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Home , Afforestation, Forest cover

Impacts of , , and on Cover in China from 1949 to 2003

Yuxing Zhang and Conghe Song

China’s increased from 8.6% in 1949 to 18.21% in 2003. The change of forest cover in 1996; State Administration of China can be characterized in three stages: (1) transition stage (1949–1981), (2) slow increase stage China 2000, 2005), which were conducted (1982–1993), and (3) rapid increase stage (1994–2003). Afforestation is the primary factor by the Ministry of Forestry before 1998 and increasing forest cover in China. Cumulative areas of afforestation in China from 1949 to 2003 were the State Forestry Administration since 1 241 million ha, of which 90 million ha eventually established as , i.e., about 37% of then. Afforestation refers to forest planting the afforested area reach forest status. Harvesting consumed 13 billon m3 in timber volume from 1949 and/or seeding in areas that previously were to 2003. Natural forests were the major source of timber production during the early years, and not classified as forests. The areas of new plantation forests became a major source of timber supply as they matured. Of the 90 million ha plantation forests that contribute to national plantation forests, 53 million ha remained in 2003, the rest were harvested. The remaining forest cover in a year are not equal to the new in 2003 contributed 5.0 of the 6.4 percentage points of increase in China’s overall forest cover afforested areas in the year but are equal to ABSTRACT from1962 to 2003. Large areas of afforestation, intensive timber harvesting, and reforestation have the areas that reach the minimum cover of forests from all the previously affor- made forest ecosystems in China become dominated by young stands, which has profound implications ested areas. Deforestation is the conversion in their ecological functions in the terrestrial ecosystems. of forests to another land use or long-term reduction of canopy cover below the mini- Keywords: afforestation, deforestation, reforestation, forest cover mum of that defined as forests. In China, timber harvesting is by far the major mech- anism of deforestation. Reforestation occurs orests play a critical role in the global (FAO 2001, 2005). However, little is in a deforested area through natural or as- terrestrial ecosystems, including, but known regarding what factors are changing sisted natural regeneration or natural regen- F not limited to, providing a tempo- the forest cover in a country and how these eration in a previously nonforest area. rary in the global carbon cycle factors are working from the FRAs produced The initial natural resources survey (Wofsy et al. 1993, Dixon et al. 1994, by FAO. The objective of this study was to took place during 1950–1962 for 2.95 mil- Goodale et al. 2002), preservation of biodi- understand the impacts of afforestation, de- lion km2 or 30.7% of the country area. Dur- versity (Dobson et al. 1997), and conserva- , and reforestation on forest cover ing the early 1950s, the survey was based on tion of and water resources (Lal 1997, in China from 1949 to 2003. statistics obtained from measurements of Woo et al. 1997). Therefore, it is extremely sample plots made on the ground. In the important to know the extent of land areas Data mid-1950s, air photos were used for large covered by forests to understand the func- Data for afforestation, deforestation, area survey. In the late 1950s, the angle tions of terrestrial ecosystems. The Food and and reforestation were obtained from an ini- Organization (FAO) of the tial natural resources survey and six subse- United Nations provided four Forest Re- quent national forest inventories (NFI) in sources Assessments (FRA) for 1980, 1990, China during 1949–2003 (Chinese Minis- 1The Ministry of Forestry in China was replaced with 2000, and 2005 by country, respectively try of Forestry 1977, 1983, 1989, 1994, the State Forestry Administration in 1998.

Journal of Forestry • October/November 2006 383 Table 1. Forest cover and areas from natural resources survey and NFIs from 1949–2003.

