A Framework and Key Questions for Adapting to Climate Variability and Change

There is a critical need to collectively understand, to develop adaptation options to enhance the benefits, and to reduce the social and economic vulnerabilities induced by climate variability and change. This paper uses key questions to help build a framework for adaptation by first organizing the questions into adaptation science, management and option components, including their respective sub-categories. The process of adaptation depends on many factors, including who or what adapts, what they adapt to, how they adapt and what and how resources are used. This conceptual model is designed to organize concepts regarding adaptation, to help stimulate ideas, and to explore the linkages among parts of the adaptation cycle. Predictive models need to be developed to determine the outcomes of planned adaptation strategies. For the best and most realistic evaluation of climate problems, adaptation and impacts should be considered together. This joint approach improves the assessment of the significance and dangers of the current and future climate, as well as the determination of solutions (e.g., how to prepare for a changing climate) and their priorities. Challenges of adaptive management are discussed in terms of a framework with linkages to adaptation science and options. Adaptation research and applications work continue to build on the foundation of science and management frameworks to address the risks and uncertainties in the decision-making process and to identify adaptation options.     

Canadian prairie rural communities: their vulnerabilities and adaptive capacities to drought

Droughts can have severe negative effects on the environment, society and economy. The drought of 2001–2002 caused severe strain on economic and social activities in western Canada, particularly on rural communities through changes in water resources. This paper examines physical and social vulnerabilities and associated adaptation measures undertaken and the adaptive capacity in communities in the South Saskatchewan River Basin, Canada. Although all of these communities were exposed to the 2001–2002 drought, they had different levels of impacts, resulting in different types of drought adaptation measures, some due to experience with previous droughts and some in response to the 2001–2002 drought. Communities with unreliable water supply were the most vulnerable to these droughts. This vulnerability resulted in historic adaptations being implemented (e.g., Hanna, Alberta) and re-active adaptations (e.g., Cabri, Saskatchewan). It is important to examine the effectiveness of the current adaptive strategies to cope with more extensive and extended drought situations. First Nation communities, such as the Kainai Blood Indian Reserve, have many social and environmental issues but the impacts from the drought were minor. The Reserve had implemented economic changes in the late 1980s to make it less vulnerable to drought but resulted in negative impacts to the Reserve’s social health. It is imperative to determine how vulnerable First Nation communities are and will to improve future adaptive capacity. This paper provides a snap shot view of how Canadian Prairie Communities have adapted to drought and how vulnerable they are to future drought situations.     

Effects of pH and feeding regime on methylmercury accumulation within aquatic microcosms

The effect of pH (pH 5, 6 or 7) on accumulation of radiolabelled methylmercury was examined using a laboratory microcosm system. Accumulation of labelled mercury at three trophic levels, primary consumers (Daphnia magna), secondary consumers (rainbow trout, Salmo gairdneri) and tertiary consumers (walleye, Stizostedion vitreum) was not significantly affected by pH. Our results are in direct contrast with field observations of elevated methylmercury concentrations in fish from low pH water and indicate that the elevated mercury residues observed in the field result from factors other than the direct effects of pH on accumulation of methylmercury by aquatic organisms. Both water and diet were important as sources of the labelled mercury which was accumulated by walleye. Walleye which were fed rainbow trout, that had accumulated labelled mercury from within the experimental microcosms, accumulated almost twice as much labelled mercury as walleye fed non-labelled prey, or walleye which were not fed. Walleye fed non-labelled rainbow trout accumulated slightly more labelled mercury than walleye which were not fed, presumably as a result of the higher metabolic rate of the fish which were fed.     

The Importance of Systematic Biology in Defining Units of Conservation

Abstract: Conservation biology is linked inextricably with systematic biology. The principles of systematic biology, however, have not been integrated completely into the practice and principles of conservation biology. Systematists have recognized for some time that a number of evolutionary processes lead to the diversification of lineages. Yet some present units of conservation, such as the evolutionarily significant unit ( Waples 1991), primarily emphasize only one of these processes, adaptation. Allopatric speciation produces biodiversity without requiring any adaptive shift (and consequent adaptive differences between daughter species), so definitions of conservation units that emphasize adaptation may underestimate biodiversity. We estimated the frequency of different modes of speciation for three groups of vertebrates. The frequency of allopatric speciation varies among these groups, but is an important type of speciation in two of the three groups studied. Our results, and the results of other published studies of the frequency of modes of speciation, demonstrate that any unit of conservation defined solely in terms of adaptation is likely to underestimate biological diversity.     

Soil temperature,nitrogen concentration,and residence time affect nitrogen uptake efficiency in citrus

We try to elucidate which environmental and soil factors control nitrogen uptake efficiency in citrus. Effects of residence time and nitrogen (N) concentration (three 500-mL applications of 7 mg N L(-1), representative of reclaimed water used for citrus irrigation in central Florida, or one 150-mL application of 70 mg N L(-1)) on nitrogen uptake efficiency (NUE) of young citrus seedlings were studied. Increasing residence times from 2 to 8 h increased NUE from 36 to 82% and from 17 to 34% for high and low application frequencies, respectively. We developed a model to predict N uptake based on root density, N concentration, and soil temperature (Ts). Assuming a base temperature (Tb) of 10 degrees C, N uptake temperature sum (UTS) = sigma(Ts - Tb)/24 (degrees CdN, degree day units of N uptake). To eliminate the risk of N leaching for young seedlings, minimum uptake periods of 5 and 16 degrees CdN were required at initial soil N concentrations of 0.9 and 2.5 mg N L(-1), respectively. After correcting for differences in root length, this information was then used to predict the effect of irrigation practices on N uptake from reclaimed water for mature trees. Applying 2500 mm yr(-1) vs. 400 mm yr(-1) reclaimed water reduced the NUE of N in this water from 100 to 63% during the summer and from 100 to 28% during the winter. Reductions in NUE at higher irrigation rates appeared to be related to N displacement below the root zone prior to complete N uptake.