Predictors of species richness in the deep-benthic fauna of the northern Gulf of Mexico     

Richard L. Haedrich  Jennifer A. Devine  Valerie J. Kendall 《Deep Sea Research Part II: Topical Studies in Oceanography》2008,55(24-26):2650

Species richness in macrofauna and megafauna collected with box cores and trawls from 35 standard stations over a depth range of 175–3720 m in the northern Gulf of Mexico was examined in terms of two primary questions: (1) are observed patterns random? and (2) if not, what environmental factors might account for the patterns? A null model tested whether richness vs. depth distributions were random. Groups with species that had broad vertical depth ranges fit the null model better than groups with small ranges, but for almost all phyla a non-random pattern was indicated. With randomness as a proximal explanation ruled out, further examination of the relationship between richness and environmental factors was justified. A generalized linear model (GLM) showed that a suite of 18 factors categorized as food-related, habitat-related, pollution-related and location-related were significantly related to richness patterns, but that different mixes of factors applied to different phyla. No one factor accounted for any observed patterns. Thus, each taxonomic group needs to be examined individually, and no generally applicable explanation for the causes of richness patterns may exist. Nonetheless, mapping richness itself indicates valuable areas in the Mississippi Trough that must receive special consideration and possible protection.  相似文献   

贵州开发面临的挑战及可持续发展战略研究     

肖进原 《地球信息科学学报》2001,3(4):7-11

本文系统地分析了贵州大开发中,面临的种种来自生态环境方面的挑战,并针对其挑战,提出了若干战略对策。  相似文献   

滩地林业血防工程抑螺效应及其成因研究   总被引：4，自引：0，他引：4  

汤玉喜  吴敏  吴立勋  唐洁  林建新 《湿地科学与管理》2006,2(4):8-13

在洞庭湖区滩地对不同类型杨树抑螺防病林采取定位观测的研究方法,对滩地钉螺种群变化与抑螺防病林营造措施、林龄的关系及其内在机制进行了研究。结果表明:林分郁闭前,通过林农复合等林地土壤管理措施,改造钉螺孳生环境,可有效降低活螺和感染螺密度;林分郁闭后,林地水分、光照、植被等环境因子朝着不利于钉螺孳生的方向演变;滩地抑螺防病林生态系统抑螺效果具有显著性和持续性。  相似文献   

泥河湾盆地大长梁剖面河湖相沉积物的岩石磁学性质   总被引：3，自引：1，他引：2       下载免费PDF全文

敖红 《地球物理学报》2008,51(4):1029-1039

以热磁分析为主,对中国北方泥河湾盆地更新世河湖相地层中灰绿色粉砂和灰黄色粉砂/细砂两种典型沉积物进行了详细的岩石磁学研究,有效确定了这两类沉积物中磁性矿物的种类、粒度特征以及加热过程中磁性矿物的变化过程和产物,并对其包含的古环境意义进行了初步探讨.灰绿色粉砂样品主要含有磁铁矿和赤铁矿两种磁性矿物,磁性相对较弱,颗粒相对较细;灰黄色粉砂/细砂主要含有磁铁矿和磁赤铁矿,磁性相对较强,颗粒相对较粗.在氩气环境中经700℃加热处理后,这两种沉积物中的绿泥石都分解,并生成超细粒（处于超顺磁和单畴颗粒区间）的磁铁矿,导致磁化率大幅升高.因此泥河湾盆地沉积物的热磁特征可以用来检测样品中绿泥石的相对含量,进而反映该地区化学风化作用强度的变化.此外,灰绿色粉砂样品中绿泥石含量比灰黄色粉砂/细砂样品的含量高,在氩气中加热后,磁化率升高幅度也较高,可能反映了化学风化相对较弱的沉积环境.  相似文献   

Citizen preferences on private-public co-regulation in environmental governance: Evidence from Switzerland     

《Global Environmental Change》2021

Environmental policy is touching on ever more aspects of corporate and individual behavior, and there is much debate over what combinations of top-down (government-imposed) and bottom-up (voluntary private sector) measures to use. In democratic societies, citizens’ preferences over such combinations are crucial because they shape the political mandates based on which policymakers act. We argue that policy designs that involve private-public co-regulation receive more citizen support if they are based on inclusive decision-making, use strong transparency and monitoring mechanisms, and include a trigger for government intervention in case of ineffectiveness. Survey experiments in Switzerland (N = 1941) provide strong support for these arguments. Our research demonstrates that differences in co-regulation design have major implications for public support. Another key finding is that there seems to be a contradiction between inclusiveness and democratic accountability for policy outcomes. The findings are surprisingly consistent across two very different green economy issues we focus on empirically (decarbonization of finance, pesticides). This suggests that our study design offers a useful template for research that explores public opinion on green economy policy designs for other issues and in other countries.  相似文献   

