Unit: 4 Forests
There are two types of Forests.
1- Productive Forests:
a. These are the natural forests.
b. Tree density is very high.
c. These forests having close canopy.
d. These forests having high commercial value
e. Source of timber (wood)
i. Fuel wood
ii. Construction industries
iii. Paper industries
iv. Sports goods industry
2- Protection Forests:
a. Planted by man
b.
c. Tree density is low
d. Linear plantation (symmetry)
e. Same kind of species
f. Less commercial value
g. Mainly planted along roads, railway lines and parks
h. main purpose is to protect the soil from erosion
i. keep the temperature and provide shade
Importance of Forests:
1- keep the temperature low of the area
2- causing the rainfall due to transpiration
3- provide oxygen to the living organisms
4- decrease in pollution (absorbs carbon dioxide)
5- provide shade
6- it provide natural habitat to wild life and shelter for birds
7- provide raw materials to the different industries (construction, sports goods, paper, furniture, medical
herbs (pharmaceutical industries)
8- it protects the area from flood
9- it protect the land from erosion
10- provide the food and fruit
11- provide employment opportunities for different industries
12- fallen leaves from trees make humus (decayed leaves)
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Products of Forests:
1- Main Products:
a. Fuel wood
b. Timber (wood that is used for construction, sports goods, furniture, paper)
c. Food / fruit
2- Minor Products:
a. Resin (varnish)
b. Mazri (baskets, mats, packing purpose)
c. Ephedra (pharmaceutical industries /medicinal herb)
Types of Forests grown in Pakistan:
1- Alpine
2- Coniferous
3- Sub-Tropical Scrub Forest
4- Sub-Tropical Thorny Forest /Rakh
5- Riverain/Bela Forests
6- Mangroves
7- Irrigated Forests
Important thing to discuss about each fortes:
1- Area of production (growing)
2- Natural characteristics (adoption / appearance)
3- Importance of forests
4- use of these forests / reason for deforestation
5- Affects of deforestation
Types of Forests:
1- Alpine Forests:
Areas of growing:
- Grown from 4000m above sea level to below 4500m (snow line)
- Mainly grown in northern mountains
- Main growing area (Chitral, Dir, Shangla, Kohistan
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Description / appearance / natural characteristics:
- Stunted (short) growth due to severe climate conditions (low temperature) during winter season and lack
of liquid water. (these are having short summer season for growth)
- Having spread roots to have better grip on the ground against fast winds.
- