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111.
The paper presents new applications of marked point processes in forestry. The tools are pair correlation functions and mark connection functions. Studies of the structures of even-aged pine forests in Siberia show a tendency of development from clustering in young stands towards random distribution in elder stands for the trunk positions. The tree tops as the movable parts of trees are still more regular in old forests. Furthermore, in Siberian fir forests interesting tendencies of attraction between members of several tree classes are detected. Finally, studies of the distribution of damaged trees in some central European forests show that there the damaged trees appear as singletons; dominating trees are preferentially damaged. 相似文献
112.
Passive microwave remote sensing from satellites and ground stations has contributed uniquely, and substantially, to the study of atmospheric chemistry, meteorology, and environmental monitoring. As user requirements are raised, in terms of the accuracy and the spatial resolution, a mechanically scanning radiometer, with a real aperture, becomes impractical due to the requirement for a very large antenna size. However, an aperture synthesis interferometric radiometer presents a valuable alternative. The work presented in this paper was devoted to high spatial resolution imaging, using the 37 GHz band interferometric radiometer, developed by ourselves. The spatially adaptive Capon beamforming method was exploited for the imaging, which outperformed the conventional Fourier Transform method. We concluded that the high spatial resolution imaging of the brightness temperature of the atmosphere could be accomplished with an interferometric radiometer equipped with the developed Capon beamforming imaging algorithm. 相似文献
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Estella F. Vedrova Fedor I. Pleshikov Vladimir Ya. Kaplunov 《Mitigation and Adaptation Strategies for Global Change》2006,11(1):173-190
The study was carried out in the Turukhansk Research Station of Yenisei Transect (65°46′N, 89°25′E). Larch (Larix gmelinii (Rupr.) Rupr.) is the dominant overstory tree species. The research has been conducted on four permanent test plots in same-age mature
(110-year old) and overmature (380-year old) post-fire larch stands of green moss and lichen groups of forest type. Carbon
cycle parameters were assessed based on a biometric method. Quantitative analysis of carbon pools and fluxes shows that net
ecosystem production of north taiga larch stands averages 32% of net primary production. Sink of atmospheric CO2 makes 1.22 and 0.74 t C ha− 1 year− 1 for mature and overmature green moss larch stands, and 0.65 and 0.35 t C ha− 1 year− 1 for lichen type. Net carbon sink in the tree layer make up 9% of net primary production carbon, ground vegetation – 15%,
and dead plant residues accumulation – 8% of atmospheric carbon uptake via photosynthesis. 相似文献
116.
Gennady G. Matishov Vladimir V. Denisov Sergey L. Dzhenyuk Oleg V. Karamushko Dag Ddaler 《Ambio-人类环境杂志》2004,33(1):53-57
本文提供了联合国环境规划署"全球国际水域评估"项目(UNEP-GIWA)评估俄罗斯各海域所使用的背景材料和分析结果.它概述了过去100年中巴伦支海和亚速海两海域的渔业发展状况.讨论了巴伦支海和亚速海渔业发展的主要阶段和渔业产量降低的主要原因.这两个在物理和地质特征方面明显不同的海域却在渔获量动态方面表现出相似的趋势.海洋生态系统的自然波动和对自然生态系统功能的人为干扰已导致了对生态系统健康的重大负面影响并造成渔获物构成和数量的消极变化.俄罗斯各海域渔获量的下降已成为俄罗斯联邦的关注焦点,有关俄罗斯渔业管理的各项修改政策也已实行.政策文件"2020年之前俄罗斯联邦有关渔业发展概念"也在此加以讨论. 相似文献
117.
