Land Cover Changes During Agrarian Restructuring in Northeast China

ARTICLE IN PRESS

Applied Geography 26 (2006) 312–322 www.elsevier.com/locate/apgeog

Land cover changes during agrarian restructuring in Northeast China

Jay Gaoa,Ã, Yansui Liub, Yifu Chenb

aSchool of Geography and Environmental Science, University of Auckland, Private Bag 92019, Auckland, New Zealand bInstitute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China

Abstract

During the last quarter of the 20th century the agrarian sector in China went through a series of reforms. Changes in government policy on land use led to extensive changes in land cover, culminating in the 1990s. These changes were detected from multi-temporal Landsat TM images of 1990, 1995 and 2000 for Northeast China. Overlay of the mapped land cover in ArcInfo showed that farmland and grassland decreased while water, built-up areas, and woodland increased. More than three-quarters of the detected changes occurred during 1990–1995. Farmland changed mainly to woodland, water, and built-up areas while woodland and grassland were converted chieﬂy to farmland. Spatially, the change from woodland to farmland adjoined the margin of natural forests while change in the opposite direction was restricted to the agropastoral west. Paradoxically, reclamation of grassland to farmland also took place in the agropastoral west. These conﬂicting changes were caused primarily by lack of stability and consistency in the government’s land use policies. r 2006 Elsevier Ltd. All rights reserved.

Keywords: Land use/cover change; Land use policy; Agrarian restructuring; Northeast China

ÃCorresponding author. E-mail addresses: [email protected] (J. Gao), [email protected] (Y. Liu), [email protected] (Y. Chen).

Introduction

Land cover and land use changed drastically towards the end of the 20th century throughout China due to a plethora of factors. One of the most important factors is the widespread and profound economic reform during which the government’s economic objectives kept shifting. This process initiated in the late 1970s with the introduction of the ‘‘household responsibility system’’ into the agrarian sector in an attempt to boost agricultural output. In transforming centralized decision-making in agricultural production to market-oriented economy in the early 1990s farmers were given more freedom in their operations. During this era changing government policies on land use resulted in further and sometimes conflicting changes to land cover. These changes were especially pronounced in Northeast China due to its role as one of the most important ‘‘grain bases’’ in China. This means that it is subject heavily to government’s changing policies on land use. The consequences of these changes have caught the attention of a number of researchers. Tong, Hall, and Wang (2003) studied land cover change during 1961–1998 using historical data of rice, wheat, and maize production. Li and Wang (2003) went one step further by examining the magnitude of changes in agricultural land use intensity throughout the country to identify the causes for regional disparity. Han and He (1999) examined changes in farmland loss between 1993 and 1996 based on officially released data. Similarly, Lin and Ho (2003) systematically analyzed land use data gathered from the first ever nation- wide land use survey of 1996. Through comparison with the 1949 data they determined the characteristics of land use change. It is well known that statistical data released by the Chinese government may not be reliable due to under-reporting for taxation purposes (Lin & Ho, 2003). The data are also less comparable when they span a few decades for both the definition of terms and the method of data collection may have changed in the interim. Instead of relying on government statistical data, this study takes advantage of satellite imagery data in studying land use/cover changes. As an effective means of acquiring information about the Earth’s surface, satellite imagery has been used to map land use/cover (Lo & Fung, 1986). At a medium resolution of 30 m, Landsat Thematic Mapper (TM) data enable mapping of important crops and primary cover types, and the interpretation of grassland cover features (Wright & Morrice, 1997). Changes can be detected from overlaying multiple land use/cover maps produced from multitemporal satellite images in a geographic information system (GIS, Hayes & Sader, 2001; Kaufmann & Seto, 2001). Existing studies (Ridd & Liu, 1998; Seto et al., 2002) on land cover changes are limited in that the changes detected are restricted to a period between an initial state and an end state. Thus, it is difficult to gain insights into the process of change. Although Shi, Chen, and Pan (2000), and Muller and Zeller (2002) studied land cover change in three different years, they focused their attention either on the final outcome of the changes or on the characteristics of the changes themselves. The process of change and its temporal dynamics escaped their attention. Most importantly, inadequate attention was paid to the mechanisms of change in these studies. Reid et al. (2000) explored changes from the combined effects of drought and migration, changes in settlement and land tenure policy, and changes in the severity of the livestock disease at the landscape scale. Lo and Yang (2002) analyzed the causes of land use/cover change from the perspectives of demography, socio-economic variables, and spatial proximity to established urban facilities. ARTICLE IN PRESS 314 J. Gao et al. / Applied Geography 26 (2006) 312–322

Land cover changes at the regional scale can be triggered by a variety of variables, of which government policy on land use is featured prominently in a country where land ownership is held in the public hand. The impact of government policy on land use/cover change has caught the attention of Erickson (1995) and Krausmann et al. (2003). Erickson (1995) addressed the impact of local land use policies on changing forest cover and its distribution in a Midwestern (USA) watershed. Krausmann et al. (2003) analyzed the relationship between changes in land cover and socioeconomic metabolism in Austria. They found that stable and consistent policy there has not caused any negative impact on land cover change. This is in stark contrast to China during the 1990s when government policies on land use kept changing as a result of agrarian restructuring. The purpose of this study is to elucidate the impact of institutional constraint on conflicting land use/cover changes in Northeast China during the 1990s when its agriculture went through profound restructuring. Specifically, we attempt (1) to reveal the spatial pattern of and regional disparity in land use/cover changes; (2) to explore the temporal dynamics of these changes and their driving forces at different stages; and (3) to expound how the observed changes have been caused by inconsistent and even conflicting government policy on agricultural land use/cover at different stages of economic development, and by the market-oriented reform in the agrarian sector.

Northeast China

Northeast China encompasses three provinces of Heilongjiang, Jilin, and Liaoning (Fig. 1) at a combined territory of 791,800 km2, of which nearly 30% is arable. Natural settings of the Northeast fall roughly into three distinct physiographic zones (Fig. 1). The first zone, adjoining North Korea and Russia in the east and northeast, consists of valleys and low-lying terraces formed by three rivers, the Heilong, Wusu (Ussuri), and Tumen. Lying to the west of zone 1 is the mountainous and hilly zone that encompasses the Greater and Lesser Hinggan Mountains in the north and Changbai Mountain in the south. Originating from these mountains is the Nen River, a major tributary of the Songhua River that flows eventually to the Heilong River. Home to one of the remnant virgin forests in China, zone 2 is well covered by mature trees. Situated in the east, the third zone is made up mostly of plains. At a size of 302,000 km2, it accounts for two fifths of the total territory of the study area. Inside this zone lies the largest fertile Northeast Plain in China. It is comprised two smaller plains, Songnen in the north and the Liao River in the south. Lying to the west of the Northeast Plain is the interlocked agropastoral area with a continental climate and less precipitation. Thus, it is highly vulnerable to desertification by encroaching sand dunes from West China (Liu, Gao, & Yang, 2003). This area has been selected for study because it experienced massive changes in land cover. In the late 1970s the old collective farming system was replaced by the household production system to unleash farmers’ incentives for higher productivity and more income. However, as users of the land (but not owners) farmers still had to honor grain production quotas imposed by the government. Historically, the government attached great importance to grain self-sufficiency. Under the yiliang weigang (taking grain production as the guiding principle) policy, grain production was increased through zealous reclamation of marshland, grassland, marginal woodland, and even fallow land as farmland. However, this over-emphasis on grain quantity while ignoring its quality ARTICLE IN PRESS J. Gao et al. / Applied Geography 26 (2006) 312–322 315

Fig. 1. Location of the study area. devastated agriculture in the Northeast by the mid-1990s as its products (e.g., soy bean and wheat) were not competitive in the market. Soon after the abandonment of this policy, another one was issued. Alarmed by a huge loss of cultivated farmland to urban and industrial use, the government momentarily froze all new development projects that involved conversion of cultivated land to non- agricultural use. With the promulgation of the gengdi zhongliang dongtai pingheng (dynamic balance of the total quantity of cultivated land) policy in 1997, the farmland lost to urban uses must be compensated for by reclamation of other types of land, usually in the distant frontier regions such as the Northeast. Cultivation of such newly reclaimed land in a highly vulnerable environment (e.g., infertile soil, steep terrain and semi-arid climate) caused enormous environmental problems, including land degradation, desertiﬁcation, and even severe ﬂooding. To restore the deteriorated environment the policy of tuigeng huanlin (reversing cultivated land to woodland) was introduced later in the decade. During ARTICLE IN PRESS 316 J. Gao et al. / Applied Geography 26 (2006) 312–322 the correction of the legacy of previous policies, land use/cover accordingly underwent more changes. Thus, Northeast China is a textbook case to explore the role of institutional policy constraints in causing environmentally detrimental changes to land use/cover.

Identiﬁcation of land cover changes

Land cover changes were identified from land cover maps produced from Landsat TM and Enhanced TM Plus (ETM+) satellite images. They were recorded in 1990, 1995 and 2000 in a season when the spectral disparity among different land covers was maximized. These images, which had been geometrically rectified in PCIs (version 7.0), were visually interpreted to produce a land cover map of farmland, woodland, grassland, built-up areas, water, and fallow land in the respective year via on-screen digitization. Farmland refers to any land used for cultivation of crops, which may include rice, wheat, soybeans, maize, and sugar beet. Woodland is defined as areas covered by either natural forest or by sparsely populated regenerating forest. Also included in this category are bushes and shrubs. Fallow land refers to any unused land, including marshland, salinized land, sandy land, and barren land. The accuracy of these maps was verified in the field. Changes in land use/ cover between any two times were mapped through overlaying two land use/cover maps of respective years in ArcInfos (version 8.02). After intersection with the administrative boundary of the three provinces, these change maps were quantitatively analyzed by province. In order to quantify land use/cover changes and their regional disparity, a land-use dynamic degree (LDD) was calculated using Eq. (1): , Xn Xn 1 LDDk ¼ DSij Si ðt2 t1Þ 100%; i; j ¼ 1; 2; 3; 4; 5; 6; iaj, (1) ij i¼1 where LDDk stands for annual dynamics of land use/cover changes for province k (k ¼ 1, 2, 3) from time t1 to t2, Si is the area of land cover type at time t1, DSij is the change in area for a land parcel whose cover type changed from i to j between t1 and t2; n represents the total number of land cover types which is six. Able to show dynamics of land cover changes and their variation across different regions (Liu, 1999; Liu, Liu, & Zhuang, 2003b), LDD was calculated for two time intervals, from 1990 to 1995, and from 1996 to 2000.

Detected land cover changes

Among all detected changes, farmland experienced the most drastic reduction by 1,021,576 ha (Table 1). Of this reduced farmland, 524,160 ha were converted into woodland, a benign outcome of the government’s effort on afforestation since the mid- 1980s. The other two signiﬁcant losses to farmland occurred in the form of conversion to water at 257,639 ha and to built-up areas at 178,361 ha. To a large extent, the loss in farmland was partially compensated by the conversion of a large chunk of woodland (338,130 ha) in the opposite direction. Another signiﬁcant gain in farmland was conversion from grassland at 229,545 ha. There are three reasons for the changes from woodland and grassland to farmland. First and foremost, the government policy of gengdi zongliang dongtai pingheng was introduced. ARTICLE IN PRESS J. Gao et al. / Applied Geography 26 (2006) 312–322 317

Table 1 Matrix of land use/cover changes during 1990–2000 (unit: ha)

Land cover Farmland Woodland Grassland Built-up Water Fallow Decrease

Farmland — 524,160 55,801 178,361 257,639 5615 1,021,576 Woodland 338,130 — 6142 8435 9290 30,294 392,291 Grassland 229,545 24,833 — 7442 22,468 41,006 325,294 Built-up 0 2702 0 — 0 0 2,702 Water 61,703 2138 888 0 — 1,058 65,788 Fallow Land 6,002 31,141 122,388 2695 14,987 — 177,213 Increase 635,380 584,973 185,219 196,934 304,384 77,973 1,984,864 Net Change 386,195 192,683 140,075 194,231 238,596 99,240 —

Across: original cover type of change; destination cover type of change.

