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1.
Plato and Aristotle place opinion intermediate between knowledge and ignorance with all opinions under the suspicion of error. Kant summarized that opinion is a consciously insufficient judgement, subjectively and objectively. Belief is subjectively sufficient, but is recognized as being objectively insufficient. Only knowledge is subjectively and objectively sufficient. Despite this philosophically doubtful value of opinions, thinkers such as Milton, Locke, Montesquieu and Mill maintain that the freedom of opinion and speech are the basis of open societies but find limits when it represents a definite risk of damage, either to an individual or to the public. Also the UN Covenant on Civil and Political Rights proclaims the right to hold opinions without interference provided that it respects the rights or reputations of others and does not interfere with the protection of public health. Hate speech and propaganda for war are expressively prohibited. Postwar US politicians formulated the position that every man has a right to his own opinion, but no man has a right to be wrong in his facts. The impact of this discussion on opinions about control measures of the COVID-19 pandemic is explored in this editorial.  相似文献   

2.
The Great Lakes region is an important ecological asset for the United States, yet studies show that several environmental risks threaten its viability. As a result, it is important to respond to these risks with effective policies. When and how policy is implemented often depends on public opinion and perceptions; yet, we understand little about how individuals from the Great Lakes region construct opinions about the threats facing the lakes. We seek to understand how individuals from the state of Michigan form opinions on three risks to the lakes: invasive Asian carp, climate change, and offshore drilling. To do this, we evaluate the utility of two dominant models of environmental opinion formation: trust and deference to scientific authority, and partisan bias and motivated reasoning. We find that when issues have been politicized, opinion is greatly influenced by political factors like partisanship but that trust and deference as well as underlying environmental attitudes play a more important role for issues that have not been politicized. We discuss the implications of these findings in terms of policy and communication in Michigan, arguing that if we want Michiganders to support policy consistent with science, they must view risk in ways that are consistent with scientific consensus. For that to happen, advocates and policy makers must focus on reducing the political rhetoric around these threats, developing communication that taps into underlying trust and deference to science, and using underlying attitudes about the role of government in environmental protection to promote environmental policy.  相似文献   

3.
长白山典型林区森林资源利用适宜性分析   总被引:3,自引:0,他引:3  
天然林保护不是简单的禁伐,东北林区作为天然林保护的限伐林区,目前仍有一定数量的成过熟林采伐任务,如何科学合理地选择伐区非常重要.鉴于传统森林资源采伐利用操作中存在顾此失彼的问题,现代科学的森林资源经营理论认为,森林资源利用要坚持可持续利用原则,并且要更多考虑森林资源的生态效益,遥感(RS)数据及地理信息系统(GIS)技术,通过提供空间选择技术支撑,可以准确定位符合采伐标准的森林资源地理位置,并确定其面积、森林类型等信息,从而促进森林资源的科学合理利用.本文综合考虑各方面要素,以长白山典型林区露水河林业局为例,以最大程度发挥森林生态系统的生态功能为原则,进行了森林资源利用状况评价,对研究区森林资源未来利用的空间选择以及采伐利用方式进行了探讨,以期为将来制订科学的森林经营策略提供依据。  相似文献   

4.
Opinion mining is a well-known problem in natural language processing that has attracted increasing attention in recent years. Existing approaches are mainly limited to the identification of direct opinions and are mostly dedicated to explicit opinions. However, in some domains such as medical, the opinions about an entity are not usually expressed by opinion words directly, but they are expressed indirectly by describing the effect of that entity on other ones. Therefore, ignoring indirect opinions can lead to the loss of valuable information and noticeable decline in overall accuracy of opinion mining systems. In this paper, we first introduce the task of indirect opinion mining. Then, we present a novel approach to construct a knowledge base of indirect opinions, called OpinionKB, which aims to be a resource for automatically classifying people’s opinions about drugs. Using our approach, we have extracted 896 quadruples of indirect opinions at a precision of 88.08 percent. Furthermore, experiments on drug reviews demonstrate that our approach can achieve 85.25 percent precision in polarity detection task, and outperforms the state-of-the-art opinion mining methods. We also build a corpus of indirect opinions about drugs, which can be used as a basis for supervised indirect opinion mining. The proposed approach for corpus construction achieves the precision of 88.42 percent.  相似文献   

