ACADEMIC

project on environmental scarcities, state capacity, & civil violence

Deforestation and Desiccation in China: A Preliminary Study

by Wang Hongchang1

I. INTRODUCTION

The goal of this paper is to discover the impact of deforestation on the desiccation of China’s north and northwest. The study starts with a brief discussion of the long-term impact of deforestation on precipitation. It continues with a rough estimate of China’s forest cover and rate of deforestation, followed by an evaluation of the impact of deforestation on China’s water resources, environment and economy. The paper concludes with a number of recommendations for afforestation.

For the purpose of this study the term “desiccation” refers to the gradual reduction of water resources in a geographical region. Desiccation can involve a reduction of surface water (including ice and snow), ground water, and atmospheric moisture, as well as water present in plant and animal life. North and northwest China, where the average annual precipitation has decreased by one third between the 1950s and the 1980s,2 has been experiencing just such a desiccation process. Evidence is clear and abundant. For example, lake Lobnor vanished in 1972, and lake Kukunor, since the beginning of Holocene period, has dwindled in area by one third and in depth by 100 m.3 Finally, the depth of lake Ohlin, at the head of the Yellow River, has been dropping by over 2 cm annually.4

This paper identifies astronomical and geological factors, as well as deforestation as contributing to desiccation. While important, the first two factors are not subject to human control; therefore, this study is limited to the impact of deforestation. Deforestation causes forests to shrink thereby lessening their capacity to intercept and retain precipitation. Instead of trapping precipitation which then percolates into the soil, deforested areas become sources of surface water runoff. Deforestation also contributes to decreased evapotranspiration, which lessens atmospheric moisture and precipitation levels. This is exemplified by precipitation levels in the Black River basin, a tributary of the Min River in Sichuan province, where since the 1970s, precipitation has declined by 8 to 20 percent during the months of July and August.5

 

The Long-Term Impact of Deforestation on Precipitation Levels

The impact of deforestation on precipitation levels is not limited to deforested areas alone; it also impacts on precipitation levels downwind from the deforested area. Deforestation can have a negative impact on the flow of moisture in the atmosphere, and while we know very little about this flow, its magnitude may be equivalent to that of surface water.

In his study of atmospheric moisture flows in northwest China, Cui Yuqin discovered that the majority of moisture flows in the northwest arrive from the Indian and Pacific Oceans. Of 356 storms observed in the eastern half of northwestern China, 166 came from the Bay of Bengal, 87 from the South China Sea, 19 from the Yellow Sea, and 83 from the East and Yellow Seas. Only one arrived from the west (Mediterranean and Atlantic Oceans).

The Tarim and Qaidam Basins constitute sections of an extremely arid band stretching through China’s northwest. The east Tarim and the Qaidam basins receive moisture from the Arctic. Moisture imports for these regions were measured for the winter and summer months between 1984 and 1986:

 

Table 1: Total Movement of Moisture Between, 1984 and 1986
Region Quantity (billion m3)
North -483.4
East Tarim and
Qaidam Basins
380.4
East -461.6
South -219.0
Southwest 1276.8
Northwest 583.5
* a (-) sign refers to net moisture export

The largest forest stocks in China are on the Qinghai-Tibet Plateau, which enjoys average annual precipitation of 713.2 billion m3, equivalent to 11.5 percent of the national total. Huang and Shen conducted a study of moisture over the Qinghai-Tibet Plateau between May and August of 1979. In their study the Plateau was divided into five regions, and the intensity of moisture flow into each region was measured. The eastern part of the plateau and western Sichuan receive by far the most intensive influx of moisture from the south, and hence play a key role in China’s ecosystem.6 Moisture from the Arabian Sea, the Bay of Bengal, and the South China Sea gathers in these regions, moving northward through the various river-basins that run in a north-south direction, and eventually arrives in Qinghai, Gansu and Shaanxi provinces. This process is highly dependent on the forest cover of the East Plateau and West Sichuan region.

If the East Plateau and West Sichuan region were well forested, a water molecule originating in the Indian or Pacific Oceans would fall on the forests as precipitation. It would eventually evapotranspire back into the atmosphere, returning repeatedly as precipitation as it proceeded northward. However, as a result of deforestation, water molecules from the ocean fall as precipitation, run into streams, and return to the sea, severely depleting the moisture available for the northwest.

 

Forests in China

 

Pre-Historic Forests

In order to provide a quantitative base-line for analysis, I begin by estimating forest cover in China at the dawn of the Neolithic age. The Chinese Ministry of Forestry designates lands suitable for forests as lands presently covered by trees and lands with the potential to support forest growth. I first suppose that all present farmland was covered by forests. This assumption is correct for the south, but will lead to inflated figures for the north. I also assume that all modern roads and built-up areas (i.e., developed areas, in U.S. Bureau of Census parlance) were once forested. Due to a lack of reliable Chinese government data on developed areas in China, data from studies conducted in the U.S. are adopted.7 Per capita developed land of the states in acres is regressed on their density of population per mileaccording to the following formula:

Y = 1.145 – 0.16X r = -0.67
Population densities of the provinces in China are substituted in the regression equation and the built-up area is derived. The sum of cropland, built-up land, and lands suitable for forestry are assumed to be the estimated area of forest cover in ancient times (Table 2).

A drawback of this system of delineating potential forest-land is its failure to take climate changes into account. The climate in ancient times most likely differed, with regions that are today arid and semi-arid perhaps far milder, and thus more able to support forests.

The Pamir Plateau is a good example. The Pamir Plateau is the watershed of Inner Asia. All rivers to the west of the Pamir Plateau flow to the Aral Sea, while all to the east flow into the Lobnor. The Suler River at the west end of Gansu once flowed westward to the Lobnor lowlands, but now it, and all other riverbeds west of Gansu province are dry. Geologists drilling a nine meter core in central Lobnor discovered that the four upper meters affirmed predictions that Lobnor was a fresh water lake during the Holocene era. The geologists also discovered that the uppermost 30 centimeter layer was salty, suggesting that Lobnor became a saltwater lake about 750 years ago. Clearly, with fresh water once in abundance, it is safe to assume that the region encompassed by present-day Xinjiang province was far richer in flora and fauna during ancient times. Therefore, the estimated 6 percent forest cover for Xinjiang province found in Table 2 may be too low.

Differences may also have existed between pre-historic and modern-day precipitation patterns, with summer monsoons possibly transporting more moisture and more heat to the north than occurs at present. The flow of the Yellow River and other inland rivers may also have been far greater. If higher moisture availability and heat levels did, in fact, exist in pre-historic times, the forests in the north would have absorbed and retained more heat and moisture. Greater heat and moisture retention would result in milder climates than exist in present day arid and semi-arid northern regions, resulting in more wildlife, less soil erosion, and denser vegetation.

 

Table 2: Estimate of the Total Area of Forests in Pre-Historic China
Province Land
Currently
Suitable for
Forestry

(1,000 ha)
Built-up
Land 

(1,000 ha)
Cropland
(1,000 ha)
Forested
Areas in 

Pre-Historic
Times 

(1,000 ha)
Forest
Cover
(1,000 ha,
% of total
area)
Beijing 630 90 409 1,129 67
Tianjin 50 75 430 555 50
Hebei 6,210 1,801 6,544 14,555 77
Shanxi 5,770 1,832 3,681 11,283 75
Inner Mongolia 44,094 4,705 5,082 53,881 49
Liaoning 6,710 1,647 3,452 11,809 79
Jilin 8,769 2,076 3,932 14,777 82
Heilongjiang 21,537 4,438 8,905 34,880 76
Shanghai 10 110 318 438 75
Jiangsu 504 567 4,522 5,592 56
Zhejiang 5,898 521 1,691 8,109 81
Anhui 3,550 478 4,334 8,462 64
Fujian 8,875 1,278 1,229 11,381 95
Jiangxi 10,578 1,765 2,337 14,680 92
Shandong 1,937 706 6,798 9,441 63
Henan 3,839 727 6,887 11,453 72
Hubei 7,403 1,830 3,422 12,654 70
Hunan 11,730 2,056 3,296 17,082 81
Guangdong 12,244 3,478 2,879 18,601 85
Guangxi 13,963 2,694 2,611 19,268 84
Sichuan 19,031 6,764 6,256 32,050 57
Guizhou 9,010 2,067 1,849 12,926 76
Yunan 26,124 4,085 2,858 33,062 87
Tibet 11,721 832 224 12,777 11
Shaanxi 12,487 2,234 3,488 18,208 96
Gansu 6,132 3,226 3,482 12,839 33
Qinghai 3,037 1,323 580 4,940 7
Ningxia 621 599 801 2,021 31
Xinjiang 2,694 4,084 3,134 9,911 6
Taiwan 1,970 166 1,284 3,420 95
Total 413,983 43

 

Forest Cover in 1948

Deforestation and desiccation are both time-related processes. The time element is illustrated in the decline of forest cover that occurred between the Neolithic era and the present day. It is also visible in the period since 1949.

