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1.
Colin P. R. McCarter Stephen D. Sebestyen Susan L. Eggert Randall K. Kolka Carl P. J. Mitchell 《水文研究》2020,34(26):5354-5369
Sustainable fuels legislation and volatility in energy prices have put additional pressures on the forestry sector to intensify the harvesting of biomass for “advanced biofuel” production. To better understand how residual biomass removal after harvest affects forest hydrology in relatively low slope terrain, a Before-After-Control-Impact (BACI) study was conducted in the USDA Forest Service's Marcell Experimental Forest, Minnesota, USA. Hydrological measurements were made from 2010–2013 on a forested hillslope that was divided into three treatment blocks, where one block was harvested and residual biomass removed (Biomass Removed), the second was harvested and residual biomass left (Biomass Left), and the last block was left as an Unharvested Control. The pre-harvest period (2 years) was 2010–11 and post-harvest (2 years) was 2012–13. Water table elevation at the upslope and downslope position, subsurface runoff, and soil moisture were measured between May–November. Mixed effect statistical models were used to compare both the before-after and “control” treatment ratios (ratios between harvested hillslopes and the Unharvested Control hillslope). Subsurface runoff significantly increased (p < .05) at both harvested hillslopes but to a greater degree on the Biomass Left hillslope. Greater subsurface runoff volumes at both harvested hillslopes were driven by substantial increases during fall, with additional significant increases during summer on the Biomass Left hillslope. The hydrological connectivity, inferred from event runoff ratios, increased due to harvesting at both hillslopes but only significantly on the Biomass Left hillslope. The winter harvest minimized soil disturbance, resulting in no change to the effective hydraulic conductivity distribution with depth. Thus, the observed hydrological changes were driven by increased effective precipitation and decreased evapotranspiration, increasing the duration that both harvested hillslopes were hydrologically active. The harvesting of residual biomass appears to lessen hydrological connectivity relative to leaving residual biomass on the hillslope, potentially decreasing downstream hydrological impacts of similar forestry operations. 相似文献
2.
Paul Claval 《GeoJournal》2004,60(4):321-328
The way that space is thought of is at the heart of the cultural approach in geography. The passing down of all the components
of a culture depends upon the way data is aquired and processed, the results memorized or broadcast. Communication shapes
the experience and the knowledge of space and time. It gives to everyone the idea that the real world is doubled by a beyond
which plays a central role in social life, since it is upon such a beyond that normative thinking relies and that a significance
is given to individual and social life. The spheres of lived-in and known space and time, as well as that of the beyond, vary
according to available technologies.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
《Marine Policy》2016
Marine scientific research is crucial to forge solutions in the development of a new international legally binding instrument for the conservation and sustainable use of marine biological diversity in areas beyond national jurisdiction (ABNJ) under the 1982 United Nations Convention on the Law of the Sea . The transfer of marine technology, capacity development and marine genetic resources are key issues. This paper examines how the Intergovernmental Oceanographic Commission (IOC), as a competent international organisation for marine scientific research and technology transfer, can inform the development of the instrument. Synergies between marine technology transfer and non-monetary benefit sharing of genetic resources are illustrated. Four key lessons from the IOC are examined: 1. Coordinating international cooperation in marine scientific research; 2. Enabling open access to data and knowledge; 3. Facilitating capacity development through scientific training and education; and 4. Governance of marine scientific research. Realising the potential of the IOC to advance governance solutions for ABNJ will depend on increased political will from Member States and strengthened partnerships to reduce resource constraints and enhance the IOC's capacity at global and regional scales. 相似文献
4.
Conservation and management of coastal lagoons envisage direct human intervention. To prevent siltation and to preserve the hydrodynamics features of the lagoon system, the inner channels undergo regular maintenance dredging. 相似文献
5.
Massimo Ponti Andrea PasterisRoberta Guerra Marco Abbiati 《Estuarine, Coastal and Shelf Science》2009
Coastal lagoons are ephemeral habitats whose conservation requires human intervention, such as maintenance dredging of inner channels. Dredging can reduce the abundance of benthic species due to the removal of individuals with the sediment, modify sediment properties, and resuspend fine sediment, nutrients and pollutants, which can lead to eutrophication, hypoxic events and increasing toxicity. Both direct effects in the dredged channel and possible indirect effects in surrounding shallow areas could be expected. This study assesses the effects of the channel maintenance dredging, performed between October 2004 and August 2005, on the invertebrate assemblages both in channels and adjacent ponds in the northern Adriatic coastal lagoon of Pialassa Baiona. The lagoon is affected by eutrophication, chemical and thermal pollution from wastewater treatment and power plants. Three impacted sites were located in the dredged channel and three in the adjacent interconnected shallow water ponds, while three non-impacted sites were located in a channel and in a pond far from the dredged area. Replicate samples were collected from each site one time before and one time after the dredging operations. Despite the extent of the intervention, effects of the dredging on macrobenthic assemblages were detected only within the dredged channel, while in the surrounding ponds no clear and unequivocal effects were found. In particular the dredging could have promoted the increase of the abundance of the polychaete Streblospio shrubsolii in the southern and central parts of the dredged channel and the increase in abundance of the amphipod Corophium insidiosum in the northern side, compared to the controls. Instead, species diversity was reduced in the central and northern parts of the dredged channel. These effects on the macrobenthic invertebrate assemblages could be related to the observed changes of sediment characteristics, contamination and toxicity. Overall, direct effects on benthic assemblages in the dredged channels were more detectable than the possible secondary effects in the surrounding shallow ponds, where the higher spatial heterogeneity can mask any relevant effects. 相似文献
6.
