Integrated physical geography and relative landscape ecology are important branches of physical geography. In the past few years, significant progress has been made in the development of China's integrated physical geography which consists of both academic and applied dimensions. The contents of this paper include the following parts: (1) a brief historical review of the discipline development; (2) the major progress of theories, methods and techniques in integrated physical geography and landscape ecology, and its contribution to the development of physical geography; the applications of research results and the contributions to national development; and (3) the prospects proposed for future discipline development, including analysis of opportunity and challenge, and key research fields. As for the future development trends of integrated physical geography and landscape ecology, the following aspects should be further focused on: (1) to promote the comprehensive and integrated study level, and to strengthen the multidisciplinary and interdisciplinary study mechanisms to explore more complicated the problems of land surface system; (2) to upgrade the level of observation techniques and modeling simulation to solve more complex spatiotemporal eco-geographical process and pattern issues; (3) to expand the applications of research results to provide scientific support for the sustainable development of national resources, environment and socio-economy. Integrated physical geography, as a forthgoer of integrated study in geography, should strengthen international exchanges and open wider to the outside world.
The fundamental research of biogeography in China is mainly supported by the National Natural Science Foundation of China in which the Department of Earth Sciences plays a dominant part. In the past few years, the objectives of plant geography study are mainly focused on alpine vegetation as well as arid and semi-arid land vegetation. The relationships between biodiversity, vegetation, alpine timberline and the effect of mountains are the main topics of alpine vegetation study. More and more field work and comparative studies have been conducted on various mountain types and regions. The limitation of water and salt to plants and the adaptation of the physiological and ecological function of these plants to the habitats are the main topics of plant geography study in arid and semi-arid areas. These studies show concerns for a wide range of fields, including plants, populations, biological communities and ecosystems. There are some advances in the studies of biological soil crust as well as of the ecophysiological response and morphological adjustment of desert shrubs with the variation of summer precipitation. However, zoogeography has not been extensively studied as plant geography has in the geographical community of China. In this field much emphasis is placed on soil animals and soil ecological function. Although biogeography study has made much progress in recent years, some curious problems should be solved to promote its development in the future. These problems are as follows. The number of professional researchers of biogeography is too small; potential researchers of biogeography with the background of geography are unlikely to get systematic trainings of biological sciences; the development is not balanced between the sub-branches of biogeography.
In this study, several important study fields of plant ecology in southern China have been reviewed and discussed, including the biodiversity conservation of subtropical forest community, the mechanisms of forest succession, the carbon and nutrients cycles in forest ecosystems, the ecological restoration of upland degraded land, the regeneration of wetland, the protection regime of biodiversity, the mechanisms of biological invasion, the greenhouse gas emissions, the reconstruction of urban plant, the mitigation of urban heat island and the carbon balance of urban green land. Several research priorities about plant ecology in southern China have been supplied in order to restore and reconstruct degraded ecosystems, accelerate the conservation of biodiversity, maintain habitation environment and human health, improve adaptability of ecosystem to global change, and enhance ecological safety.
Through 50 years of development, theory and methodology of DEM itself and DEM based digital terrain analysis (DTA) have been matured gradually, and played key roles in hydrology, geomorphometry, soil sciences, environmental science, agriculture, geologic hazard, civil engineering and military affairs. Based on an overall retrieval analysis of previous researches, this paper classifies different methods of DTA into four classes, i.e. analysis of terrain factor, terrain feature extraction, terrain statistical analysis and DEM based geo-modeling. Secondly, uncertainty and the scale issue of DTA are discussed. Besides, this paper points out that scale effect, optimal scale and scale transform are three basic scale issues of DTA. Thirdly, applications of DTA in geomorphometry, hydrology, soil science, agriculture, geologic hazard are introduced. Finally, this paper proposes that the conceptual framework of DTA, the accuracy of DEM modeling and the method of terrain analysis need to be improved, especially the integrated method of DEM embedded geographical modeling, for the simulation of more lifelike natural environment.