Rapidly urbanizing provinces/municipalities (e.g., Shanghai), unable to conserve arable land, first had to lease land in the Northeast and then had local farmers reclaim it as cropland to make up their quota. Second, felling of natural forest was strictly prohibited by the central government in the Greater Hinggan Mountains to conserve the natural forests in the early 1990s. Within three years a total of 53,000 loggers were laid off (Heilongjiang Environment Protection, 2000). Without any prospect of finding jobs in nearby cities, most resorted to subsistence farming by reclaiming woodland at the margin of natural forests. Third, newly arrived migrants from other parts of China were contracted to grow cash crops such as sunflower seeds, for which woodlands and grasslands were reclaimed as dry fields for farming. In spite of reclamation, farmland experienced a net loss of 386,195 ha. A direct consequence of such a large loss was the considerable decrease in per capita farmland, despite a slight drop in rural population from 60.17 million to 60.11 million during the same period. Woodland experienced the second most extensive changes. On the one hand, 392,291 ha of woodland were lost to other uses, mainly farmland (86%). On the other, 524,160 ha of woodland were created out of farmland, resulting in a net gain of 192,683 ha (Table 1). The third most drastic change of cover was grassland that experienced a net loss of 140,075 ha due to its reclamation as farmland, even though 122,388 ha of fallow land were also changed to farming. As a result, fallow land had a net decrease of 99,240 ha. Built-up and water areas expanded by 194,231 and 238,596 ha, respectively. The expansion in built-up areas was caused by urbanization. Permanent urban residents (excluding seasonal migrants) in the Northeast grew markedly from 38.83 million in 1990 to 46.44 million in 2000, or by 19.6%. Population growth demanded expansion of urban areas at the expenseoffarmlandthatmadeupmore than 90% of the expanded built-up areas. Water gained its acreage from all other covers except urban, even though 85% of the increase came from farmland. Two reasons accounted for this change. First, waterlogging after the 1998 flooding in the catchment area of the Nen and Songhua Rivers changed some farmland to water. Second, some farmland was converted into artificial lakes or fishponds for the purposes of irrigation and aquaculture.

Spatiotemporal variation of changes

The identified changes exhibit a unique pattern of spatial distribution that is associated closely with regional settings. The Greater and Lesser Hinggan Mountains in the east ARTICLE IN PRESS 318 J. Gao et al. / Applied Geography 26 (2006) 312–322 experienced little change owing to its protected status. Rapid development of towns and cities formed a linear expansion of built-up areas along the Shengyang–Harbin transportation corridor. The change from woodland to farmland was distributed in hilly areas around the margin of natural forests. Expansion of grassland was restricted to the border of the agropastoral interlocked west where there was a serious problem of farmland degradation. It is here that fallow land expanded. Considerable reclamation of fallow land (mostly marshes) as farmland took place over the Three Rivers Plain, triggering severe shrinkage in water acreage in the Songnen Plain. Regional disparity in land use/cover changes can be appreciated from LDD that shows a decreasing northward trend (Fig. 2). Liaoning’s LDD value of 0.40 is more than three times as high as that of Heilongjiang’s 0.12 (Fig. 2), indicating that Liaoning experienced much more change in land use/cover than Heilongjiang. The smallest LDD for Heilongjiang is attributed to the extensive cover of protected natural forests, and large- scale state farms which were less likely to change their mode of agricultural production than elsewhere. There is a striking temporal variation in the detected changes between the first and the second half of the decade. All covers except fallow land experienced significantly more changes during 1990–1995 than during 1995–2000 (Fig. 3). For instance, farmland decreased by 363,169 ha during the first half, but by only 23,027 ha during the second half. Similarly, woodland increased by 165,400 ha during the first half, in sharp contrast with an

Fig. 2. Land-use dynamic degree (LDD) and its change by province.

