Analysis on Dynamic Characteristics of Landscape Patterns in Hailer and around Areas
This paper analyzed the spatial-temporal dynamic changes of landscape patterns in Hailer and around areas. Firstly, landscape patterns types of research area were divided into water, sand, farmland, city and grassland based on remote sensing images of 1986, 1991, 1996 and 2001 and field investigation. Then the grassland was classified into higher coverage grassland, high coverage grassland, medium coverage grassland and low coverage grassland by Normalized Difference Vegetation Index. Finally, the spatial-temporal dynamic changes of above-mentioned eight kinds of landscape patterns were analyzed using landscape ecology principle. The results indicated that human activities intensified significant from 1986 to 2001in research area. The area of grassland landscape decreased quickly, and the fragmentation extent intensified. The dominant landscape in research area changed from higher-high coverage grassland to medium-low coverage grassland. The expansion of sand landscape is obvious in periphery of road, city and farmland. The grassland vegetation degenerated seriously. Fragmentation of city landscape lightened, and city landscape patches tended to decrease and centralized. Economy development pattern of research area is in a stage that is transforming from extensive pattern to intensive urbanization pattern.
Effect of Road on High-frigid Grassland Vegetation of Zoige
As one of the most valuable low latitude high-frigid wetland in the world,Zoige plateau is still a heavy disturbed area by intense grazing and road construction.The national road G213 which connects Chengdu and Lanzhou goes through there. Our studies focus on the effect of road to surrounding ecosystems.A survey on the vegetation of Zoige high-frigid grassland along the section of Huahu of G213 was carried out in 2005.Plots were arranged along transects which are perpendicular to the road with distance of 10,50 and 200m away from it.Total of 19 transects,57 plots and 130 quardrads were arranged.Analysis on the flora,community structure and biodiversity are applied.The vegetation types along the road are chiefly subalpine dwarf Kobresia and forb meadows.They are further divided by cluster analysis into 8 associations.Of which 85% belongs to Assoc.Lenotopodium——Saussurea——Potentilla——Kobresia,and 7% to Assoc.Potentilla anserine——Plantago——Potentilla bifurca.There are totally about 110 species belonging to 29 families and 73 genera.We haven't found rare and endemic species in this area.The flora of this area is mainly of the nature of north temperate,comprising 55% of total species.The next largest one is cosmopolitan type,comprising 25.7% species.Families with most species are Asteracea,Gramineae and Ranunculaceae,they account for 36.8% of total species.The species richness is 27.8±8.2,with the lowest value at the plots nearby of summer settlement house of nomads.The wetland plots have a moderate value of species richness.The mean biodiversity index expressed as Shannon-Wiener index is 1.95±0.48 with the similar pattern as species richness.The highest biodiversity index occurred in the plots on the winter pastureland of Hongxing village and the meadow near Huahu Lake.Although plant diversity index is slightly biased near to the roadsides,the species richness is almost the same.This result means that a homogenization process of vegetation occurred along the road.Difference on land use(summer and winter pastureland) has a prominent effect on vegetation structure and aboveground biomass.With long time of usage and presence of grazing,the road effect in this area is not clear.
The relation of food quantity to rumination behavior.
Preliminary work suggested that the quantity of food ingested by retarded individuals who usually ruminated following meals was related to the frequency and duration of ruminating responses. This possible relation was experimentally examined by systematically varying food quantity from regular portions to satiation levels for three retarded individuals who exhibited high levels of ruminating. A clear functional relation of food quantity to ruminating emerged, with satiation procedures producing rapid and large decreases in the relatively high frequencies and durations of ruminating characteristic of baseline food quantity conditions.