Sex-different effects of tributyltin on brain aromatase,estrogen receptor and retinoid X receptor gene expression in rockfish (Sebastiscus marmoratus)     

《Marine environmental research》2013

Since the brain plays important roles in reproduction, the brain aromatase (Cyp19b), estrogen receptor (ER), retinoid X receptor (RXR) α and peroxisome proliferator-activated receptor γ were examined in rockfish after TBT exposure (1, 10, and 100 ng L⁻¹). The results showed that the Cyp19b expression was elevated in the male rockfish, while no effect was produced in the females. Inconsistently, serum testosterone and 17β-estradiol showed no change in the males, while an increase of testosterone and a decrease of 17β-estradiol were observed in the females. TBT affected the ER expression in the males depending on the concentrations, however, no change was observed in the females. In addition, TBT elevated the RXRα expression in the males but produced an opposite effect in the females. In conclusion, TBT might have had sex-different effects on the brain Cyp19b, ER and RXR expression in rockfish, indicating a complex endocrine disrupting effect of TBT.  相似文献   

Advances in Palaeoclimatic Research Recorded by Peat in China since the Last Deglaciation     

《地球科学进展》2012,27(1)

泥炭记录的环境演变是过去全球变化（PAGES）研究的重要领域之一,分析了中国泥炭记录的古气候演化研究的区域范围,当前主要以东北哈尼、青藏高原的红原、神农架大九湖以及华南定南大湖四个位于东部季风区的研究工作最为集中。泥炭沉积高分辨率综合信息揭示了末次冰消期以来中国气候变化的时空特征：冷暖干湿变化既有一致性又表现出区域差异,末次冰消期东北地区、东部山地、华南地区都表现出冷偏湿的气候特点,而青藏高原却为冷偏干或凉偏干;Younger Dr-yas（YD）事件之后,全新世早期和中期青藏高原、东部山地、华南地区气候总体以温湿为主要特征,而东北地区有效降水减少,到全新世晚期,呈现出干旱的变化趋势。并对B～A事件,YD事件,8.2ka以及4.2 ka等重大气候突变事件研究工作进行了综述。最后指出今后应拓展与重建更多区域古气候环境变化序列的对比,加强泥炭沉积及环境指标的基础理论,重视和提高大气沉降泥炭档案以及气候变化背景下泥炭地碳循环机制等研究工作。  相似文献   

吉林复兴村金矿工程环境地质问题研究     

宋丙剑  陈文雅 《城市地质》2012,7(2):24-26

复兴村金矿将进入矿山建设开发阶段,矿山开采会引发边坡及采空区稳定性问题。预测潜在环境工程地质问题,提出防治措施,为矿山建设提供依据。  相似文献   

http://www.sciencedirect.com/science/article/pii/S1674987112000345   总被引：3，自引：0，他引：3  

Li Wu  Feng Li  Cheng Zhu  Lan Li  Bing Li 《地学前缘(英文版)》2012,3(6):875-892

Holocene environmental change and environmental archaeology are important components of an international project studying the human-earth interaction system.This paper reviews the progress of Holocene environmental change and environmental archaeology research in the Yangtze River Valley over the last three decades,that includes the evolution of large freshwater lakes.Holocene transgression and sea-level changes,Holocene climate change and East Asian monsoon variation,relationship between the rise and fall of primitive civilizations and environmental changes,cultural interruptions and palaeoflood events,as well as relationship between the origin of agriculture and climate change.These research components are underpinned by the dating of lacustrine sediments,stalagmites and peat to establish a chronology of regional environmental and cultural evolution.Interdisciplinary and other environment proxy indicators need to be used in comparative studies of archaeological site formation and natural sedimentary environment in the upper,middle and lower reaches of the Yangtze River Valley.Modern technology such as remote sensing,molecular bioarchaeology,and virtual reality,should be integrated with currently used dating,geochemical,sedimentological.and palaeobotanical methods of analysis in environmental archaeology macro- and micro-studies,so as to provide a greater comprehensive insight into Holocene environmental and cultural interaction and change in the Yangtze River Valley area.  相似文献   

北京市地面沉降防治形势与对策     

杨艳  贾三满 《城市地质》2013,(4):6-10

本文从区域地质环境条件、水资源供给形势、地面沉降灾害影响情况、防治目标及防治工作5个方面分析了北京市地面沉降防治形势,提出了防治对策。  相似文献