水文气象因素对东南山区水库硅藻异常增殖的影响

硅藻异常增殖是影响我国许多水库水质安全的生态灾害.为揭示水库硅藻异常增殖的影响因素,以我国东南丘陵地区大(Ⅱ)型水库天目湖沙河水库为例,基于8年逐月浮游植物群落结构及相关环境因子的监测,分析了硅藻(Bacillariophyta)及其优势属生物量与温度、降雨、水位、营养盐等环境因子之间的关系.结果表明,春季硅藻及其优势属的生物量主要受温度的影响,与水文、营养盐关系较弱;不同硅藻优势属与水温的关系差异较大:针杆藻(Synedra)的最佳生长温度为27℃,小环藻(Cyclotella)与曲壳藻(Achnanthes)的最佳生长温度为19℃,直链藻(Melosira)适合在低温下生长,生物量随温度升高而降低;硅藻生物量与环境因子的多元统计分析表明,硅藻总生物量、针杆藻和曲壳藻等优势属生物量峰值与降雨量显著性正相关(P0.05),小环藻生物量峰值与总磷、降雨量和水位显著性正相关,而与换水率显著性负相关,直链藻生物量峰值与总磷显著性正相关.年度硅藻峰值强度可以用降雨量强度和时间、冬春季的积温和溶解性总磷浓度等综合因素拟合预测.研究表明,对于我国东南丘陵山区中营养水平的水库而言,硅藻优势属的异常增殖事件受水文气象因素异常事件的影响较大,相比较而言对氮磷营养盐响应偏弱;在防控水库硅藻异常增殖灾害方面,除了积极开展流域营养盐削减措施之外,应当密切关注极端天气综合影响,采取相应的水文调节措施,开发切实有效的灾害预警技术.     

Vertical movement and habitat of opah (Lampris guttatus) in the central North Pacific recorded with pop-up archival tags

Data from 11 pop-up archival transmitting tags attached to opah (Lampris guttatus, F. Lampridae) in the central North Pacific between November 2003 and March 2005 were used to describe their vertical movement and habitat. In the subtropical gyre northwest of the Hawaiian Islands, opah generally inhabited a 50–400 m depth range and 8–22°C temperatures. They were frequently found in depths of 50–150 m at night and in greater depths (100–400 m) during the day, but were constantly moving vertically within this broad range. At night, excursions below 200 m were not uncommon and during the day they were very likely to spend some time at depths <175 m. Their vertical speeds were generally <25 cm s⁻¹ but on one occasion an opah descended at a burst speed of 4 m s⁻¹. Vertical habitat use by individual opah apparently varied with local oceanographic conditions, but over a 24-h period the average temperature experienced was always in the narrow range of 14.7 to 16.5°C.

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亚热带东部壳斗科6种常绿植物叶的生态解剖

选取亚热带东部替代分布明显的壳斗科6种常绿树种（青冈，小叶青冈，细叶青冈，苦槠，甜槠和石乐）的11个种群叶片进行生态解剖，并用SPSS，DCA和TWINSPAN比较分析，结果表明：（1）尽管6种11个种群叶的结构仍属中生叶型，但有着不同程度的趋旱适应；（2）叶的解剖性状在属间，种间和种群间均存在着不同程度的差异，这是它们适应各自生境的结果，青冈和石栎的种内差异较大，反映出它们对环境变化有较强响应能力；（3）叶片的不同解剖性状在属，种类和种群间的变化并不同步，其中叶片和栅栏组织厚度等性状差异突出，反映它们更易受环境的饰变，是生态适应性状，而海,上角质膜，特别是下表皮厚度等性状差异较小，显示出这些性状的稳定性，可以认为是系统演化性状；（4）苦槠，青冈具有较厚的叶片，栅栏组织，角质膜和发达输导和机械组织，苦槠还具有复表皮，表现出对旱化生境的适应；甜槠尽管具有复表皮和较厚的叶片，但这是海绵组织增厚的结果，是对中生生境的适应；小叶青冈和细叶青冈具有较垢叶片和栅栏组织，角质膜厚度居中等特点，可能是对中山凉湿生境的。图版1图2表2参24     

