In this paper the authors advance a new method called Phenological Frequency Distribution Pattern for determining the seasonality of natural landscapes and divide the phenological season in the foot area of the West Hill of Beijing into 12 stages using the data of the local phenological calendar. The result shows that each season stage has the typical morphological and coloration combination of plant phenology and the unique seasonal aspect, and is coincident with the seasonal distribution of air temperature and precipitation. Comparing this method with former methods, the new one has several characteristics, such as using quantitative and integrative indexes, determining more detailed season stages, comprising substantial season contents and having extensive regional applicability.
A high resolution pollen record from Maili Bog, Horqin sand land, central Norhteast China, shows that the open sand land forests around the bog have continuously delined since 3100 a B.P., and the main herb taxa have experienced consistent rise in abundance. The most significant changes were in the pollen percentages and pollen concentration of Quercus mongolica, Artemisia and Chenopodiaceae. Furthermore, the changes of the herb pollen generally lagged behind those of trees, and the rise in Chenopodiaceae seems to follow that of Artemisia. It is thus possible that the stable sand dunes covered with open forest were first turned to partly stable sand dunes with Artemisia as the dominant taxa, and this was followed by the change from partly stable sand dunes to mobile sand dunes which usually support only Chenopodiaceae. Archaeological relics and documentary records show an increased human population and agricultural activities in this region beginning from Gaotaishan Culture (3300-3000 a B.P.). The farmers may have come from the southern regions of Liaoning Province, which was in turn influenced by the advanced agriculture of the middle and lower reaches of the Yellow River. The above mentioned vegetation changes in the Maili region, therefore, may have been mainly induced by the human interference with the sand dune system. This inference is generally supported by charcoal count data from the pollen profile, the different changes in pollen between extra region Pinus and intra region Quercus, and pollen data from the other sites in Northeast China. It is thus obvious that caution should be taken when one reconstructs the late Holocene climate changes using pollen data in such a region. It is also suggested that the past reconstruction works of the middle to late Holocene climates in some regions of the country may need to be re assessed.
Based on multi time remote sensing and landscape pattern analysis, we used transferring matrix as main analyzing tool to study the element transferring condition and landscape changing course of Changping town from 1988 to 1996. The most important problems that we studied were the main source of non agricultural construction area coming from, transferring pattern of natural and agricultural elements to town, and landscape changing stages. The results indicated that 1) most new construction area came from arable land, orchard and water area, the transferring amounts were 1460 ha, 660 ha and 330 ha respectively. Because of geomorphologic impact, there was only 70ha of woodland that was changed to town area. 2) There were two kinds of transferring pattern, direct and indirect, to change natural and agricultural elements to construction area. The direct transferring pattern was the chief changing way, and more than 80% of new increasing town area came from this way. 3) The landscape changing course of Changping town during past 8 years could be divided into three stages, which were agricultural stage (1988 to 1991), town and county mixed stage (1992 to 1994), and town stage(1996). 4) Human disturbance was the driving force of landscape changing in Changping town, and high speed and large changing scale were main characteristics of its landscape dynamics.
