Impacts of climate change on wheat development and production in the northern China

In this paper, impacts of climate change on wheat development rate and production in the northern China are discussed. The results show that the temperature is a controlling factor of development rate but the precipitation is not. The higher the temperature is. the faster the development and the shorter development period will be. Without consideration to varieties and cropping system, meteorological yield of winter wheat would decrease 170.40, 134.25, 98.70 and 97.20 kg/hm2 in the north China and 13.97, 7.95, 39.60 and 19.80 kg/hm2 in the northwest China compared with that in 1950s, 1960s, 1970s and 1980s, respectively, when the CO2 concentration in the atmosphere is doubled. In drought and semi-drought regions, the spring wheat yield would drop with the temperature rise in and raise with the precipitation increase. The influence of temperature on weight of leaf and stalk is also remarkable.     

CLIMATE CHANGE AND NATURAL HAZARDS IN NORTHERN CANADA: INTEGRATING INDIGENOUS PERSPECTIVES WITH GOVERNMENT POLICY

A study of the relationship between natural hazards and climate change in the international context provides the background for a discussion of the expected changes. In the context of this global discussion, this paper reviews the current perspectives of those natural hazards that are likely to be influenced by climate change, using northern Canada as a regional case study. The northern implications of the United Nations Framework Convention on Climate Change are examined, including the status of climate change action by the northern territorial governments, the evolving role of indigenous people, and the responsibility for climate change impacts. The difficulties surrounding natural hazards research in remote locations, and the approaches of indigenous people to natural hazards are then presented. The paper concludes with a suggested policy approach for climate change and natural hazards in northern Canada, underscoring the need for more comprehensive adaptive strategies to complement the current tendency to focus on the mitigation of greenhouse gases produced in this region.     

四川省蔬菜基地的气候优势及其开发利用

利用四川省10年气候资料与蔬菜生产资料，经过多年的实地考察研究及统计分析，找出四川省蔬菜基地群分布随海拔高度变化的规律、产供销特点，并提出了发展四川省蔬菜产业的对策。     

皖南山区中华猕猴桃的气候适宜性区划

本文在简要分析皖南山区气候特征的基础上，根据中华猕猴桃的生长习性，提出了发展只结猕猴桃的适宜栽培高度区划，为合理利用山区气候资源发展猕猴桃生产提供科学依据。     

北京地区15000年以来环境变迁中灾害性气候突变事件的讨论

通过高分辨率孢粉分析及烧失量、炭屑实验结果的统计分析，结合１４Ｃ、古地磁等，对北京房山东甘池１５０００ａ以来植被变化和环境变迁进行了较为深入的研究，特别强调气候变化的灾害性突变事件。初步得知约在１４１００～１４０００ａＢ．Ｐ．前后曾出现与哥得堡反转相对应的事件，在１００００ａＢ．Ｐ．左右出现类似与新仙女木事件相对应的事件，在大约５７７０ａＢ．Ｐ．和４５６０ａＢ．Ｐ．左右及２８５０～２６５０ａＢ．Ｐ．出现了大暖期的突然降温事件。     

全球增暖对自然灾害的可能影响

近年来，气候对环境的影响已受到全球科学家越来越多的重视，中国是一个有１１亿人口的大国，生态环境较为脆弱，全球变暖将严重影响我国社会与经济生活的各个方面。本文初步研究了全球变暖对自然灾害的可能影响。结果表明，在大气ＣＯ２含量加倍的情况下，全球变暖将可能导致暴雨频度和洪涝风险增加，西北干旱趋势仍将延续；森林火灾、台风、滑坡与泥石泫灾害可能加剧；农林病虫害危害增加，范围扩大。同时，全球变暖导致的海平面上     

The GaNE programme in a global perspective

This paper provides the background to this special issue, outlining the extent to which the global atmospheric nitrogen cycle has been modified by human activity and outlining the range of effects. The global total emissions of reduced and oxidized nitrogen, amount to 124 Tg N, and exceed those from natural sources (34 Tg N) by almost a factor of four showing the extent to which anthropogenic activity has taken over the global N cycle. Of the 124 Tg N, 70 Tg N is emitted in the oxidized form, largely as NO and 70% of which results directly from anthropogenic activity. The remaining 54 Tg N is emitted as NH₃, (66% anthropogenic). The enhanced nitrogen emissions are associated with a range of local, regional and global issues including, acidification, eutrophication, climate change, human health and tropospheric O₃. The paper also places the Global Nitrogen Enrichment (GaNE) research programme in the UK in a wider perspective.     