Plantation forest areas Total forest areas Total forest cover Plantation forest cover New planted areas Years (ϫ106ha) (ϫ106ha) (%) (%) (ϫ106ha)

1949 — — 8.60 — — 1950–1962 5.11 113.36 11.81 0.53 34.12 1963–1972 — — — — — 1973–1976 (I) 23.69 121.86 12.70 2.47 56.13a 1977–1981 (II) 22.19 115.28 12.00 2.31 22.44 1984–1988 (III) 31.01 124.65 12.98 3.23 43.63b 1989–1993 (IV) 34.25 133.70 13.92 3.57 27.76 1994–1998 (V) 46.67 158.94 16.55 4.86 25.29 1999–2003 (VI) 53.26 174.91 18.21 5.55 31.85

Forest cover is calculated based on the country area of 960 million ha (i.e., 9.6 million km2) for China, including Taiwan, Hong Kong, and Macao. Forests in Taiwan, Hong Kong, and Macao are not separated into plantation and natural forests in the NFIs. New planted areas are the areas planted during the inventory period. These areas are not forests until the canopy cover reaches 30 and 20% before and after the fifth NFI, respectively. There are numerous reports for forest areas in China in the literature. However, existing reports are inconsistent. Discretion should be given to the definition of forests in various reports. For example, the Global FRA 2000 and 2005 of the United Nations FAO reported larger forest areas for China than we reported here because of the difference in forest definitions (FAO 2001, Su et al. 2005). Data in this table are direct results from NFI (Chinese Government Documents 1977–2005). The roman numbers indicate sequence of NFI. There was no forest resource information during 1963–1972. a This figure includes new planted areas during 1963–1972. b This figure includes new planted areas during 1982–1988. gauge instrument or prism was introduced, consistencies were inevitable. However, the might have been harvested at least once, and which significantly expedited the process. data set reflects the overall trajectory of many areas may have been harvested multi- There was no national forest resource infor- change of forests in China. We have ex- ple times. From 1962 to 2003 China’s forest mation in China during 1963–1972. tracted the total new forested areas from af- cover increased 6.4 percentage points, of The first NFI was performed during forestation, deforestation, and reforestation which 5.0 percentage points was contrib- 1973–1976, in which a stratified systematic from this data set. Consequently, we were uted by afforestation. sampling technique was used to locate NFI able to assess the impact of these activities on Impacts of Afforestation, Deforesta- sample plots. Each province, autonomous China’s forest cover from 1949 to 2003. tion, and Reforestation. Table 2 shows the region, or municipal city designed one or changes in China’s forest cover caused by more sampling populations according to the Analysis and Results afforestation, deforestation, and reforesta- physiographic conditions and forest re- Overall Forest Cover Dynamics. Chi- tion from 1949 to 2003. The impacts are source distributions. The size of the sample na’s forest cover increased dramatically from assessed for plantation and natural forests, plots varied from 0.06, 0.08, and up to 1.0 8.6 to 18.21% from 1949 to 2003 (Table 1). respectively. The net change in forest cover ha in circular, square, or rectangle shapes. It is the result of the combined effects of ϫ of plantation forests is the decrease caused by The sampling grid varied from 1 2kmup afforestation, deforestation, and reforesta- deforestation of plantation forests after com- ϫ tion. From 1949 to 2003, the cumulative to 8 8 km. The second NFI took place pensation of the increase in plantation forest during 1977–1981. A total of 160,000 sam- planted areas in China were 241 million ha, areas from afforestation. The net change in pling plots were measured, of which equivalent to 25 percentage points in forest forest cover of natural forests is the decrease 140,000 were permanent plots. An NFI sys- cover (Table 1). However, the actual contri- caused by deforestation of natural forests af- tem began to emerge. bution from afforestation was equivalent to ter compensation of the increase in natural The third, fourth, and fifth NFIs took an increase of 9.4 percentage points in forest forest areas via reforestation. The net change place during 1984–1988, 1989–1993, and cover or 90 million ha in forest areas. The in overall forest cover is the sum of the net 1994–1998, respectively. These subsequent majority of the afforested areas failed to inventories were performed with additional reach minimum canopy cover required to be changes from plantation and natural forests. standardized techniques and provided more classified as forests. Only 37% of the affor- Because of World War II and the sub- information than the earlier NFIs. Starting ested areas eventually established as planta- sequent Civil War in China before the estab- from the fourth NFI, remote sensing sample tion forests. The most recent NFI in 2003 lishment of China, data were scarce for ac- plots were established. The most recent one, found that plantation forests covered 53 curate estimates of China’s forest cover in the sixth NFI, took place during million ha of the country’s land area, sug- 1949. The former Ministry of Forestry esti- 1999–2003, covering the entire country for gesting 37 of the 90 million ha of the estab- mated China’s forest cover was 8.6% in the first time. This NFI established 415,000 lished plantation forests were harvested. The 1949. The initial forest resource survey dur- permanent sample plots and 2,844,400 re- total timber volume harvested from both ing 1950–1962 found that natural forests mote sensing sample plots. Data from the plantation and natural forests during 1949– decreased 1.20 percentage points in forest sixth NFI were released in August 2005. 2003 was 13.0 billion m3, equivalent to 16 cover, and plantation forests increased 0.53 Data from the initial forest resources percentage points in forest cover at a stock- percentage points in forest cover. However, survey and the subsequent six NFIs are the ing volume of 85 m3/ha. In reality, timber overall forest cover was estimated to be most comprehensive data set available for harvesting had affected much larger areas be- 11.81% in 1962. This increase in forest forest resources in China. Because of the fact cause of selective and staged cutting, imply- cover can not be explained by the contribu- that NFIs were an evolving process, data in- ing almost all forests suitable for harvesting tion from afforestation, deforestation, and

