| The grassland types and their landscape dynamic of pastoral-agriculture ecological system in Sanjiaochen Sheep Breeding Farm Qinghai Province were studied through the thorough investigation. The data about climate, soil, vegetation, conversion efficiency of solar radiation, energy storage as well as the ecological benefit were collected. The technologies applied in this research were TM image, remote sensing and geographic information system(GIS). The images taken by the remote sensor were analyzed, the modeling of the geographic database was built, the characters of the spectrum of the grasslands were analyzed and the investigations of the grassland resources were conducted. The data systematic analysis presented the results as following:Grassland types in Sanjiaocheng Sheep Breeding Farm mainly are Alpine steppe,Alpine meadow,desert steppe etc. Among them Alpine steppe and Alpine meadow not only occupy the largest area compare to other types but also play an important role in livestock production as well as ecological protection. In terms of vegetation distribution characteristics and soil hygroscopic water conditions, dominant species and sub-dominant species that represent different grassland types in different altitudes ( from 3100m to 3700m ) are in order as follows:Triglochin maritimum , Potentilla anserine→Achnatherum splendens,Festuca ovina→Poa crvmophila,Stipa purpurea→Kobresia humilis,Kobresia humilis. Vertical distribution zonation of grassland type was clearly showed here; higher the elevation is, lower plant height and aboveground biomass are, it is certified that fierce environment condition in high altitude puts special stress on grassland productivity. The equilibrium of hygroscopic water in different soil level is not reached simultaneously at different altitude. Higher the elevation is,earlier this equilibrium is reached. It is proved that there are remarkable differences in hygroscopic water content within a small area due to elevation events.The species diversity(a diversity index)of plant community decreased and important value increased with the aggravation of degraded degree. The diversity indexes of Stipa purpurea community with moderate and heavy degradation were 2.50,2.26 respectively,the important value of dominant species were 19.09,23.8 respectively. The diversity indexes of Kobresia capillifolia community with moderate and heavy degradation were 2.6069,2.4167 respectively,the important value of dominant species were 13.31,22.81 respectively. Season dynamic of abovegroung population phytomass of Stipa purpurea and Kobresia capillifolia grassland types take on single apex curve,the value of apex appeared in the last ten day of August,the phytomass of aboveground population of two grassland types have clear difference. The equation y=ea+bx simulate season dynamic curve of aboveground phytomass of Stipa purpurea and Kobresia capillifolia grassland type well.The dry weight ratio of the grasses of Stipa purpurea type to community decreased but that of forbs increased with the aggravation of degradation. The rate of dry matter accumulation decreased,which finally lead to decreasing net primary production. The net production of above-ground phytomass of moderate-degraded plot of Kobresia capillifolia type was more than heavy-degraded plot,because of grazing in germination,the grasses percentage of moderate degraded plot of Kobresia capillifolia type was less than heavy-degraed plot. The net production of above-ground phytomass of Stipa purpurea community with moderate and heavy degradation were 104.99g/m2.a,48.38 g/m2.a respectively. The net producion of above-ground phytomass of Kobresia capillifolia community with moderate and heavy degradation were 144.82g/m2.a,87.96g/m2.a respectively. The more than 80% belowground phytomass distributed at 0～20cm soil layer,the equation y=ax+b simulate mean phytomass and its percentage of individually soil layer at growing period. Under the 40 centimeter deep soil layer,the net production and turnover value of belowground-ground phytomass of Stipa purpurea community with moderate and heavy degeneration were 849.6g/m2.a,32.45%,1346.05g/m2.a,51.93% respectively. Those of below-ground phytomass of Kobresia capillifolia with moderate and heavy degradation were 787.13 g/m2.a,26.08%,1190.6g/m2.a,51.33% respectively.The ratio of below-ground phytomass to above-ground phytomass increased with the aggravation of degradation. The ratios of below-ground phytomass to above-ground phytomass of Stipa purpurea community with moderate and heavy degradation were 16.86,51.51 respectively. The ratios of below-ground phytomass to above-ground phytomass of Kobresia capillifolia community with moderate and heavy degradation were 24.61,27.22 respectively.The measures of caloric value of every plot showed that:The caloric value of above-ground more than that of below-ground,the caloric value of above-ground was the highest on the forage flourishing stage,the lowest on green up period,on the withering stage in the second level. the caloric value of above-ground more than that of the terraneous. The energy storage of above-ground,under-ground and total community were linear positive significance to the biomass. The net production of spatial distribution decreased with the aggravation of degraded