Quantifying the connections—linkages between land-use and water in the Kathmandu Valley,Nepal

Land development without thoughtful water supply planning can lead to unsustainability. In practice, management of our lands and waters is often unintegrated. We present new land-use, ecological stream health, water quality, and streamflow data from nine perennial watersheds in the Kathmandu Valley, Nepal, in the 2016 monsoon (i.e., August and September) and 2017 pre-monsoon (i.e., April and May) periods. Our goal was to improve understanding of the longitudinal linkages between land-use and water. At a total of 38 locations, the Rapid Stream Assessment (RSA) protocol was used to characterize stream ecology, basic water quality parameters were collected with a handheld WTW multi-parameter meter, and stream flow was measured with a SonTek FlowTracker Acoustic Doppler Velocimeter. A pixel-based supervised classification method was used to create a 30-m gridded land use coverage from a Landsat 8 image scene captured in the fall of 2015. Our results indicated that land-use had a statistically significant impact on water quality, with built land-uses (high and low) having the greatest influence. Upstream locations of six of the nine watersheds investigated had near natural status (i.e., river quality class (RQC) 1) and water could be used for all purposes (after standard treatments as required). However, downstream RSA measurements for all nine watersheds had RQC 5 (i.e., most highly impaired). Generally, water quality deteriorated from monsoon 2016 to pre-monsoon 2017. Our findings reinforce the importance of integrated land and water management and highlight the urgency of addressing waste management issues in the Kathmandu Valley.     

Undue concentration of research and education: multi-criteria decision approach to assess jurisdiction eligibility for NSF funding

Research and education tend to concentrate in specific geographical areas, while many jurisdictions receive limited federal research funding. This has resulted in reduced opportunity for students as well as limited ability of science to influence solving problems at the jurisdiction level. The National Science Foundation’s Experimental Program to Stimulate Competitive Research (EPSCoR) was intended to address the “undue concentration of research and education” by providing direct funding to improve research infrastructure, hire researchers, develop outreach, and to enhance local research capacity. Despite many successful outcomes attributed to EPSCoR, the aim and the execution of the program have generated controversy. Decision analytic tools can provide a systematic approach to EPSCoR prioritization that improves transparency and addresses the program’s intent. The wording of NSF’s mission and EPSCoR legislation suggest the intent of maximizing NSF’s benefit to the nation by directly supporting scientific research product across all jurisdictions and by supporting development of competitive scientific capabilities within particular jurisdictions. These components may be quantified via data-driven metrics producing indicators of ultimate benefit. Using illustrative scenarios within a multi-criteria decision model, we explore how such decision models may generate insights and how their guidance compares with current eligibility determinations.     

A multi-criteria geographic information systems approach for the measurement of vulnerability to climate change

A flexible procedure for the development of a multi-criteria composite index to measure relative vulnerability under future climate change scenarios is presented. The composite index is developed using the Weighted Ordered Weighted Average (WOWA) aggregation technique which enables the selection of different levels of trade-off, which controls the degree to which indicators are able to average out others. We explore this approach in an illustrative case study of the United States (US), using future projections of widely available indicators quantifying flood vulnerability under two scenarios of climate change. The results are mapped for two future time intervals for each climate scenario, highlighting areas that may exhibit higher future vulnerability to flooding events. Based on a Monte Carlo robustness analysis, we find that the WOWA aggregation technique can provide a more flexible and potentially robust option for the construction of vulnerability indices than traditionally used approaches such as Weighted Linear Combinations (WLC). This information was used to develop a proof-of-concept vulnerability assessment to climate change impacts for the US Army Corps of Engineers. Lessons learned in this study informed the climate change screening analysis currently under way.     