Based on the data of temperature and wind speed for the meteorological observation stations in China, and according to the latest WCT formula, this paper analyzed the wind-chill temperature changes in winter over China during the past 50 years. The mean WCT in winter rises by 3.2 oC in the period, with a rate of about 0.64 oC/10a. The warming rates of Southwest China, North China, Southeast China and Tibetan Plateau are 0.79 oC/10a, 0.84 oC/10a, 0.81 oC/10a and 0.80 oC/10a respectively; Simultaneously, the decreasing trend of the WCT in southern China (< 35 oN) is significantly lower than in northern, 0.39 oC/10a. The changes of WCT are the outcome of the combined effects of increasing temperature and decreasing wind speed. The fraction solely relates to the temperature. The wind speed is 2.4 oC and 0.8 oC in WCT, respectively. The results show that WCT might be affected by Siberian High, Arctic Oscillation, western Pacific teleconnection pattern and Eurasian pattern. The four circulation factors can explain the variance for mean winter WCT over China is 46.7%.
In this paper, the precipitation data from 30 weather stations for 1958-2007 and 248 rain gauges for 1995-2004 are examined and compared using linear regression, 5-year moving average, Mann-Kendall trend analysis, Kolmogorov-Smirnov test, Z test and F test methods; the WS data are used to extend the short record of RG data series; the temporal and spatial variations of precipitation in the Haihe River basin are studied. The results show that: (1) The precipitation of 1958-2007 has been decreasing except for the spring. The decline trend is significant in summer, and this trend is stronger after the 1980s; (2) The annual precipitation from both WS and RG records are normally distributed, with minor difference in the mean value and variance. In addition, their correlation degrees are higher, and it is statistically feasible to extend the precipitation of RG by weather station precipitation; (3) The temporal and spatial patterns of summer and annual precipitation in the Haihe River Basin are similar: in the piedmont of the Taihang Mountains and Yanshan Mountains there exists a rainfall rich zone, while on the leeward slope of the mountains and in the plain area there is less rainfall. In addition, the rainfall declines from the south to the north, and from the coast to the inland; winter sees the least water vapor and less precipitation in the north than in the south; while spring and autumn often witness a transition from winter to summer. In recent 50 years, the declining trend is most significant around the Wutaishan station, as well as some regions in the piedmont, and the changing trends are different in different seasons.
Based on the observational data in Xi'an and three other sites surrounding it from 1951 to 2006, this paper analyzes the impact of urbanization on surface air temperature change, including mean surface air temperature (Tm), maximum surface air temperature (Tmax) and minimum surface air temperature (Tmin). To get a better understanding of the influence of urban heat island (UHI) effect on warming trend, we study the differences of Tm, Tmax and Tmin between the city site and the other sites in different periods and at different time scales, respectively. The results show there are distinct seasonal differences in urban heat island effects on Tm trend, and different UHI effects are observed in different time periods. There is little difference in linear trend coefficient in annual mean surface temperature, maximum surface temperature and minimum surface temperature between the city site and the surrounding sites before 1980, and the linear trend coefficients of annual mean surface temperature (Tm), maximum surface temperature (Tmax) and minimum surface temperature (Tmin) at the city station are larger than those of the other three sites after 1980. Especially after 1993, the linear trend coefficients of Tm, Tmax and Tmin in the city are much larger than those of the surrounding sites, and the linear trend coefficient of annual mean Tm is 1.6 to 3.5 times that of the surrounding sites, indicating that the urban heat island effect increases with the increase of both the surface air temperature and the warming rate. We also found that the most significant warming trend occurs at all the four sites in spring, with a rate of 2.20 oC/10a in Xi'an in spring, which is 2-4 times that in the other three seasons, followed by autumn, and the least significant warming occurs in summer. The maximal influence of UHI effect on Tmax is observed in spring, but on Tmin in winter.
