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61.
Abstract: Livestock grazing (without modern fertilizers), mowing, and other traditional methods of animal husbandry are used in Europe for managing human-made habitats such as seminatural grasslands. From a review of essential literature, I hypothesize that traditional animal husbandry partially compensates for the loss of natural processes that have been suppressed by humans. There is indirect evidence that livestock grazing and mowing have made possible the continued existence of many species threatened by the human overkill of megaherbivores and other large herbivores. Many species that were dependent on natural fires and floods may have benefited from grazing and mowing, which also may be effective tools for mitigating the negative effects of eutrophication. As partial surrogates, traditional grazing and mowing have obscured the importance of natural disturbances to European biodiversity. Thus, the end of traditional animal husbandry, together with the suppression of natural disturbances, may cause even more adverse effects to biodiversity than is generally recognized.  相似文献   
62.
Mass differences less than 100 microg must be correctly measured in gravimetric analysis of particles collected on filters. Even small variations in mass measurement may contribute significant errors to calculated concentrations. In addition to the collected particles, a number of other factors affect the observed mass difference between the measurements before and after sampling. The most often controlled of these factors are static charge, temperature, and humidity. Using 951 laboratory blank filter weights, we have statistically analyzed these and other factors that affect the observed filter weight. Some of these are controllable or correctable; others are not and enter into the final results as errors. The standard deviation of differential blank filter weighing after applying all corrections was 2.7 microg. The most important correctable factors are air buoyancy variation and filter storage time. When weighing blank Teflon filters at relative humidity < 50%, these are an order of magnitude more important than weighing-room humidity. Using field blank filters in each weighing batch could control these three factors but also doubles the errors caused by balance random variation and filter handling contamination, because four weighing measurements and the handling of two filters are needed to obtain one corrected differential mass result.  相似文献   
63.
Siikamäki J  Newbold SC 《Ambio》2012,41(Z1):78-89
Deforestation is the second largest anthropogenic source of carbon dioxide emissions and options for its reduction are integral to climate policy. In addition to providing potentially low cost and near-term options for reducing global carbon emissions, reducing deforestation also could support biodiversity conservation. However, current understanding of the potential benefits to biodiversity from forest carbon offset programs is limited. We compile spatial data on global forest carbon, biodiversity, deforestation rates, and the opportunity cost of land to examine biodiversity conservation benefits from an international program to reduce carbon emissions from deforestation. Our results indicate limited geographic overlap between the least-cost areas for retaining forest carbon and protecting biodiversity. Therefore, carbon-focused policies will likely generate substantially lower benefits to biodiversity than a more biodiversity-focused policy could achieve. These results highlight the need to systematically consider co-benefits, such as biodiversity in the design and implementation of forest conservation programs to support international climate policy.  相似文献   
64.
Effects of industrial pollution on the behaviour of radionuclides in spruce forest ecosystems were studied along a gradient from of a copper-nickel smelter in Monchegorsk, NW Russia. A reference site was situated in Lapland, Finland, 152 km west of Monchegorsk. Most of the total 137Cs activity in soil was in mineral (E and B) horizons, except at the reference site where the major part was still in the organic surface layer. Most of the total 90Sr activity still remaining in the soil profile was found in the surface layer, but the relative amount decreased with increasing level of industrial pollution. Pollutants from the smelter clearly affected the chemical speciation of radionuclides. Smaller amounts of exchangeable radionuclides were present in the organic surface layer at the most polluted sites. The decline of 137Cs with decreasing distance from the smelter correlated strongly with a similar depletion in exchangeable K and Mg. Total concentrations of 137Cs and 90Sr showed high correlations with exchangeable cations, particularly in the E and upper B horizon. A sudden change in behaviour of 137Cs in the lower B horizon may be associated with changes in clay mineralogy along the soil profile caused by weathering.  相似文献   
65.
