(2-A) - Sustainable Yield - [A1] Global, [A2] Asian Sub-Continent, [A3] Australia, [A4] Canada, [A5] Developed Countries, [A6]~ Europe, [A7] Africa, [A8] Russia, [A9] Southeast Asia, [A10] Tropical Forests, [A11] US-Eastern, [A12] US-Western, [A13]~ Plantations, [A14] Hybrid- and Genetically-Modified Trees,
(2-B) - Forest Biomass - [B1] Global, [B2] Tropical Forest Biomass, [B3] Temperate Forest Biomass, [B4] Biomass Partitioning,
(2-C) - Effects of Diseases, Insects, Pollution, Grazing - [C1] Insects and Disease; [C2] Pollution;
[C3]~Cattle Grazing,
(2-D) - Aridity- and Climate-Related Issues - [D1] History of Climate, [D2] Precipitation Limits to Tree Survival, [D3] Savanna/ Forest Interface, [D4] Altitude Limits, [D5] Desertification,
(2-E) - Forest Fires and Wind Damage - [E1] Global, [E2] Tropical Forests, [E3] Temperate/ Boreal Forests,
(2-F) - Reforestation - [F1] Plantations, [F2] Africa, [F3] Canada, [F4] British Isles, [F5] Far East, [F6] South America, [F7]~ Southeast Asia, [F8] Asian Sub-Continent, [F9] Europe, [F10] US, [F11] USSR (former) ,
(2-G) - Side Effects of Deforestation - [G1] Erosion/ degradation of Croplands, [G2] Siltation of Dam-backwaters and Irrigation Systems, [G3]~ Water Quality Degradation, [G4] Reduced Rainfall, [G5] Floods and Landslides, [G6] Collapse of Civilization, [G7]~ Desertification,
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SECTION (2-A) - Sustainable Yield - [A1] Global, [A2] Asian Sub-Continent, [A3] Australia, [A4] Canada , [A5] Developed Countries, [A6] Europe, [A7] Africa, [A8] Russia, [A9] Southeast Asia, [A10] Tropical Forests, [A11] US-Eastern, [A12]~ US-Western, [A13] Plantations, [A14] Hybrid- and Genetically-Modified Trees,

Above-ground growth of the world's forest is estimated to be 13 billion tonnes/ year (79S4). Comments: This figure is probably growing stock plus branches, twigs, etc. and is assumed to be green wood, not dried wood, since estimates of growth of "growing stock" are far less than this figure. Comments: 13 billion tonnes/ year, if it is assumed to be 38% coniferous (Density = 0.56 tonnes/ m³ (91M1)) and 62% hardwood (Density = 0.64 tonnes/ m³ (91M1)), translates to a volume growth rate of 21.4 billion m³/ year.

Hagler estimates that the world's 20.7 million km² of "available" forests can support a sustainable long-term harvest of 3.7 billion m³ (under bark) of fuelwood and industrial fibers (38% coniferous and 62% hardwood) (Hagler, 1995, in (96N1)). Comments: Hagler's estimate of the "closed forest" area of the world is 38 million km². (See Section (3-A).) (la)

Growth rate of useable timber in natural forests: 100-300 m³/ km²/ year (97S1).

Forest growth in plantations is expected to increase global wood supply by 0.1 billion m³/ year, although plantation wood productivities tend to be less that expected, often by a significant amount (96N1).

Growing "miracle trees" in tropical soils is discussed in Ref. 14 of (84G1). These trees deplete soil nutrients and water, and yields drop dramatically after one harvest. Examples of such trees include gmelina- or Caribbean pine on 7-12-year rotations, and eucalyptus on 15-25-year rotations. For comparison, teak takes 60-80 years to mature (84G1).

It takes 15 years to grow pine large enough to cut for pulp in Alabama. Rotations of eucalyptus for pulp in Brazil can be as short as 6-8 years. Pulp productivities per unit area in Brazil can exceed those in Nordic countries by 16 times (98M1).

(Forest Certification) Only about 200 patches of global forest (44,000 km²) have been "certified" (01U2). Comments: Certification is a process to gain some assurances that the forest is managed according to some recognized standards, including sustained yield.

[A2a] - Sustainable Yield - Asian Sub-Continent -Bangladesh -
Potential sustainable forest yield is 0.03 tonnes/ capita/ year (80R3).

[A2b] - Sustainable Yield - Asian Sub-Continent - India -
Woodlands in India can support a harvest of no more than 39 million m³/ year. (Government projections show India's demand for wood climbing to 289 million m³/ year by 2000.) (91P1).

In 1982, India's remaining forestland could sustain a harvest of 39 million tons/ year - far below the estimated fuelwood demand of 133 million tons/ year (88B1). Comments: There may be a units error here, although wood weighs about 0.5 tonnes/ m³.

[A2c] - Sustainable Yield - Asian Sub-Continent - Nepal -
Each km² of farmland needs 3.48 km² of forest to support it. The people of Nepal's middle hills need over 50,000 km² of forests for fuel, fodder and timber, but have only 40,000 (87S2).

[A2d] - Sustainable Yield - Asian Sub-Continent - Pakistan -
Potential sustainable forest yield in Pakistan is 0.06 tonnes/ capita/ year (80R3). Comments: Obviously obsolete due to population growth.

During an 80-100-year rotation, average MAI (mean annual increment) of native eucalypt forests in Australia range from 100 m³/ km²/ year in low-quality mixed-species stands to 800 m³/ km²/ year in better quality forests (96N2). Comments: These rotation lengths suggest sawtimber production, not pulpwood.

Wedel et al (1995) and Williams et al (1977) have estimated that the implementation of sustainable forest management would result in a decrease in harvest volume of 10-25% in Canada's boreal zone, and 30-40% on the coast in British Columbia (99N1).

Canada net timber growth: 161.7 million m³ from coniferous forests + 32.4 million m³ from deciduous forests (99N1).

Estimates of industrial wood supply in Canada (See 99N1):

• Official estimate of industrial roundwood production ("probable supply") (million m³/ year): 183 in 1995, 213 in 2010.
• Hagler (1997), WRI(1998) "probable supply" (million m³/ year): 182 in 1995, 163 in 2010.
• Aspey and Reed (1995) "probable supply" (million m³/ year): 212.5 in 1995, 165.2 in 2010.

Bernhard Fernow (one of Canada's foremost forestry experts in the late 1800s) reported to the government: "I have become thoroughly satisfied that the timber wealth of Canada has been greatly over-rated. There is a vast extent of woodland, but a relatively small amount of forest fit and capable of commercial exploitation of timber. Throughout, Canada is extensively wooded but poorly supplied with timber." (83S1).

A Canadian government report noted: "The evidence is unmistakable. The limits are in sight for premium softwood sawlogs in many locations, and supplies of larger, high quality logs have become very scarce. Pulpwood shortages are emerging in local communities across Canada. Only a fraction of Canada's forests are being managed for sustained production, even today, and in most cases, the timber resource is renewable only if action is taken following harvest or natural calamity" (83S1).

