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21.
Adaptation options in agriculture to climate change: a typology   总被引:9,自引:0,他引:9  
Adaptation in agriculture to climate change is important for impact andvulnerability assessment and for the development of climate change policy. A wide variety of adaptation options has been proposed as having thepotential to reduce vulnerability of agricultural systems to risks related toclimate change, often in an ad hoc fashion. This paper develops atypology of adaptation to systematically classify and characterize agriculturaladaptation options to climate change, drawing primarily on the Canadiansituation. In particular, it differentiates adaptation options in agricultureaccording to the involvement of different agents (producers, industries,governments); the intent, timing and duration of employment of theadaptation; the form and type of the adaptive measure; and the relationshipto processes already in place to cope with risks associated with climatestresses. A synthesis of research on adaptation options in Canadianagriculture identifies four main categories: (i) technological developments,(ii) government programs and insurance, (iii) farm production practices,and (iv) farm financial management. In addition to these `directadaptations', there are options, particularly information provision, that maystimulate adaptation initiatives. The results reveal that most adaptationoptions are modifications to on-going farm practices and public policydecision-making processes with respect to a suite of changing climatic(including variability and extremes) and non-climatic conditions (political,economic and social). For progress on implementing adaptations to climatechange in agriculture there is a need to better understand the relationshipbetween potential adaptation options and existing farm-level andgovernment decision-making processes and risk management frameworks.  相似文献   
22.
Partial amniotic carbon dioxide insufflation (PACI) involves insufflating the amniotic sac with carbon dioxide (CO2) and, in some cases, draining some of the amniotic fluid. The creation of a gaseous intra-amniotic compartment improves visualization, even in the presence of limited bleeding, and creates the work space required for complex fetoscopic procedures. Clinically, PACI is mostly used to perform fetoscopic myelomeningocele (MMC) repair, enabling a minimally invasive alternative to open fetal surgery. However, evidence of the fetal safety of PACI is limited. Previous animal experiments in sheep demonstrate that PACI induces fetal hypercapnia and acidosis with largely unknown short and longer term implications. In this review, we examine the literature for the physiological effects of intrauterine insufflation pressure, duration, humidity, and the role of maternal hyperventilation on fetal physiology and well-being.  相似文献   
23.
A field ammonia (NH3) release experiment and open top chambers containing moorland monoliths continuously fumigated with NH3 or sprayed with NH4Cl were used to assess the potential for using 15N values in determining the area of influence around a point NH3 emission source. 15N values are being increasingly used as environmental tracers and we tested the hypothesis that the 15N signal from an NH3 emission source is observable in nearby vegetation. Using modified monitoring devices, atmospheric NH3 concentrations were found to decrease with distance from source, with 15N values also reflecting this trend, producing a signal shift with changing concentration. Open top chamber studies of 15N values of Calluna vulgaris (L.) Hull indicated a correlation with deposition treatments in current year shoots. Analysis of Calluna shoots from the NH3 release showed a similar trend of 15N enrichment. Significant linear correlations between 15N and percent N in plant material were found, both in the controlled conditions of the open top chambers and at the NH3 release site, illustrating the possible use of this technique in N deposition biomonitoring.  相似文献   
24.
A model was developed for remote terminal use to compare the costs of alternate designs of air quality monitoring networks with varying sophistication, ranging from totally manual to completely automated systems. Of special interest is the isolation of manual sample analysis and manual data analysis for comparison with instrumental sensors and automated data processing.

The model allows for 10 levels of sophistication, and 6 were used in sample runs. As many as 50 samplingsite locations, with three different site types, may be specified, and each site type may have any configuration of chemical and/or meteorological sensors. Amortization, labor rates, instrument costs and lifetimes, telephone line charges, and other variables are readily changed by the user as desired.

It was concluded that for systems with fewer than 20–25 sensors, fully automated systems may not be justified on cost alone, at least for producing the same data (hourly) as the manual or semiautomatic systems. (Much more than hourly data is obtained with the automated system, of course.) For larger systems, labor costs put the nonautomated systems at a disadvantage after a few years of operation.  相似文献   
25.
Mercury uptake and accumulation by four species of aquatic plants   总被引:10,自引:0,他引:10  
The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively.  相似文献   
26.
Briles CE  Whitlock C  Skinner CN  Mohr J 《Ecology》2011,92(3):590-601
The influence of substrate on long-term vegetation dynamics has received little attention, and yet nutrient-limited ecosystems have some of the highest levels of endemism in the world. The diverse geology of the Klamath Mountains of northern California (USA) allows examination of the long-term influence of edaphic constraints in subalpine forests through a comparison of vegetation histories between nutrient-limited ultramafic substrates and terrain that is more fertile. Pollen and charcoal records spanning up to 15000 years from ultramafic settings reveal a distinctly different vegetation history compared to other soil types. In non-ultramafic settings, the dominant trees and shrubs shifted in elevation in response to Holocene climate variations resulting in compositional and structural changes, whereas on ultramafic substrates changes were primarily structural, not compositional. Fire activity was similar through most of the Holocene with the exception of declines over the last 4000 years on ultramafic substrates, likely due to the reduction of understory fuels and cooler wetter conditions than in the middle Holocene. These results suggest that the tree and shrub distributions were more responsive to past climate changes on non-ultramafic substrates compared to those on ultramafic substrates. The combination of these dynamics may help explain high levels of plant diversity in the Klamath Mountains and provide insights for managing these complex ecosystems.  相似文献   
27.
地方环境举措国际理事会 (ICLEI)城市气候保护运动与地方政府一起工作,采用综合的和战略的能源管理手段减少温室气体排放 .对参加气候保护运动的 43个国家的 386个城市地方政府的抽样调查表明,实质性的行动已经改善了地方的能源管理并且减少了温室气体( GHG)排放 .  相似文献   
28.
29.
Catches of the spanner crab, Ranina ranina (Linnaeus, 1788), in southern Queensland, Australia in 1982 and 1983 showed a seasonal cycle, with peak catches from August to September. In most catches, males outnumbered females. Catches of both male and female spanner crabs declined in November and December, when a high proportion of females caught were ovigerous. Fish, echinoderms and polychaetes were the main food items. Closed-circuit time-lapse video recording was used to study the emergence behaviour of R. ranina in a 6 m-diameter tank. Spanner crabs in this tank were buried most of the time, emerging on average for only 1.7 h d-1. They emerged mainly between 16.00 and 24.00 hrs and, less often, between 01.00 and 15.00 hrs. Males remained emerged significantly longer than females. The duration of emergence of the females peaked before the spawning season, becoming shorter during the period when they were ovigerous. Temperature and emergence were negatively correlated. It is concluded that reproductive behaviour has a strong influence on catch composition of spanner crabs.  相似文献   
30.
Non-OECD countries will account for the greatest share of growth in future energy demand. Policy-makers, in response to public concern that the continued use of fossil-fuels could bring about global climate change have sought out policies which will reduce future energy demand. However, economic instruments which can do so, such as carbon taxes, provoke significant distributional and equity issues. Most OECD governments have set CO2 reduction targets, but few of those targets are backed up by effective legislation and programmes. Instead, most governments seem to count on increasing energy efficiency, seemingly 'spontaneously', to bring about CO2 reductions. Realization of OECD CO2 reduction targets would be insignificant on a global scale, but they are nevertheless very ambitious when compared to recent changes in the OECD's energy-derived CO2 emissions. Reliance on market forces alone may therefore not be enough.  相似文献   
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