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对虾养殖生态系中有机碳的初步研究本研究由 总被引:1,自引:0,他引:1
对于围隔养殖对虾生态系中有机碳的变动进行了研究 ,结果表明 :溶解有机碳 (DOC)含量波动在 5 .2 99~ 13.39mg/ L之间 ,平均为 8.5 3mg/ L± 2 .2 5 mg/ L;颗粒有机碳 (POC)含量波动在0 .6 5~ 6 .6 3mg/ L之间 ,平均为 3.2 5 mg/ L± 1.76 mg/ L;总有机碳 (TOC)含量波动在 6 .92~ 2 0 .0 2mg/ L之间 ,平均为 11.78mg/ L± 3.82 mg/ L ;其中 DOC∶ POC∶ TOC为 0 .72∶ 0 .2 8∶ 1。各种有机碳组分的含量明显高于自然海水中各种有机碳的含量 ;各种有机碳组分的含量在养殖期间总体上呈上升的趋势 ;其变化与 DCOD的变化呈显著线性正相关的关系。 相似文献
3.
气候环境变化作为影响或制约古文化发展、演化的重要因素,虽然经常受到质疑,但依然被越来越多的考古工作者,包括一些古气候学者所接受。关中地区是我国古代文明重要的发源地之一,为探讨气候环境变化与古文化演化之间可能存在的联系提供了条件。本文对已有很好研究基础的渭南全新世黄土剖面的孢粉、植硅体、蜗牛化石及磁化率和粒度记录进行综合分析,研究得出该区全新世以来有3次突出的气候温暖湿润期(9000~7300aB.P.,6800~5500aB.P.和4500~4300aB.P.)和3次明显而短暂的寒冷干旱期(7300~6800aB.P.,5500~5000aB.P.和约4000aB.P.)。温暖湿润气候期与关中地区的老官台(8000~7000aB.P.)、仰韶(7000~5000aB.P.)、龙山(5000~4000aB.P.)等文化繁盛期几乎是同步的,而发生在7300~6800aB.P.,5500~5000aB.P.及4000aB.P.前后的寒冷干旱气候环境,不是简单的气候冷暖变化,而是影响了生物、水、大气等表生地球系统的气候变化事件,改变了该区的植被类型和生物群落的变迁,这3次气候变化事件时间上大致对应了老官台-仰韶-龙山-夏商文化交替的时间。然而,根据目前的气候记录及时间分辨率还难以判断更次一级的气候环境变化与各文化期不同文化类型变化之间的关系。对关中地区泉护遗址植硅体的分析显示,4500aB.P.以来水稻含量的增加与气候变干的趋势并不一致,推测可能与古人利用渭河水资源种植水稻有关。研究认为关中地区气候环境变化与文化发展之间的关系,有一定的规律可寻,但是由于目前对古气候-古环境变化的幅度、详细的考古文化性质的认识不足,以及时间分辨率和年代学的限制,还无法确切说明什么程度的气候环境变化对哪些文化类型通过什么机制产生了何种程度的影响。 相似文献
4.
世界自然遗产事业发展潜势分析 总被引:1,自引:0,他引:1
世界遗产(以下简称遗产)的申报和保护在策略、重点与工作方式上出现许多新的趋向。《凯恩斯决议》的修订突出对生态、地质演进及生物多样性价值的重视,并提高人们对自然遗产的认识水平,有助于完善自然遗产地的覆盖范围和世界遗产名录平衡性问题。这将加快自然类遗产的申报,尤其是涉及水圈的自然遗产,如海洋、淡水、山地及与此有关的生物多样性的自然遗产地的保护成为热点。国际协作使得跨国自然遗产的联合申报成为必然趋势。随着遗产保护地由点向线、面的扩展,绿色廊道遗产的建设将促进自然遗产事业的发展。 相似文献
5.
Racism has become a fact of life in Australia over the past decade or so, yet there are relatively few studies of its nature or extent, and still fewer on its geography. Using a social constructivist approach, this study draws on a survey of 5056 respondents to investigate attitudes to racism and cultural diversity in New South Wales and Queensland, and of perceptions of out-groups as instances of ‘strangers in our midst’. On racism, results show the presence of a continuum of attitudes ranging from generally tolerant to generally intolerant, a presence which cuts across compositional (social or aspatial) characteristics to emphasise the existence of a distinctive geography, an everywhere different nature to racist and non-racist attitudes which transcends urban–rural and traditional social layers. On the other hand, perceptions of out-groups are not uniformly correlated with presence or absence of cultural diversity. In many cases, the ability to make judgements about significant ‘others’ or out-groups has been shown to relate more to abstract notions of self and national identity, reproduced in public by mainstream news media and political leaders. In particular, it may reflect an Anglo (or Anglo-Celtic) view on nationalism, which is a hallmark of the ‘new racism’: an assimilationist or ethnocultural view of Australian society which is different from the ‘civic nation’ ideal envisaged by multiculturalism. That the geography of attitudes and perceptions people have towards and about different cultural groups is so ‘everywhere different’ has important implications for attempts to address and redress issues of intolerance in Australia. 相似文献
6.