In Canada, the total cut mandated by law (the "Annual Allowable Cut") exceeds long-term capacity by over 20%. Government investigations "made it clear that provincial cut levels were being driven by forest industry demands for timber rather than a clear understanding of the productivity of the forest land base", according to an independent study by BC Wild (98A2).

Future "sustainable wood supply" AAC in British Columbia (Miller, 1994) (in 99N1) (million m³/ year): 71.6 in 1994, 63.7 in 2010, and 53.1 beyond 2010. (Reed (1998) (in (99N1))) estimates a "probable supply" in 2010 of 47.0) Comments: "Probable Supply" data in Canada take better account of sustainability issues than AAC data that tend to have a large "political" component.

The sustainable yield of B.C.'s forests is 80% of the minimum cut for the past 3 years (i.e. 80% of 73 million m³/ year) (93D3).

The sustained yield of B.C.'s forests is 30% under the amount logged, i.e. 30% less than 85 million m³/ year (Ref.19 of (91P1)).

The sustainable yield of timber from the 25% of B.C.'s forests considered "productive forest land" is estimated to be 59 million m³/ year (91M2).

The minimum cutting age in British Columbia is 60-80 years (80W2).

"Probable supply" in Ontario (Aspey and Reed, 1995) (in 99N1) (million m³/ year): 32.5 in 1995, 26.5 in 2020.

"Sustainable wood supply" (AAC) in Ontario (Callagan, 1994) (in 99N1) (million m³/ year): 36.1 in 1995, 31.0 in 2035.

"Probable supply" in Quebec (Aspey and Reed, 1995) (in 99N1) (million m³/ year): 52.7 in 1995, 41.0 in 2020.

Wood-harvest utilization: up to 95% (97U2).

A national quota has been established to limit timber harvests from its shrinking forests (Ref. 37 of (81B2)). Comments: "Shrinking" is disputed, since peat lands are being drained to create additional forest, and the volume of growing stock is said to be increasing.

Timber-processing capacity exceeds forest growth rate (Ref. 75 of (80W1)).

About 15% of each tree cut is used commercially (97U2).

Logging contributed to a 10-20% reduction in Siberia's growing stock from 1966-88 (94S4).

The sustainable yield of Russia's hardwoods is 0.25 billion m³/ year (Harvests exceed this by 25%.) (Ref. 71 of (84P1)).

Average tree growth in Siberia is 33-50% of that in the rest of the Soviet Union (92R5). The average diameter of mature trees in Siberia is 24 cm. (92R5).

Russia's Federal Forest Service reports a 1995 net increment of 0.822 billion m³/ year on Russia's closed forested areas (96N1). Tentative results from work done at IIASA (Shvidenko et al., 1995) indicate that the net increment on Russia's forested areas may be 1.15 billion m³/ year (96N1).

[A9] - Sustainable Yield - Southeast Asia -
[A9a] - Sustainable Yield - Southeast Asia -Thailand -

The sustainable supply of fuelwood in northeast Thailand is 6.3 million m³/ year (as compared to a demand of 15.1 million m³/ year) (Northeast Thailand statistics for 1985: 170,000 km² total land area; 14% forested; 18.06 million population) (88P4). Comments: These data indicate a fuelwood productivity of 265 m³/ km²/ year.

The World Bank estimates Indonesia's current rates of harvest are 50-100% higher than can be sustained. These rates continue to increase (98R1).

Despite clear timber shortages and a 1993 World Bank assessment that found timber harvests 50% higher than sustainable levels, the Indonesian government plans to raise harvest levels by 57% (98A2).

Potential sustainable forest yield in Viet Nam = 0.48 ton/ year/ person (80R3).

In the late 1980s, under 0.1% of tropical forests were managed for sustained yield (98A2).

A 1989 study for ITTO found that under 0.1% of tropical logging was sustainable (90R1), (90R2). Dr. Frank Wadsworth, Director of USFS Tropical Forest Research Center in Puerto Rico stated that 3% of the world's tropical forests are under management plans that may secure their future productivity (80R1). In 17 ITTO-member countries, only 8,000 km² are being managed sustainably. In India, another 36,000 are managed over successive rotations. This means that 44,000 of the world's 8.28 million km² of tropical forests are being managed sustainably (90W1). Comments: Harvest rates in Brazil and Zaire imply some sort of sustained yield, but this is merely because much of the forest in these countries are not yet accessible.

As many as 50% of the world's fuelwood users face fuel shortages, and as many as 100 million already experience virtual fuelwood famine (FAO data) (99A1).

Net growth of eastern US hardwood growing stock was 8.7 billion ft³/ year (246 million m³/ year) in 1976, 116% above removals. Net growth of hardwood sawtimber in the eastern US was 22.9 billion ft³/ year (649 million m³/ year) in 1976, 66% more than removals (p. 380 of (80H1)).

Cumulatively the 140 mills of the US south are being fed by clear-cutting about 1.2 million acres/ year (4900 km²/ year) of southern forest. Even the wood-products industry's own trade journals admit that this cutting rate cannot be sustained (97L1). (The timber industry contends that most of the southern forests have been so relentlessly high-graded that only economically poor-quality stands of trees remain - trees appropriate only for chip mills (97L1).)

The current harvesting rate of pine in the southern US is probably surpassing the growth rate by 12-14% (98M1).

The hardwood harvesting rate in the southern US is expected to overtake the growth rate by 2010 (98M1).

Oregon's sawmill capacity was well above sustained yield even in the 1930s (reported by Advisory Committee on Forestry for Oregon State Planning Commission) (77A1).

The USFS projection is for an 18% drop in Pacific Northwest timber supplies over the next several decades (78C1). All 11 studies of Pacific northwest timber supplies agreed that if current practices continue, the supply of timber products over the next several decades would not be able to keep pace with increased demand. Many of these studies projected production declines unless changes are made (78C1).

In Chile and New Zealand, radiata pine (plantation) grows 2500 m³/ km²/ year. Loblolly pine in the southern US grow at 1250 m³/km²/ year. Eucalyptus (plantation) grows 40 m³/ km²/ year in Brazil and 26 in Chile. (Comments: Might there be an error of units in these eucalyptus data? m³/ ha/ year sounds more reasonable.) Comparable hardwood species in Sweden grow 500 m³/ km²/ year (99A2). Comments: These figures must surely refer to pulpwood production, not sawtimber.

Studies of the growth of slash pine in plantations on some of the more infertile soils of the southern Coastal Plain (in Louisiana) found that 10-year-old slash pine of the second rotation had 24% less volume compared to the previous rotation (96T1). Several other studies of Alabama and Georgia sites were cited that found 3-31% reductions on the second rotation, and another study was cited that found a "modest" decline in the productivity of slash pine and a "dramatic" decline in loblolly pine in the second rotation (96T1).

Ref. (96N2) cites a 1992 study by Horne and Carter that found no declines in yield in managed blackbutt forest in Australia over the past 200 years. Comments: This may not be referring to tropical soils and tropical forests - where there are lots of doubts as to the long-term sustainability of yields.

During a 30-40-year rotation, an average MAI (mean annual increment) in radiata pine plantations (in Australia??) of 2000-3000 m³/ km²/ year is common (96N2).