THE INFLUENCE OF CLIMATE VARIATION ON THE ESTIMATION OF LOW FLOWS USED TO PROTECT WATER QUALITY: A NATIONWIDE ASSESSMENT1

ABSTRACT: Historical flow records are used to estimate the regulatory low flows that serve a key function in setting discharge permit limits through the National Pollutant Discharge Elimination System, which provides a nationwide mechanism for protecting water quality. Use of historical records creates an implicit connection between water quality protection and climate variability. The longer the record, the more likely the low flow estimate will be based on a broad set of climate conditions, and thus provides adequate water quality protection in the future. Unfortunately, a long record often is not available at a specific location. This analysis examines the connection between climate variability and the variability of biologically based and hydrologically based low flow estimates at 176 sites from the Hydro‐Climatic Data Network, a collection of stream gages identified by the USGS as relatively free of anthropogenic influences. Results show that a record of 10 to 20 years is necessary for satisfactory estimates of regulatory low flows. Although it is possible to estimate a biologically based low flow from a record of less than 10 years, these estimates are highly uncertain and incorporate a bias that undermines water quality protection.     

MODELING THE IMPACTS OF WATER LEVEL CHANGES ON A GREAT LAKES COMMUNITY1

ABSTRACT: Recent research that couples climate change scenarios based on general circulation models (GCM) with Great Lakes hydrologic models has indicated that average water levels are projected to decline in the future. This paper outlines a methodology to assess the potential impact of declining water levels on Great Lakes waterfront communities, using the Lake Huron shoreline at Goderich, Ontario, as an example. The methodology utilizes a geographic information system (GIS) to combine topographic and bathymetric datasets. A digital elevation surface is used to model projected shoreline change for 2050 using water level scenarios. An arbitrary scenario, based on a 1 m decline from February 2001 lake levels, is also modeled. By creating a series of shoreline scenarios, a range of impact and cost scenarios are generated for the Goderich Harbor and adjacent marinas. Additional harbor and marina dredging could cost as much as CDN $7.6 million. Lake freighters may experience a 30 percent loss in vessel capacity. The methodology is used to provide initial estimates of the potential impacts of climate change that can be readily updated as more robust climate change scenarios become available and is adaptable for use in other Great Lakes coastal communities.     

A Quantitative Tool for Assessing the Integrity of Southern Coastal California Streams

We developed a benthic macroinvertebrate index of biological integrity (B-IBI) for the semiarid and populous southern California coastal region. Potential reference sites were screened from a pool of 275 sites, first with quantitative GIS landscape analysis at several spatial scales and then with local condition assessments (in-stream and riparian) that quantified stressors acting on study reaches. We screened 61 candidate metrics for inclusion in the B-IBI based on three criteria: sufficient range for scoring, responsiveness to watershed and reach-scale disturbance gradients, and minimal correlation with other responsive metrics. Final metrics included: percent collector-gatherer + collector-filterer individuals, percent noninsect taxa, percent tolerant taxa, Coleoptera richness, predator richness, percent intolerant individuals, and EPT richness. Three metrics had lower scores in chaparral reference sites than in mountain reference sites and were scored on separate scales in the B-IBI. Metrics were scored and assembled into a composite B-IBI, which was then divided into five roughly equal condition categories. PCA analysis was used to demonstrate that the B-IBI was sensitive to composite stressor gradients; we also confirmed that the B-IBI scores were not correlated with elevation, season, or watershed area. Application of the B-IBI to an independent validation dataset (69 sites) produced results congruent with the development dataset and a separate repeatability study at four sites in the region confirmed that the B-IBI scoring is precise. The SoCal B-IBI is an effective tool with strong performance characteristics and provides a practical means of evaluating biotic condition of streams in southern coastal California.