Prior to 1949, the forested area of what is present-day Sichuan totaled 14.4 million ha (Mha). According to the Sichuan volume of The Forests in China series, by the early 1950s, forested area in Sichuan decreased to 0.7 Mha with a growing stock of 1.6 billion m3 .8 It also reported the average annual consumption rate of growing stock as 9 million m3.9

In a study of Tibet, the pre-1949 Guomindang government reported that forested area totaled 1.5 Mha. By contrast, a recent survey conducted by the General Investigation Group of the Qinghai-Tibet Plateau reported a much larger total of 6.135 billion ha of forested area and 1.4 billion m3 of growing stock. In 1994 The Beijing Evening Paper reported total new forested areas in Tibet equaled 7.17 Mha, with new growing stock at 2.084 billion m3.

Table 3 provides an estimate of forest area and growing stock in China in 1948. Tables 5 and 6 provide equivalent data for the years 1976, 1981, and 1988.

 

Table 3: Forest Cover in 1948 China (1,000 ha)
Region Actually Forested Area Land Suitable for Forest Cover
Northeast 30,690 38,062
Northwest 6,156 94,928
Shaanxi 1,990 4,682
Gansu 2,285 8,760
Ningxia 59 7,864
Qinghai 1,456 34,225
Xinjiang 366 39,397
Southwest 26,676 80,227
Sichuan 8,289 6,055
Xikang 6,139 22,690
Guizhou 1,588 7,236
Yunan 9,167 10,762
Tibet 1,493 33,485
East 5,866 16,279
Jiangsu 275 1,838
Zhejiang 808 2,122
Anhui 713 3,567
Shandong 108 4,504
Fujian 2,179 3,753
Taiwan 1,783 496
Central South 11,921 35,611
Henan 103 5,061
Hubei 2,367 4,917
Hunan 4,094 6,679
Jiangxi 2,019 4,542
Guangdong 2,238 6,715
Guangxi 1,099 7,696
North 1,496 24,487
Hebei 126 4,089
Chahar 155 7,350
Suiyuan 243 7,545
Shanxi 971 5,503
Total 82,805 289,594
Source: Lee Ting et. al. (ed.) Forestry of Contemporary China (The Social Sciences Publishers of
China: Beijing, 1985) pp. 608-9. This Table draws on The Classification of Lands in China,
published by the Ministry of Agriculture and Forestry of the Guomindang government (January,
1948)

 

Table 4: An Alternative Estimate of Forest Cover in 1948 China
Province Forested Area
(1,000 ha)
Growing Stock
(million m3)
Hebei 635 10
Shanxi 367 10
Inner Mongolia 13,740 848
Liaoning 1,884 67
Jilin 4,270 610
Heilongjiang 16,707 1848
Jiangsu 275 4
Zhejiang 808 13
Anhui 713 22
Fujian 2,179 120
Jiangxi 2,019 72
Shandong 108 1
Henan 103 4
Hubei 2,367 52
Hunan 4,094 171
Guangdong 3,720 106
Guangxi 1,099 34
Sichuan 8,700 1,600
Guizhou 1,588 87
Yunan 9,167 908
Tibet 6,320 1,436
Shaanxi 1,990 87
Gansu 2,285 231
Qinghai 191 21
Ningxia 59 3
Xinjiang 366 54
Taiwan 1,783 205
Total 87,538 8,624
Total Coverage 9.1%

 

Table 5: Forest Cover in China – 1976, 1981, and 1988 (1,000 ha).
Province 1976 1981 1988
Beijing 200 144 215
Tianjin 30 30 62
Hebei 2,010 1,677 2,011
Shanxi 1,090 810 993
Inner Mongolia 10,700 13,740 13,836
Liaoning 3,420 3,653 3,939
Jilin 6,510 6,079 6,231
Heilongjiang 16,660 15,294 15,615
Shanghai 10 8 9
Jiangsu 340 325 386
Zhejiang 3,960 3,429 4,037
Anhui 1,750 1,792 2,261
Fujian 5,900 4,496 5,003
Jiangxi 6,100 5,462 5,992
Shandong 1,320 905 1,596
Henan 1,790 1,420 1,571
Hubei 4,360 3,779 3,854
Hunan 6,580 6,872 6,754
Guangdong 7,480 5,879 4,864
Hainan 866
Guangxi 5,510 5,227 5,227
Sichuan 7,460 6,811 10,872
Guizhou 2,561 2,309 2,221
Yunan 9,560 9,197 9,327
Tibet 6,320 6,320 6,320
Shaanxi 4,580 4,471 4,708
Gansu 1,870 1,769 2,029
Qinghai 190 195 266
Ningxia 60 95 118
Xinjiang 1,440 1,121 1,497
Taiwan 2,069 1,970 1,970
Total 121,860 115,277 124,653

 

Table 6: Growing Stock in China’s Forests – 1976, 1981 and 1988
(million m3)
Provinces Total 1976
Growing
Stock
Total 1981
Growing
Stock
Total 1988
Growing
Stock
Forests
1976
Forests
1981
Forests
1988
Beijing 4 4 5 3 1 4
Tianjin 2 2 2 1
Hebei 73 48 62 62 26 43
Shanxi 57 53 45 39 33 38
Inner Mongolia 946 946 1,025 848 848 865
Liaoning 87 109 132 83 100 121
Jilin 730 711 760 695 608 710
Heilongjiang 1,580 1,552 1,481 1,468 1,434 1,317
Shanghai 1 1
Jiangsu 13 15 28 5 3 7
Zhejiang 82 99 101 63 79 88
Anhui 47 70 85 40 55 71
Fujian 243 431 379 224 296 264
Jiangxi 263 303 242 218 236 169
Shandong 23 24 47 12 5 11
Henan 79 68 92 50 32 40
Hubei 96 118 124 92 99 107
Hunan 189 199 183 150 160 141
Guangdong 212 232 152 199 203 128
Hainan 63 58
Guangxi 193 266 242 171 221 204
Sichuan 1,347 1,153 1,410 1,298 1,049 1,273
Guizhou 159 159 140 141 126 108
Yunan 989 1,321 1,349 946 1,097 1,097
Tibet 1,436 1,436 1,436 1,403 1,401 1,401
Shaanxi 244 279 295 243 252 259
Gansu 198 173 192 189 164 172
Qinghai 31 23 35 24 17 30
Ningxia 5 4 7 3 3 5
Xinjiang 237 235 232 213 200 183
Taiwan 186 227 227 186 227 227

Sources:

  1. Zhang Jianguo, Economic Problems in Chinese Forestry (People’s Publishers: Fujian, 1985) pp. 83-84, Table 5-1. Data were collected after a decision to reduce the size of Inner-Mongolia, while simultaneously expanding the size of neighboring provinces. Later this decision was reversed. As a result I was forced to make some adjustments which I based on information provided by the corresponding volumes of the Forests in China series published by the Forestry Publishers of China: Beijing (1986).
  2. Lee Ting, Forestry of Contemporary China (The Social Sciences Publishers of China, 1985) pp. 614-5.
  3. The Ministry of Forestry, National Statistics of Forest Resources 1984-1988 (Beijing, 1989).