In Brazil, for stemwood production of rosegum on 8-12-year rotations, it was estimated that the yield of the second crop of trees is likely to be substantially reduced because of an insufficient supply of K. Even adding 200 kg. K/ ha. to the first rotation (twice the optimum needed level) still leaves the soil with insufficient levels of "available" K to sustain productivity in the next crop (96N2).

Ref. (96N2) concluded that it is unrealistic to expect to sustain productivity of plantation forests at economically acceptable rates of productivity and maintain soil quality without inputs (e.g. fertilizers and weed-control). Comments: Does this statement refer to both tropical and temperate plantation forests?

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Around half of the forest carbon is located in boreal forests, more than one-third in tropical forests, and roughly one seventh in temperate forests. The world's forests account for 65% of net plant-growth and carbon-fixation on land (96M2).

Forests account for 67% of all dry-matter net-primary-production (NPP) on land, and 45% of total NPP on land and water (Ref. 1 of (76S1)).

In tropical forests, the bulk of available nutrient elements are bound in the biomass (leaves, twigs, branches, trunks, roots, etc.) and are tightly conserved in a closed nutrient cycle (75S2). Comments: Translation: Tropical soils are extremely poor in plant nutrients, except for the dead plant litter on the surface of the soil.

The average carbon density of tropical forests in 5300 tonnes carbon/ km² (84B4), compared to 12,400 tonnes carbon/ km² from an earlier study by the same authors, and 18,800 tonnes carbon/ km² from Whittaker and Likens (Ref. 5 of (84B4)). (includes below-ground biomass) Old-growth forests can accumulate up to 30,000 tonnes carbon/ km² (91M1). Comments: Biomass is assumed here to be 50% carbon, so the weights are dry weights.
Loss of the world's rainforest would be tantamount to losing 80% of the world's vegetation (p. 364 of (91J1)). Tropical rainforests contain 20% of the world's terrestrial carbon pool of 500 Gt. - 46% of this is in living forests (84G1).

Biomass of the world's tropical forests is estimated to be 205 billion tonnes. Weighted biomass densities for undisturbed closed- and open broadleaf tropical forests are 17,600 and 6,100 tonnes/ km² respectively (84B4).

* Not included in the calculation of the mean because these two forests are typical of open-forest formations. Trees in this formation tend to branch more, and have a larger proportion of their biomass in branches and belowground. For open forests, Ref. (84B4) takes 2.9 as the average total biomass/ stemwood biomass.

Ratio of other forest biomass to stem-wood: 0.4-1.1 (Ref. 30 of (92K1)).

The ratio of carbon in tree roots to carbon in forest litter-fall is about 2.6 (based on global data) (89R2). Comments: Litter-fall is apparently defined as woody parts under 1 cm. in diameter plus leaves, buds, etc.

The definition of "roundwood" used in forest surveys by the US Forest Service (the merchantable stems or boles of trees in the forest at least 5" d.b.h. including all wood above a 1-ft. stump, and extending up to a 4" top) accounts for roughly 20-25% of all photosynthetic materials produced on Earth (76S1).

Under-story and other minor forest vegetation seldom comprises over 5% of the phytomass (Ref.57 of (75P1)) or nutrient content (Ref. 15 of (75P1)) of fully stocked, mature stands of trees on good sites (75P1). Understory accounts for fewer than 2% of the all biomass (including below-ground) of closed tropical forests (Refs.12-16 of (84B4)).

100 m³ of green logs yield 63 m³ of rough green lumber + 10 m³ of sawdust + 27 m³ of wood chips. 63 m³ of rough green lumber yield 60 m³ of roughdry lumber (after being kiln-dried). 60 m³ of rough dry lumber yield 45 m³ of finished lumber + 15 m³ of shavings and trim (76F1).

100 m³ of green logs yield 55 m³ of green veneer, which yield 52 m³ of dry veneer, which yield 45 m³ of finished plywood (+5 m³ depending on log diameter) (76F1).

In closed-canopy forests in which trees account for most or all of the NPP (Net Primary Production), a highly variable percentage (8-67%) of the net tree production is allocated to fine roots. ((96K1) - 3 supporting refs. cited) Comments: The upper portion of this range seems way out of line - does fine root hair production annually exceed leaf- and twig production?

Armentano and Ralston (1980) found that in the early 1970s, 1650 million m³ of wood used for construction and fiber was harvested annually in the northern temperate zone (including China). At 0.6 tonnes/ m³, this corresponds to 0.99 Gt./ year of organic material (86V1).

Stocks of carbon (biomass) in closed forests are typically 3-5 times higher (per unit area) than in open or dry forests (87H1). Comments: A table in Chapter 3 from Ref. (84B4) gives more information on this ratio and the inventory data upon which it is based.

Armentano and Loucks (1984) estimate that the overall ratio of total forest biomass to the merchantable fraction is 1.96. Johnson and Sharpe measured 2.7 in temperate deciduous forests; 2.3 when forest detritus is excluded (86V1).

Herbs (grasses etc.) are assumed to contain 48% carbon (dry weight) (89R2).

Forest litter-fall is assumed to contain 48% carbon (dry weight) (89R2). Comments: Carbon content of vegetation: about 45-50% (dry weight).

Carbon loss from the top 1 meter of soils following wood harvest and clearing for cultivation is believed to be about 20% and 25% respectively (87H1). A 1986 review of the literature found that earlier assumed values (50%) were too high (87H1). Comments: Soil carbon (1-3% of soils) plays a key role in soil fertility and erosion resistance.

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SECTION (2-C) - Effects of Diseases, Insects, Pollution, Grazing - [C1] Insects and Disease, [C2] Pollution, [C3]~ Cattle Grazing,

Mortality losses (from insects, diseases and fires) in US commercial forests are about 20% (18.6 billion ft³/ year of net growth (not including harvests); 4.5 billion ft³/ year mortality loss; 4.5/(4.5+18.6) = 0.2) (76S1). The USFS uses 20% in its analyses of net growth of US forests (76S1). Ref.(76S1) estimates that this mortality could be reduced to 15% with sufficient investment. Comments: "Sufficient investment" should be read "sufficient government subsidy".

Until recently, US markets were closed to Russian roundwood imports because of concerns over the introduction of new pest species into US forests. However, new rules were enacted by the US Department of Agriculture in August 1995 lifting the ban on the import of raw logs. Under these regulations, Russian raw logs must be sterilized to kill pests prior to reaching US shores. These regulations have been challenged by environmental groups as being too weak (95U3).

(Global) Insects deplete 1.4 million m³/ year. Diseases deplete 14.6 million m³/ year (80W3).

(Siberia) In Taseyevo, Motygino and Kazachinskoye districts in the Krasnoyarsk region of Siberia, silkworms have eaten through 1300 km² of fir trees (Pittsburgh Post Gazette, 6/19/95).

(Canada) In Canada in 1993, insects affected 200,000 km² (420,000 in 1992) (96K1).

(Canada) British Columbia's average loss of wood to fire and pests is 19 million m³/ year (1966-76) (80W2).

(Plantations) Ref. (88P1) cites several examples of problems associated with monoculture plantations of trees in terms of increased susceptibility to insects and diseases.