5.
A means of deriving a disturbance index reflecting forest use history is demonstrated here to establish a disturbance gradient and enable comparison of different forest areas within and across individual forests. Detailed reference is made to Kakamega Forest in western Kenya for which a long‐term time series has been established, although the study is spread to four further forests in Kenya and Uganda. A wide variety of sources are drawn upon for spatially resolved data that are integrated in a geographic information system. Three indices are derived: for commercial disturbance, local disturbance, and forest cover change. Results show a wide range of disturbance values (from low to heavy) for the research sites within Kakamega Forest, while results for Budongo and Mabira Forest sites show low and moderate levels, respectively. Correlations of low disturbance levels with nature or national reserves appear to be marked, while a correlation of disturbance with differing management authority is also suggested with Kenya Wildlife Service achieving the lowest disturbance levels. Results from the index are reviewed against other means of estimating disturbance with the conclusion that disturbance evaluations should be both spatially resolved and long‐term in nature.  相似文献   

6.
The purpose of this study was to contribute to filling the knowledge gap in public opinion and knowledge about forest and its certification in Japan, as well as to identify key elements and the possible role of public opinion within integrated bottom-up policies, bridging the sectors of forest, environment and energy. For the study 1930 questionnaires were disseminated in a small town in early 2007. Results from the statistical analysis indicated that forest was perceived as an ecosystem with a protective function against e.g. soil erosion or flooding, rather than a place that might serve for wood production and providing jobs. Forest certification and bioenergy from forest were identified as key elements for future integrated bottom-up policies that need to concentrate on facilitating the linkage between forestry and renewable energy as well as on promoting environmentally sound management and forest certification.  相似文献   

7.
This paper presents a practitioner's perspective of the Keren Kayemeth Leisrael's (KKL – Israel's Forest Service) forest management policy, including actions encouraging biological diversity attributes to Israel's planted conifer forests. These changes are reviewed in light of institutional changes within the KKL, recent global initiatives and scientific trends concerning biodiversity, ecologically oriented forestry and sustainable forest management.

The management of Israel's planted conifer forests for biological diversity values is a relatively new phenomenon. Most of Israel's high forests were planted and consist primarily of a small core group of native and exotic Mediterranean conifers. Over time, these simplified afforestations evolved into a complex set of forest stands – a “near-native” type of forest ecosystem embodying a sum total of natural and artificial processes. They can thus serve as models to help visualise and understand how plantation-type forests can be converted into complex afforestations systems possessing a higher degree of structural, functional, compositional and genetic diversity.  相似文献   


8.
Opinion dynamics focuses on the opinion evolution in a social community. Recently, some models of continuous opinion dynamics under bounded confidence were proposed by Deffuant and Krause, et al. In the literature, agents were generally assumed to have a homogeneous confidence level. This paper proposes an extended model for a group of agents with heterogeneous confidence levels. First, a social differentiation theory is introduced and a social group is divided into opinion subgroups with distinct confidence levels. Second, a multi-level heterogeneous opinion formation model is formulated under the framework of bounded confidence. Finally, computer simulations are conducted to study the collective opinion evolution, focusing on three key factors: the fractions of heterogeneous agents, the initial opinions, and the group size. The simulation results demonstrate that the number of final opinions depends on the fraction of close-minded agents when the group size and the initial opinions are fixed; the final opinions converge more easily when the initial opinions are closer; and the number of final opinions can be approximately modeled by a linear increasing function of the group size and the increasing rate is the fraction of close-minded agents.  相似文献   

9.
As scientists we like to think that modern societies and their members base their views, opinions and behaviour on scientific facts. This is not necessarily the case, even though we are all (over-) exposed to information flow through various channels of media, i.e. newspapers, television, radio, internet, and web. It is thought that this is mainly due to the conflicting information on the mass media and to the individual attitude (formed by cultural, educational and environmental factors), that is, one external factor and another personal factor. In this paper we will investigate the dynamical development of opinion in a small population of agents by means of a computational model of opinion formation in a co-evolving network of socially linked agents. The personal and external factors are taken into account by assigning an individual attitude parameter to each agent, and by subjecting all to an external but homogeneous field to simulate the effect of the media. We then adjust the field strength in the model by using actual data on scientific perception surveys carried out in two different populations, which allow us to compare two different societies. We interpret the model findings with the aid of simple mean field calculations. Our results suggest that scientifically sound concepts are more difficult to acquire than concepts not validated by science, since opposing individuals organize themselves in close communities that prevent opinion consensus.  相似文献   

