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The agricultural mobilization of land resources has played a fundamental role in shaping both the civilization of China and its cultural landscapes and since ancient times has formed the foundation of the Chinese economy. In China, as elsewhere, agriculture is at once a craft, a business and a way of life, and, notwithstanding the tremendous transformations that have taken place in the structure of the national economy since the founding of the People's Republic in 1949, the agricultural traditions of the nation have remained strong.
Further, China's land resources are complex and varied, as befits a vast territory of 9.6 million kmē, which extends from the cold, continental zone, near Siberia. to south of the Tropic of Cancer, embraces a wide range of climatic and biotic zones. and includes a great variety of topographical types. The diversity of environments thus formed is reflected in the areal differences in natural resource endowment and land use, and in the regional imbalance in the development and use of primary resources. The fertile and well-watered deltas of the great rivers, such as the Yangzi and Zhu, for example, are among the most intensively cultivated, highly productive, and densely populated regions on earth where almost every inch of cultivable land is made to produce food, vegetable oils, fibres, and fuel, and the waters are intensively used for raising fish and aquatic macrophytes. But, on the other hand, China has vast, virtually unused tracts of desert and mountains covered with perennial snows, categories of land which together account for more than 19 per cent of the nation's territory.
Yet, despite the historical and contemporary importance of its agricultural sector, no complete, official land survey has ever been conducted in China, hence consistently reliable land-use statistics do not exist for the nation as a whole, a deficiency that inhibits effective long-range planning. Only estimates rather than statistics, senso strictu, are available. To remedy this, and to provide a more realistic quantitative estimate of land-use categories in the nation, the Institute of Geography of the Chinese Academy of Sciences (Beijing) prepared a Map of China's Land Utilization, at a scale of 1:6,000,000. (This was published in 1980 by the Map Press, Beijing.) From that exercise it was estimated that of China's area of 9.54 million kmē, only 14.6 per cent is cultivated at present, while 40.8 per cent is in grazing, 8.6 per cent is under forests, 7 per cent is used for industry, communication, and urban purposes, and 6.6 per cent is devoted to other uses. Of the remaining 22.4 per cent, much is high and barren desert, or under permanent snowfields, or not yet in use, or unable to be used with available technologies.
In addition to the lack of reliable data for planning, other problems beset the development of China's land resources. One problem is that of the appropriate development and management of resources. Most of the nation's vast pastures and grasslands, for example, have been degraded, their area and quality having been reduced by over-grazing and lack of maintenance, and through desertification and the depredation of rodents. Another problem is that much cultivated land remains low-yielding, owing mainly to edaphic conditions. Slopeland in the Loess Plateau Region, for example, yields grain at a rate of less than 0.75 t/ha, owing mainly to serious soil erosion; some depressions in the North China Plain suffer from serious salinization or alkalinization; and hills south of the River Yangzi remain a fuelwood preserve, since the lateritic soils of that region are of limited fertility. Yet another problem is that most hilly and mountainous areas remain underdeveloped. China is essentially a mountainous country with about 66 per cent of its land surface classed as either mountains or hills. But China lacks comprehensive, nationwide resource planning, and agriculture, animal husbandry, forestry, fisheries, and the like are usually administered separately by different government agencies, thereby inducing a fairly low level of agricultural production and the improper use of upland areas. However, China's uplands are important since they are inhabited by about 30 per cent of the nation's population, contain about 40 per cent of its cultivated land, and produce some 90 per cent of its grains. For China as a whole, cultivated land has been more intensively used since the establishment of the People's Republic in 1949. In large part this has been achieved through the wider application of multicropping and interplanting, which have significantly raised the nation's cropping index and greatly contributed to increases in agricultural productivity. The northern limit of double cropping has been pushed farther north beyond the Great Wall, and many places in the North China Plain previously under monocropping are now double-cropped with summer rice and winter wheat, as a result of better irrigation practices. And south of the River Huai there has been widespread application of the double-cropping system of rice plus winter wheat or rape-seed, thus permitting three harvests a year. However, there is always a limit to the increase in the cropping, and any attempt to raise the cropping index without careful consideration of limiting factors can only be unsuccessful.
To meet the needs of an expanding population, China must open up more land for farming. Approximately 32 million ha of arable land has been put under the plough since 1949, and about 2,500 State Farms have been established in reclaimed areas, thus enlarging the nation's food-production capacity. The State Farms in Heilongjiang Province and Xinjiang Uygur Autonomous Region have become the key components of China's new food bases, whereas those on Hainan Island and in southern Yunnan Province have become the nation's new tropical crop plantations. All potentially reclaimable land, however, has not been fully developed, and an additional 43 million ha may be suitable for reclamation and farming. But, as the bulk of the reclamation work has been undertaken in border regions, either along the margins of forest land or in the transitional zone between the farming and grazing regions, disputes among the farming, forestry, and animal husbandry sectors are frequent.
Thus there is a pressing need for a critical evaluation of the nation's land resources, a task that must be completed before appropriate policies for optimal land use can be made. To that end the Institute of Geography of the Chinese Academy of Sciences. assisted by other institutes of the Academy and by universities, is making a nationwide land-use survey. The project will be carried out in three stages: sample studies of areas with different types of land use and preparation of land-use maps at scales between 1: 10,000 and 1 :50,000; the compilation of land-use maps for each province and autonomous region at scales of 1 :100,000 and 1:500,000, depending on the size of the area; and the compilation of a set of land-use maps for the entire nation on the scale of 1:1,000,000, based on the provincial maps. The important set of maps of national land use to be completed in the third stage will use a system of land-use classification that will become the standard for the nation. The completion of this set of maps will provide planners with more accurate areal figures for different types of land-use. It will also be an important benchmark in the modernization of Chinese agriculture. Maps of land types, geomorphology, natural vegetation, soils, and land potential are also being compiled by various institutes of the Academy, all on a scale of 1 : 1,000,000. When completed, these maps will also become basic tools for national agricultural planning.