degree. The net production of spatial distribution of Stipa purpurea community with moderate and heavy degradation were 0.1667,0.0439 respectively,that of Kobresia capillifolia community with moderate and heavy degradation were 0.2257,0.1049 respectively.The conversion efficiency of solar radiation of above-ground decreased with the aggravation of degradation.The conversion efficiency of solar radiation of above-ground of Stipa purpurea community with moderate and heavy degradation were 0.03%,0.013% respectively , that of below-ground were 0.178%,0.303% respectively,that of total community were 0.208%,0.317% respectively. The conversion efficiency of solar radiation of above-ground of Kobresia setchwaneusis community with moderate and heavy degeneration were 0.04%,0.024%,that of below-ground were 0.177%,0.234% respectively,that of total community were 0.216%,0.259%.Based on the analysis of nature and social economy status of SanJiaocheng sheep breeding farm eco-system in Qinghai Province,the emergy theory and method were applied to calculate and analyze the NEYR,RIR,ELR and ESI of the SanJiaocheng sheep breeding farm during the year 2002-2006: The total emergy quantity input on the San Jiaocheng sheep breeding farm was 5.00×1029sej, including renewable environment resources,non-renewable environment resources,non-renewable industry attached energy and renewable organic energy which occupied the total input emergy of 7.39%,7.68%,35.15% and 49.77% respectively. The input environment resources occupied 15.08% of the total emergy. In the input attached energy,the renewable organic energy occupied 58.61% of the total input attached energy. In the input environment resources,the non-renewable environment resources occupied 50.96% of the total input environment resources. The EIR of San Jiaocheng sheep breeding farm in Qinghai Province increased from 0.0489 in 2002 to 0.734 in 2006 gradually,and the overall EIR fluctuates between 0.05 and 0.07. The EYR of SanJiaocheng sheep breeding farm in Qinghai Province increased from 57.4 in 2002 to 83.7 in 2005,and the overall tendency of EYR was on the rise,which indicated that the energy efficiency of economic activity on Sanjiaocheng sheep breeding farm in Qinghai Province increased year by year,and the competitive ability obviously enhanced. The EIR of SanJiaocheng sheep breeding farm in Qinghai Province increased from 0.0489 in 2002 to 0.734 in 2006 gradually,and the overall EIR fluctuates between 0.05 and 0.07,which indicated that the degree of economy opening to the outside world and the utilization of various outside"resources"was low in that area. The ELR of SanJiaocheng sheep breeding farm in Qinghai Province increased from 31.3 in 2002 to 71.4 in 2006, and the general tendency was on the rise,which indicated that the pressure of economic development on the environmental system increased gradually in that area. The EDR of SanJiaocheng sheep breeding farm in Qinghai Province showed a tendency of rising year by year,it increased from 1.50×1014sej/$ in 2002 to 7.98×1014sej/$ in 2006,this mainly because that the gross agricultural production of that area increased slowly during the year 2002-2006 and the decreased exploiting degree of economic system. During the year 2002-2006 the ESI of SanJiaocheng sheep breeding farm in Qinghai Province decreased from 58.46 to 21.8,the general tendency was on the decrease,and the ELR increased from 31.3 to 71.4 at the same period,which showed a rapid rising tendency. From the equation ESI=NEYR/ELR thus it can be seen that the decrease of ESI during the year 2002-2006 was due to the growth rate of ELR was higher than that of NEYR at the same period on the SanJiaocheng sheep breeding farm in Qinghai Province. Reflection characteristics of TM image bands for different objects. Ten objects were chosen for their band comparison,including rocky mountain glacier,saline and alkaline area,reservoir,bare land, alpine steppe,alpine,meadow,river,artificial grassland,lake and swamp. Three vegetation types were also selected for plant band comparison,such as alpine steppe,alpine meadow and mountain meadow. The results showed: among TM1,TM2,and TM3 bands,spectral reflectance of bog and lake is much higher than that of other objects. There is no significant difference among these three types of vegetation. While within band 4,spectral reflectance of green plants is different from each other,therefore,band 4 is good at distinguishing different vegetation. As for band 5,spectral reflectance of alpine meadow,bare land and alpine grassland is much higher than other objects. As for band 6,there is no distinctive variation for all objects.Soil lines of different soil types. According to linear relationship between spectral reflectance of infrared band and near-infrared band,their correlative relationships were linear regressed to get soil lines of 4 soil types: Swamp: NIR=0.46R +13.91,relevance 0.83; Dark chestnut soil: NIR = 0.44 R+22.66, relevance 0.78; Mountain steppe soil: NIR = 0.52R +12.62, relevance 0.80; Mountain meadow soil: NIR =0.57R + 6.91,relevance 0.90. As we can see from the comparison of different soil lines,slope: alpine meadow soil>alpine steppe soil>swamp soil>dark chestnut soil; intercept: alpine meadow soil |
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