In this paper, tree-ring latewood stable oxygen isotope composition (δ18O) of Lijiang fir (Abies forrestii) was used to estimate the climatic response of tree-ring δ18O by comparing the δ18O values with meteorological records from Lijiang meteorological station. The annually resolved tree-ring δ18O chronology spans the period of 1902-2004. Results indicate that tree-ring δ18O values of latewood were significantly correlated with climate conditions during the growth season. Tree-ring δ18O was mainly correlated with precipitation and relative humidity of the wet season in summer (August to October). Temperature had a weak influence on the tree-ring δ18O, indicating a relatively high correlation with δ18O in May and June (r = 0.35), prior to the rainy season. The strongest correlation was found between the total cloud cover and tree-ring δ18O covering the whole wet season (June to October). Furthermore, tree-ring δ18O shows negative and significant correlations with South Asia monsoon index and East Asia monsoon index in different periods. Meanwhile, a strong correlation between tree-ring δ18O and SOI during the period of 1902-2004, to some degree, indicates that the tree-ring δ18O recorded a large amount of atmospheric circulation information.
With the aid of GIS technology, the authors made a study on man-land relationship in the perspective of environmental archaeology. The GIS database was set up based on 7534 spatial data of ancient cultural sites in the middle reaches of the Yangtze River since 8500 a BP. The ArcGIS software was employed for the analysis of the data to reveal the spatial distribution patterns of different cultural sites in different time periods. Results showed that the natural factors, such as topography, altitude, and slope, etc., had very close relationships with the distribution patterns of the ancient cultural sites. The Neolithic sites were mainly distributed on the loess terra in the piedmont hills and high alluvial plains, where the altitude was higher and the slope varied. During the Western Zhou Dynasty, the main distribution of the cultural sites shifted from the loess terra to the alluvial plain with lower altitude and gentler slope. From the Qin Dynasty to the Qing Dynasty, the cultural sites were mainly located in the lowest alluvial plain and the lake-deposit plain. During the past 8000 years the average altitude of the different cultural sites moved down about 12 m.
A correspondence was found between Holocene environmental changes and coastal dune rock development by comparing the features of the sea-level and climate changes in Holocene period with the ages, scales, and cemented styles of the dune rocks on South China coasts. The finding can well explain some unresolved problems in the previous researches on the coastal dune rocks in South China: (1) There was no dune rock that formed before 5000 aBP in South China because the dune rocks that formed before 5000 aBP were covered by the sea water rise in the late periods; (2) The dune rocks with ages of around 3000 aBP were widely seen in South China today because the coastal dunes were cumulated on a large scale at that time as a result of temperature fall since the end of Megathermal; (3) Medieval Warm Period was the main period for the aeolian dunes to be cemented into the coastal dune rocks in South China; (4) Lack of dune rock of less than 1000 a BP was due to the fact that the climate conditions in recent 1000 years were not suitable for the cementation.
Methodology is a key issue concerning the nature and development direction of geography. Case studies are an important method for methodological research. This paper takes "Exceptionalism in Geography: A Methodological Examination", a classical article in the history of geographical thought, and the debate caused by the article, as a case study. It re-examines and evaluates the background and significance of Schaefer-Hartshorne Debate and makes an in-depth analysis of the nature of the geographical methodology. The case study indicates that methodology is not a set of methods, but the scientism, logic and integration of methods. The basic nature of methodology is the evolutionary dynamics. The approaches to developing methodology in geography can be induced to the traditional type, the innovation type and the adaptation-based type, all of which are essential and equally important for geography. The development of methodology in geography experiences continuously a "negation of negation" dialectic process. Geographers should continue to pursue the methodological research. It is an ungent task for Chinese geographers to hunger for innovation of the methodological research, and a platform should be set up to discuss the methodology. This is the common responsibility of geographers.
With the further study on the Cenozoic stratum in the field of stratigraphy at home and abroad, the stratigraphic classification constantly has been updated by the international stratum field since 1996. Up to now, the status of the Quaternary period of the Cenozoic Era is uncertain in the International Stratigraphic Chart (ICS, 2008), which might include Pleistocene, and its age of the bottom limit can go back to about 2.6 MaB.P. Along with the higher international status of Chinese experts on Quaternary research, the advice on the stratigraphic classification of Cenozoic Era will become more and more important.