(Plantations) Like virtually all large-scale monocultures, plantations are susceptible to disease- and pest outbreaks, so they require heavy applications of insecticides and fungicides - and herbicides to prevent invasion of competing vegetation. New Zealand's plantation managers have used over 30 different pesticides, including highly toxic organochlorines - usually broadcast from aircraft (98M1).

[C2a] - Pollution - Europe -
25% of trees in 29 European countries, and nearly 50% of oak trees older than 60 years, have suffered extensive damage due to pollution and bad weather. In the Czech Republic, 72% of trees were found to be significantly damaged (Pittsburgh Post Gazette, 9/12/97). Comments: The Czech Republic is known to have the worst air pollution in Europe - to the extent that human life-expectancies have been reduced.

23% of the trees examined in 35 countries in and around Europe had defoliated over 25%. The report covered 81% of Europe's 549 million acres (2.2 million km²) of forest. The worst damage occurred in: Czech Republic (53% defoliation), Moldova (51) Poland (50%) (Wall Street Journal, 8/15/94).

A 1989 count by ECE found 82% of Poland's forests showing signs of air-pollution damage, 78% of Bulgaria's, 73% of Czechoslovakia's, 57% of East Germany's, and 36% of Hungary's (91F1).

A survey of trees in 34 countries finds 24% of the trees in Europe are severely defoliated. More than 50% of the forests in the Czech Republic may have suffered irreversible damage (World Watch, 8(6) (1995) pp.6-7).

Europe, exclusive of the Soviet Union, shows 310,000 km² of damaged forest (over 20% of the forested area) (88B1).

75% of Europe's forests are experiencing damaging levels of sulphur deposition. The cost of these losses is estimated at $30.4 billion/ year (93B1) (IIASA estimates).

In a 1991 survey, of 75% of Europe's forests, the UN Economic Commission for Europe and the European Community found 22.2% of Europe's forests to be damaged, up from 20.8% in 1990 (94D3). The UK had 57% of its trees showing damage. Of fir trees over 60 years old in Poland, 77% are damaged. Total area of damaged forest is 475,000 km². Air pollution damage to Europe's forests is $35 billion/ year. In the former Soviet Union, air pollution is reducing log harvest by over 13%/ year (35 million m³/ year) (94D3).

Most forests of the Jizera and Giant Mountains (on the Czech-Polish border) have been damaged or destroyed by acid rain (95D1).

SO2 emissions from INCO's metal smelter in Sudbury Ontario (in Canada) have killed all vegetation within a 1865 km² area (88H1). In 1958 researchers measured and documented severe damage to white pine from SO2 from a Sudbury Ontario smelter (71H1). In 1963 an iron smelting plant at Wawa Ontario emitted SO2 that damaged white pine as far as 30 miles downwind (71H1). A smelter at Trail, British Columbia, damaged trees as far as 40 miles down the Columbia River before corrective measures were taken in 1931 (71H1).

Severonikel Smelters near the Norwegian and Finnish borders pump 300,000 tons of SO2/ year into the air. Over 2000 km² of local forests are dying (Ref. 21 of Ref. (92Y1)).

Industrial emissions are blamed for killing off (a total of) 10,000 km² of Russia's forestland, whereas the 1986 Chernobyl nuclear power plant accident contaminated 40,000 km² of forests within Russia, Belarus, and the Ukraine (92K2) (94P3).

Air pollution from huge nickel smelters in the Arctic city of Norilsk (in Russia) has killed 3500 km² of forest and has damaged another 1400 km². The Norilsk plant emits 2.3 million tonnes of sulfur dioxide/ year - 5 times the total sulfur emissions of Sweden (93O1).

In China, Sichuan's Maocaoba pine forest over 90% of the trees have died (5.4 km²). On Namshan Hill in Chongqing China, a 1.8 km² forest of dense masson pine have been reduced by almost 50%. Both regions have highly acid rain (88H1).

A Civil War smelter in the Copper Basin emitted SO₂ and made 17,000 acres (69 km²) totally barren, while damaging trees on 30,000 acres (121 km²). Much of this land is still barren and gullied (71H1).

A 1969 aerial survey of Jeffrey ponderosa pine in San Bernardino National Forest found heavy smog damage on 46,239 acres (187 km²), and moderate damage on 53,920 acres (218 km²) (71H1).

All dominant ponderosa pine and Jeffrey pines on San Bernardino and Angeles National Forests are dying from air pollution (79W1). An 800-mile swath of smog-damaged forest extends from the Mexican border to the Feather River in the northern Sierra Nevada (79W1).

Browning and dying of ponderosa pine within 50 miles of an aluminum-ore reduction plant near Spokane was traced to fluoride poisoning (71H1).

A smelter near Anaconda Mountain damaged forests heavily in the early 1930s (71H1).

Table 6.17 of Ref. (80H1) gives mortality of US growing stock and sawtimber in 1976 by ownership for hardwoods and softwoods.

Ref. (95S2) lists and summarizes a large number of studies demonstrating that cattle grazing has played a major role in the over-stocking- and forest health problems on western US forests. Comments: The USFS has never acknowledged this, and the timber industry has called for massive increases in timber harvests on US national forests as the way to deal with forest health and over-stocking problems.

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SECTION (2-D) - Aridity- and Climate-Related Issues - [D1] History of Climate, [D2] Precipitation Limits to Tree Survival, [D3]~ Savanna/Forest Interface, [D4] Altitude Limits, [D5] Desertification,

Extensive reviews of available rainfall records in the countries of North Africa reveal no evidence of a decline in rainfall over the past century, though the desert continues to expand northward at 1000 km²/ year (UNFAO data) (76E1).

Forests generally occur only where annual precipitation exceeds 60 cm/ year (24"/ year) (Ref. 64 of (91M1)). Comments: Croplands (with less biomass per unit-area of land than forests) become marginal at about 20" (50 cm.) of precipitation yearly. (la)

Ref. (72R1) cites references (Korstran and Baker and Ronco) that found that Engelman spruce require some shade to regenerate. Spruce seedlings are injured by excess light ("solarization"), and survive poorly when exposed to prolonged periods of sunlight. This explains why many clear-cut patches in the arid West (e.g. Wyoming) fail to regenerate.

Most tropical savannas occur in areas of low or strongly seasonal rainfall. Savannas, where climate does not exclude forests, are argued to be a result of anthropogenic effects, e.g. burning and removal of seed sources (86B1).

Half the closed forests of Brazilian Amazonia depend on deep-rooted systems to maintain green canopies during the dry season. Evergreen forests in northeastern Para State maintain transpiration during the 5-month dry period by absorbing water from soil depths of over 8 m. The forest soil below 1 m. depth contains more carbon than does above-ground biomass, and as much as 15% of this deep soil carbon turns over an annual or decadal time scale (94N1).

Tree lines in the western US decrease from 3500 meters (11,500 ft.) in the southwest to 2000 m. (6600 ft.) in northern Montana. In Alaska, tree lines occur at under 1000 meters (under 3280 ft.). In the northeastern US, tree lines occur at 1500 m. (4900 ft.) (Ref. 39 of Ref. (78B2)). (la)

Major symptoms of desertification (81S2)

• Declining groundwater tables;
• High topsoil erosion rate;
• Salinity increases in topsoil and water;
• Loss of native vegetation.
• Reduction of surface water;

Destruction of trees in open forests is believed to be a causal factor in desertification, a process claiming 50,000 km²/ year (UNEP estimate) (80U1).