10.
This paper reports a preliminary investigation about National Wetlands Inventory (NWI) maps to see how they might be used in conjunction with other sources of information to provide offsite wetlands regulatory delineation. A geographic information system was used to overlay and compare NWI maps with ground-based tree species composition data from the US Department of Agriculture Forest Service Forest Inventory and Analysis program (FIA). Ninety plots located in the Apalachicola National Forest in northern Florida were used. The NWI mapped 42 of the 90 plots as wetlands. FIA data was used to calculate Prevalence Index (PI) scores. Twenty-four additional plots had PI < 3.0 and thus had hydrophytic vegetation. These plots may also have been wetlands by the Cowardin definition. The hypothesis that wetland identification did not differ between natural-origin versus planted forests was evaluated. NWI classified 61% of natural stands with PI <3.0 as wetlands, whereas 38% of planted stands with PI < 3.0 were mapped as wetlands. There were statistically significant differences (P < 0.05) in the relationships between hydrophytic vegetation and wetland status for plantations and natural-origin stands. FIA data was used to compare the actual frequency of species found in wetlands with the frequency ranges assigned for the NWI Regional Indicators. The observed frequency of occurrence in NWI-mapped wetlands agreed with the Regional Indicator frequency range for 6 of the 18 species. Most species not in agreement were reasonably close to their assigned frequency range, but some differed substantially. While this was a pilot-scale study, we believe that this technique can ultimately yield valuable new information on the tree characteristics of NWI wetlands, especially at larger spatial scales, such as states or regions.  相似文献   

11.
Our aims were to quantify and map the plant ecoregions of the Atlantic Forest, a biodiversity hotspot that covers ca 150 million ha in eastern South America. We used a data set on the distribution of 4378 shrub and tree species across 711 localities. Plant ecoregions were identified using analyses of species turnover for both species occurrences and relative abundances. We interpolated NMDS axes of compositional variation over the entire the Atlantic Forest extent, and then classified the compositional dissimilarity according to the number of biogeographical ecoregions previously identified through K‐means analyses. We assessed the ability of environmental, historical vegetation stability and the current human footprint to explain the occurrence of the identified ecoregions through multinomial logistic regression models. We identified 21 spatially cohesive occurrence and 14 abundance ecoregions. Aridity, soil and historical biome stability were retained in the best model explaining both occurrence and abundance ecoregions. Broad compositional zones were identified through UPGMA cluster analysis of ecoregions, and formed north and south compositional blocks. Our work confirms the existence of a broad north–south divide within the Atlantic Forest, previously suggested based on climatic and amphibious data. Differences between the occurrence and abundance maps suggest the location of transition zones to neighbouring domains and endemism centres. Due to the aggregate nature of our analyses, site‐level disturbance degree was not considered, implying that human impacts could be broader then we could detect. There was limited overlap between our results and previous Atlantic Forest regionalization efforts, indicating that multi‐taxa, physiognomic and environmental regionalization schemes based on expert opinion or vegetation maps are poor proxies for compositional ecoregions.  相似文献   

12.
Forest biomass represents 25–30 % of the annual biomass available in the USA for conversion into bio-based fuels, bio-based chemicals, and bioproducts in general. The USDA Forest Service Research and Development (R&D) has been focused on producing products from forest biomass since its inception in 1905, with direct combustion, solid sawn lumber, pulp and paper, ethanol as fuel, and silvichemicals all among the mission areas of product research and development. The renewed national interest in biomass conversion to fuels and chemicals is supportive of the most critical need of USDA Forest Service R&D, uses for small-diameter trees and other forest biomass that needs to be removed in the fuel mitigation–fire suppression and forest restoration work of the USDA Forest Service. This paper will summarize the recent USDA Forest Service research on direct combustion, fuel pellets, and conversion of forest biomass to ethanol, both as stand-alone biorefinery processes and as an addition to the traditional wood pulping process.  相似文献   

13.
红皮云杉林(Picea koraiensis Forest Alliance)是以红皮云杉为群落共优势种的森林植被类型,具有结构复杂及物种多样性高等特点。在遵从《中国植被志》研编规范的基础上,提出了红皮云杉林新的分类系统,包括5个群丛组8个群丛,分别归属于常绿针叶林、落叶与常绿针叶混交林和针叶与阔叶混交林3个植被型。群丛组分类主要基于群落层片分化,以及乔木层的共优势种和特征种的差异,并以常绿针叶树层片重要值的66%为阈值划分常绿针叶林和针叶与阔叶混交林。在群丛分类中,通过双向指示种分析筛选特征种,综合考虑群落生境和群落演替阶段等因素确定分类方案。该分类方案是《中国植被志》研编规范的一个应用示例,对植被分类工作的借鉴意义表现在4个方面。(1)作为植被分类的重要凭证,样方数据质量控制是植被分类工作的重要环节;其中,物种的准确鉴定对确保植被分类方案的合理性至关重要。(2)对于乔木层物种组成丰富、优势种不明显的群落,群落层片分化和特征种是植被类型划分的重要依据。(3)以特定物种组合为共建种所组成的多个植被类型可归属为不同的植被型。(4)森林采伐等人类活动可能对植被与环境的关系形成干扰。因此,在...  相似文献   

