Classification and Assessment of Freeze-Thaw Erosion in Tibet, China

Based on the analysis of existing relevant research result, a theoretical basis for the defining freeze-thawerosion zones of Qinghai-Tibet Plateau was been put forward, and a equation for calculating the altitude of the lower bound of the freeze-thaw erosion zones of Qinghai-Tibet Plateau was been established in this paper. Moreover, the freeze-thaw erosion zones in Tibet was been identified by using Geographical Information System (GIS) software. Next, based on thecomprehensive analysis of impact factors of freeze-thaw erosion, this paper chooses annul temperature range, slop and vegetation as three indexes, works out the criteria for relative classification of freeze-thaw erosion, and realizes the relative classification of the freeze-thaw erosion in Tibet under the support of GIS software. Then, a synthetic assessment of freeze-thaw erosion in Tibet was been done according to the relative classification result.     

Floristic Characteristics of the Rare and Endangered Plants and the Conservation Countermeasures in Tibet, China

The floristic elements and the geographical distribution are analyzed in this paper based on statistics of elements of rare and endangered plants in Tibet. The results have been gained as following:① According to ““““the National Important Wild Conservative Plants List (List 1)““““ and ““““the National Important Wild Conservative Plants List (List 1)““““, there are a total of 54 plant species (48 genera and 33 families); ② The geographical elements are very complicated in Tibet with 12 of 15 distribution patterns of genera classified byacademician Wu; ③ There are obvious temperate genera with 28 genera accounting for 60.40% of the total genera; ④ There are abundant endemic speciesaccounting for 18.52% of total species but poor endemic genera; ⑤ The geographical distribution is uneven and a great of species distribute in the areas be-tween 1 000 m and 3 500 m above sea level; ⑥ To protect the rare and endangered plants efficiently, six conservation measures are proposed, and 35 species are suggested for the conservative plants of the autonomous conservation level.     

Diversity of Plant Species of Alpine Grassland in Nakchu of Tibet, China

0Introduction Biologicaldiversityconcernedwiththesumofvariouslivingbeingsandtheirprocesses,aswellasthebasisofharmonious coexistencebetweenmanandnatureplaysanimportantroleinecology,economy,esthetics,ethics,etc.Duetodeteriorationofglobal environment,acceler…     

Evaluation of Eco-Environmental Stability Based on GIS in Tibet, China

By making an evaluation index system and using Analytical Hierarchy Process (AHP) to determine the evaluation factor‘s weights, this paper builds the valuation model of Eco-environmental stability of Tibet and uses the overlay function of raster-GIS (geographic information systems) to make a result map and finds the distribution characteristics of Eco-environmental stability of Tibet based on the analysis of result map. The study shows that the Eco-environmental stability of Tibet is almost good and the unstable region which isonly 9. 78% of the total area of Tibet is distributed in the middle and low reaches of Yarlung river. To protect the Eco-environmental of the unstable area from farther degenerating, the government should pay more attention on the Eco-environmental construction work on this area.     

Evaluation on the Essentiality Grades of Water Conserving in Tibet, China

Taking Tibet as an example, the functional essentiality degrees of water resources conserving of regions were discussed in this paper. At first, based on the status of regional vegetation, whether the region has the function of water conserving was made certain. And then, according to the impacted objects of water resources conserving, taking into account the demands for water and regional supply capacities of water and the requirement of environmental protection, the functional grades of regional water resources conserving of Tibet were evaluated in this paper.     

Fractal Characteristics of Soil under Different Land-Use Patterns in the Arid and Semi-Arid Region of the Western Tibet Plateau, China

0Introduction Changesinsoilstructureoftenaccompanychangesinmanagementpracticesandmayaffecttheeffectivenessofthesepractices.Parametersareneededto quantifythesechanges.Sizedistributionsofsoilparticleandmicroaggregatehavebeenfoundtobeagood indicatorofchanges…     

Quantitative Assessment on Endangerment Degree of Rare Animal and Plant Species in Tibet, China

It is of profound theoretical and practical significance to study endangerment status of rare species in Tibet. Index system is firstly set down for quantitative assessment of rare animal and plant species, then endangerment degree of wildlife under special state protection are calculated, which is expressed by value E. The results reveal that Yunnan snub-nosed monkey （Rhinopithecus bieti）, Himalayan tahr （Hemitragus jemlahicus） and Gigantic Cypress （Cupressus gigantea） have the highest E respectively in animals and plants. According to value E, all species are categorized into 4 ranks： critically endangered（0.6-0.8）, endangered （0.4- 0.6）, vulnerable （0.2-0.4） and lower risk （ E ≤ 0.2）. By comparison of the first five animals and plants of the highest E, each sub-ecozone bears a distinct identity.     

Population Characteristics and Future Population Countermeasures for the Studied Counties in Tibet, China

Focusing on the 18 counties along ““““One River and Two Tributaries““““ region, and based on the data from China 3^nd , 4th and 5^th population censuses, this article has analyzed the time and spatial changing patterns of the population in this region, The analyses show that since the 3^al population census, total population, average age and total birth rate have all changed considerably: ① Total population has grown fast, with most counties‘ annual average growth rate of more than 10. ② In terms of the region‘s average age, in 2000 the age inthe 18 counties is younger than 30 years old. ③ Compared with the 3^rd population census, labor force by the 5^th census is much younger. ④ Countermeasures are proposed to control population by controlling birth rate as the result of the local resident‘s quality improvement by education.     

