Human Influence on the Spatial Structure of Threatened Pacific Salmon Metapopulations

Abstract: To remain viable, populations must be resilient to both natural and human‐caused environmental changes. We evaluated anthropogenic effects on spatial connections among populations of Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) (designated as threatened under the U.S. Endangered Species Act) in the lower Columbia and Willamette rivers. For several anthropogenic‐effects scenarios, we used graph theory to characterize the spatial relation among populations. We plotted variance in population size against connectivity among populations. In our scenarios, reduced habitat quality decreased the size of populations and hydropower dams on rivers led to the extirpation of several populations, both of which decreased connectivity. Operation of fish hatcheries increased connectivity among populations and led to patchy or panmictic populations. On the basis of our results, we believe recolonization of the upper Cowlitz River by fall and spring Chinook and winter steelhead would best restore metapopulation structure to near‐historical conditions. Extant populations that would best conserve connectivity would be those inhabiting the Molalla (spring Chinook), lower Cowlitz, or Clackamas (fall Chinook) rivers and the south Santiam (winter steelhead) and north fork Lewis rivers (summer steelhead). Populations in these rivers were putative sources; however, they were not always the most abundant or centrally located populations. This result would not have been obvious if we had not considered relations among populations in a metapopulation context. Our results suggest that dispersal rate strongly controls interactions among the populations that comprise salmon metapopulations. Thus, monitoring efforts could lead to understanding of the true rates at which wild and hatchery fish disperse. Our application of graph theory allowed us to visualize how metapopulation structure might respond to human activity. The method could be easily extended to evaluations of anthropogenic effects on other stream‐dwelling populations and communities and could help prioritize among competing conservation measures.     

Using Coral Disease Prevalence to Assess the Effects of Concentrating Tourism Activities on Offshore Reefs in a Tropical Marine Park

Abstract: Concentrating tourism activities can be an effective way to closely manage high‐use parks and minimize the extent of the effects of visitors on plants and animals, although considerable investment in permanent tourism facilities may be required. On coral reefs, a variety of human‐related disturbances have been associated with elevated levels of coral disease, but the effects of reef‐based tourist facilities (e.g., permanent offshore visitor platforms) on coral health have not been assessed. In partnership with reef managers and the tourism industry, we tested the effectiveness of concentrating tourism activities as a strategy for managing tourism on coral reefs. We compared prevalence of brown band disease, white syndromes, black band disease, skeletal eroding band, and growth anomalies among reefs with and without permanent tourism platforms within the Great Barrier Reef Marine Park. Coral diseases were 15 times more prevalent at reefs with offshore tourism platforms than at nearby reefs without platforms. The maximum prevalence and maximum number of cases of each disease type were recorded at reefs with permanently moored tourism platforms. Diseases affected 10 coral genera from 7 families at reefs with platforms and 4 coral genera from 3 families at reefs without platforms. The greatest number of disease cases occurred within the spatially dominant acroporid corals, which exhibited 18‐fold greater disease prevalence at reefs with platforms than at reefs without platforms. Neither the percent cover of acroporids nor overall coral cover differed significantly between reefs with and without platforms, which suggests that neither factor was responsible for the elevated levels of disease. Identifying how tourism activities and platforms facilitate coral disease in marine parks will help ensure ongoing conservation of coral assemblages and tourism.     

Communities of Wood-Attacking Fungi in the Region of Oil and Gas Production

The communities of xylotrophic fungi were studied in the northern and middle taiga subzones of western Siberia, in forests growing in the region of oil and gas production and exposed to various anthropogenic factors (emissions of petroleum gas flares, oil pollution, spills of mineralized oil-field water, etc.). Structural and functional rearrangements in these communities were revealed, and the prevalence of rot in the tree stand was assessed.     

Special features of fish species composition and community structure in small rivers of the Udmurt Republic

The composition and species richness of ichthyofauna have been studied in 36 stretches of small rivers in the Udmurt Republic to estimate the dependence of species richness on the distance from the river source and the level and type of anthropogenic load. Some specific features of modification of the fish community structure under the influence of agriculture, urbanization, and industry (oil production) have been revealed. Basic trends in the change of dominant complexes of fish species with an increase in the distance from the river source are described for small rivers flowing in different natural and anthropogenic landscapes of the Udmurt Republic.     