A comparison of absorption and assimilation efficiencies between four species of shallow- and deep-living fishes

We captured two species of deep-sea zoarcids, Melanostigma pammelas and Lycodapus mandibularis, from Monterey Bay California and maintained them in the laboratory. One shallow-water zoarcid, Eucryphycus californicus, and an ecologically and morphologically similar stichaeid fish Xiphister atropurpureus were collected from intertidal and subtidal habitats in Monterey Bay. We investigated the absorption and assimilation efficiencies of these fishes to determine whether deep-sea species have evolved mechanisms to increase their efficiency of food use. Fishes were placed in experimental chambers and fed a known quantity of food. Ammonia excretion was measured and feces were collected daily. Both food and feces were analyzed for water, protein, lipid and ash to determine specific absorption efficiencies. Absorption ranged from 87.7 to 92.4% and assimilation efficiencies from 84.0 to 86.5%. Meal sizes from 0.5 to 4.0% of body weight did not affect the results. No significant differences were found between deep-sea and shallow-water species fed single meals or fed ad libitum for 10 days. This suggests that the selective pressure to maximize absorption and assimilation is universal and is not affected by the productivity of the habitat occupied. However, the relative size of the intestine in the deep-sea species was significantly smaller suggesting that they had a lower metabolic cost to maintain their digestive apparatus. It could not be concluded whether this was the result of pressure to conserve energy or rather the tendency of the shallow-living species to ingest more refractory material (i.e. sediment, algae).     

Simulating forest structure, timber production, and socioeconomic effects in a multi-owner province.

Protecting biodiversity has become a major goal in managing coastal forests in the Pacific Northwest--an area in which human activities have had a significant influence on landscape change. A complex pattern of public and private forest ownership, combined with new regulations for each owner group, raises questions about how well and how efficiently these policies achieve their biodiversity goals. To develop a deeper understanding of the aggregate effect of forest policies, we simulated forest structures, timber production, and socioeconomic conditions over time for the mixture of private and public lands in the 2.3-million-ha Coast Range Physiographic Province of Oregon. To make these projections, we recognized both vegetative complexity at the stand level and spatial complexity at the landscape level. We focused on the two major factors influencing landscape change in the forests of the Coast Range: (1) land use, especially development for houses and cities, and (2) forest management, especially clearcutting. Our simulations of current policy suggest major changes in land use on the margins of the Coast Range, a divergence in forest structure among the different owners, an increase in old-growth forests, and a continuing loss of the structural elements associated with diverse young forests. Our simulations also suggest that current harvest levels can be approximately maintained, with the harvest coming almost entirely from private lands. A policy alternative that retained live trees for wildlife would increase remnant structures but at a cost to landowners (5-7% reduction in timber production). Another alternative that precluded thinning of plantations on federal land would significantly reduce the area of very large diameter (>75 cm dbh) conifer forests 100 years into the future     

Changing the Course of Biodiversity Conservation in the Caatinga of Northeastern Brazil

Abstract:  The 735,000-km² Caatinga is a mosaic of thorn scrub and seasonally dry forests, with more than 2000 species of vascular plants, fishes, reptiles, amphibians, birds, and mammals. Endemism in these groups varies from 7% to 57%. Inappropriate land use has already caused serious environmental damage and accelerating desertification, which is currently threatening about 15% of the region. Moreover, the rich and diversified biota of the Caatinga is poorly protected: only 11 reserves (<1% of the region) are strictly protected areas. A conservation strategy for the Caatinga biota should be designed to (1) avoid further habitat loss and desertification, (2) maintain key ecological services necessary for improving the living standards of the rural population, and (3) promote the sustainable use of the region's natural resources. Implementing an effective conservation agenda for the Caatinga is not an easy task but, with creativity and consistent financial support, it should be possible to nurture this unique biome and guarantee the preservation of its rich and diversified fauna and flora, and, with this, the well-being of its rural populations.     

Compensation for “Meaningful Participation” in Climate Change Control: A Modest Proposal and Empirical Analysis

The debate over an international climate change regime has thus far focused primarily on efficiency concerns in developed countries. This paper suggests a means by which equity concerns may be addressed in the ongoing negotiations. A system of transfers is developed that is motivated by the difference between the damage caused by a country and the damage suffered by that country as a result of climate change. Illustrative calculations of the magnitude and direction of these transfers are made. We find that in general transfers flow from temperate to tropical countries but that the degree of uncertainty associated with these calculations is very large.