Heilongjiang Province: A Case Study10

Between 1896 and 1940 forest cover in Heilongjiang shrank from 70 to 55 percent, declining from 33.1 Mha to 25.818 Mha. Concurrently, growing stock declined by 890 million m3, from over 4 billion m3 to 3.11 billion m3. Forest cover and growing stock continued to decline, and by 1948 shrank to 16.707 Mha and 2 billion m3 respectively. In 1948 average growing stock per ha was 110.6 m3, and forests covered 35.6 percent of the province. By late 1986, forested area in the province shrank to 15.771 Mha, and growing stock declined to 1.45 billion m3, the equivalent of 83.3 m3/ha. In sum, between 1896 and 1986 forested area in Heilongjiang declined by 17.329 Mha, a drop from 70 percent forest cover in the province, to only 34.7 percent, and growing stock shrank by 2.55 billion m3.

A key cause of deforestation in Heilongjiang province has been commercial lumber production. Heilongjiang is China’s largest supplier of lumber for commercial use, producing 465 million m3between 1949 and 1986. To produce this quantity of lumber the province required 734 million m3 of growing stock. However, lumber production for commercial use is not the sole contributor to deforestation in Heilongjiang. Of the 795,000 ha deforested since 1976, only 297,000 ha were actually used for the production of commercial lumber. Slash and burn farming accounts for an additional 62,000 ha, and unauthorized felling of trees accounts for 199,000 ha. Six thousand ha of Quercus Mongolica were destroyed for the culture of silkworms and edible fungi, and 125,000 ha were cleared for construction of railroads, highways, and high voltage lines. Finally, 47,000 ha were lost to forest fires.

Gao Yonglu et. al. estimated that in 1984 forests in Heilongjiang retained 6.6 billion m3 of water, equivalent to 9 times the total water storage capacity of all the reservoirs in the province.11 If we assume that the water-retention capacity of a forest is proportional to its growing stock, then we can infer that forests in Heilongjiang had the capacity to retain 8.4 billion m3 of water in 1948, and over 12.2 billion m3 in 1896. Gao et al. also estimated that as a result of larger forests, Heilongjiang attracted an additional 25 mm of precipitation to the province in 1984. Given the greater extent of forest cover in earlier periods, we can infer that as a result of greater forests, Heilongjiang attracted an additional 32 mm of precipitation in 1948 and an additional 69 mm in 1896.

China’s northeast includes the provinces of Heilongjiang, Jilin, and Liaoning, as well as the northeastern corner of Inner Mongolia. Deforestation of this region impacts on regions to its west, including the adjacent province of Inner Mongolia (at an elevation of 1,000-1,300 m above sea level) and the Qinghai-Tibet plateau to the west of Inner Mongolia (at an elevation of 4,000-5,000 m above sea level). During the spring and summer months the northeast monsoon originating in the Sea of Okhotsk, and the southeast monsoon originating in the Pacific Ocean, reach the northeastern region. These monsoons push the air from above the northeastern region in a westward direction. The more humid the air above the northeastern region, the more moisture will reach Inner Mongolia, and eventually, the Qinghai-Tibet plateau. Based on our argument that deforestation causes a decrease in precipitation levels, we infer that deforestation in Heilongjiang results in decreasing moisture levels in Inner Mongolia, and eventually, on the Tibet-Qinghai plateau. As a result of decreased moisture levels both Inner Mongolia and the Tibet-Qinghai plateau suffer from rising desiccation rates.

The Affect of Deforestation in Sichuan on Provinces in China’s Northwest

Sichuan province is a precipitation-rich province adjacent to the arid provinces of Qinghai and Gansu. Monsoons from the Indian and Pacific oceans pass through Sichuan as they move north-eastward towards Qinghai and Gansu. The monsoons are normally replenished by evapotranspiration in Sichuan, however, as noted earlier, deforestation limits the amount of evapotranspiration that takes place. Therefore, the provinces of Qinghai and Gansu are adversely affected by deforestation in Sichuan.

 

Table 7: The Decline of Forest Cover in 20th Century Sichuan12
Year Forest Cover (% of province)
1937 34.0
1948 20.0
1962 11.5
1976 13.3
1980 12.0
1988 19.2

In the early 1950s Sichuan had a growing stock of 1.6 billion m3. By 1980 the growing stock had decreased by 550 million m3. Significant deforestation has also occurred in Sichuan’s two southern neighbors, Yunan and Guizhou. Between 1963 and 1975, total growing stock in Yunan decreased by 140 million m3, while in Guizhou, growing stock decreased by 2 million m3 between 1975 and 1987. The impact of deforestation in Sichuan and its southern neighbors on Gansu and Qinghai is similar to the previously noted impact of deforestation in Heilongjiang on Inner-Mongolia and the Qinghai-Tibet plateau. Such deforestation may constitute the most serious blow dealt to China’s already fragile ecosystem since 1949.

Forest Cover in Sichuan

Afforestation and lumber production in Sichuan have occurred in parallel over the years.

 

Table 8: Average Annual Afforestation and Lumber Production in Sichuan
Year Afforestation
(ha)
Lumber Production
(1,000 m3)
1949 187 29
1950-1959 110,467 1,175
1960-1969 142,000 2,333
1970-1979 255,067 3,031
1980-1989 501,933 3,919

It should be noted that while afforestation is a province-wide occurrence, the main effort is concentrated in the east. This can be explained by the fact that western Sichuan is mountainous, sparsely populated and hard to access, whereas the east is flat, densely populated, and easily accessible.

 

Table 9: Distribution of Afforestation and Lumber Production in Sichuan Province
Region Total Afforestation
(%)
Total Lumber
Production
(%)
East 70 16.5
West 30 83.5

The Min River is an example of the affect of deforestation on moisture. The Min River, flowing out of the Min Mountains in Sichuan, is the largest tributary of the Yangzi River. During the Yuan Dynasty, the upper reaches of the Min River valley were 50 percent forested. However, by 1950 forest cover had declined to 30 percent, and by 1980 to only 18.8 percent. This decrease in forest cover produced a number of changes in the environment of this region. For example, in the 1970s the level of summer precipitation along the river’s upper reaches declined by 8 to 20 percent. In addition, wind velocity increased, as is exemplified by Muo County where wind speeds increased from an average 2.1 m/s in the 1950s, to 3.2 m/s in the 1960s, and to 4.0 m/s in the 1970s. Between the 1950s and 1970s water volume in the upper Min River increased by 38.27 m3/s during periods of flooding, and decreased by 10.82 m3/s during periods of drought. Snow accumulation also declined along the Min River valley. While still considered a wetland, these changes have resulted in the appearance of some signs of desiccation in the Min River valley.

The upper reaches of other rivers in Sichuan, such as the Gold Sands River, the Yalong River, the Dadu River, the Fu River, the Tuo River, and the Jialin River, experienced similar deforestation and desiccation. The deforestation that has occurred along these rivers in Sichuan province has reduced the amount of moisture available for the adjacent arid regions of Qinghai and Gansu province.

 

Deforestation During the Great Leap Forward

There are no comprehensive data to enable a quantitative analysis of deforestation during the Great Leap Forward (1958 to 1961). However, the Forests in China series does supply data that span the Great Leap Forward period for a number of provinces. Unfortunately, the figures quoted below are not all specific to the Great Leap Forward, rather, they encompass additional time periods.