辽宁省人为源大气污染物排放清单及特征研究

为全面评估辽宁省关键大气污染物排放状况,系统收集和整理全省基础活动水平信息,采用排放因子法建立了该省2012年人为源大气污染物排放清单.结果显示,2012年辽宁省SO_2、NO_x、CO、PM10、PM_(2.5)、BC、OC及NH_3排放总量分别为1434.8×10~3、1632.3×10~3、6682.9×10~3、1529.9×10~3、1087.8×10~3、74.5×10~3、176.1×10~3t及880.4×10~3t.BC和OC最大贡献源为生物质燃烧源,排放集中分布在辽宁中、西部;NH_3主要来自畜禽养殖与化肥施用,排放高值区位于辽宁中部农业畜牧业发达地区;其他污染物主要来自固定燃烧源和工艺过程源,集中分布在辽宁中部城市群以及大连金州区、甘井子区和普兰店区.大连、沈阳是SO_2、NO_x、NH_3和颗粒物主要排放城市,鞍山和本溪由于钢铁行业发达,成为CO排放量最大的城市.基于卫星观测获得的NO_2垂直柱浓度对NO_x排放空间分布进行评估,两者相关性系数为0.57(p0.01).辽宁省级排放清单与国家尺度排放清单在一定程度存在差异,主要原因在于采用的活动水平和污染物控制效率的不同,基于详细本地化污染源信息建立的省级排放清单可以较好地反映实际情况.建议完善点源排放特征信息并加强本地化测试,进一步降低省级排放清单不确定性.     

基于曲面响应建模的PM2.5可控人为源贡献解析

以东莞市PM_(2.5)重污染月份为例,使用强力法(Brute Force)和RSM/CMAQ曲面响应模型法分别解析了珠三角地区人为源排放对东莞PM_(2.5)的贡献,以及区域传输的可控人为源SO_2、NO_x和一次颗粒物(PM)在不同控制比例下(25%、50%、75%和100%)对东莞PM_(2.5)的累积浓度贡献.强力法研究结果表明,2014年1月珠三角地区人为源二次转化对东莞市PM_(2.5)的贡献(约58.10%)大于一次PM排放贡献(约41.90%),其中,人为源NH_3排放贡献最大,约占总量的21.66%.RSM/CMAQ动态源贡献结果显示,东莞市PM_(2.5)的人为可控源排放贡献(SO_2、NO_x和一次PM)占比为82.17%,受本地排放影响较大,且叠加区域排放的影响;一次PM减排对PM_(2.5)环境浓度的贡献高于仅减排SO_2和NO_x.在减排比例较低时,一次PM减排可有效削减东莞市PM_(2.5)浓度;随控制比例加大,二次前体物(SO_2和NO_x)减排对东莞市PM_(2.5)浓度削减率的影响加大.进一步使用HYSPLIT模式和轨迹聚类分析方法研究了2014年1月东莞市PM_(2.5)污染传输过程.结果显示,该时段共有6条长、短距离污染传输路径,污染物主要来自东莞市东、东北及东南方向,途经其上风向区域(惠州、深圳和广州等)传输至东莞;惠州是各主导上风向出现频率最高的城市,因而其区域传输对东莞PM_(2.5)的贡献也较大,深圳次之.     

Major ion chemistry and control of weathering of Bhimtal Lake, Humaun Himalaya, India

ＭａｊｏｒｉｏｎｃｈｅｍｉｓｔｒｙａｎｄｃｏｎｔｒｏｌｏｆｗｅａｔｈｅｒｉｎｇｏｆＢｈｉｍｔａｌＬａｋｅ，ＨｕｍａｕｎＨｉｍａｌａｙａ，Ｉｎｄｉａ￥ＭａｎｐｒｅｅｔＳｉｎｇｈ；Ｂ．Ｋ．Ｄａｓ（ＣｅｎｔｒｅｏｆＡｄｖａｎｃｅｄＳｔｕｄｙｉｎＧｅｏｌｏｇ...     

Atmospheric Deposition, Mineralization and Leaching of Nitrogen in Subtropical Forested Catchments, South China

In recent years, China has conducted considerable research focusing on the emission and effects of sulphur (S) on human health and ecosystems. By contrast, there has been little emphasis on anthropogenic nitrogen (N) so far, even though studies conducted abroad indicate that long-range atmospheric transport of N and ecological effects (e.g. acidification of soil and water) may be significant. The Sino-Norwegian project IMPACTS, launched in 1999, has established monitoring sites at five forest ecosystems in the southern part of PR China to collect comprehensive data on air quality, acidification status and ecological effects. Here we present initial results about N dynamics at two of the IMPACTS sites located near Chongqing and Changsha, including estimation of atmospheric deposition fluxes of NO_x and NH_x and soil N transformations. Nitrogen deposition is high at both sites when compared with values from Europe and North America (25–38 kg ha^–1 yr^–1). About 70% of the deposited N comes as NH₄, probably derived from agriculture. Leaching of N from soils is high and nearly all as NO₃ ^–1. Transformation of N to NO₃ ^–1 in soils results in acidification rates that are high compared to rates found elsewhere. Despite considerable leaching of NO₃ ^–1 from the root zone of the soils, little NO₃ ^–1 appears in streamwater. This indicates that N retention or denitrification, both causing acid neutralization, may be important and probably occur in the groundwater and groundwater discharge zones. The soil flux density of mineral N, which is the sum of N deposition and N mineralization, and which is dominated by the N mineralization flux, may be a good indicator for leaching of NO₃ ^–1 in soils. However, this indicator seems site specific probably due to differences in land-use history and current N requirement.