Climate has not changed significantly in the past 2000 years (78D1). Comments: The basic contention being made here is that desertification is not due to long-term decreases in rainfall.

See the desertification map of the world in Ref. (78D1).

SECTION (2-E) - Forest Fires and Wind Damage - [E1] Global, [E2] Tropical Forests, [E3] Temperate/ Boreal Forests,

Forest fires, globally, destroyed at least 50,000 km² in 1997 (WorldWatch, 11(2) (1998) p. 8). Comments: 1997 was a particularly bad year for forest fires due to El Nino making parts of Southeast Asia very dry.

Forest fires, exacerbated by droughts associated with El Nino, burned 25 million acres (100,000 km²) of woodlands over the last 2 years. (UNFAO's biannual State of the World's Forests report of 3/1/99) (AP/Boston Globe, 3/2/99). (global data)

Globally, humans initiate as much as 90% of total biomass burning (including savannas) (99L1).

Undisturbed tropical forests are usually too moist to propagate wildfires (91A1). 10-30% of forest fires are lightning-caused. The rest are man-caused (91A1).

Of the roughly 7.6 Gt./ year of carbon dioxide emitted into the global atmosphere, 1.6+0.4 Gt./ year come from forest burning in the tropics, almost all the rest stemming from combustion of fossil fuels. Net flux from forests to the atmosphere: 0.9+0.4 Gt./ year of carbon (96M2).

Recent studies find that fire in tropical moist forest creates a feedback loop that increases forest susceptibility to subsequent fires. The first fire opens the canopy, allowing sun and air movements to increase drying of the forest. Previous fire-killed trees increase fuel availability, and invading grasses and weeds add additional live fuel. So second and third fires are faster-moving, more intense, and of longer duration. Initial fires have been demonstrated to kill no more than 45% of trees over 20 cm. in diameter, whereas in recurrent fires, up to 98% of trees are liable to be killed (99C1).

Brazilian forest fires increased 50% between 1996-7, and another 86% between 1997-8 (99F1).

Fires in Amazon River basin: 24,546 during a 41-day period in 1997; 19,155 in a comparable period in 1996 (Satellite data reported by EDF in 9/97 Reuters News Service.).

In Indonesia, commercial interests (many with personal and financial ties to the president) deliberately set fires to burn 20,000 km² of forest in 1997 to clear land for palm oil-, pulp- and rice plantations, or to cover up the tracks of illegal logging (98A2).

Estimates of the total forest area burned in Indonesia during 1997-98: 6000 km² (official Indonesian government estimates) vs. over 45,000 km² based on satellite image data (99L1).

Satellite date showed that 80% of the fires that burned over 20,000 km² of Indonesian forest in 1997-98 were set mainly to clear land for palm oil- and pulpwood plantations (99A2).

80% of the fires in Indonesia in the fall of 1997 are attributed to industry burning of natural forest so that it can be labeled "degraded", thereby permitting the establishment of plantation forests on the land (98M1).

(Global) Boreal forest fires consume 2500 tonnes/ km² (91S1) (50% is carbon.) Comments: "50% carbon" suggests that the 2500 tonnes/ km² is dry matter, not green wood.

(Global) Seiler and Crutzen (1980) estimate that 38,000 km² of temperate and boreal forests are subject to wildfires yearly (91A1).

A variety of references support the view that Argentina's pampas and Russia's Steppe are grasslands only because of fire - probably man-caused (56S2).

(North America) Within boreal forests, detailed records for the US and Canada reveal that annual area burned has more than doubled in the past 30 years (99K1).

(North America) Ref. (56S2) cites a number of references that contend that prairie fires have been the deciding factor in determining the distribution of forests in the Middle West (Wisconsin, Illinois, Ohio, Michigan, Kentucky, Indiana) (i.e. the prairie that early settlers discovered were fire-caused, and when fire was suppressed, forests expanded.)

(North America) In Canada in 1993, fire affected about 20,000 km² (9,000 in 1992) (96K1).

(North America) US forest fires burned over 40 million acres/ year in the early 1900s, and under 5 million acres/ year in the 1950s (Forest Watch, 7/91).

In forests of the Blue Mountains of Oregon, fuel loads (for fire) have increased by a factor of 10 over the past 25 years. (Hall, 1994, in (97B3)) In central Arizona, fuel loads have increased by a factor of 9 over the past 100 years. (Covington and Moore 1994 in (97B3)) As a result, what otherwise might be low-intensity surface fires develop into intense conflagrations, resulting in high tree mortality (97B3). The increase in fuel loads is attributed to grazing (97B3).

In the northern Rocky Mountains, the average fire-free interval was 5-20 years in ponderosa pine stands, and 15-30 years in mixed-conifer stands (97B3).

The mean fire interval was 4-5 years in some parts of the Southwestern US, 10 years in southern California, and 5-38 years in the Northwest (97B3).

Fire scar studies have shown that low-intensity fires occurred frequently in ponderosa pine forests of pre-settlement times, with an average return interval of 5-12 years throughout the Western US (97B3).

British Columbia's loss of wood to fire and pests: 19 million m³/ year (1966-76) (80W2).

British Columbia forest burn: 800 km²/ year of forests (80W3). These fires cause a commercial wood loss of 2.9 million m³/ year (80W3).

In British Columbia, denudation by wildfire on accessible productive forest was 160 km²/ year during 1974-78 (80W2).

Natural regrowth of forests is occurring in many industrialized countries in areas where agriculture is no longer an economically viable land use. This process has been occurring for several decades, and is particularly evident in some countries within the Commonwealth of Independent States (CIS), including the Russian Federation. The FRA 2000 (Forest Resource Assessment of 2000) pan-tropical remote sensing survey also revealed that 10,000 km² of "other lands" (See Sect. (7-D)) in the tropics revert to forest each year. Along with the establishment of plantations in Asia, these new forests contribute significantly to a lower net deforestation. The above findings are illustrated in Table 2 below that shows the broad fluxes of land use by major domain and in Table 3 where the gross and net changes in forest cover are summarized (91F1).

- - |Tropical Countries|Natural|Plant-|Other
- - | into 2000 - - - -|forest |ations| land
from| ~ ~Natural forest| - - - | ~ 1.0| 13.5
1990| ~ ~ ~ Plantations| ~ n.s.| ~ - -| n.s.
- - | ~ ~ ~ ~Other Land| ~ ~1.0| ~ 0.8| - -

Plantation yields are often as much as 50% below initial expectations (FAO data). Single-species plantations do not allow for biodiversity of flora or fauna. But in spite of the high degree of failure of forest plantations throughout the World, the World Bank has paid out $1.42 billion to fund plantations in the past two years, and in the past decade has financed the establishment of over 29,000 km² of forest plantations. The Bank plans to fund establishment of over 10,000 km² of additional plantations (96G1).