Between 1957 and 1962 Fujian Province lost 1.72 Mha of forested area and 39.5 million m3 of growing stock. Over a period stretching from the early 1950s to 1976, Sichuan Province lost 1.24 Mha of forested area and 250 million m3 of growing stock. From 1956 to 1963, Guangdong province lost 630,000 ha of forested area and 41.2 million m3 of growing stock. The growing stock of forests in Hubei province declined by 14 million m3 within a short period starting in 1958, and growing stock in Hunan province declined by 104 million m3 between 1958 and 1961.

The proportion of growing stock destroyed in these provinces during the Great Leap Forward ranges from one third (Hunan, Hubei) to one tenth (Sichuan). The situation in many other provinces was no better. This trend of declining forest cover during the Great Leap Forward continued through the early 1980s.

 

II. METHODOLOGY

The movement of surface water is visible whereas that of atmospheric moisture is invisible but of equal magnitude. High elevations in China’s west, declining to the east, result in all surface waters flowing either eastward or southward. Only the influence of the northwestward moving summer monsoons causes atmospheric moisture to move in the opposing direction. The movement of moisture among regions is also affected by the diffusion process. If humidity levels in one region are higher than those in another region, moisture will shift from the relatively humid region to the relatively dry region, even in the absence of winds.

Observed values of precipitation in any province are subject to periodic fluctuations and random influences. After filtering out these components what remain are trend values. I posit that precipitation trends are influenced by various factors, including the quantity of forested area. Increased deforestation effects a reduction in evapotranspiration, precipitation, and air humidity, lessening the quantity of moisture available for export to other regions.

Precipitation levels within a specific province are affected by deforestation that occurs within the province, as well as by precipitation that occurs outside its borders. For example, imagine an air stream over the Beijing-Canton Railway that carries moisture from the southern province of Guangdong where monsoons bring heavy rains, via the provinces of Hunan, Hubei, Henan, Hebei arriving eventually in Beijing. Deforestation in Guangdong will reduce the moisture exported to Hunan. Reduced moisture imports from Guangdong will cause a drop in precipitation levels in Hunan that are also influenced by local deforestation. Declining precipitation levels in Hunan will reduce moisture exports to Hubei. As is the case in Hunan, local deforestation also decreases precipitation in Hubei. This process continues through the provinces on to Beijing. As a result of the impact of deforestation on precipitation levels, the further a province is from the starting point of the monsoons, the greater its vulnerability to desiccation. This is known as the cumulative effect of deforestation, and it presents a gloomy picture for the arid regions of China. Fortunately both deforestation and desiccation are, to some extent, reversible. Furthermore, arid regions will enjoy a disproportionate benefit from general afforestation in China.

China has a total land area of 960.272 Mha, of which 27.8 percent, or 267.429 Mha are defined as “land suitable for forestry.” Of the land suitable for forestry, only 46.6 percent, or 124.653 Mha, is actually forested. There remain 142.776 Mha of unforested land suitable for forest growth in China, an extremely valuable ecological resource.

In densely forested areas of China, approximately 38.7 percent is new growth, and approximately 31.9 percent is middle-aged growth. As a result of the felling of mature trees, and concurrent afforestation programs, China’s forests are generally becoming younger.

 

Table 10: Types of Land Suitable for Afforestation
Type of Land Cover 1,000 ha
Sparse Forests 19,637
Shrubs 28,116
Newly Planted Forest Area 7,288
Nurseries 185
Barren Slope Lands 87,551

In time, both the sparse forest areas and newly planted forest areas should become dense forests. If regions dominated by barren slope lands were afforested, the climate in areas covered with shrub growth would likely improve to the point where full growth trees could survive. In such a scenario, forest cover might reach approximately 27.8 percent of total land area instead of the 13 percent that existed in 1988.

Forests and Water Resources, An Exercise

We can calculate the additional evapotranspiration that would occur if all potentially forested lands were actually forested. We assume that one half of all additional moisture accrued as a result of afforestation efforts will remain within the borders of each province, with the remainder exported to downwind provinces. Though we can safely assert that afforestation increases the production of atmospheric moisture, and that this moisture will travel northward on the summer monsoon, in fact, we know very little about atmospheric moisture. For example, Guangdong province may export additional moisture to the provinces of Hunan and Jiangxi, but we do not know the quantity. In addition, Hunan province may import additional moisture from the provinces of Guangdong and Guangxi, yet we are again unable to assess the quantities. These uncertainties limit our ability to construct a reliable model. Nonetheless, we are able to arrive at some tentative conclusions.

Based on the figures in Table 11 it appears that precipitation levels in Inner Mongolia will rise by 13.9 percent with an increase of forest cover. Inner Mongolia has a 400 mm isohyet more than 1000 km long. The distance between the 400 mm and 300 mm isohyet amounts to more than 400 km at the east end of the province, 200 km in the middle and 100 kilometer at the west end. The possibility of an additional 13.9 percent of precipitation might extend the forest lands by about 100,000 km2. Similar projections could be made for the provinces of Qinghai, Gansu and Ningxia.

 

Table 11: Afforestation and Precipitation
Province Precipitation
(billion m3)
Evapotranspiration
(billions m3)
Additional
Forests 

(1,000 ha)
Hebei* 120.7 100.4 5,384
Shanxi 83.1 71.6 5,637
Inner Mongolia 318.3 281.2 18,856
Liaoning 100.0 67.5 1,809
Jilin 114.0 79.5 2,885
Heilongjiang 248.1 183.4 7,327
Jiangsu** 108.2 82.3 230
Zhejiang 159.7 71.2 1,916
Anhui 159.0 97.3 1,920
Fujian 203.3 86.5 3,976
Jiangxi 266.0 124.4 4,504
Shandong 111.0 84.6 1,137
Henan 129.0 97.9 2,130
Hubei 216.6 122.0 3,726
Hunan 302.0 140.0 4,996
Guangdong*** 375.7 164.6 6,021
Guangxi 362.1 174.1 8,309
Sichuan 588.9 275.8 15,904
Guizhou 209.4 105.9 6,229
Yunan 482.4 260.3 15,685
Tibet 713.2 265.0 5,401
Shaanxi 137.1 95.1 7,417
Gansu 129.7 102.4 4,658
Qinghai 206.4 144.1 2,830
Ningxia 15.7 14.9 526
Xinjiang 242.9 163.6 3,367
Taiwan 87.4 23.7
Total 6,188.9 3,477.4 142,776

 

Table 11 Continued:
Province Additional
Precipitation
(billion m3)
Additional
Evapotranspiration
(billion m3)
Enhancement
of Precipitation
(%)
Hebei* 40.0 29.9 33.1
Shanxi 20.3 30.9 24.4
Inner Mongolia 44.3 55.0 13.9
Liaoning 5.0 10.0 5.0
Jilin 8.3 14.6 0.5
Heilongjiang 20.6 35.4 8.3
Jiangsu** 3.1 2.1 2.9
Zhejiang 11.5 16.1 7.2
Anhui 10.8 16.2 6.8
Fujian 18.9 34.0 9.3
Jiangxi 29.0 40.3 10.9
Shandong 5.7 7.6 5.1
Henan 13.8 15.0 10.7
Hubei 21.4 29.3 9.9
Hunan 29.0 39.6 9.6
Guangdong*** 18.8 31.0 5.0
Guangxi 41.7 66.8 11.5
Sichuan 72.3 92.9 12.3
Guizhou 35.8 44.8 17.1
Yunan 71.1 128.0 14.7
Tibet 15.4 14.0 2.2
Shaanxi 33.8 41.1 24.7
Gansu 23.6 12.7 18.2
Qinghai 10.7 6.8 5.2
Ningxia 6.2 1.4 39.2
Xinjiang 3.0 4.0 1.2
Taiwan
Total 614.1 819.5 9.9

Source:

  1. Liu Hong, Facts of China (State Commission of Planning: Beijing, 1990).
  2. The Ministry of Forestry, National Statistics of Forest Resources(1984-1988) (Beijing, 1989).
    * Tianjin and Beijing are included in the figures for Hebei province.
    ** Shanghai is included in the figures for Jiangsu province.
    *** Hainan is included in the figures for Guangdong province.
    1) North China (Hebei, Shanxi, Inner Mongolia) might have an increment of precipitation of 104.6 billion m3, or a 20.0 percent increase.
    2) Northwest China (Shaanxi, Gansu, Ningxia, Qinghai, Xinjiang) might have additional precipitation of 77.3 billion m3, or a 10.6 percent increase.
    3) The Loess Plateau (Shaanxi, Shanxi, Gansu, Ningxia, Qinghai) might have additional precipitation of 94.6 billion m3, or a 16.5 percent increase.