Fig. 3. Area of land use/cover changes by type in the Northeast during 1990–1995 and 1996–2000. ARTICLE IN PRESS J. Gao et al. / Applied Geography 26 (2006) 312–322 319 increase of a mere 27,300 ha during the second half. The changes during the first half of the decade were so substantial that they accounted for 93.5% and 91.7% of the decadal total for farmland and woodland, respectively. The percentages for built-up and water were lower at 85.8 and 75.8, respectively. These changes were characterized by a transformation from farmland to woodland and built-up areas during 1990–1995. However, this general trend of change was reversed during the second half of the decade, during which new woodlands and grasslands were changed back to farmland or fallow land after the newly reclaimed farmland had been severely degraded. The subdued changes during 1996–2000 could also be appreciated from the changes in the LDD value that ranged widely from a minimum of 0.07 (Heilongjiang) to a maximum of 0.34 (Liaoning) over the first half of the decade. This range was reduced to only 0.04 (from 0.02 to 0.06) (Fig. 2). The variation between the two time frames was more impressive for individual provinces. For instance, LDD value changed by 12-fold for Liaoning, and by 5.7 times for Jilin, but by only 1.4 times in Heilongjiang. Woodland increased by 165,414 ha during 1990–1995 thanks to heavy government investment into the construction of the ‘‘Three North’’ forest, also known as China’s ‘‘Green Great Wall’’ using loans from the World Bank. However, such investment stopped during the second half of the decade, resulting in a slowed growth of only 27,268 ha during 1996–2000. Implemented forcibly in the late 1990s, the ‘‘tuigeng huanlin’’ policy did not seem to have had much impact on the increase in woodland area. Water increased by 167,653 ha during the first half of the decade, but by only 70,943 ha during the second half. After the Land Administration Law came into effect in 1998 the change from farmland to reservoirs and fishponds was virtually prohibited. The small rise in water area during 1996–2000 was due mainly to the 1998 flooding in the catchment of the Nen and Songhua Rivers.

Role of land use policies

The conflicting changes in land use/cover in the Northeast described above can be traced largely back to the centralized decision-making behind land use. Changes took place on a grand scale whenever a totally new agricultural policy was issued by the central government. The identified policies of ‘‘yiliang weigang,’’ ‘‘tuigeng huanlin,’’ and ‘‘gengdi zhongliang dongtai pingheng’’ all played a significant role in the detected changes. In a country where the government is the sole owner of land, change in land use/cover is subject to the economical focus of the government at a particular time. Thanks to its rich and fertile land, Northeast China has always been the major resource of grain and natural resources for the Chinese economy since the founding of the New China in 1949. The government has always attached special importance to this region, the largest base of undeveloped farmland in China. Therefore, the Northeast has been left with a lasting imprint of these agricultural policies. Changing policy on agriculture in different periods over the last few decades has directly impacted changes in land use/cover. To make matters worse, this region has been frequently used as a site to experiment with new policies before they are widely implemented in the remainder of the country after significant modification or revision. The influence of these policies is characterized by distinct temporal variation and geographic differentiation in land use. Of the three policies, yiliang weigang exerted the longest influence. Food security in the most populous country in the world and the preservation of farmland, considered critical ARTICLE IN PRESS 320 J. Gao et al. / Applied Geography 26 (2006) 312–322 to the healthy development of the nation’s economy, were featured prominently in the agenda of the newly founded republic in 1949. The government’s obsession with food self- sufficiency was finally fulfilled through the fervent enforcement of the ‘‘yiliang weigang’’ policy until the mid-1980s. Cultivated land was created through reclamation of wetland and grassland. In total, two million ha of wetland was reclaimed as cultivated land. Accompanied by this reclamation was the establishment of 105 large-scale state farms. This policy was not abandoned until a decade later when grain supply far exceeded demand. Geographically, the influence of this policy was the most profound in the Songnen Plain. The influence of the ‘‘gengdi zongliang dongtai pingheng’’ policy was restricted to the second half of the 1990s. Its implementation was in direct response to the ‘‘zone fever’’ in the early 1990s (Cartier, 2001). Development of many economic and real estate zones consumed a huge quantity of farmland. These drastic changes alarmed the central government. Although the government promulgated a land use law as early as 1986 to forbid arable land from being used for non-agricultural purposes (Brown, 1995), this law was not effective. By 1997 a directive from the central government urgently appealed to the conservation of farmland and ordered the freezing of all construction projects. A year later a new but more stringent Land Administration Law was enacted to prevent further loss of arable land. Under this law any farmland lost to urban uses had to be created through reclamation of other land elsewhere (e.g., the frontier Northeast). This law severely curtailed the haphazard change between farmland and land of other uses witnessed in the early 1990s in the prosperous coastal region. Nevertheless, the newly reclaimed farmland in Northeast China, confined mostly to the Three-Rivers Plain, is no substitute for the fertile land lost in the rapidly industrialized South and East where annual multiple cropping is routinely practiced (Lin & Ho, 2003). By comparison, the policy of ‘‘tuigeng huanlin’’ formally promulgated in the late 1990s had the most limited impact during the study period. As a remedy to restore the deteriorated environment caused by improper land reclamation, it is credited with the benign changes from cultivated land to grassland and woodland. Through this remedy it is hoped that unusual natural disasters, such as the unprecedented flooding in 1998 could be avoided. Given that more than half of the woodland in the Greater and Lesser Hinggan Mountains was cleared for farming, this policy will have the greatest impact in this geographic area that is characterized by a hilly or even mountainous topography.

