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961.
Kang Caiyan Li Qiuyan Yi Hui Deng Hua Mo Weiming Meng Mianwu Huang Siyu 《Environmental science and pollution research international》2021,28(6):6733-6745
Environmental Science and Pollution Research - In this study, a novel magnetic cassava stalk composite (M-EMCS) was prepared through modification with ethylenediamine tetraacetic anhydride (EDTAD)... 相似文献
962.
Nadiah P. Kristensen Wei Wei Seah Kwek Yan Chong Yi Shuen Yeoh Tak Fung Laura M. Berman Hui Zhen Tan Ryan A. Chisholm 《Conservation biology》2020,34(5):1229-1240
Extinction is a key issue in the assessment of global biodiversity. However, many extinction rate measures do not account for species that went extinct before they could be discovered. The highly developed island city–state of Singapore has one of the best-documented tropical floras in the world. This allowed us to estimate the total rate of floristic extinctions in Singapore since 1822 after accounting for sampling effort and crypto extinctions by collating herbaria records. Our database comprised 34,224 specimens from 2076 native species, of which 464 species (22%) were considered nationally extinct. We assumed that undiscovered species had the same annual per-species extinction rates as discovered species and that no undiscovered species remained extant. With classical and Bayesian algorithms, we estimated that 304 (95% confidence interval, 213–414) and 412 (95% credible interval, 313–534) additional species went extinct before they could be discovered, respectively; corresponding total extinction rate estimates were 32% and 35% (range 30–38%). We detected violations of our 2 assumptions that could cause our extinction estimates, particularly the absolute numbers, to be biased downward. Thus, our estimates should be treated as lower bounds. Our results illustrate the possible magnitudes of plant extirpations that can be expected in the tropics as development continues. 相似文献
963.
Efficacy of extracting indices from large‐scale acoustic recordings to monitor biodiversity
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Rachel T. Buxton Mary Clapp Erik Meyer Erik Stabenau Lisa M Angeloni Kevin Crooks George Wittemyer 《Conservation biology》2018,32(5):1174-1184
Passive acoustic monitoring could be a powerful way to assess biodiversity across large spatial and temporal scales. However, extracting meaningful information from recordings can be prohibitively time consuming. Acoustic indices (i.e., a mathematical summary of acoustic energy) offer a relatively rapid method for processing acoustic data and are increasingly used to characterize biological communities. We examined the relationship between acoustic indices and the diversity and abundance of biological sounds in recordings. We reviewed the acoustic‐index literature and found that over 60 indices have been applied to a range of objectives with varying success. We used 36 of the most indicative indices to develop a predictive model of the diversity of animal sounds in recordings. Acoustic data were collected at 43 sites in temperate terrestrial and tropical marine habitats across the continental United States. For terrestrial recordings, random‐forest models with a suite of acoustic indices as covariates predicted Shannon diversity, richness, and total number of biological sounds with high accuracy (R2 ≥ 0.94, mean squared error [MSE] ≤170.2). Among the indices assessed, roughness, acoustic activity, and acoustic richness contributed most to the predictive ability of models. Performance of index models was negatively affected by insect, weather, and anthropogenic sounds. For marine recordings, random‐forest models poorly predicted Shannon diversity, richness, and total number of biological sounds (R2 ≤ 0.40, MSE ≥ 195). Our results suggest that using a combination of relevant acoustic indices in a flexible model can accurately predict the diversity of biological sounds in temperate terrestrial acoustic recordings. Thus, acoustic approaches could be an important contribution to biodiversity monitoring in some habitats. 相似文献
964.