There is a positive feedback relationship between forests and precipitation. More forests produce more precipitation, which, in turn, makes further afforestation possible. Of course, the process cannot continue indefinitely, and forests and precipitation eventually reach a new equilibrium.

 

Economic Losses Resulting From Deforestation

A comparison of pre-historic forested areas with those in 1988 shows that China depleted 289.33 Mha of forests. It can be argued that deforestation was the necessary cost of building Chinese civilization. However, it can also be argued that a more nature-friendly policy that paid serious attention to conservation efforts may have enabled the construction of Chinese civilization without depleting China’s forests. The existence of 142.776 Mha of potentially forestable land suggests that at least some of the deforestation that occurred was excessive. The following section evaluates the approximate damage wrought by excessive deforestation.

According to a study conducted by the State Environment Protection Bureau, by the year 2000 during moderately dry years, there may be a water shortfall of 70 billion m3. Approximately 70 percent of the shortfall (50 billion m3) will occur in the Yellow-Huai-Hai Plain and the Liao River Basin. The Yellow-Huai-Hai Plain includes Beijing and the provinces of Hebei, Tianjin, Henan, Shandong and Anhui. This area contains 24 Mha of cropland, 24 percent of the national total.

Table 11 demonstrates a decline in precipitation of 614.1 billion m3 for China as a result of excessive deforestation. Of the total decline, 75.3 billion m3 occurred in the Yellow-Huai-Hai Plain and the Liao River Basin regions. The Loess Plateau also suffered declining precipitation, with a decrease of 94.6 billion m3, causing the Yellow River basin to undergo a drastic reduction in water runoff. These facts would seem to suggest that China’s contemporary water shortage is a result of excessive deforestation.

A monetary value for precipitation is an essential tool that will enable us to choose the most cost-effective approach to providing water resources. However, despite the obvious importance of precipitation, economists have been reluctant to assign it a monetary value. This study attempts to provide such a value by developing an equation based on a number of estimates: the average runoff coefficient for China is approximately 44 percent, and excessive deforestation has decreased runoff by approximately 614.1 billion m3. The equation is as follows: 614.1 billion m3 x 44% = 270 billion m3.

The Chinese central government is presently studying the feasibility of a south-to-north water diversion project to overcome growing water scarcity in the north. The envisaged project would require an investment of 120 billion yuan in order to provide the infrastructure necessary to divert 52 billion m3 of water from the Yangzi River to the Yellow, Huai, and Hai Rivers. The average unit investment cost per m3 of water per annum will be 2.31 yuan. Assuming a 10 percent interest rate per annum, the cost in interest per ton of diverted water would be 0.23 yuan. To this figure we add annual operating expenses of approximately 0.07 yuan per ton of diverted water. Therefore, the total annual cost of 1 ton of diverted water would be approximately 0.30 yuan. Based on these figures, the total loss of water resources due to excessive deforestation can be assigned a monetary value of 0.30 (yuan) x 270 billion (m3 of water) = 81 billion (yuan).

Economic Losses Resulting from the Impact of Deforestation on Declining Lumber Resources

Annual lumber production grew from 5.7 million m3 in 1949 to 61.7 million m3 in 1992; in addition to these ofical production figures, 70 million m3 of unofficial lumber is produced. More than one m3 of forest resources must be consumed in order to produce one m3 of lumber; therefore, to provide the above noted quantities of lumber, more than an equivalent amount of wood mass must be harvested. Furthermore, 68 million m3 of fuelwood is harvested each year. The statistics for 1985 found below may exemplify the typical situation:

 

Table 12: Division of Forest Resource Consumption
Causes of
Decreasing Forests
Millions
of m3
Percent
Total Consumption of
Forest Resources
399 100
Natural degradation 44 11.1
Lumber Production for
Human Consumption
237 59.5
Lumber Production 231
Lumber lost during
Preparation of Products
5
Lumber lost during Transport 1
Construction in Forested
Regions
2 0.5
Community Consumption 13 3.4
Edible Fungi Cultivation, etc. 5
Village Enterprise Processing 4
Slash and Burn Farming 4
Energy Consumption 98 24.5
Fuelwood for private purposes 87
Fuelwood for Industrial
purposes
10
Losses due to Disasters 4 1.0
Forest Fires 2
Pestilence and Flooding 2
SourceForestry Yearbook of China (1987).

The annual consumption rate of growing stock in China is 400 million m3. Although not an excessive consumption rate given China’s population, lumber remains scarce and expensive. Lumber shortages are not a result of present consumption rates, rather, they are a result of China’s past lumber consumption practices.

In the first survey of forest resources that was conducted between 1973 and 1976, the average annual consumption rate of lumber was found to be 190 million m3, approximately equal to the maximum available supply. However, both the second survey conducted between 1977 and 1981, and the third survey conducted between 1984 and 1988, found that consumption had increased beyond annual replacement levels.

 

Table 13: Forest Resources (million m3)
Survey Period Annual Growth Annual
Consumption
Deficit
1977-1981 275 294 19
1984-1988 316 344 28
Source: Yong Wentao, Research on the Roads of Development of Forestry in China, Forestry
Problem
, No. 1(9) Beijing (1991).

On February 29, 1992 Mr. Gao Dezhan declared that growing stock in China had increased to 10.868 billion m3 resulting in an equilibrium between annual growth and annual consumption. Since the average annual increase of growing stock in China is 3.46 percent, China can theoretically consume 10.868 billion m3 x 3.46% = 376 million m3 per year of growing stock on a sustainable basis. Were it not for the excessive deforestation that occurred in China’s past, present consumption rates might have included an additional 10.465 billion m3 of growing stock. As a result, China might have had an additional 362 million m3 of growing stock available, resulting in the production of approximately twice the present quantity of lumber.

In 1989, in reaction to increasing scarcity, the provincial government of Fujian raised the price of growing stock of Cunninghamia and Pine timber to 160 and 70 yuan/m3 respectively. By averaging the price at 115 yuan/m3 it is possible to evaluate the economic loss of rising lumber prices that were a result of excessive deforestation. As far as the value of fuelwood is concerned, we may use a value of 26.32 yuan/m3 set as a special tax in Guizhou province since 1987.13

 

Table 14: Cost of Lost Wood Resources
Use Million m3 Cost Per m3
(yuan)
Billion yuan
Lumber 131.7 115 15.15
Fuelwood 68 26.32 1.79
Total 199.7 16.94

 

Economic Losses Resulting from the Impact of Deforestation on Desertification

In addition to genuine deserts, in 1989 China had 17.6 Mha of desertified land and 15.8 Mha of lands that are vulnerable to desertification. From the 1950s through the 1970s desertification in China increased at an annual rate of 156,000 ha.14 We argue that with increasing afforestation will come increasing precipitation which will enable afforestation of desertified regions.

In China, 3.9 percent of all desertified lands are located in semi-humid regions with annual precipitation of 500 to 600 mm. These areas include the lower reaches of the Neng River and the Second Sunghua River, located in the eastern section of Baicheng Prefecture, in Jilin province, as well as the northern section of the middle reaches of the East Liao River, and the southeastern section of the Horqin Sandy Lands of Inner-Mongolia. Desertification in these regions is a result of human activities and could be reversed through agroforestry.

