Threats to Riparian Ecosystems in Western North America: An Analysis of Existing Literature1

Poff, Boris, Karen A. Koestner, Daniel G. Neary, and Victoria Henderson, 2011. Threats to Riparian Ecosystems in Western North America: An Analysis of Existing Literature. Journal of the American Water Resources Association (JAWRA) 47(6):1241–1254. DOI: 10.1111/j.1752‐1688.2011.00571.x Abstract: A total of 453 journal articles, reports, books, and book chapters addressing threats to riparian ecosystems in western North America were analyzed to identify, quantify, and qualify the major threats to these ecosystems as represented in the existing literature. Publications were identified either as research, policy, literature review, historical comparison, or management papers. All papers were evaluated based on year of publication, area of interest, and type(s) of threats addressed. Research papers, however, were assessed in more depth. The publications ranged from the 1930s to 2010 and addressed the following threats: dams, pollution (point and nonpoint), grazing, land use change, timber harvesting, water diversion, road construction, recreation, mining, groundwater pumping, invasive species, climate change, salinity, fire, insect and diseases, woody encroachment, watershed degradation, elimination of native vegetation, beavers, fire suppression, and fuel management. While the types of threats vary on spatial and temporal scales, some persist through decades in western North America. This analysis shows that grazing has been perceived as a dominant threat since the 1980s, but has been diminishing in the past decade, while invasive species, dams and, in recent years, climate change are increasingly represented in the literature as threats to riparian ecosystems in western North America.     

Effects of Eastern Hemlock Decline on Large Wood Loads in Streams of the Appalachian Mountains

Evans, Daniel M., C. Andrew Dolloff, W. Michael Aust, and Amy M. Villamagna, 2012. Effects of Eastern Hemlock Decline on Large Wood Loads in Streams of the Appalachian Mountains. Journal of the American Water Resources Association (JAWRA) 48(2): 266‐276. DOI: 10.1111/j.1752‐1688.2011.00610.x Abstract: Eastern hemlock (Tsuga canadensis), a foundation species important to riparian forests of the Appalachian Mountains, is in decline due to the hemlock woolly adelgid (HWA) (Adelges tsugae). The effect of this insect on large wood (LW) production and recruitment to streams is largely unknown. We measured LW load, riparian forest composition, and T. canadensis health in 47 streams from Maine to Alabama and developed a conceptual model that frames the expected forest stand and instream LW response to the disturbance caused by HWA. In stands with HWA, 24.3% of the overstory T. canadensis basal area was stressed and 7.5% was dead, whereas only 3.0% was stressed and 2.0% was dead in stands without HWA. Mean T. canadensis effective LW load was 0.20 m³/100 m² in streams with adjacent stands infested by HWA, almost three times higher than in streams flowing through uninfested stands (p = 0.048). Higher frequencies of LW were found at streams with HWA present and there was a positive association between the percent of dead T. canadensis and T. canadensis LW load (ρ = 0.4468; p = <0.0001). Greater total LW loads were associated with higher stream gradients, lesser bankfull widths, and streams at lower latitudes. Our research supports the hypothesis that HWA infestation of T. canadensis in riparian forest stands has increased LW loads in streams. This episodic disturbance to the riparian forest overstory may have lasting impacts on aquatic ecosystem structure and function.     

试述《野生动物保护法》的修改

《野生动物保护法》施行三十余年,对于促进野生动物保护起着至关重要的作用.然而,在新冠肺炎疫情的冲击下,其中的部分内容显露出不足,全国人大常委会出台的《决定》可以应一时之急,但最根本的办法是对《野生动物保护法》进行修改.通过对现行法律的考察,检视《野生动物保护法》在立法理念、监管职能以及法律责任等方面存在的问题,并提出相...     