Land Use Change and Its Effect on Environment Based on Farmers＇ Behaviors： A Case Study in Agricultural Areas of Tibet, China

In the case study in Agricultural Area of Tibet, the process and characteristics of farmers‘ land use were surveyed by semi-structural interview questionnaire. By comparing the change of land covers and farmers‘ land decision in two periods, the spatial connection of them was obtained. And the relations among farmers‘ land decision, land use change and environment were examined by calculating emergy and value flow. The results show that: hunting the maximal profits is the primary aim of farmers‘ land decisions farmers‘ land decision is incompatible with sustainable land use presently; farmers‘ land decision and land cover can be embodied spatially by each others the change of farmers‘ land decision can be monitored by observing the change of land cover, and the sustainability of farmers‘ land decision can be appraised by calculating emergy and value flow.     

Two Village Ecosystems in the Upper Minjiang River, China： A Comparison of Emergy Flow

By using the concept of emergy and method of emergy analysis, this paper has studied two mountain settlement (village) ecosystems in two aspects: input and output of energy in the agro-systems and the use of fuel energy. The result reveals that the settlement agro-system in the valley of Minjiang River is better in both structure and function than that at the so-called half-high mountain. The former one is higher than the latter one regarding such indices as emergy yield ratio, labor productivity of emergy and emergy sustainable index, but lower than the latter one regarding environmental loading ratio. In terms of fuel emergy, the settlement in the valley enjoys more diversified sources and is less depending on bio-energy while the settlement at the half-high mountain has only one source (i. e. fuel wood), much depending on bio-energy, may exert a greater pressure on environment.     

Impacts of Overgrazing and Reclamation on Soil Resources in Rangeland Ecosystems in Huailai Basin, Hebei, China

The soil constituents and relations between the variation of soil resources and plant communities in three adjacent sites representing the overgrazing, reclamation and comparatively undisturbed communities respectively were quantified and examined in study area in Huailal Basin, Hebei Province, China. There have been significantly greater constituent of C, N, P in the soilsof shrubland site. Corg, Ntotal, Navail and Pavail were between 1.18 and 3.90 times more concentrated in the soils of shrubland site in comparison with the other two sites. Although the Ptotal concentration was lower in shrubland soils than inovergrazed rangeland soils, the Parval concentration, however, was significantly greater in the soils of shrubland site, and increased by 59. 1% and even 289.6% in the soils of shrubland site comparing to those in the soils of rangeland and millet field sites. Among the three sites, CV exceeding 40% werefound for SO4 , Cl, and F ion. The CV of organic carbon also exceeded 40% but only in the soils of millet field site. The highest CV were found for F, SO4 ion in the soils of shrubland and overgrazed rangeland sites, while for Cl and SO4 ion in those of millet field site. The results also showed that the introductions of shrubs are of vital importance for the accumulation of soil nutrients and maintenance of soil fertilities, and also for the restoration and reconstruction of desertified ecosystems.     

Analysis on Landscape Pattern in the Upper and Middle Reaches of Yarlung Zangbo River：Taking Zhongba County, Angren County, Rikaze City as Example

Taking Zhongba County, Angren County, Rikaze City located at the Upper and Middle Reaches of Yarlung Zangbo River as landscape units , this paper studied the difference of the landscape pattern under various degrees of human disturbance in the three areas. The results showed that： the three areas all reflected the same characteristic of landscape pattern in Qinghai-Tibet Plateau, the natural landscapes were in the absolute dominant position. However, from Zhangba to Rikaze, with human disturbance intensity increasing, anthropogenic features of landscapes became more and more outstanding, In Zhongba, the landscape structure appeared to be simpler with coarse grains and a less rich diversity, Conversely, in Rikaze, the landscape showed a complicated shape with finer grains and a relatively richer diversity, This reflected that the impact of human activities to natural landscape behaved a gradually-growing trend from the upper reach to the middle one of Yarlung Zangbo River Basin.     

Since Lamb Is Made,Why Is Tyger Created,Then——An Analysis of“The Lamb”and“The Tyger”

Different people have different opinionson the symbolic meaning of William Blake’spoem＂The Tyger＂.The writer of thispaper is trying to make some comparativediscourse analyses on Blake’s twocollections＂Songs of Innocence＂and＂Songs of Experience＂,especially on his twopoems＂The Lamb＂and＂The Tyger＂,so asto point out that the symbolic meaning of＂The Tyger＂is the cruel outside world inBlake’s time.＂The Tyger＂is Blake’shopeless lament on the existing society ofman-eating-man.     

An in situ zircon Hf isotopic,U-Pb age and trace element study of banded granulite xenolith from Hannuoba basalt： Tracking the early evolution of the lower crust in the North China craton

Backscattered electron images, in situ Hf isotopes, U-Pb ages and trace elements of zircons in a banded granulite xenolith from Hannuoba basalt have been studied. The results show that the banded granulite is a sample derived from the early lower crust of the North China craton. It is difficult to explain the petrogenesis of the xenolith with a single process. Abundant information on several processes, however, is contained in the granulite. These processes in-clude the addition of mantle material, crustal remelting, metamorphic differentiation and the delamination of early lower crust. About 80% of zircons studied yield ages of 1842 ±40 Ma, except few ages of 3097-2824 Ma and 2489-2447 Ma. The zircons with ages older than 2447 Ma have high εHf (up to +18.3) and high Hf model age (2.5-2.6 Ga), indicating that the primitive materials of the granulite were derived mainly from a depleted mantle source in late Archean. Most εhf of the zircons with early Proterozoic U-Pb age vary around zero, but two have