Nikitin AI Chumichev VB Valetova NK Katrich IY Kabanov AI Dunaev GE Shkuro VN Rodin VM Mironenko AN Kireeva EV 《Journal of environmental radioactivity》2007,96(1-3):138-143
Data on content of (90)Sr, (137)Cs, (239,240)Pu and (3)H in water of the Tobol-Irtysh part of the Techa-Iset-Tobol-Irtysh-Ob river system (through which the "Mayak" PA radioactive wastes are transported) are presented and discussed. The data were received in 2004-2005 under the ISTC project on radioecological monitoring of the Tobol and Irtysh rivers. Monthly observations of (137)Cs, (90)Sr and (3)H content in water in the area of the Tobol and Irtysh confluence have been conducted starting from May 2004. To obtain information on the investigated river system as a whole, the radioecological survey of the Tobol and Irtysh rivers at the section from the mouth of the Iset River to the confluence with the Ob River was carried out in 2004. It is shown that the impact of "Mayak" PA waste transport by (90)Sr is distinctly traced as far as the area of the Irtysh and Ob confluence. 相似文献
118.
Daria Ryabchuk Mikchail Spiridonov Vladimir Zhamoida Elena Nesterova Aleksander Sergeev 《Journal of Coastal Conservation》2012,16(3):233-242
Traditionally the coastal zone of the easternmost (Russian) part of the Gulf of Finland has not been considered as an area of active litho- and morphodynamics, but a recent study has shown that the easternmost part of the coastal zone suffers from erosion. Within some coastal segments the shoreline recession rate reaches 2 ?C 2.5?m/year. As well as determining the hydrodynamic reasons for recent erosion acceleration, important geological and geomorphic features of coastal zone which influenced the lithodynamics were established. The Kurortny District of St.Petersburg is located along the northern coast of the Gulf of Finland to the west of the St. Petersburg Flood Protection Facility. It has special importance as a unique recreation zone of the North-West of Russia. Coastal erosion is one of the most serious problems of the area. The analysis of historical materials, archive aerial photographs and modern high-resolution satellite images have shown that advancing parts of coast are almost non-existant with most sections of the coast being eroded and further retreating. Field monitoring between 2004 and 2007 showed intense damage to sandy beaches during autumn and winter storms and progressive erosion of the dunes system. Among the most important natural reasons for the erosion processes are that the coastline is open to storm waves induced by westerly and south-westerly winds, the geological structure of coastal area (easily eroded Quaternary deposits) and a sediment deficit. In some areas sediment loss was the result of the submarine coastal slope morphology (a steep slope of a narrow submarine terrace within the area of sediment drift discharge), with erosion of an alongshore submarine sandy terrace and erosion runnels at the depth 8?C12?m. The situation becomes worse due to anthropogenic impact. The southern coastal zone dynamics are also very active. According to an aerial and satellite photos analysis from 1975?C1976 to 1989?C1990, sandy beaches to the west of Lebyazhye village were eroded up to 30?m, and near Bolshaya Izora village up to 70?m. The comparison of coastine GPSsurvey with old nautical and topographic charts published in the 1980s shows the considerable change. 相似文献
119.
INTEGRATING DIFFUSEINONPOINT POLLUTION CONTROL AND WATER BODY RESTORATION INTO WATERSHED MANAGEMENT1
Vladimir Novotny 《Journal of the American Water Resources Association》1999,35(4):717-727
ABSTRACT: The objective of water quality/watershed management is attainment of water quality goals specified by the Clean Water Act. The Total Maximal Daily Load (TMDL) planning process is a tool to set up watershed management. However, TMDL methodologies and concepts have several problems, including determination of Loading Capacity for only low flow critical periods that preclude consideration of wet weather sources in water quality management. Research is needed to develop watershed pollutant loading and receiving waters Loading Capacity models that will link wet and dry weather pollution loads to the probability of the exceedence of water quality standards. The long term impact of traditional Best Management Practices as well as ponds and wetlands, must be reassessed to consider long term accumulation of conservative toxic compounds. Socioeconomic research should focus on providing information on economic and social feasibility of implementation of additional controls in water quality limited watersheds. 相似文献
120.