Implications for sustainable land use

The three identified policies do not aim for the same achievement. ‘‘Yiliang weigang’’ was intended to provide food security while gengdi zongliang dongtai pingheng aimed at conserving farmland which is only indirectly related to food production. The government might take pride in achieving food self-sufficiency, even though this achievement by no means represented a rational use of land resources, let alone a sustainable use. On the contrary, such an achievement was gained at the expense of severe environmental degradation and rapid depletion of natural resources. According to Fischer and Sun (2001), if China increased its grain imports to about 10–15% of its current total output, the pressure on cropland and water resources would be sufficiently reduced to reach a sustainable level, especially in the Northeast. The policy of ‘‘gengdi zongliang dongtai pingheng’’ is single-minded and shortsighted, and hence is counterproductive to the ARTICLE IN PRESS J. Gao et al. / Applied Geography 26 (2006) 312–322 321 optimal use of land resources. It may help prevent farmland from being lost to other uses in the short term, but is detrimental to the maintenance of a sound ecology. Fortunately, all of the three northeastern provincial governments have realized the importance for supporting ‘‘ecologically sound’’ policies. Accordingly, more efforts have been made to protect wetland, woodland, and Phaeozern. Only the ‘‘tuigeng huanlin’’ policy was meant to restore the environment that was degraded due to the enforcement of the previous two policies. Lack of stability and consistency in land use policy promulgated by different ministries at different times has harmed the harmonic relationship between farmers and their land in the past. Such institutional constraints have prevented the implementation of environmentally sound integrated land use. In order to avoid these unnecessary and sometimes fruitless changes, policy makers at the top level should take other relevant factors into consideration before enacting a new policy and consider its long-term effect. Furthermore, as the market economy gains dominance, government as the major holder of land leases should interfere less with grain production. Instead, efforts should be directed at assisting farmers to improve the quality of the land to prevent it from degradation and to guide them in using land and water resources sustainably.

Conclusions

Widespread changes in land use/cover took place in Northeast China during the 1990s, a period highly coincidental with drastic restructuring in the agrarian sector. Most of these changes were confined to the first half of the decade. Spatially, these changes exhibited a trend of northward decrease. They are attributable mostly to institutional constraints. The ‘‘yiliang weigang’’ policy caused reclamation of marshland, grassland, and marginal woodland as cultivated land. The ‘‘gengdi zongliang dongtai pingheng’’ policy was blamed for the unsustainable tillage of marginal land since the mid-1990s. These conflicting and occasionally devastating land cover changes can be traced back to changing government policies on land use. Since the ‘‘tuigeng huanlin’’ policy facilitated the increment in woodland acreage, it should be vigorously enforced to lessen excessive and irrational exploitation of land resources and to rehabilitate the degraded environment in the study area.

Acknowledgements

This research was ﬁnancially supported by the National Basic Research Program of China (No. 2006CB400505), and the Key Projects of National Natural Sciences Foundation of China (Grant number: 40635029). Additional funding came from the Visiting Researchers by Outstanding Overseas Scholar Fund at the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences. The Northeast Institute of Geography and Agricultural Ecology offered assistance during ﬁeldwork of this study. Two anonymous referees made valuable comments on an earlier version of this paper. ARTICLE IN PRESS 322 J. Gao et al. / Applied Geography 26 (2006) 312–322

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