Libby Porter 《The Australian geographer》2006,37(3):355-374
Aboriginal cultural heritage protection, and the legislative regimes that underpin it, constitute important mechanisms for Aboriginal people to assert their rights and responsibilities. This is especially so in Victoria, where legislation vests wide-ranging powers and control of cultural heritage with Aboriginal communities. However, the politics of cultural heritage, including its institutionalisation as a scientific body of knowledge within the state, can also result in a powerful limiting of Aboriginal rights and responsibilities. This paper examines the politics of cultural heritage through a case study of a small forest in north-west Victoria. Here, a dispute about logging has pivoted around differing conceptualisations of Aboriginal cultural heritage values and their management. Cultural heritage, in this case, is both a powerful tool for the assertion of Aboriginal rights and interests, but simultaneously a set of boundaries within which the state operates to limit and manage the challenge those assertions pose. The paper will argue that Aboriginal cultural heritage is a politically contested and shifting domain structured around Aboriginal law and politics, Australian statute and the legacy of colonial history. 相似文献
7.
Brian Murton 《New Zealand geographer》2006,62(1):25-38
Abstract: This paper examines how the cultural politics of resource management were played out on the North Kaipara beach between about 1900 and 1971 between Māori and the representative of the Crown, the Marine Department. Particular attention is devoted to how, after regulations were introduced to protect toheroa, the giant surf clam, Māori struggled to assert their rights through a range of transgressions. The paper argues that this illustrates how cultural politics works both from the top down (the Marine Department's implementation of policy) and the bottom up (Māori resistance). It concludes that through an examination of this particular 'culture war', the foreshore emerges as a contested domain where politics, culture and epistemology are inseparable. 相似文献
8.
Abstract: This paper discusses three walking tour guides prepared for the 12th International Conference of Historical Geographers. It argues that the guides are innovative in terms of format, content and ironic sensibility. It construes them as devices for re-imagining Auckland's urban heritage. 相似文献
9.
In the central part of the internal Western Alps, widespread multidirectional normal faulting resulted in an orogen-scale radial extension during the Neogene. We revisit the frontal Piémont units, between Doire and Ubaye, where contrasting lithologies allow analysing the interference with the N–S trending Oligocene compressive structures. A major extensional structure is the orogen-perpendicular Chenaillet graben, whose development was guided by an E–W trending transfer fault zone between the Chaberton backfold to the north and the Rochebrune backthrust to the south. The Chaberton hinge zone was passively crosscut by planar normal faults, resulting in a E–W trending step-type structure. Within the Rochebrune nappe, E–W trending listric normal faults bound tilted blocks that slipped northward along the basal backthrust surface reactivated as an extensional detachment. Gravity-driven gliding is suggested by the general northward tilting of the structure in relation with the collapse of the Chenaillet graben. The stress tensors computed from brittle deformation analysis confirm the predominance of orogen-parallel extension in the entire frontal Piémont zone. This can be compared with the nearby Briançonnnais nappe stack where the extensional reactivation of thrust surfaces locally resulted in prominent orogen-perpendicular extension. Such a contrasting situation illustrates how the main direction of the late-Alpine extension may be regionally governed by the nature and orientation of the pre-existing structures inherited from the main collision stage. 相似文献
10.
In the Alexander von Humboldt National Park in eastern Cuba many endemic animals and plants are found in various different natural habitats, which are considered to be the most important ones for in-situ conservation in the entire Insular Caribbean. In some areas of the National Park agriculture is practised. Thus, the objective of this study was to document and analyse the different land use activities and their consequences for local resource management and conservation of biodiversity in two village areas. A particular question was: what has changed since the foundation of the National Park in 1996? As time series data for land use and aerial photographs were not available for this part of Cuba, a qualitative evaluation was carried out. For this, six different land use units were mapped in 2001 and additional information gathered for areas with special interest related to sustainable land use and resource conservation. Although most parts of the study area are influenced to various degrees by human impact, the different types of land use seem presently not to have a crucial or detrimental impact on the land resources of the Alexander von Humboldt National Park. However, exploitation of the natural resources in certain areas could be improved with different management options to reach sustainability as well as to meet the conservation objectives of the National Park. This includes reduced or abandoned agricultural use of steep slopes to reduce erosion risk as well as a facilitated regeneration of natural vegetation in many parts of the study area to be able to conserve the high valuable biodiversity of the Park. Environmental education seems to have played an important and successful role since the foundation of the Park in 1996. Since then, cropping on steep slopes as well as illegal logging and poaching could be reduced. 相似文献