Ref. (88P1) gives a table on establishment of plantations in the tropics during 1976-80, with projections for 1981-85.

11,000 km² of plantations were created in Africa in the early 1980s. In Africa the cut/ plant ratio was 29/1; in Asia 5/1. In tropical Latin America, 77% of industrial-, and 92% of non-industrial plantations are in Brazil, mainly in the south (88P1).

In Brazil the pulp plantation industry plants 1000 km²/ year of eucalyptus and pine (99A2).

A Sub-Saharan area studied showed "a 2.3%/ year increase in tree density between 1972-81, in the wake of the disastrous drought of the late 1960s and early 1970s when pressure on woody vegetation from human and natural sources must have been intense." Field investigations in Uganda and Mali drew similar conclusions (95M3).

Central government has supervised planting of 35 million seedlings since 1991 (survival rate unknown). Local communities have planted nearly 3 million more (Amicus Journal, Fall 1997, p. 16).

A shelterbelt project covers over 710 km² - 15% of cropland area (Ref. 27 of Ref. (88P1)).

[F2c] - Reforestation - Africa - Rwanda -
Scattered trees planted by rural people cover 2000 km² - more than the combined area of Rwanda's natural forests and all state- and communal plantations (88P1).

The average area replanted in British Columbia is 505 km²/ year (440 km²/ year of recently disturbed area + 65 km²/ year of not-satisfactorily restocked (NSR) land) (80W2). Average area being added to NSR lands is 245 km²/ year. NSR inventory is 5930 km²; recently disturbed inventory is 4960 km² (80W2).

British Columbian reforestation during 1978 was 500 km² replanted + 480 km² prepared for planting (80W3). Present rate of reforestation in British Columbia is not sufficient to meet the rate of denudation by logging and wildfire on accessible forestland (80W3).

During 1919-39, the British Forestry Commission replanted 2430 km² of forest. Private landowners planted 510 km² more. These replaced the 1820 km² of woodland felled during and just after WWI (77H2).

In 1969, Britain had 7,290 km² of forest plantations, 4,860 km² in subsidized management schemes on private land. 2,024 km² of plantation are planned by 1978, and 810 more km² of private planting are planned (73N1). In 1950 Britain had 6.4% of its surface in forests and woodlands - less than any European country except Ireland (73N1).

Since the early 1960s, Government- and private plantings in the UK have increased net forest cover by 300-400 km²/ year (Ref.17 of (88P1)).

In the British Isles and northwestern Europe, a uniform cover of heather supplants the temperate forest. When sheep are removed, birch and pine immediately invade the heather (56G2).

During 1948-78 the Chinese established trees on 330,000 km², and forest cover increased from 8.6 to 12.7%. During 1979-83, forest cover declined by 50,000 km² despite annual plantings of 40,000 km². In 1985, plantings doubled to 80,000 km²/ year (88P1). In 1950, Chinese forests covered 8% of its land area of 9.6 million km². Since then, reforestation has occurred on 380,000 km² (93W2).

Chinese national reforestation programs are often sabotaged at night by wood-starved pheasants seeking fuel wood (75E2).

During 1949-78, China's forested area expanded from 5% to 12.7% of the country (Ref.46 of (81B2)). China's forested area has increased by 300,000 to 600,000 km² over the past 3 decades (Ref. 47 of (81B2)).

Persson (Ref. 9 of (77B1)) estimates that, during the past 3 decades, 300-600,000 km² have been planted in China, and about 100,000 km² have been planted in other developing countries (77B1).

By 1963, China planted trees on 700,000 km² around the Gobi Desert. But the survival rate was as low as 10% due to inexperienced planting, poor maintenance, uprooting for fuel, and inhospitable growing conditions (76E1), (76E2).

A "Great Green Wall" of trees planted for 1600 miles across Northern China has made Beijing less windy and has reduced dust-fall from 301 to 252 tonnes/ km²/ year (87X1).

As many as 1,000,000 km² may have been planted since afforestation began around 1950. However seedling-survival has been low. An FAO study estimates 300,000 km² of plantation trees in China in 1970, plus another 23,000 km² in other Asian Lesser-Developed Countries (81B1).

China's reforestation efforts during 1950-80 planted 1.3 million km², but less than 30% of the trees survived.

In 1990, 50,000 km² were planted in China (Ref. 39 of (95R2)).

Illegal timber harvests in China remove 4,500 km² of forest annually (Ref. 40 of (95R2)). (Copied to Chapter 6, Sect. E.)

Planting for fuel-wood in China: 5,500 km²/ year - 20% of need (Ref. 18 of (88H1)).

[F5b] - Reforestation - Far East - Japan -
Since 1945, 45,000 km² have been planted to cedar in Japan (93H1).

[F5c] - Reforestation - Far East - South Korea -
Since 1945, 45,000 km² have been planted to cedar in South Korea (93H1).

Chile has 13,000 km² of plantations (85% Monterey pine). 770 km²/ year were planted during 1978-86 (91P1).

3,270 km² of pines were established in Chile by 1974, largely through the government-owned National Forestry Corporation. In 1974, incentives were increased, and the reforestation rate doubled. By 1985, pine plantations covered 11,000 km². (Chile's natural forests cover 200,000 km².) (Refs. 40 and 41 of Ref.(88P1)).

[F6b] - Reforestation - South America - Colombia -
A recent UN reforestation program near the Colombian town of Ayapel on formerly tree-covered slopes is suffering from severe erosion and had to be abandoned because the project area was invaded by disenfranchised squatters (Ref.5 of (76E1)).

[F6c] - Reforestation - South America - Ecuador -
Reforestation in Ecuador has replaced 3.4% of the trees lost in 1980 (85W1).

Since 1985, 240,000 acres (972 km²) of Indonesia have been "reforested", as compared to the cut during this period of 11 million acres (44,500 km²) (90H1).

The Land Resources Mapping Project reported in 1985 that 698 km² of forest had been planted or managed as protected forest. The World Bank computed in 1984 that Nepal needs to plant 500 km²/ year until 1990, and 100 km²/ year until 2000 to meet human needs (87S2).

Local Portuguese farmers have opposed massive eucalyptus planting because it dries up small streams and wells. Proponents claim drought-resistant, fast-growing eucalyptus makes an effective windbreak, reduces soil erosion and is a good, light fuel (88M1).

US landowners replant 3 million acres/ year (Forest Watch, 7/91).

In the 1920s, 40 million acres were added to the US forest base - mostly former pastures no longer needed for horses (Forest Watch, 7/91).

More than 2.5 million acres (10,100 km²) were reforested in the US during 1984 - 5 times the average reforested annually 35 years ago (Ref. 2 of (85P1)).

• 85% of these acres were on private lands. (Non-industrial private forest owners planted 731,000 acres (2,960 km²). Industry planted 1.4 million acres (5,670 km²) on company land. )
• 15% involved federal- and other public forestland (85P1).

The US CCC planted 2.3 million acres (9,300 km²) to forest trees over a 9-year period in the 1930s and early 1940s. The Soil Bank planted 2.25 million acres (9,100 km²) over 5 years in the late 1950s and early 1960s. The Agricultural Conservation Program, authorized in 1936, established the first continuous tree-planting program in the US. 6.5 million acres (26,300 km²) of trees have been planted under this program (85P1).

