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471.
The karst landscape in the interior of the Philippines' Bohol Province represents one of the world's premier kegelkarst (cone karst) environments. Government efforts to protect some of this karst, exemplified by the establishment of the Rajah Sikatuna National Park and the Chocolate Hills Natural Monument, have proven to be significant catalysts of social conflict. In Bohol there is a long history of traditional land tenure, which has recently been supplanted by a Westernized model. Protected area establishment is a response to deforestation, agricultural exploitation and uncontrolled quarrying. However, the imposition of protective legislation to prevent further degradation has disenfranchized and marginalized many local farmers and residents. The conflict between the obligation of the State to ensure environmental protection and the perceived property rights of landowners and farmers has provoked an escalation in civil unrest and armed conflict. 相似文献
472.
Acacia nilotica is a tree of international significance both as a beneficial plant and as a species prone to thicket formation and negative impacts on savannas throughout much of its range. While fire has been identified as a useful tool for controlling negative impacts of some Acacia species in Africa, A. nilotica adult trees are apparently fire tolerant. The effects of fire on seed bank mortality, viability and germination, and on juvenile plants of this species are unknown. We undertook a study to investigate the impacts of fire on seeds and first and second year seedlings in Australian Astrebla savannas. The primary objective was to determine the effects of control burns applied during the early stages of invasion and thicket formation. Because of high rates of seedling dessication post fire in 1997, supplementary watering was undertaken until fire mortality could be measured the following year. High seed mortality occurred for seeds located either in cattle dung (100%) or on the soil surface (c. 80%). Germination of those seeds that survived was enhanced following exposure to fire. Very high fire mortality (99%) was observed among first year seedlings and moderate mortality (60%) for second year seedlings even after a low intensity burn. Negative impacts on major pasture species were minimal. The implications of these findings are discussed in relation to A. nilotica fire ecology and to the efficacy of fire as a tool for managing this species. 相似文献
473.
Most studies of ethnic residential segregation in Australian cities have used single-measure indices of dissimilarity and segregation, which access the degree of unevenness between two maps. Segregation is a multi-dimensional concept, however, and in this paper we introduce an alternative way of measuring residential concentration which incorporates several of the key dimensions. The procedure is illustrated using birthplace and language-used-at-home data for collection districts in metropolitan Sydney in 1996. Results show no evidence of extreme spatial concentration of ethnic groups. 相似文献
474.
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476.
Michael Feige 《GeoJournal》2001,53(3):323-333
Kiryat-Arba and Jewish Hebron are communities planted in the most heated front of the Israeli-Palestinian conflict. This paper examines how the Hebron Jewish settlers' collective memory interprets the `truth' of Hebron as a typical Israeli Place that reveals Zionism in its purest form. Today the populations of Kiryat-Arba and of the Hebron Jewish enclaves number about 5,000 and 500, respectively. Kiryat-Arba functions as an economic and educational centre for the nearby Jewish settlements in the region. Rejecting the segregative concept of a separate Jewish settlement overlooking Hebron, the settlers treat Kiryat-Arba as part of Hebron. Some 70,000 Palestinians live in Hebron, many more residing in neighbouring towns and villages, cutting Hebron – Kiryat–Arba off from the nearest Jewish urban centres of Jerusalem and Beer-Sheva. The settlers initiated the narrative of `Return' to the city after the massacre of Jews in 1929 in the city, as the key symbol Symbolically, the first place Hebron Jews reidentified with was its ancient Jewish graveyard. Today, IDF soldiers protect settlers and their visitors who want to tour Hebron. The huge gulf between `metaphorical Hebron' as a symbolic centre and `actual Hebron' as a poor development town creates tensions fuelling violent events. The Jews in Hebron take the Israeli logic of `Place' making to its extreme, thus testing concepts of Israeli territoriality. If Israeli society rejects Hebron as a `Place' constructed from intense memories and violent national encounters, it would leave the Hebron Jews out of the so-called Israeli normalcy. 相似文献
477.
Philipp Strauss Michael Wagreich Kurt Decker Reinhard F. Sachsenhofer 《International Journal of Earth Sciences》2001,90(3):549-559
The Miocene intramontane Fohnsdorf-Seckau Basin is situated at the junction of the sinistral Mur-Mürz-fault system and the dextral Pöls-Lavanttal fault system. The basin comprises a 2,400-m-thick coal-bearing fluviodeltaic-lacustrine succession (Lower to Middle Miocene, Upper Karpatian?/Lower Badenian) which is overlain by a 1,000-m-thick alluvio-deltaic conglomeratic succession (Apfelberg Formation, ?Middle/Upper Badenian) in the south. A three-stage model for the basin evolution has been reconstructed from structural analysis and basin fill geometries. During a first pull-apart phase, subsidence occurred along ENE-trending, sinistral strike-slip faults of the Mur-Mürz fault system and NE-SW to N-S-trending normal faults, forming a composite pull-apart basin between overstepping en-echelon strike-slip faults. The Seckau and Fohnsdorf sub-basins are considered as two adjacent pull-aparts which merged into one basin. During the second phase, N-S to NNW-SSE extension and normal faulting along the southern basin margin fault formed a half-graben, filled by wedge-shaped alluvial strata (Apfelberg Formation). During the third phase, after the end of basin sedimentation, the dextral Pöls-Lavanttal fault system reshaped the western basin margin into a positive flower structure. 相似文献
478.
In 1900 the city of Chicago began diverting sizable amounts of water from Lake Michigan to move its sewage down the Illinois River. This diversion launched a series of continuing legal controversies involving Illinois as a defendant against claims by the federal government, various lake states, and Canada who wanted the diversion stopped or drastically reduced. During the past 96 years extended dry periods have lowered the lake levels. Using these dry periods as surrogates for future conditions, their effects on the past controversies were examined as analogs for what might occur as a result of climate change from an enhanced Greenhouse effect. The results reveal that changing socioeconomic factors including population growth will likely cause increased water use, and Chicago will seek additional water from the Great Lakes. New priorities for water use will emerge as in the past. Drier future conditions will likely lead to enhanced diversions from the Great Lakes to serve interests in and outside the basin. Future lower lake levels (reflecting a drier climate) will lead to conflicts related to existing and proposed diversions, and these conflicts would be exacerbated by the consequences of global warming. In any event, a warmer, drier climatic regime will challenge existing laws and institutions for dealing with Great Lakes water issues. 相似文献
479.
Geophysics and Shallow Faults in Unconsolidated Sediments 总被引:1,自引:0,他引:1
480.