三峡水库“水华”成因初探 总被引:8,自引:0,他引:8
2004年3月、5月、7月、8月、10月和2005年5月对长江干流29个站点进行了5次调查。2004年3月(旱季)在三峡库区坝前(秭归)发现藻类“水华”,藻类密度达2.73×106 cells/L,优势种类为拟多甲藻。2004年8月(雨季)和2005年4月(旱季)沿香溪河下游及河口区以及香溪河口到三峡大坝干流江段进行了2次6个断面分层调查,两次调查中在香溪河下游以及香溪河口区发现了严重的藻类“水华”,藻类密度高达1.87×107 cells/L 和1.67×107 cells/L,优势种分别为蓝隐藻(1.84×107 cells/L)和美丽星杆藻 (1.34×107 cells/L)。相关分析结果表明:三峡库区干流藻类数量和生物量与水库的出水流量有着显著的负相关(Spearman,r=-1.000, r=-0.900, p<0.05),而与可溶性营养盐(NO3 N, PO4 P, SiO3 Si)的浓度无显著的相关性;在2004年7~8月(雨季)香溪河下游及河口区浮游植物生物量与主要营养盐(NO3 N, PO4 P,SiO3 Si)的浓度呈显著负相关(Spearman,p<0.01, p<0.05,p<0.01, n=21);在2005年4月(旱季)该河段藻类密度与主要营养盐(NO3 N N,SiO3 Si)呈显著负相关 (Spearman, p<0.05,p<0.01,n=28),但与PO4 P无显著的相关性。香溪河口到秭归的坝前库区河段藻类数量与主要营养盐(NO3 N, PO4 P,SiO3 Si)没有显著相关性(Spearman, │r│<0.2, n=20)。然而香溪河下游及河口区主要营养盐(NO3 N, PO4 P, SiO3 Si)浓度却低于长江干流。可以推断三峡库区蓄水后干流和支流发生“水华”的最主要原因是筑坝后库区内水动力条件的改变而非营养盐浓度较高。随着三峡工程的全面完工,库区内水体滞留时间的进一步延长,三峡库区水体富营养化趋势将会进一步加剧。 相似文献
965.
王徽 《中国人口.资源与环境》1996,6(2):51-56
1992年联合国通过了《联合国气候变化框架公约》。在同年6月地球首脑会议上,155个国家签署了该公约。随着公约内容的具体化,围绕缔约国之间控制温室气体排放这个主议题,将展开政治、经济、法律、环境诸方面的分工协作以控制全球气候的变化。因此有必要在多边谈判和实施公约的工作中,讨论协商性谈判问题。本文探讨了该问题并就协商性谈判提出一些原则性建议。 相似文献
966.
We report a case of fetus in fetu presented as a complex intra-abdominal heterogeneous cystic lesion during ultrasound examination of the fetus at 25 weeks of gestation. Progressive growth of this mass was noted in the prenatal period. Fetal magnetic resonance imaging provided additional information to aid in the prenatal diagnosis. This allows proper counselling for the parents and helps to plan the postnatal management. Surgical excision was carried out in the early neonatal period and the diagnosis of fetus in fetu was confirmed. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
967.
Li Xiao-Juan Wang Chen Chen Wei-bin Bora Shilpi Yap Jeffrey Boon Hui Samuel Bimenyimana 《Environment, Development and Sustainability》2022,24(10):11626-11650
Environment, Development and Sustainability - With the acceleration of urbanization process in China, the usage of sustainable green buildings is getting a great attention and significance in order... 相似文献
968.
Wang Feng Dong Mingru Ren Jing Luo Shan Zhao Hui Liu Juan 《Environment, Development and Sustainability》2022,24(4):5531-5550
Environment, Development and Sustainability - For a long time, air pollution caused by unreasonable urban spatial structure and excessive urban sprawl has been a prominent environmental problem in... 相似文献
969.
970.
Xin Yan Wang Dongchuan Zhang Lihui Ma Yingyi Chen Xing Wang Haiqing Wang Hongyi Wang Kangjian Long Hui Chai Hua Gao Jianshe 《Environment, Development and Sustainability》2022,24(3):3687-3703
Environment, Development and Sustainability - The western region of China has always been the main battlefield for poverty alleviation. It is essential to explore the interaction mechanism between... 相似文献