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"5·12"大地震后,茂县牟托地区的地形地貌和生态系统受到很大的破坏。本文对茂县牟托地区典型斜坡的植物生长状况、土壤颗粒组成、土壤含水率进行了调查分析,获得了土壤颗粒大小、渗透性、含水率与植物生长之间的关系;研究表明,土壤颗粒组成中,细颗粒所占比例越高,其渗透系数越小,土壤含水率越大,植物的生长状况愈佳;土壤细颗粒所占比例相近的情况下,含水率高的地区植物生长好。根据研究成果,结合生态恢复的技术和方案实施的安全性以及可行性,提出水泥喷灌、修筑挡水阶梯和排水沟、种植植物等生态恢复的方案以及保持斜坡稳定的措施。 相似文献
84.
2012年1月9日,河南省国土资源厅印发通知,正式授予禹州市华夏植物群省级地质公园建设资格。
禹州市位于嵩箕地块南部,地貌上处于伏牛山与华北平原的过渡地带,境内二叠纪地层出露完整,发育最佳,层位连续,保存良好,不仅形成了著名的“北型南相”含煤地层,而且古植物化石含量极其丰富,河南中北部地区分布的石炭纪——二叠纪地层共发现古植物化石约130属540种, 相似文献
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中生代义马盆地不仅以中原唯一的中生代产煤盆地而著名,而且早中侏罗世的义马组含煤地层和晚三叠世地层中,保存了大量完美的各类动植物化石。长期以来,随着煤田勘查和开发,许多著名的地质、古生物学家进行了大量地质调查及地质古生物科学研究工作,取得了多项有世界性影响的科研成果。其中银杏化石植物群的发现,在世界上引起轰动,这是全世界迄今发现最古老的银杏化石群,被国际地质、古生物学术界命名为“义马银杏”, 相似文献
86.
Stress Responses to Rapid Temperature Changes of the Juvenile Sea Cucumber (Apostichopusjaponicus Selenka) 总被引:2,自引:0,他引:2
DONG Yunwei JI Tingting DONG Shuanglin 《中国海洋大学学报(英文版)》2007,6(3):275-280
Activities of hexokinase (HK), pyruvate kinase (PK), superoxide dismutase (SOD) and catalase (CAT) and Hsp70 level were measured to evaluate the response of the commercially important sea cucumber (Apostichopus japonicus Selenka) to rapid temperature changes in laboratory. Animals were subjected to a higher temperature (from 10 to 20℃) (Tinc treatment) or to a lower temperature (from 20 to 10℃) (Tddec treatment) for 72 h. At 1, 3, 12, 24, 72 h of exposure, animals were removed and prepared for further analysis. Results showed that the effect of acute temperature changes on enzyme activities was significant. In Tinc treatment, activities of SOD and CAT increased immediately. The significant enhancement of SOD and CAT activities suggested that oxidative stress increases significantly when ambient temperature increasing from 10 to 20℃. The up-regulation of Flsp70 in Tinc and Tdec treatments indicated that Hsp70 was a bioindicator of thermal stress in the sea cucumber, and the expression pattern depended on the thermal treatment. 相似文献
87.
The phytoplankton reproduction capacity (PRC), as a new concept regarding chlorophyll-a and primary production (PP) is described. PRC is different from PP, carbon assimilation number (CAN) or photosynthetic rate ( P^B ) . PRC quantifies phytoplankton growth with a special consideration of the effect of seawater temperature. Observation data in Jiaozhou Bay, Qingdao, China, collected from May 1991 to February 1994 were used to analyze the horizontal distribution and seasonal variation of the PRC in Jiaozhou Bay in order to determine the characteristics, dynamic cycles and trends of phytoplankton growth in Jiaozhou Bay; and to develop a corresponding dynamic model of seawater temperature vs. PRC. Simulation curves showed that seawater temperature has a dual function of limiting and enhancing PRC. PRC‘s periodicity and fluctuation are similar to those of the seawater temperature. Nutrient silicon in Jiaozhou Bay satisfies phytoplankton growth from June 7 to November 3. When nutrients N, P and Si satisfy the phytoplankton growth and solar irradiation is sufficient, the PRC would reflect the influence of seawater temperature on phytoplankton growth. Moreover, the result quantitatively explains the scenario of one-peak or two-peak phytoplankton reproduction in Jiaozhou Bay, and also quantitatively elucidates the internal mechanism of the one- or two-peak phytoplankton reproduction in the global marine areas. 相似文献
88.
有绚丽夺目的色彩,有从沙漠到山地森林,有从潮湿的土壤到干燥的岩石,有在人迹罕至的悬崖绝壁上,有的爬在整个树干的基部,有的挂在树枝上,还有的为岩石披上了一层绿装,更多的是紧贴大地,它们就是植物世界中的——地衣。 相似文献
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М.Lebedeva 《山地科学学报》2009,6(2):132-138
Micromorphology of solonetz species with special attention to natric horizon was studied in microcatenas at the Dzhanybek Research Station (northwestern Caspian Lowland). The solonetzic (natric) horizon is easily identified, and it occurs at varying depths, which are the criteria for subdividing solonetzes into 4 species, namely, crusty, shallow, medium and deep. In this sequence, the depth of humus-accumulative horizons increases, and the upper boundary of salinity manifestations goes down. The following micromorphological features are assumed as typical for natric horizons: angular blocky microstructures with partially accommodated aggregates having sharp boundaries and narrow plane-like packing voids; b-fabric speckled in the aggregates' centers and monostriated at their peripheries merging into stress coatings; very few interpedal voids; organo-clay coatings; humus- enriched infillings; no calcite and gypsum pedofeatures. A complete set of "natric" features was found only in the crusty solonetz; the shallow solonetz lacks only illuviation coatings, while the medium and deep species have several modifications of fabric elements: blocky aggregates have a rounded shape and are penetrated by biogenic channels favoring their further biogenic reworking; plant residues became more abundant and diverse, and blackened tissues occur; illuviation clay coatings evolved into papules; stress coatings gave birth to striated bfabrics, thus maintaining a high plasma orientation. The thin sections of natric horizons made 50 and 20 years ago were examined to study the influence of environmental changes (increase in precipitation and rise of ground water table) on micropedofeatures. The following processes took place: (i) in the topsoil: humus accumulation and biogenic structurization; (ii) in the natric horizon - re-arrangement of clay coatings into micromass b-fabrics; and (iii) in the lower part of the natric horizon - development of pseudosand fabric, calcite and gypsum formation. The trends revealed are in good agreement with the environmental events. 相似文献