384 • October/November 2006 Table 2. Change in forest cover caused by afforestation, deforestation, and reforestation in China from 1949 to 2003.

New plantation Plantation forests Natural forests Natural forests Planted Natural Net forest Years forests harvested regenerated harvested net change net change change

1949 — — — — — — — 1950–1962 0.53 0.0 1.18 Ϫ2.38 0.53 Ϫ1.2 ϩ3.21a 1963–1972 — — — — — — — 1973–1976 1.94 0.0 2.58 Ϫ3.63 1.94 Ϫ1.05 ϩ0.89 1977–1981 0.45 Ϫ0.61 0.69 Ϫ1.23 Ϫ0.16 Ϫ0.54 Ϫ0.70 1984–1988 2.14 Ϫ1.22 0.60 Ϫ0.54 0.92 0.06 ϩ0.98 1989–1993 1.34 Ϫ1.00 0.73 Ϫ0.13 0.34 0.6 ϩ0.94 1994–1998 1.42 Ϫ0.35 1.08 Ϫ0.74 1.07 0.34 ϩ2.63b 1999–2003 1.56 Ϫ0.89 0.78 Ϫ0.23 0.67 0.55 ϩ1.66c

Units in all columns are in percentage points (%) with respect to the country area (960 million ha). Natural net change is the sum of natural forests regenerated and natural forests harvested; planted net change is the sum of new plantation forests and plantation forests harvested; net forest change is the sum of natural net change and planted net change. a The net increase in forest cover does not match the survey results, indicating that China forest cover in 1949 might have been underestimated. b The net increase in forest cover includes 1.22 percentage points in forest cover caused by change in forest definition from 30 to 20 in minimum canopy cover. c The net increase in forest cover includes 0.39 percentage points from special purpose scrubs that were previously excluded as forests and 0.05 percentage points from Taiwan, Hong Kong, and Macao.

Table 3. Timber volume resources in China’s forests and timber volume harvested from 1949 to 2003.

Total volume in stock Mean volume density Total volume growth Total volume havested Years (ϫ109 m3) (m3/ha) (ϫ106 m3/yr) (ϫ106 m3/yr)

1949 — — — — 1950–1962 10.2 98.9 126.0 87.8 1963–1972 — — — — 1973–1976 (I) 9.5 79.0 226.9 195.6 1977–1981 (II) 10.3 83.4 275.3 294.1 1984–1988 (III) 10.6 79.2 316.0 344.0 1989–1993 (IV) 11.8 83.7 420.0 320.0 1994–1998 (V) 12.5 78.1 457.5 370.0 1999–2003 (VI) 13.6 84.7 497.0 365.0