A plot of US tree-plantings by ownership-class and cost-sharing program accomplishments during 1950-84 is given in Ref. (85P1).

Over the past decade, 1.7 million acres (6,880 km²) have been reforested under the Forestry Incentives Program. Currently 150,000 acres/ year (607 km²/ year) are planted - down from 200,000 acres/ year a few years ago due to reduced funding (85P1).

A USFS analysis of forest inventory data showed total US reforestation needs of 37 million acres (150,000 km²) on all commercial non-industrial private US forestland (85P1).

Since WWI, US reforestation has occurred on 500,000 km², counteracting the 60% (1.5 million km²) deforestation that occurred prior to WWI (Ref. 20 and 21 of (79S1)). Comments: Much of this reforestation occurred on croplands abandoned for economic reasons, particularly in the South where cotton monocultures had destroyed soil productivity.

About 65% of Siberia's forests are in the permafrost zone. Logging exposes frozen soils to sunlight, and once the top layer of permafrost melts, these areas often convert to swamps, making reforestation impossible (94S4) (92S1).

10,000 km²/ year have been reforested since _____ (91P1).

Reforestation: 45,000 km² in 1980 (97B2).

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SECTION (2-G) - Side Effects of Deforestation - [G1] Erosion/ Siltation/ Degradation of Croplands, [G2]~ Siltation of Dam-backwaters and Irrigation Systems, [G3] Water Quality Degradation, [G4] Reduced Rainfall, [G5] Floods and Landslides, [G6]~ Collapse of Civilization, [G7] Desertification,

Many non-desert tropical areas worldwide have lateritic soils. When forest cover is removed from these soils, the soil becomes brick-like. Such soils have virtually no nutrients other than iron and aluminum (77J1).

Ref. (81B1) concludes that erosion, siltation and other problems associated with deforestation are likely to have become a severe constraint on food production by 2000 in south- and Southeast Asia. It seems likely that some of the region's present potential to supply human populations will have become irretrievable lost (81B1).

Flood damage in India attributable to deforested catchments amounted to $1-2 billion/ year in the early 1980s (Ref.16 of Ref. (95M2)).

In the Khaniara area of India's Himachal Pradesh, slate mines have stripped up to 60% of the forest cover, triggering countless landslides (Ref. 34 of (95D1)). Comments: The ability of forest soil to absorb water is vastly greater than that of croplands. This difference is described on p. 425 of Vol.1 of Man's Role in Changing the Face of the Earth, Univ. of Chicago Press, 1956.

In Nepal a UN forester wrote that deforestation in Nepal's hills was "becoming catastrophic, and (the resultant) erosion causes loss of property and human lives" (76E1).

In Sri Lanka Ref. (86U2) claims deforestation causes serious erosion- and landslide problems. Recent landslides 90 miles east of Colombo left over 3000 homeless. The World Bank continues to finance deforestation projects in Sri Lanka (86U2).

In Thailand, deforestation during 1985-88 caused landslides that cost 40,000 people their homes (90R1).

Deforestation in Indonesia, followed by bad agricultural practices, has resulted in 150,000 km² being covered with worthless Imperata Cylindrica grasslands (84G1). Indonesia has over 160,000 km² of non-productive land that is incapable of supporting agriculture or forests without major rehabilitation (Ref. 8 of Ref. (88P1)).

In the Philippines, 30% of 170,000 km² of forestland suffers from various types of soil erosion (85C1).

Research in Sarawak concluded that soil loss from logged areas was over 10,000 tons/ km²/ year, as opposed to 10 ton/ km²/ year from primary forest (96G2).

Deforestation of upper slopes around Sumatra's Lake Toba (Indonesia) increased runoffs enough to destroy the utility of agricultural terraces at lower elevations (56B1).

In Java/ Bali 400,000 km² are badly eroded as a result of deforestation (84G1).

In Peru a government study of the more densely settled areas of Peru, such as the Lake Titicaca Basin, reports that wood is so scarce that all available dung is burned for fuel, and people pull roots out of the ground to burn as they cut the remaining shrubs (Ref. 27 of Ref. (76E1)).

In the United States the USFS is withholding information showing roads and logging caused an estimated 2000 mudslides on Idaho's Clearwater National Forest during the winter of 1995-96 (Chuck Pezeshki, Wild Clearwater Coalition press release, 9/11/97).

In the US Pacific Northwest, where many hundreds of landslides now occur annually, 94% originate from clear-cuts and logging roads (98A2).

The Ambuklao Dam (Philippines) will be useful for only 32 years due to silt from deforestation in the upper Agno River watershed (76E1).

The $600 million Mangla Reservoir in Pakistan was started in 1967 and was expected to last 100 years. Sediment measurements after a few years of operation indicate its water-holding capacity will be gone in 55-75 years. If deforestation and over-grazing in the Jhelum River basin continue, the reservoir's life-time will be even less (76E1). The reservoir receives about 0.1 Gt. of sediment/ year - 80% from the deforested catchment of the Jhelum River (78M1).

The 40% reduction in forest cover in the Himalayan foothills since the 1950s has resulted in the irrigation systems in Uttar Pradesh in India being choked by 6 Gt. of topsoil (84G1).

The $1 billion salmon industry in the US Pacific Northwest is dependent on the region's old-growth forests (93D2).

Lake Victoria, the world's second-largest freshwater lake (27,000-sq.mi.), (20% of the world's freshwater supply), is being destroyed by nutrients carried in soil from deforested land, according to International Center for Research in Agro-forestry. Satellite sensing detected a plume of nitrogen-and- phosphorous-rich sediments which feed the water hyacinths, which starve fish and plankton of oxygen and sunlight, cause the lake to stagnate, and block traffic, and serve as a breeding ground for malaria-bearing mosquitoes and snails that host bilharzia, a parasite that attacks the liver, lungs and eyes. Vegetation, which used to filter the water of sediments from rivers that flow from the hills to the lake, has been removed (11/4/99 Nando Times).

Evidence from across West Africa indicates that deforestation has lowered rainfall, increased ground temperatures, dried up rivers and thus has spread deserts (90M1). (650,000 km² of West Africa have been overrun by deserts in the past 5 decades (90M1).)

NOTE: See the Soils Loss review document for data on the capacity of forest soils to absorb rainwater. That capacity is far greater than that of soils under other uses, although wetlands are even better. This helps to explain the observed relationship between deforestation and flooding which is becoming far more broadly recognized.

In 1998, natural disasters left far more people (globally) needing aid than armed conflicts did (99R1).

The number of people (globally) needing aid after disasters like floods and earthquakes: less than 500,000/ year in 1992; over 5.5 million/ year in 1998 (99R1).

The editors of the UN magazine Ceres wrote in 1975: "It is no coincidence that in all the countries with major crop failures in recent years due to drought or floods (Bangladesh, Ethiopia, India, Pakistan and the Sahel countries) the forests had been razed to the ground (76E1).

Flooding in Bangladesh made 30 million temporarily homeless (Pittsburgh Post Gazette, 11/28/98).