Beach nourishment is increasingly being implemented to address problems of erosion. However, the ecological consequences of nourishment are poorly understood, especially in Australia. In Botany Bay, sand was piped from an intertidal borrow area at Elephant's Trunk to nourish the nearby eroding beach at Towra Point. The effects on an intertidal exoedicerotid amphipod, Exoediceros fossor (Stimpson, 1856), were examined using a beyond-BACI (Before–After, Control–Impact) sampling design. Sampling was conducted before and after engineering operations at sites within the borrow and nourishment locations and multiple control locations. Hypotheses concerning impact and recovery were tested using asymmetrical ANOVAs and two-tailed F-tests. These examined the effects on abundance and spatial variability, respectively. The impact of the engineering operations on abundance was very large at both borrow and nourishment locations. However, recovery started within several weeks and, using space × time interactions as a criterion, appeared to be complete within a year. This conclusion is made cautiously because of low statistical power and because other criteria for recovery suggest that it was not complete at some sites. As beach erosion is likely to increase in severity with rising sea levels and greater storm surges associated with climate change, management authorities will need a better understanding of the ecological effects of beach nourishment. 相似文献
7.
《Marine Policy》2014
For nearly a decade, governments have been discussing the need to improve efforts to conserve and sustainably use marine biodiversity in areas beyond national jurisdiction (ABNJ). Support for a new international agreement under the United Nations Convention on the Law of the Sea (UNCLOS) – an Implementing Agreement – on the conservation and sustainable use of marine biodiversity in ABNJ has been growing. In June 2012, at the United Nations Conference on Sustainable Development held in Rio de Janeiro, Brazil, States agreed to take a decision on the development of an international instrument under UNCLOS before the end of the 69th session of the United Nations General Assembly (UNGA), which runs from September 2014 to August 2015. In follow-up to this commitment, it was agreed to consider the “scope, parameters and feasibility” of this instrument. To inform these international discussions, this article highlights some potential options for the content of a new UNCLOS Implementing Agreement. It first reviews the history of UN discussions, and then elaborates on options to address key elements identified as priorities for States in 2011: marine genetic resources, including the sharing of benefits, area-based management tools, including marine protected areas, environmental impact assessments, capacity-building and the transfer of marine technology. It addresses cross-cutting issues such as the governing principles, institutional structure as well as on other critical points such as High Seas fishing and flag State responsibilities. The article concludes with suggestions on possible next steps in order to succeed in the negotiations for an agreement. 相似文献
8.
《Marine Policy》2014
United Nations discussions on the governance of marine areas beyond national jurisdiction have questioned, but not yet reached a decision, on whether existing institutional agreements and structures are sufficient to meet global commitments to protect marine biodiversity, or if additional mechanisms may be required. This paper considers two very different efforts to protect marine biodiversity in these areas: (1) in the North-East Atlantic through the efforts of OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic; and (2) in the central Atlantic, through the efforts of the Sargasso Sea Alliance led by the Bermuda government. In each case, action has been strongly supported by non-governmental organisations and subsequent progress has hinged upon on-going dedicated efforts of “champion” governments to bring other States on board. This paper outlines the difficulties that they have faced, and consequently why they have been time-consuming, and are not yet completed. The paper then considers 10 common recommendations that can be drawn from the experiences of these two distinct initiatives, and their relevance to on-going UN deliberations. 相似文献
9.
OA Bergstad ÅS Høines R Sarralde G Campanis M Gil F Ramil 《African Journal of Marine Science》2019,41(1):11-28
Most of the Southeast Atlantic Ocean is abyssal, and global bathymetries suggest that only ～3.2% of the areas beyond national jurisdiction (ABNJ; also known as the high seas, as defined in the United Nations Convention on the Law of the Sea [UNCLOS]) are shallower than 2 500 m. This study mapped bathymetry and characterised substrates in selected seamount summit areas, including several that have been or may become fishing areas. The southernmost location, the Schmitt-Ott Seamount, has exposed volcanic bedrock with surrounding flats covered by thin biogenic sediments and/or coral rubble that appears ancient. At Wüst, Vema, Valdivia and Ewing seamounts the basaltic base appears to be overlain by coral caps and other coral substrates (sheets, rubble). Adjacent summit plains have biogenic sediments of varying thickness. Vema has a flat, roughly circular summit, <100 m deep, with the shallowest point being a 22-m-deep summit knoll; the upper slopes have ancient coral framework, but the summit has a mixture of coralline and volcanic rock and coarse sediments, including extensive areas with coralline algae and kelp forests. Valdivia Bank is a 230-m-deep, flat, rocky area (～11 × 5 km), protruding steeply from the extensive multi-summit Valdivia subarea of the Walvis Ridge. The distribution of past fisheries in the Convention Area of the South East Atlantic Fisheries Organisation (SEAFO) was considered in relation to the new information on bathymetry and substrate. 相似文献
10.
20世纪50年代和60年代是曹聚仁随笔散文写作的高峰期。这一时期,无论是内地还是港台,政治气氛都十分浓厚。而作为国共两党的联系人的曹聚仁疏离政治,可以自由地往来于大陆和港台之间,仍然保持与母体文化联系,从而使他在写作上保持一定的文化优势。曹聚仁在随笔写作中重在对所游之地、所读之书的文史挖掘,显示出深厚的文化底蕴。曹聚仁以随笔散文的方式传承着民族文化的血脉,独自守望着古老而深厚的民族文化,具有十分重要的意义。 相似文献