Some 65 percent of desertified lands are located in semi-arid zones, such as the eastern and central sections of Inner Mongolia, as well as northern Hebei, northwestern Shanxi, northern Shaanxi, and southeastern Ningxia provinces. Annual precipitation in these regions is 250 to 500 mm. If all forestable lands in China were afforested, precipitation levels might increase to such an extent that these semi-arid zones could be rehabilitated through agroforestry and sustainable grazing.

The remaining 30 percent of desertified lands in China are located at the fringes of deserts or oases in arid zones. Desertification of these regions is a result of natural desiccation and human activities, specifically overgrazing and deforestation. Afforestation of all forestable lands might enable the rehabilitation of at least some of these desertified lands.

The influence of deforestation on precipitation levels has not been limited to desertified regions. For example, the Qilian mountain range has also been influenced by deforestation. The Qilian mountain range forms a humid island separating the northwestern provinces of Gansu and Qinghai. Equi-precipitation lines form closed ellipses around this mountain range. Precipitation levels decrease the greater the distance from the mountains. Continued deforestation in China inhibits the movement of moisture towards the northwest, causing the equi-precipitation ellipses around the Qilian mountains to contract. Contracting isohyets have resulted in decreased water flow in regional river systems.

China has a total of 17.644 Mha of desertified land. Those desertified areas found in semi-humid and semi-arid zones may be a result of global deforestation and local elimination of natural vegetation. We argue that unjustified deforestation was responsible for one half of the desertified lands in arid zones. Desertification of one ha of cropland results in the loss of 2,333 kg of grain (based on the lowest figures on yields in Gansu province). As peasants in traditional China usually paid one half of the harvest to the landlord, 1,166 kg (valued at 823.2 yuan) are taken as losses arising from desertification per ha. Losses resulting from potentially desertified lands are assumed to be one half of this figure (416.6 yuan).

 

Table 15 : Cost Arising from Desertification of Land
Land Area (1,000 ha) Cost (billion yuan)
Desertified land 14,936 12.3
Potentially desertified land 15,800 6.5
Total loss 30,736 18.8

 

Economic Losses Resulting from the Impact of Deforestation on Soil Erosion

Deforestation has reduced water-retention capacity in China. As a result, summer rains cause flash floods, and much of the water that was once retained by forests now flows into the sea or to neighboring countries, taking along large amounts of soil, without contributing to biological cycles. Due to deforestation, 222.3 billion m3 of the summer rains, a major source of water in China, are lost annually as runoff.15 In monetary terms the cost of this lost water is 0.30 yuan x 222.3 billion m3 = 66.7 billion yuan.

Increased soil erosion is another outcome of deforestation. Water is the main agent of erosion. Erosion is most grave during China’s rainy season which runs through the months of July, August, and September. It is during this period that 74.1 percent of all silt transportation occurs. This is exemplified by the Shaan County section of the Yellow River, where 76.5 percent of the annual silt load is transported during these summer months.

The source of the Yangzi River is in the western sections of Sichuan and Yunan provinces. Four tributaries of the Yangzi – the Gold Sands, Dadu, Min and White Dragon Rivers – flow through this region, which is interspersed with high mountains (often over 2,000 m) and deep valleys. Topsoil on the steep mountain slopes of this region is very thin and extremely vulnerable to erosion once natural vegetation is removed. Over the last three decades forest cover in western Sichuan has declined by 9.9 percent, and in western Yunan by 16 percent. Annual summer rains have caused rapid erosion of the topsoil, leaving bare and stony mountains after only a few years.

Every year more than 5 billion tons of soil are eroded.16 Our research suggests that excessive deforestation may be the cause of half of the annual soil erosion in China, or 2.5 billion tons/year. With every ton of soil lost 18 kg of nitrogen, potassium and phosphorous may be lost as well. Nitrogen, potassium and phosphorous are essential plant nutrients with an average retail price of 909.9 yuan/ton. Therefore, the economic loss caused by soil erosion in terms of plant food can be estimated as 909.9 yuan x 0.018 ton x 2.5 billion tons = 41 billion yuan.

Between 1949 and 1977, 8,420 ha of barren land was afforested in the provinces of Yanan and Shaanxi. From 1978 to 1985, another 29,707 ha were afforested. As a result of these efforts the rate of soil erosion decreased by 1.14 million tons annually. In Nianzhuang District of Yanan province the previous annual soil erosion rate was 324,000 tons. Following afforestation efforts, annual erosion rates were reduced by 157,000 tons, or, 48.5 percent. Similar examples are commonplace.

Economic Losses Resulting from the Impact of Deforestation on the Siltation of Reservoirs

In a study of 1,105 water reservoirs in the United States it was discovered that, on average, 0.21 percent of reservoir capacity was lost to siltation every year. By contrast, a study of 34 reservoirs in China revealed that, on average, 1.36 percent of reservoir capacity was lost to siltation every year. Among those reservoirs sampled, the Bronze Gorge and Salt Pot Gorge Reservoirs lost an exceptionally high 17.4 percent and 17.0 percent of their capacities respectively each year. Reservoirs in the provinces of Shaanxi, Gansu, Shanxi, and Inner Mongolia, with a total capacity of 3 billion m3, lost 1.15 percent of their capacity every year between 1949 and 1975. An additional 169 reservoirs, with a total capacity of 11.7 billion m3, lost 0.52 percent of their capacity annually. Irrigation reservoirs on the Tuo, Fu and Jialin Rivers in Sichuan province have an annual sedimentation rate of over 1 percent. The largest hydroelectric station in southwestern China, the Gongzui Hydroelectric Station, has an annual sedimentation rate of 3.5 percent.

We assume that 0.5 percent of total annual sedimentation in China is a result of excessive deforestation. In 1992 China had 84,130 reservoirs with a total capacity of 468.8 billion m3. Based on these figures, we suggest that sedimentation caused by excessive deforestation can be estimated as 0.5% x 468.8 billion m3 = 2.3 billion m3/year. The cost of each m3 of water for construction purposes in Shaanxi Province in 1992 was 0.31 yuan. By extrapolating this number to China as a whole, we can estimate the economic costs of reservoir sedimentation resulting from excessive deforestation as follows: 0.31 yuan x 2.3 billion m3 = 0.7 billion yuan/year.

There are 2,848 lakes in China with a total area of 80,465 km2. These lakes constitute natural reservoirs. Dongting Lake in Hunan Province has an area of 2,400 km2. Every year about 200 million tons of sediment settle in it causing the lake bed to rise by 4 cm. As a result, the holding capacity of Dongting lake decreases each year by 0.04 m3 x 2,400 km2 = 1.0 billion m3.

We assume that sedimentation causes the total holding capacity of lakes in China to shrink by 0.5 billion m3 per annum and that excessive deforestation is the cause of one half of all sedimentation. We also assume that the unit cost for reservoir sedimentation of 0.31 yuan/m3 can be applied. Based on these figures, the economic cost of lake sedimentation resulting from excessive deforestation can be estimated as: 0.31 yuan x 0.5 billion m3 x 0.5 = 0.1 billion yuan.

Economic Losses Resulting from the Impact of Deforestation on the Siltation of Navigable Rivers

The deforestation of China has brought desiccation throughout the northern regions of the country, resulting in dropping river volumes. Dropping river volumes have affected the navigability of once major waterways. For example, in 647 B.C., various grains were transported from Fengxiang in Shaanxi province via the Wei, the Yellow, and the Feng Rivers, to Yicheng in Shanxi province. Today, even during the rainy season, both the Wei and the Feng Rivers are no longer navigable.

Between 1949 and 1981 soil erosion and river bed aggradation reduced the navigable length of rivers in Sichuan province from 14,000 km to 7,000 km. In Hubei province, similar factors caused a decrease in the navigable length of rivers from 14,400 km in 1960 to 7,900 km in 1979, affecting even the Yangzi River. In February 1995, the middle reaches of the Yangzi River became impassable for two weeks due to insufficient water volume and river bed aggradation.