Impact assessment of a hydroelectric project on the flora in the Western Himalayan region based on vegetation analysis and socio-economic studies

This study provides an overview of the impacts of a proposed hydroelectric power project in the Western Himalayan region in India, using a primary database on floristic diversity and vegetation analysis. The remote sensing data revealed that in the submergence zone only mixed deciduous forest that occupies 807.5 ha area and has a wood biomass volume of 4,027,503 m³ is likely to be lost due to impoundment. A total of 165 plant species found in the submergence zone also occur in the influence and free draining catchment area of the project. In the influence zone of the project area only one tree species (Acer oblongum) is found under conservation threat category, which is also present in the free draining catchment of the project. The project affected population (6716 people) residing in the submergence and influence zone depend upon the surrounding forests for fuel wood, fodder, wild edibles etc., and most likely they will settle in the nearby areas, thus mounting more pressure on residual forests of the influence zone for various forest products. Further, from the vegetation analysis it is evident that several tree species (e.g. Lannea coromandelica, Terminalia alata, T. bellerica etc.), may face more pressure from exploitation as they provide a number of useful products and are represented in lower numbers in the forests of the project area. To compensate for the loss of various goods and services provided by the forests falling in the submergence zone and to offset the increased pressure of the project affected families on the forests of influence zone, a biodiversity management plan is suggested incorporating socio-economic considerations.     

Stream Condition in Piedmont Streams with Restored Riparian Buffers in the Chesapeake Bay Watershed1

Orzetti, Leslie L., R. Christian Jones, and Robert F. Murphy, 2010. Stream Condition in Piedmont Streams with Restored Riparian Buffers in the Chesapeake Bay Watershed. Journal of the American Water Resources Association (JAWRA) 46(3):473-485. DOI: 10.1111/j.1752-1688.2009.00414.x Abstract: This study tested the efficacy of restored forest riparian buffers along streams in the Chesapeake Bay watershed by examining habitat, selected water quality variables, and benthic macroinvertebrate community metrics in 30 streams with buffers ranging from zero to greater than 50 years of age. To assess water quality we measured in situ parameters (temperature, dissolved oxygen, and conductivity) and laboratory-analyzed grab samples (soluble reactive phosphorus, total phosphorus, nitrate, ammonium, and total suspended solids). Habitat conditions were scored using the Environmental Protection Agency Rapid Bioassessment Protocols for high gradient streams. Benthic macroinvertebrates were quantified using pooled riffle/run kick samples. Results showed that habitat, water quality, and benthic macroinvertebrate metrics generally improved with age of restored buffer. Habitat scores appeared to stabilize between 10 and 15 years of age and were driven mostly by epifaunal substrate availability, sinuosity, embeddedness, and velocity depth regime. Benthic invertebrate taxa richness, percent Ephemeroptera, Plecoptera, Trichoptera minus hydropsychids (%EPT minus H), % Ephemeroptera, and the Family Biotic Index were among the metrics which improved with age of buffer zone. Results are consistent with the hypothesis that forest riparian buffers enhance instream habitat, water quality, and resulting benthic macroinvertebrate communities with noticeable improvements occurring within 5-10 years postrestoration, leading to conditions approaching those of long established buffers within 10-15 years of restoration.     

试行高校学生体质健康标准的情况分析

本文通过对我校试行高等学校《学生体质健康标准》,对04级827人的身高体重指数、分数、耐力指数、握力指数等测试结果进行统计学分析和总结评价,从而得出了对《学生体质健康标准》的几点初步认识。     

Epilithic biofilm as a reservoir for functional virulence factors in wastewater-dominant rivers after WWTP upgrade

Virulence factors (VFs) confer upon pathogens the ability to cause various types of damage or diseases. Wastewater treatment plants (WWTPs) are important point sources for the emission of pathogens and VFs into receiving rivers. Conventional WWTP upgrades are often implemented to improve the water quality of receiving ecosystems. However, knowledge on the pathogens, VFs, and health risks to receiving aquatic ecosystems after upgrade remains limited. In this study, we investigated detailed pathogenic information, including taxa, pathogenicity, and health risk, in two wastewater-dominant rivers after WWTP upgrade. Using 16S rRNA gene sequencing, we screened 14 potential pathogens in water and epilithic biofilm samples, though they were significantly more enriched in the biofilms. Combining 16S rRNA and metagenomic sequencing data, we identified Pseudomonas and Aeromonas as the dominant pathogenic taxa carrying functional VFs (e.g., mobility and offensive) in the epilithic biofilm. Moreover, strong pathogen-specific VF-host co-occurrence events were observed in the epilithic biofilm samples, indicating the importance of biofilms as reservoirs and vehicles for VFs. Further, we demonstrated that mobility VF is crucial for biofilm formation and pathogens in biofilm carrying offensive VF may be highly invasive. Quantification and health risk assessment suggested that the skin contact risk of P. aeruginosa carrying VFs was higher than the acceptable probability of 10^?4 in both water and epilithic biofilm samples, which may threaten ecological and human health.     

