受植物采样调查发现,该区域采样土壤中汞的含量均在50 mg·kg-1以上,达到重度汞污染水平。对该地区野生植物的采样分析发现,蔷薇科植物悬钩子不仅数量较多,单株植物生物量较大,表现出很强的耐汞毒性的能力,而且植株内可以很大程度地富集汞,在其植株中汞的含量可达20 mg·kg-1左右,属于汞富集植物,另外发现野蒿对汞也具有较强的富集能力,其植株中汞的含量可达10 mg·kg-1以上。该类型植物的发现将为植物的汞耐受以及汞富集机理研究提供新的素材,为汞污染土壤的植物修复技术提供新的植物类型,也为进一步开发汞污染土壤处理技术提供了一种可能。  相似文献   

10.
张磊 《生态毒理学报》2014,9(5):933-939
为查明长期黄金开采冶炼对城市汞污染的影响,以"金都"招远为研究对象,于2011年4月,采集了招远市区常见绿化植物柏树、落叶松、冬青的茎叶样品30份,并同步采集相应表层土壤样品34份。采用冷原子吸收法测定样品总汞含量,分析了土壤的理化性质。结果表明,招远市区表层土壤中汞含量范围为0.002~0.815 mg·kg-1,平均值为0.149 mg·kg-1。土壤汞含量与有机质呈极显著正相关,与p H、粗颗粒比例呈显著正相关关系,而与阳离子交换量、黏粒比例呈显著负相关。不同城市区域相比,处于金矿区污染源下风向、且与矿区距离较近的梦芝区土壤汞含量要显著高于其它区域。常见绿化植物茎叶汞含量范围为0.021~0.782 mg·kg-1,不同植物中的汞含量没有显著差异,但同种植物中茎、叶中汞含量存在极显著正相关。植物中的汞在各城市区域没有显著差异,与土壤汞含量也不存在显著相关性。研究结果显示,招远市区土壤和植物受周边金矿开采和黄金冶炼的影响,存在一定程度汞污染。  相似文献   

11.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.  相似文献   

12.
Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación  相似文献   

13.
Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.  相似文献   

14.
15.
Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.  相似文献   

16.
An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.  相似文献   

17.
Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.  相似文献   

18.
Biogeographic theory predicts that rare species occur more often in larger, less‐isolated habitat patches and suggests that patch size and connectivity are positive predictors of patch quality for conservation. However, in areas substantially modified by humans, rare species may be relegated to the most isolated patches. We used data from plant surveys of 81 meadow patches in the Georgia Basin of Canada and the United States to show that presence of threatened and endangered plants was positively predicted for patches that were isolated on small islands surrounded by ocean and for patches that were isolated by surrounding forest. Neither patch size nor connectivity were positive predictors of rare species occurrence. Thus, in our study area, human influence, presumably due to disturbance or introduction of competitive non‐native species, appears to have overwhelmed classical predictors of rare species distribution, such that greater patch isolation appeared to favor presence of rare species. We suggest conservation planners consider the potential advantages of protecting geographically isolated patches in human‐modified landscapes because such patches may represent the only habitats in which rare species are likely to persist. Influencia Humana y Predictores Biogeográficos Clásicos de la Ocurrencia de Especies Raras  相似文献   

19.
Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.  相似文献   

20.
The macro-algae communities observed in the south lake of Tunis are characterized by the predominance of nitrophilous algae which are in the order of biomass importance:Ulva, Cladophora andEnteromorpha. We have noted seasonal changes of alga distribution. The wind appears to be one of the most important factors influencing this distribution. The total biomass reaches a maximum in the spring. Rapid decomposition of the biomass leads to a severe ecological imbalance, resulting in crises of anoxia and fish death. A restoration project has already started. It aims at removal of contaminated muds and the introduction of a new circulation system. The main objectives of this work were to collect information on the distribution and biomass of the phytobenthic communities as a first step in the constitution of a database for further comparison.  相似文献   

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