14.
Summary Cluster analysis and canonical ordination were used as complementary techniques to identify major associations in a lower montane rain forest in Puerto Rico. These techniques were applied to forestry inventories from both secondary and primary communities. Eight major forest types were identified from the analyses and were confirmed by field checks. Distribution of these types was strongly correlated with past land-use and topographic position.Comprehensive ecological surveys are rare in moist tropical forests; however, forestry inventories are common and the results of this study suggest that valuable ecological information can be obtained from these data sets as well.Scientific Journal Series No. 10793 of the Minnesota Agricultural Experimental Station. Plant nomenclature according to Little & Wadworth (1964) and Little, Woodbury & Wadsworth (1974).This research was conducted while the senior author was stationed at the Institute of Tropical Forestry, USDA Forest Service, Rio Piedras, Puerto Rico.  相似文献   

15.
Under certain circumstances such as lack of information or bounded rationality, human players can take decisions on which strategy to choose in a game on the basis of simple opinions. These opinions can be modified after each round by observing own or others payoff results but can be also modified after interchanging impressions with other players. In this way, the update of the strategies can become a question that goes beyond simple evolutionary rules based on fitness and become a social issue. In this work, we explore this scenario by coupling a game with an opinion dynamics model. The opinion is represented by a continuous variable that corresponds to the certainty of the agents respect to which strategy is best. The opinions transform into actions by making the selection of an strategy a stochastic event with a probability regulated by the opinion. A certain regard for the previous round payoff is included but the main update rules of the opinion are given by a model inspired in social interchanges. We find that the fixed points of the dynamics of the coupled model are different from those of the evolutionary game or the opinion models alone. Furthermore, new features emerge such as the independence of the fraction of cooperators with respect to the topology of the social interaction network or the presence of a small fraction of extremist players.  相似文献   

16.
Abstract Aim To examine how the genetic diversity of selected taxa of forest‐dwelling small mammals is distributed between and within the major rain forest domains of Amazonia and Atlantic Forest and the intervening interior forests of Brazil, as inferred by the relationships between gene genealogies and geography. I also addressed the historical importance of the central Brazilian forests in connecting Amazon and Atlantic Forest populations of rodents and marsupials. Methods I evaluated variation in the mitochondrial cytochrome b gene to estimate the levels of sequence divergence between those taxa occurring throughout the Amazon, Atlantic Forest, and forests in the Cerrado and Caatinga regions. I inferred the hierarchical relationships between haplotypes, populations and formal taxa using the cladistic approach of maximum parsimony. I compared areas and the clades identified by superimposing cladograms on the geographical distribution of samples. The degree of concordance both in phylogeny and the depth of the nodes in these phylogenies, in addition to patterns of geographical distribution of clades, permitted me to make inferences on how, when and where the taxa differentiated. Results Sequence similarity is often greater between samples from the Atlantic Forest and either Amazon or central Brazilian forests than it is within each of the two rain forest domains. The Atlantic Forest clades are either not reciprocally monophyletic or are the sister group to all the other clades. There is some indication of northern and southern components in the Atlantic Forest. Given the geographical distribution of clades and the relatively deep levels of divergence, the central Brazilian area does not behave as a separate region but is complementary to either Amazon or Atlantic Forest. Patterns of area relationships differ across taxa, suggesting that different processes and/or historic events affected the diversification within each lineage. Main conclusions The Amazon and the Atlantic forests are not exclusive in terms of their small mammal faunas; both overlap broadly with taxa occurring in gallery forests and dry forests in central Brazil. Central Brazilian forests are an integral part of the evolutionary scenario of lowland small mammals, playing an important role as present and past habitats for rain forest species. Therefore, representatives from this area should always be included in analyses of the evolutionary history of lowland rain forest faunas. The incongruence of branching patterns among areas is in agreement with recent results presented for Neotropical passerine birds and indicates that a single hypothesis of Neotropical area relationships is unlikely. These findings reinforce the idea that speciation in the Neotropics will not be explained by any single model of vicariance or climatic changes.  相似文献   