We assume that in 1992 about 1.1 million people were employed in various aspects of inland water transport (their average wages being 3,738 yuan per year). If it were not for heavy silting resulting from excessive deforestation, river traffic, and employment in labor-intensive loading and unloading, could roughly double. This means that the the total maximum economic loss attributable to excessive deforestation is roughly 4.1 billion yuan (3.738 x 1.1 million), or, 4.6 billion yuan per annum in 1993 Renminbi.

Economic Losses Resulting from the Impact of Deforestation on Flooding and Droughts

According to the Statistical Yearbook of China, any farm region is declared a disaster area if floods or droughts cause crop yields to decrease by over 30 percent. From 1975 to 1992, an average 16.34 Mha were declared disaster areas each year. Of the 16.34 Mha, 5.2 Mha were flood related, and 11.14 Mha were drought related.

The likelihood of flooding and droughts has increased over time as a result of deforestation, human activities, and nature’s whim. For example, from 25 A.D. to the 13th century, Hunan province recorded 5.5 floods per 100 years. In the 14th and 15th centuries the number of floods increased to 28.5 per 100 years, and from the 16th century to the present, the frequency of flooding increased to 90.2 per 100 years.17

A study of drought patterns between 206 B.C. and the 20th century for the provinces of Gansu, Ningxia, and Qinghai was conducted by Yuan Lin. According to this study, every three year period included one year of drought. However, if we limit the study to the period between 581 A.D. and the 20th century the frequency of droughts increases to one every two years. If we further limit the time period to 1368 A.D. through the 20th century, the frequency of droughts increases to two every three years.18 We hypothesize that excessive deforestation may be responsible for doubling the frequency.

Flooding may also result in property loss. Massive floods in the Huai River basin in 1991 resulted in direct reported losses of 24.2 billion yuan in 1992 values. These floods destroyed 8 million tons of grain valued at 4.9 billion yuan. The remaining 19.3 billion yuan lost arose from property damage equivalent to 5,170 yuan/ha.19

We suggest that afforestation of all forestable lands in China might reduce property losses resulting from floods by 5.2 Mha x 1/2 x 5,170 yuan = 13.4 billion yuan.

 

Summary of Economic Losses Resulting From Deforestation

After separately assessing the impact of excessive deforestation on various aspects of China’s environment and economy, we now combine the results in order to calculate the total annual economic impact excessive deforestation in China.

 

Table 16: Annual Economic Losses Resulting from Excessive Deforestation
Factor Cost
(billion yuan)
Reduced Precipitation 81.0
Reduced Lumber
Output
19.4
Desertification 18.8
Lost Water Runoff 66.7
Loss of Plant Nutrients 41.0
Reservoir and Lake
Sedimentation
0.8
Loss of River
Transport Capacity
4.1
Property Loss
Resulting from
Flooding
13.4
Total 245.2

If the losses due to excessive deforestation were equally distributed among China’s 1.2 billion people, the cost per capita would be 189 yuan per annum. The Chinese government has invested 1.4 billion yuan in afforestation efforts, the equivalent of 0.6 percent of the total annual loss caused by excessive deforestation.

Our calculations are far from all-encompassing. Examples of other areas affected by deforestation include landslides, air quality, water quality, forest products other than lumber, hydro-electric power, biodiversity, and the aesthetic value of nature. In addition, there are costs that cannot be measured. For example, dam sites are selected according to optimal economic considerations; however, following the siltation of reservoirs, new sites must be chosen. Clearly the new sites will not be as optimal as the original sites, increasing the cost to later generations.

There are additional shortcomings to our calculation method. For example, this study adhered to the accepted approach in economics of evaluating loss on a cost-factor basis. We did not calculate any value added by manufacturing. This approach also presupposes full employment conditions, which clearly do not exist. In fact, we contend that deforestation causes desiccation in northwest China, resulting in less biomass, less employment, and less income.

 

The Impact of Deforestation on the Chinese Economy

Let us assume that all potentially afforestable lands underwent afforestation. What impact would this have on annual farm production?

In 1992 there were 95.4 Mha of croplands in China, producing 504 billion yuan of farm products, or 5,283 yuan/ha. If afforestation reduces the size of disaster areas by one half, or 8.17 Mha, then 43 billion yuan worth of farm products would e added every year.

8.17 Mha x 5,283 yuan = 43 billion yuan

If we suppose that farm output in the northern, northwestern, and northeastern provinces will increase by the same proportion as precipitation, farm output should increase by an annual monetary value of 28.6 billion yuan.

The monetary value of forestry products in 1992 was 42.3 billion yuan. If forested areas were eventually increased by 115 percent, the value of forest products may be expected to increase to 91 billion yuan (42.3 x 2.15). If farm product output increases by 14.2% (43 + 28.6/504), forestry product output increases by 115 percent, and precipitation increases by 9.9 percent, we may safely assume that the value produced by livestock, fishing and sidelines will increase by 15 percent.

We also suppose that the value of output produced by waterworks and hydro-electric stations will increase by 9.9 percent, or, 0.8 and 0.2 billion yuan respectively.

Based on these calculations it is possible to compare the current scale of the economy and that of a post-afforestation economy:

 

Table 17: Scale Comparison of Pre – and Post – Afforestation Economy
Economic Sector Actual 1992
Economic Output
(billion yuan)
Post- Afforestation
Economic Output 

(billion yuan)
Agricultural Output 908.5 1,083.6
Mineral Output 196.0 197.0
Total Output 1,104.5 1,280.6
GNP 2,403.6 2,817.3
Proportional Comparison 100.0 117.0

Each yuan of material supports 2.2 yuan of GNP. Post-afforestation GNP in China will increase by 414 billion yuan, and per capita GNP will increase by 345 yuan.

 

III. CONCLUDING REMARKS

Ecological crises in China persist regardless of the political system. Ecological crises occurred in Imperial China, Republican China, and Communist China.20

The most likely explanation for the spreading desiccation in China’s north is deforestation in the south. Deforestation in the south increases run-off and reduces the quantity of moisture moving northward. Fortunately, this process can be at least partially reversed through afforestation efforts.

In the early 1990s, the steady trend of deforestation seems to have been supplanted by some growth in both forest area and quantity of growing stock. The four provinces of Guangdong, Fujian, Hunan, and Shandong assert that they have already afforested all potentially forestable lands in their respective regions. Other provinces claim to be following suit. Even if not completely trustworthy, these claims should be a source of some optimism regarding China’s future environment.

 

IV. ADDITIONAL READINGS

Chang Shenwen, et al., “To Green Barren Mountains and Slopes with the Yanan Spirit,” Forestry of China (No. 2, Beijing, 1992), pp. 33-34.

Chen Chunhuai, “South to North Water Transfer – An Important Strategic Measure of Water Resource Exploitation in China,” Science and Technology Review (August 1991), pp. 28-32.

Cui Yuqin, The Conversion Process of Air and Land Water Resources in the Northwest (Beijing, 1992), pp. 6, 21-26.

Cui Yuqin, “Moisture Condition in Karakorum and Kunlun Mountains,” Zang Hsian Soong and Shi Zhichu (eds.), Glaciers and Environment of the Yarkant River, Karakorum Mountains (Beijing: The Sciences Publishers, 1991), pp. 107-122.

Guo Ginhui (ed.), Physical Geography of China – Surface Water (Beijing: The Sciences Publishers, 1981), p. 12.

Huang Fujun and Shen Rujin, The Source of Moisture and its Distribution over the Qinghai Xizang Plateau during the Period of Summer Monsoon, May-August, 1979. Proceedings of the International Symposium on the Qinghai Xizang Plateau and Mountain Meteorology, March 20-24, 1984 (Beijing: Sciences Publishers, 1986), pp. 596-603.

Liu Hong, Facts of China, State Commission of Planning (Beijing, 1990).