Models were developed for predicting the decomposition of dead wood for the main tree species in Finland, based on data collected from long-term thinning experiments in southern and central Finland. The decomposition rates were strongly related to the number of years after tree death. In contrast to previous studies, which have used the first-order exponential model, we found that the decomposition rate was not constant. Therefore, the Gompertz and Chapman-Richard's functions were fitted to the data. The slow initial decomposition period was mainly due to the fact that most dead trees remained standing as snags after their death. The initial period was followed by a period of rapid decomposition and, finally, by a period of moderately slow decomposition. Birch stems decomposed more rapidly than Scots pine and Norway spruce stems. Decomposition rates of Norway spruce stems were somewhat lower than those of Scots pine. Because the carbon concentration of decaying boles was relatively stable (about 50%) the rate of carbon loss follows that of mass loss. Models were also developed for the probability that a dead tree remains standing as a snag. During the first years after death, the probability was high. Thereafter, it decreased rapidly, the decrease being faster for birch stems than for Scots pine and Norway spruce stems. Almost all stems had fallen down within 40 years after their death. In Scots pine and Norway spruce, most snags remained hard and belonged to decay class 1. In birch, a higher proportion of snags belonged to the more advanced decay classes. The models provide a framework for predicting dead wood dynamics in managed as well as dense unthinned stands. The models can be incorporated into forest management planning systems, thereby facilitating estimates of carbon dynamics.  相似文献   
66.
Biochar has been presented as a key technology for avoiding dangerous climate change. Pyrolysis converts part of the biomass feedstock into a gaseous fraction, which can be used for energy production. The remaining fraction is char, which is highly stable and resistant to biodegradation. When char is added to soil it increases carbon storage, reduces emissions and improves soil quality. Agricultural residues such as straw, stover and hulls are seen as the most accessible raw material. These residues could also be used as insulation in passive energy housing. Straw bale construction is a relatively simple technology, which has been applied for decades. It can store the carbon of the straw material into walls structures and in the process provides energy efficient housing. The climate benefits from improved energy efficiency depend on local conditions and energy production forms. In this study life cycle assessment was used to compare the climate impacts of biochar production and straw bale construction. On a life cycle perspective, straw bale construction results in higher net carbon storage than biochar production (3.3 t CO2eq vs. 0.9 t CO2eq/t of straw). However the result was found to be highly dependent on the assumptions on the overall energy efficiency of the replaced building stock.  相似文献   
67.
68.
In the paper the theoretical framework is that of credit rationing theory, the regional differences being examined in terms of both financial markets and the real economy. Empirically the focus is upon regional trends in market conditions and the timelags experienced in the effects of monetary policies in two different regions. The period of time examined is from 1970 to 1978, the changes in the marginal interest on central bank credit issued to the commercial banks being taken as the indicator of monetary policy and data on employment opportunities vacant in the regions as representing market conditions and the delay‐effects of monetary policy. The methods used are those of cross‐correlation analysis.  相似文献   
69.
ABSTRACT

During policy change, the role of the actors communicating the change to different audiences is accentuated. The media plays an increasing role, either as an actor or by providing a stage for other actors. In particular, specialised journals represent an influential, albeit understudied, sphere of policy studies. We use the narrative policy framework complemented with frame analysis to trace how specialised media can affect policy implementation through implicit suggestions for action. Using this combined approach, we analyse how specialised forest journals, which are the most important forest information source for Finnish forest owners, have conveyed the renewal of forest legislation in Finland. The core message of the journals is that forest owners should, despite their new freedom granted by the reform, rely on experts rather than experimenting when managing their forests. This suggests that the media contributes to a path-dependent continuation of a forest policy that is based on a rationalistic exploitation ethos. The innovative potential, which the policy change aimed at encouraging, is thereby partially undermined. However, the analysis of the narratives also reveals that forest expertise and professionalism are diversifying. This notion is important as diversity can eventually lead to narratives supporting more fundamental change in forests management.  相似文献   
70.
In many countries over the last decades, state initiatives have emerged to promote and support public participation in policy-making. Despite the emphasis on participation and deliberation, there are groups that remain outside the participatory proceedings. We follow through two case studies from Finland on how active citizen groups became excluded in the policy processes but decided to act nevertheless. Conceptually, the article tells two stories about multi-signification and improvisation in nature conservation processes from the citizen participation point of view. Using practice-oriented policy analysis, we explore the actors' conflicting interpretations of acting for “the sake of the lake”. We argue that in these kinds of complex policy processes, improvisation should be given more space.  相似文献   
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