17.
UNFCCC's “Cancun safeguards” (COP 16, 2010) provide a strong call for comprehensive steps to prevent harm to biodiversity from Reducing Emissions from Deforestation and forest Degradation (REDD+) activities and to support its conservation. However, as non-binding “principles” and due to their general wording, they are not operational in the present form. Additionally, the scientific literature on biodiversity monitoring for REDD+ is still very limited, particularly when it comes to REDD+ in tropical forests and at the national scale. Whereas some authors suggest that biodiversity integration can be achieved by means of standardised protocols and techniques, others consider that an effective monitoring of biodiversity in tropical forests at the national scale may be an impossible task to achieve in a cost-effective way. However, recent research offers some functional approaches to tackle the many challenges involved. This paper explores the perspectives and limits of developing and effectively incorporating appropriate biodiversity objectives and indicators in Papua New Guinea's multipurpose National Forest Inventory (PNG's NFI). The PNG's NFI is currently being designed under the UN-REDD programme as a key component of the National Forest Monitoring System that PNG is required to establish in order to participate in a future REDD+ mechanism. We conclude that the challenge cannot be effectively tackled only at the design stage of the NFI, as it needs to address a number of issues related to different stages of the REDD+ preparedness process:
  • If biodiversity integration is carried out directly at the NFI stage, it will need to rely on proxies derived from indicators designed to monitor carbon stock change;

  • At the planning stage, a carbon–biodiversity overlay map analysis would allow for a preliminary selection of areas of high biodiversity that could be threatened by REDD+ activities either directly or indirectly through “leakage”;

  • During the implementation stage, the selection could be refined by identifying a sub-sample of sites where forests are undergoing the greatest changes;

  • A comprehensive biodiversity monitoring programme involving field measurements of key species could only be designed once the priority areas have been clearly defined and limited in both number and size.

  相似文献   

18.
广州市流溪河森林公园植物区系的初步研究   总被引:8,自引:0,他引:8  
本文从植物区系地理学的角度,讨论了流溪河森林公园植物区系的基本特征、科属地理成分、与邻近植物区系的联系.以及在中国植物区系研究中的作用.本区系位于泛北极植物区、中国-日本森林植物亚区、华南地区。初步分析结果表明,该区系的热带、亚热带成分占有明显的优势,并具有向古热带印度-马来西亚植物区系过渡的特点.本区系和鼎湖山、黑石顶区系联系密切.具有相似的典型南亚热带区系成分.研究流溪河植物区系的组成和特点.对于进一步研究华夏植物区系以及我国植物区系和其它植物区系的联系.均有一定的意义。  相似文献   

19.
The impact of social influence causes people to adopt the behaviour of others when interacting with other individuals. The effects of social influence can be direct or indirect. Direct social influence is the result of an individual directly influencing the opinion of another, while indirect social influence is a process taking place when an individual’s opinion and behaviour is affected by the availability of information about others’ actions. Such indirect effect may exhibit a more significant impact in the on-line community because the internet records not only positive but also negative information, for example on-line written text comments. This study focuses on indirect social influence and examines the effect of preceding information on subsequent users’ opinions by fitting statistical models to data collected from an on-line bulletin board. Specifically, the different impacts of information on approval and disapproval comments on subsequent opinions were investigated. Although in an anonymous situation where social influence is assumed to be at minimum, our results demonstrate the tendency of on-line users to adopt both positive and negative information to conform to the neighbouring trend when expressing opinions. Moreover, our results suggest unequal effects of the local approval and disapproval comments in affecting the likelihood of expressing opinions. The impact of neighbouring disapproval densities was stronger than that of neighbouring approval densities on inducing subsequent disapproval relative to approval comments. However, our results suggest no effects of global social influence on subsequent opinion expression.  相似文献   

20.
Systematic studies of the Borajan Reserve Forest in Assam, India, were conducted in 1995, 1997, and 1998. Initially this small (5 km2) forest was inhabited by substantial numbers of five species of diurnal primates and the forest was typical of Reserve Forests in northwest upper Assam. About two thirds of the forest had canopy cover of 20 – 50% or more. Civil unrest, political problems and a lack of resources for Forest Department personnel, however, resulted in rapid degradation of the area. After three years less than one third of the forest had more than 20% canopy cover; all primate populations had declined dramatically and the small percentage of juveniles in each species indicated that all were in imminent danger of local extinction. There was no evidence of hunting or trapping nor any large scale logging. Forest degradation was due primarily to small scale harvesting of forest products, selective cutting, and collection of firewood. Although only hand tools were employed, the forest inexorably declined in response to these steady pressures. Borajan may be an object lesson as to what can happen but it need not be the harbinger of Assam’s future.  相似文献   

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