Sze Nianhai, Treatment of Ravines and Streams on the Loess Plateau, Essays of Historical Geography of China (Vol. 2, Xian: Shaanxi People’s Publishers, 1985), pp. 357-358.

Wang Yongan, “A Plan for Constructing Protection Forest System in the Yangzi River Valley,” Bulletin of Soil and Water Conservation (No. 1, Xian, 1987), pp. 33-37.

Whyte, Pauline (ed.), The Palaeoenvironment of East Asia from the Mid-Tertiary (Vol. I, Center of Asian Studies, University of Hong Kong, 1988).

Zhou Yiliang et al., Forests of China (The Sciences Publishers, Beijing, 1990), p. 10.

Institute of Geography, Chinese Academy of Sciences, Outline of Chinese Agricultural Geography (Beijing: The Sciences Publishers, 1983), p. 361.

The Ministry of Forestry, National Statistics of Forest Resources (1984-1988) (Beijing, 1989).

The General Investigation Group of Qinghai-Tibet Plateau, Forests in Tibet (Beijing: The Sciences Publishers), p. 1,085.

The Shaanxi Institute of Hydrological Science and the Qinghua University, Reservoir Siltatio, (Beijing: The Hydro-Electric Publishers, 1979).

 

V. APPENDIX

 

Worksheet for the Preparation of Table 11

  1. The additional moisture evapotranspired by additional forests of any province is designated as dE, one half of which is assumed to become additional precipitation (0.5dE). The other half is assumed to be exported to adjacent provinces.
  2. The exported moisture for each province is given a code: HB Hebei; SA Shanxi; M Inner Mongolia; L Liaoning; J Jilin; HE Heilongjiang; S Shanghai; Z Zhejiang; A Anhui; F Fujian; J Jiangxi; SD Shandong; HN Henan; HUB Hubei; HUN Hunan; GD Guangdong; GX Guangxi; SC Sichuan; GU Guizhou; Y Yunan; T Tibet; SHA Shaanxi; GA Gansu; Q Qinghai; N Ningxia; X Xinjiang; TA Taiwan.
  3. A province may export moisture to several adjacent provinces. The share any importing province has in the moisture exported by the source province is called the “moisture export coefficient.” The coefficients are arbitrarily assigned.
  4. Additional precipitation consists of two parts. (1) 0.5dE of the province; and (2) one half of the imported moisture.
  5. Formula for Individual Provinces:
    Additional Precipitation of Hebei,

    dPHB = 0.5dEHB + 0.5 (0.2HN + 0.2L + 0.7SD)

    dPSA = 0.5dESA + 0.5 (0.3HN + 0.5HB)

    dPM = 0.5dEM + 0.5(0.4L +0.2J + 0.5SA + 0.2GA + 0.5HB + 0.4HE + 0.3SHA + 0.5N)

    dPL = 0.5dEL

    dPJ = 0.5dEJ + 0.5(0.4L)

    dPHE = 0.5dEHE + 0.5(0.8J)

    dPS = 0.5dES + 0.5(0.4Z + 0.1A)

    dPZ = 0.5dEZ + 0.5(0.4F)

    dPA = 0.5dEA + 0.5(0.4Z + 0.7S + 0.1HUB)

    dPF = 0.5dEF + 0.5(0.25GD)

    dPJX = 0.5dEJX + 0.5(0.2Z + 0.25GD + 0.6F + 0.1HUN)

    dPSD = 0.5dESD + 0.5(0.3S + 0.25HN + 0.2A)

    dPHN = 0.5dEHN + 0.5(0.5HUB + 0.3SD + 0.5A)

    dPHUB= 0.5dEHUB + 0.5(0.6HUN + 0.2A)

    dPHUN= 0.5dEHUN + 0.5(0.25GD + 0.2GU + 0.3GX)

    dPGD = 0.5dEGD + 0.5(0.2GX)

    dPGX = 0.5dEGX + 0.5(0.25GD + 0.2Y)

    dPSC = 0.5dESC + 0.5(0.1HUN + 0.5Y + 0.5GU + 0.2HUB 0.5T)

    dPGU = 0.5dEGU + 0.5(0.2HUN + 0.2Y + 0.3GX)

    dPY = 0.5dEY + 0.5(0.2GX + 0.3GU + 0.1T)

    dPT = 0.5dET + 0.5(0.2SC + 0.1Y + 0.3Q)

    dPSHA= 0.5dESHA + 0.5(0.25HN + 0.5SA + 0.2HUB + 0.3SC)

    dPGA = 0.5dEGA + 0.5(0.5SHA + 0.5Q + 0.3M + 0.3SC + 0.5N)

    dPQ = 0.5dEQ + 0.5(0.3T + 0.5GA + 0.2SC)

    dPN = 0.5dEN + 0.5(0.2SHA + 0.2GA)

    dPX = 0.5dEX + 0.5(0.2Q + 0.1T + 0.1GA)


Notes:

  1. Wang Hongchang is a Fellow at the Center for Environment and Development at the Chinese Academy of Social Sciences, 14th Floor, No. 5, Jianguomennei Dajie, Beijing 100732, PRC. Telephone 5137744-2875, Fax 5126118.
  2. Please refer to: Economic News (Beijing, September 10, 1993).
  3. The Chinese Academy of Sciences, General Investigation Report of Kukunor (Beijing: The Science Publishers, 1979), p. 21.
  4. Q. Mingyang (ed.), Investigation of the Head of the Yellow River (Qinghai: Qinghai People’s Publishers, 1982), p. 171.
  5. Please refer to: The Sichuan Volume of Forests of China (Vol. 6, Beijing: The Forestry Publishers of China, 1992), pp. 21-26.
  6. Table 2: Intensity of Moisture Flow g.(cm.hPa.s)-1*
    Region West Border North Border East Border South Border
    Southwest Plateau 25.12 -2.6 -11.7 -16.34
    Yarlung Zangbo 11.7 -2.21 -14.97 19.26
    East Plateau and Western Sichuan 14.97 -9.93 8.65 29.32
    Qinghai 13.99 4.06 -4.33 6.42
    Yunan 23.9 -28.8 11.9 9.9
    *grams per hectopascal
  7. U.S. Bureau of Statistics, Statistical Abstract of the United States: 1992 (112th edition, Washington D.C., 1992), Table no. 25, p. 344.
  8. The Forests in China, p. 829.
  9. The Forests in China, p. 834.
  10. Forests in Heilongjiang (Beijing: The Forestry Publishers of China, 1993).
  11. Ibid., p. 443.
  12. Forests in Sichuan (Beijing: The Forestry Publishers of China, 1992).
  13. Hou Tzenzheng, et al., “A study of Supply, Demand, and Import of Lumber in China,” Forestry Problems (Supplement 131, Beijing, 1991), pp. 148, 150.
  14. Chu Zhenda, Desertification and Rehabilitation in China (Beijing The Sciences Publishers, 1989), p. 9.
  15. Fang Zhengsan, A Tentative Discussion of Off-Farm Economic Losses Caused by Soil Erosion (Vol. 1, Xian: Bulletin of Soil and Water Conservation, 1987), p. 66-7.
  16. The State Environment Protection Bureau, Environment of China in 2000 A.D. (Beijing, December, 1984, unpublished), p. 42.
  17. Zhu Xiang, “Studies on Flood Hazard of Hunan Province and Its Mitigation,” Journal of Natural Disasters (Vol. 3, No. 2, Beijing, 1994), pp. 56-62
  18. Yuan Lin, A Study of Historical Droughts in Gansu, Ningxia and Qinghai (No. 2, Lanzhou, 1994), p. 64.
  19. Yuan Guolin, “The Huaihe River Flood in Early Summer of 1991 and Plan to Harness It,” Science and Technology Review (Beijing, October, 1991), pp. 3-60.
  20. Mark Elvin, “Ecology and the Economic History of Asia (II),” (Vol. 14, No. 2), Asian Studies Review, (Australia, 1990), pp. 52-53.