天津滨海新区围海造地的生态环境影响分析

选择具有重要典型意义的环渤海城市快速扩张地区渤海湾西岸天津滨海新区段为例,从宏观的景观格局变化与时空演变,微观尺度上的近海生态环境变化方面分析了天津滨海新区围海造地的生态环境影响。结果显示:(1)随着天津滨海新区2006年纳入国家发展战略以及总体规划的实施,围海造地面积从2004年的52.32 km2迅速增加2010年的312.78km2,规划到2020年将增加到425.94 km2,人工岸线从41.16 km增加到217.79 km,造成景观自然性急剧下降,人类对近海的干扰强度过大。(2)对纳潮量造成影响,经过围海造地,天津滨海新区段纳潮量减少了13.7%,纳潮量的减少进一步影响了污染物的稀释与扩散。(3)海洋生态功能受到影响2,010年渤海湾天津滨海新区段的近海生态服务价值将下降18%。     

Prevalent fecal contamination in drinking water resources and potential health risks in Swat, Pakistan

Fecal bacteria contaminate water resources and result in associated waterborne diseases.This study assessed drinking water quality and evaluated their potential health risks in Swat, Pakistan. Ground and surface drinking water were randomly collected from upstream to downstream in the River Swat watershed and analyzed for fecal contamination using fecal indicator bacteria(Escherichia coli) and physiochemical parameters(potential of hydrogen, turbidity, temperature, electrical conductivity, total dissolved solid, color, odor and taste). The physiochemical parameters were within their safe limits except in a few locations, whereas, the fecal contaminations in drinking water resources exceeded the drinking water quality standards of Pakistan Environmental Protection Agency(Pak-EPA),2008 and World Health Organization(WHO), 2011. Multivariate and univariate analyses revealed that downstream urbanization trend, minimum distance between water sources and pit latrines/sewerage systems, raw sewage deep well injection and amplified urban,pastures and agricultural runoffs having human and animal excreta were the possible sources of contamination. The questionnaire survey revealed that majority of the local people using 10–20 years old drinking water supply schemes at the rate of 73% well supply,13% hand pump supply, 11% spring supply and 3% river/streams supply, which spreads high prevalence of water borne diseases including hepatitis, intestinal infections and diarrhea, dysentery, cholera, typhoid fever, jaundice and skin diseases in children followed by older and younger adults.     

北京市2014~2020年PM2.5和O3时空分布与健康效应评估

细颗粒物（PM_2.5）和臭氧（O₃）是我国的主要大气污染物,严重危害人群健康.北京市自2013年以来大力开展大气污染治理工作,现已取得显著成效.通过分析2014~2020年北京市34个大气环境监测站的PM_2.5和O₃浓度变化特征并评估大气污染防治的健康效应,对推进大气污染防治具有重要意义.结果表明,2014年北京市PM_2.5年均值和4~9月平均O₃日最大小时（O_{3_max}）值分别为92.0 μg·m^-3和81.9 nmol·mol^-1.2014~2020年PM_2.5平均每年降低7.5 μg·m^-3,但是O_{3_max}持续偏高.在季节尺度,冬季的12月和1月PM_2.5浓度最高,夏季的8月浓度最低.相反地,O_{3_max}在每年6月浓度最高.PM_2.5浓度日变化规律为,夜间22：00至次日00：00最高,14：00~16：00最低.而O₃浓度在07：00最低,随后逐步升高并在午后达到最高.在空间分布上,PM_2.5在2014和2019年都呈现南高北低的趋势,O_{3_max}在全市范围内均较高,仅在道路区域偏低.大气污染对人群健康影响的评估结果表明,2014年北京市与PM_2.5相关的心血管和呼吸道疾病超额死亡人数分别为1580人和821人,与O₃相关的呼吸道疾病超额死亡人数为2180人.2019年与PM_2.5相关的超额死亡人数仅为2014年的50%,而与O₃相关的超额死亡人数与2014年持平.北京市细颗粒物治理成效显著,但是O₃污染问题凸显,O₃已经成为危害北京市居民健康的首要大气污染物.未来需要加强PM_2.5和O₃协同治理.