Deforestation in Bangladesh and India have caused the increasing frequency and force of floods. In the past, major floods occurred only every 50 years. By the 1980's they've began occurring every 4 years. Between the late 1960s and late 1980s, India's flood-prone areas grew from 243,000 km² to 575 million km² (93U6).

The area subject to annual flooding in India expanded from 47 million acres (190,000 km²) in 1960 to 124 million acres (502,000 km²) in 1984 due largely to deforestation in the Himalayan Mountains. A Sept. 1988 flood covered 2/3 of Bangladesh (the worst on record) doing extensive crop damage (89B1).

Value of water regulation and flood control provided by India's forests is $72 billion/ year (93D2).

50-75% of the middle mountain ranges in Nepal and India have been deforested in recent decades. As a result, since 1980 Bangladesh has suffered several 50-year floods, each worse than the last (Ref. 27 of Ref. (88J1)).

Chinese Vice Premier Wen Jiabao yesterday told Chinese legislators that environmental neglect, particularly severe erosion caused by heavy logging, is partly to blame for China's devastating floods. The Chinese government is reportedly planning reforestation projects along major waterways, and rivers and lakes (Greenwire, 8/27/98).

In Yangxin, a river-crossed county on the southern banks of the Yangtze in Hubei province China, since the mid-1970s, the county government has emptied 104 lakes and turned the lake bottoms into cotton fields and housing projects. The county's population: 400,000 in 1949; 900,000 in 1998. This pattern has been repeated throughout the Yangtze River basin. Land reclamation has reduced the area of Dongting and Poyang lakes 30%, two of China's largest bodies of water, in under 30 years. The population of the river valley has more than doubled since 1949, to 200 million in 1998 (98P1).

In China's forests in Manchuria, another area of massive flooding in mid-1998, the virgin forests disappeared, as well as new-growth trees (98P1).

During the August 1998 floods, the Yangtze River's flow peaked at less than 2 million cubic feet/ second, a rate it had surpassed 23 times since 1949. So by any measure, this year's flow should not have been a problem. But the combination of land reclamation and population growth created an environmental time bomb. The lakebeds, which used to soak up excess water, became giant traps. Throughout the region, over 5.6 million houses were washed away (98P1).

Storm runoff from deforested hillsides drowned 750 people and left 1.5 million people homeless along the upper Yangtse (In China's Sichuan Province) (81F2). The Yangtze, once comparably clean, is now about as muddy as the Yellow River. Following the July (1980?) flood, the Yangtze in Sichuan Province was carrying 2.35 million cubic yards of sediment/ hour (81F2).

In response to the 1998 floods, the Chinese government began enforcing a logging ban in the upper Yangtze watershed and began reforesting the watershed. It acknowledged that water-storage value of forests is worth 3 times as much as the cut timber (99A1).

In 1998, heavy rains bought record-setting floods to many deforested regions, e.g. India, Bangladesh, Mexico. China's Yangtze watershed, which has lost 85% of its forests to logging and agriculture, suffered thousands of deaths, dislocations of hundreds of millions of people and inundation of hundreds of thousands of km² of croplands (99A1).

China's worst flood since 1954 in Yangtze River valley, left 3,656 people dead and doused 64 million acres of land in mid-1998. China's cabinet banned most logging in Sichuan province to halt the massive soil erosion that contributed to the deluge. It prohibited further land reclamation projects that squeezed the Yangtze's flood plain. It earmarked $2 billion to reforest barren hills in the Yangtze's upper reaches (98P1).

Flooding in China's Yangtse River - 3700 deaths, dislocated 223 million people, flooded 50 million acres of cropland (Pittsburgh Post Gazette, 11/28/98).

Widespread illegal logging is named as a factor in disastrous flooding that has hit the central coast of Vietnam for the second time in two months. The World Wildlife Fund says the government and provincial authorities are aware of the need to protect the forests and have been active in programs to plant more trees, but illegal logging has been stripping forests from a steep mountain range not far inland of the flooded area. Under 10% of Vietnam is covered by primary (closed??) forest (Environmental News Service, 12/9/99).

Because shrinkage of Indonesia's forests have caused floods, drought, and consequent reductions in rice production, Indonesia announced a 28% cut in timber output to 22.5 million m³/ year over the next 5 years (94H1).

Deforestation, illegal urban sprawl and corruption are blamed for the mudslides that killed several hundred people in Sarno Italy in May of 1998. The town of Sarno routinely ignored zoning laws and environmental regulations (GREENLines Issue #625, 5/12/98, Defenders of Wildlife).

Hurricane Mitch killed 15,000 people in Central America, mostly in Honduras. From a treeless hill above the capitol city, Tegucigalpa, tons of topsoil turned to mud and flowed down from hills and into a river that jumped banks to destroy markets, factories, and homes. Mitch left 2 million homeless, jobless, or otherwise damaged. Once almost entirely forested, Honduras loses about 250,000 acres/ year (1012 km²/ year) to logging, burning, and clearing of rainforest to create pasture, and to erosion from poor farming practices. About 80% of the land is sloped, so when rain is heavy, without trees to break rainfall or hold the soil in place, the land turns to sliding mud and the rivers choke, causing floods (Sierra Magazine, Nov/ Dec.2000).

Deaths from Hurricane Mitch in Honduras, Nicaragua, Guatemala, and El Salvador: 11,000 (Pittsburgh Post Gazette, 11/28/98) Comments: Much of the damage has been attributed to deforestation on steep hillsides. Deforestation has been attributed to cattle producers who have appropriated much of the best land for their ranches (See Pittsburgh Post Gazette, 11/22/98).

Death toll from massive mudslides and flooding in Venezuela: 5000+ (AP, 12/20/99).

Hurricane Mitch was the worst natural disaster in Central America in decades. But now, scientists** are arguing that humans had made the devastation even worse. Clear-cutting logging, hillside farms, and rampant housing development exacerbated mudslides and floods, scientists say. The damage was most extreme in Honduras, where loggers and farmers strip away 910 km²/ year of forests. Mud and avalanches devastated clear-cut areas. Mitch barely had an impact on small, experimental "shade-grown" plantations that mix coffee with traditional trees. On clear-cuts, the soil structure collapsed and the plants slipped down the slope. In central Honduras heavily forested areas were relatively unscathed. But regions where trees had been plundered, and slums had sprouted on hills, were denuded. Even the houses had tumbled into rivers. A survey of Honduras by the UN FAO found that 41% was forested in 1990. In 1995 35% was forested. Environmental groups say those figures are overly optimistic (98M2).

Around 1030 the Anasazi switched from ponderosa pine logs gathered 25 miles away to spruce and Douglas fir logs that grew only as the tops of distant mountains surrounding their canyon. Pinion pine needles and juniper twigs disappeared from pack rat nests around 1200 AD - the time the Anasazi vanished. The Anasazi's fuel wood requirements could easily have stripped their canyons bare by 1200 AD. Firewood problems could have caused them to abandon their canyon (87B2). Comments: There is a lot more material on this topic in the topsoil Loss Review.

Destruction of trees in open forests is believed to be a causal factor in desertification - a process claiming 50,000 km²/ year (globally) by a UNEP estimate (80U1).

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