Note that the total volumes in stock do not equal to the mean volume density times the total forest areas in Table 1 because of data inconsistency in NFI at different times. We also see that the mean volume density is higher during 1977–1981 than that during 1973–1976 even though total volume harvested exceeded total volume growth during 1977–1981, indicating comparability problems among data from different NFIs. reforestation, indicating China’s forest cover methods and concurrent efforts to protect plantation forests for the first time because might have been underestimated in 1949. natural forests. Timber harvesting shifted of continued intensive harvesting of planta- Timber harvesting during the first NFI from earlier to include selective tion forests. Plantation forests continued to from 1973 to 1976 was primarily natural and staged cuttings, which did not change be a major source of timber production. The forests, most of which were recovered overall forest cover. In fact, the total volume overall forest cover increased 0.94 percent- through reforestation. The overall forest harvested during 1984–1988 increased sig- age points during 1989–1993 (Table 2). cover increased during 1973–1976 as a re- nificantly from 1977 to 1981 (Table 3). Overall forest cover in China sharply sult of the increase in plantation forests (Ta- Thus, the actual areas affected by harvesting increased 2.63 percentage points during the ble 2). Plantation forests established earlier were much larger than the areas deforested. 1994–1998 NFI (Table 2). One major rea- began reaching harvesting status during the Because of earlier intensive harvesting of the son for the dramatic increase was a change in second NFI from 1977 to 1981, leading to a natural forests, most of the deforested areas the definition of forest. Forest definition by sharp increase in harvesting of plantation were plantation forests during 1984–1988, former Ministry of Forestry in China was forests. Consequently, harvesting of natural indicating plantation forests were becoming different from that of other developing forests decreased. However, there was a net a major source for timber production (Table countries. In the FRA 1980 and 1990 of loss of forest cover for both plantation and 2). The rapid increase in forest cover from FAO of the United Nations (FAO 2001), natural forests. The overall forest cover de- afforestation was partly caused by a higher the minimum canopy cover required to be creased 0.7 percentage points during 1977– standard for afforestation adopted in 1985, classified as a forest2 is 10% for developing 1981. raising the survival rates from 40 to 85% in countries and 20% for the developed coun- The area of natural forests harvested the south and to 70% in the north to pass tries. The same definition of a minimum continued to decrease during the third NFI afforestation inspection (Chinese Ministry 10% canopy cover was used for all countries from 1984 to 1988 because of compensation of Forestry 1989). The new standard for af- from plantation forests harvested. The over- forestation should improve the contribution all natural forest cover managed to increase rate from afforested areas to national forest marginally. Another important reason for cover in the years to come. Natural forest 2FAO definition of forest also included temporarily un- the decrease in areas of natural forests har- cover increased sharply during the fourth stocked forest areas that were not included as forested vested was the changes in timber harvesting NFI from 1989 to 1993, exceeding that of areas in China’s NFI.