This volume contains papers presented by the Chinese participants at the international conference on " Land Use Evaluation and Classification, with Special Emphasis on Wetlands, " sponsored jointly by the United Nations University and the Chinese Academy of Sciences and held in Beijing and Heilongjiang Province from 15 to 25 September 1980. It documents several aspects of the critical evaluation of land resources now underway in China.
The publication is divided into two parts. The first deals with the nationwide classification, mapping, and evaluation of land-use categories, and its local application. The second is devoted to the wetlands of north-east China, a region largely closed to outsiders since 1949. The first four chapters deal with China as a whole. In chapter 1, Xi Chengfan discusses the physical and biological basis for the division of China into eight principal land-type regions and describes their agricultural usage. This is followed by Zhao Songqiao's chapter, which describes the basis for the subdivision of the natural regions of China into first- and second-order land types, identified mainly on the basis of macro- and microlandforms and other surface features. Discussion of the natural sub-division of China is continued in chapter 3, in which Shi Yulin examines the classification of the national territory into orders (regions), classes, subclasses, groups, and types, on the basis of suitability, limitations, and potential for development for primary use, that was adopted for the 1: 1,000,000 Map of China's Land Resources. The final chapter dealing with China as a whole, by Li Xiaofang, attempts to supplement an earlier national landevaluation scheme with a simplified approach based on levels of land suitability for agriculture, animal husbandry, and forestry.
Part I concludes with two chapters of narrower geographical scope. Chapter 5, by She Zhixiang et al., illustrates some of the more generalized and theoretical points made in the preceding chapters via a study of land use on the Lake Taihu Plain in the southern Yangzi Delta, an area in which the application of complex systems of multiple cropping has resulted in greatly increased grain yields and where the cultivation of important speciality crops is carefully adapted to micro-climatic and other local environmental factors. Song Daquan's chapter on saltmarsh resources continues this illustration with a discussion of the use of coastal wetlands for agriculture, aquaculture, and salt production, with emphasis on the northern Yellow Sea coast and that of southern Zheiian Province.
The three chapters of part II are devoted to the remote and hitherto marginal wetlands of north-east China- previously known to foreigners as Manchuria. Two deal with the wetlands of the Sanjiang Plain, while the last examines those on the southeastern slopes of the Greater Khingan Range. Since large-scale reclamation of the Sanjiang Plain began three decades ago, multiple indicators of environmental deterioration have appeared. The authors of chapter 7 attribute these phenomena both to changes in the pattern of atmospheric circulation and to human activities. In this chapter important measures for regional economic development combined with environmental protection are advanced. Discussion of the problems of waterlogging and drought in the Sanjiang Plain continues in the following chapter, in which Zeng Jianping et al. describe their successful experiments with a well-pumping system that combines drainage with irrigation. The book concludes with a chapter by Chen Yongzong et al. that describes the biological and physical changes consequent upon human intervention, and the biological and engineering measures that are required to drain and reclaim the wetlands on the slopes of the Greater Khingan Range.
In many ways this book may be regarded as a measure of current geographical research in the People's Republic of China, since it embraces the main themes emphasized at present, namely agricultural regionalization, land evaluation and classification, and physical geography. In China most geographical and related research is applied to the development of the nation's natural resource endowment, and this publication provides a vivid illustration of the Chinese policy that research should be closely integrated with the needs of national development, since every chapter falls very clearly under the rubric of "applied geography." It is significant, too, that a large percentage of the contemporary national research effort has been directed at incorporating marginally productive and geographically peripheral areas more fully into the national economy, a direction exemplified here in all nine chapters, but particularly those dealing with north-east China.
In most of the original papers data were presented in traditional Chinese units. These have been converted as follows: 1 mu (mou) = 0.066 ha (or 0.165 acre); 1 fin = 0.5 kg (or 1.1 b); 1 den = 50 kg; and 1 li = 0.576 km (approx. 0.33 mile). Throughout the text binomials have been provided for only those plant taxa less familiar to Western readers.
The editors wish to express their gratitude to Dr. R.D. Hill, University of Hong Kong, Dr. J. Stadelbauer, University of Freiburg, Dr. J. Street, University of Hawaii, and several anonymous reviewers for their many invaluable suggestions regarding a first draft manuscript of this publication. Dr. L.J.C. Ma, of the University of Akron, Ohio, prepared a first draft of the conference proceedings.
Both to provide a degree of coherence to this volume and to avoid publishing already familiar material, the papers delivered at the 1980 meeting by overseas participants are not included here. Since no proceedings per se of the conference will be published, readers interested in obtaining copies of the papers presented by foreign participants should write directly to the respective authors (see the list of contributors at the end of this volume). Further, we confess to having exercised widely our prerogatives as editors, since, in the interests of clarity as well as to reduce the considerable repetitiveness inevitable in conference papers dealing with closely related topics, all chapters have been extensively edited. In so doing, we have deleted much nonessential material, and chapter 7 has been compiled from two previously separate chapters. Not everybody will be satisfied with the result, and surely errors still remain. But we accept sole responsibility for this.
Kenneth Ruddle Osaka
July 1 982
Wu Chuanjun Beijing
July 1 982