Journal of Forestry • October/November 2006 385 in FRA 2000 and 2005 (FAO 2001, 2005). needs for economic recovery after many (Table 1) and future commitments, The definition of forests in China was ad- years of war in China before 1949. Tim- China’s forest cover will continue to in- justed from a minimum of 30 to 20 percent ber volume harvested each year in- crease in the next 10 years. canopy cover in 1994, adding 1.22 percent- creased rapidly and eventually exceeded age points to overall forest cover. Thus, the timber volume annual growth during Discussion definition of forests in China remains differ- 1977–1981 (Table 3). The cumulative Forest cover is a major index of forest ent from the definition in FAO FRA 2000. areas harvested were 7.85 percentage resources in a country. Although timber vol- Therefore, the forested areas reported to points in forest cover, of which 92% was ume stocking is closely related to its forest FAO in FRA 2005 (Su et al. 2005) are dif- natural forest (Table 2). Although forest cover, they are, in fact, quite different. The ferent from the areas reported here. After cover did not decrease as much because key difference is that forest successional accounting for the increase in forest cover of compensation from afforestation and stages do not have an impact on forest cover caused by change in forest definition in reforestation, forest age structure in as long as the canopy cover reaches the China, the net contribution to the increase China was altered significantly. threshold value of forests. However, forest of forest cover from plantation and natural 2. Slow increase stage (1982–1993). Over- successional stages have a significant impact forests was 1.41 percentage points during all forest cover increased slowly. Timber on timber volume. Old-growth forests have 1994–1998. After intensive harvesting of production remained a major forest much higher timber volumes than young plantation forests during the previous two management goal, but with greater con- ones. It is clear from the data shown in Ta- NFI periods, areas of plantation forests har- sideration of ecological effects of forests. bles 1–3 that China’s forests have become vested decreased. In the meantime, harvest- Timber harvesting continued to deplete much younger because of afforestation, ex- ing of natural forests increased (Table 2). forest resources; however, a significant tensive timber harvesting, and reforestation. The sixth NFI during 1999–2003 cov- difference from the previous stage was Table 3 shows that the total forest volumes ered the entire country for the first time. that plantation forests became the major increased 33% by 2003 from the Natural forest cover increased 0.55 percent- target for harvesting as those planted 1950–1962 survey volumes, while area of age points. There was an increase in harvest- during the early years reached harvesting forest cover increased 54% during the same ing of plantation forests again after a brief status. Consequently, plantation forests period according to Table 1. A higher forest slowdown during 1994–1998. Although contributed 76% of the forest cover har- cover is not a guarantee of higher timber vol- new plantation forests increased forest cover vested (Table 2). In the meantime, ume. These forests need to be managed care- by 1.56 percentage points, timber harvesting China started a series of major ecological fully to increase China’s timber volume. of plantation forests offset the net increase in projects aimed at environmental protec- The increase in forest cover in China is forest cover to merely 0.67 percentage tion with forests, such as preventing soil consistent with the recent observation of en- points. In 2004, the definition of forests was , desert migration, and others. hanced activities from remote modified again to include special purpose Forest cover increased 1.26 percentage sensing (Fang et al. 2004, Xiao and Moody scrubs, which grow in areas with an annual points from afforestation. With a relief 2004). Caution should be taken in inter- precipitation below 400 mm or above the in harvesting, natural forests began to preting the enhanced vegetation activities line in the mountains with a minimum grow back. Although harvested timber based on vegetation index derived from sat- canopy cover of 30% and in which its pri- volume continued to increase (Table 3), ellite observations over China. This may be mary function is . harvested volume was eventually con- the result of a massive shift toward younger The expansion of forest definition to include trolled below the volume of annual forests because of extensive afforestation, de- the special purpose scrubs added 0.39 per- growth. forestation, and reforestation. Dramatic centage points to overall forest cover. Chi- 3. Rapid increase stage (1994–2003). For- change in age structure has significant impli- na’s forest cover reached 18.21% at the end est cover increased rapidly. Timber pro- cation for forest ecosystem functions. For of 2003 with an increase of 1.66% from the duction was no longer the primary goal example, deforestation of mature and old- previous inventory period (Table 2). of , but rather forest growth forests has long-lasting impacts on Characteristic Developmental Stages. ecological effects on the improvement of carbon fluxes (Harmon et al. 1990, Song Based on the change of forest cover (Table environmental conditions. The rapid in- and Woodcock 2003). The intensive timber 1), the dynamics of forests in China can be crease of forest cover resulted from in- harvesting and the rapid increase of forest characterized in three stages. The goals of creased efforts in afforestation and the cover imply that forests in China released forest management were the major factor change in the definition of forest. A new significant amounts of carbon over the last driving the change. national forest policy, aiming at sustain- 50 years, but there is a great potential for able management of forest resources and in the following de- 1. Transition stage (1949–1981). Overall environmental protection, was adopted cades. forest cover was unstable. Timber pro- in 1998 (Zhang et al. 2000). The new duction was the primary goal of forest forest policy was implemented with sig- Conclusions management during this stage. Natural nificant investments. In 1998, the Chi- Afforestation, deforestation, and refor- forests were the primary target for tim- nese government started six major forest estation have significantly modified the age ber harvesting in the early years, and projects with a total investment of over structure of forests in China, reflected in the plantation forests were the target for har- 700 billion yuan (approximately US$85 current forest ecosystems dominated by vesting as they matured. Such a manage- billion) by the end of 2010. Given the young stands. Reforestation has kept Chi- ment goal suited the immediate timber large afforested areas during this stage na’s forest cover from dramatically decreas-

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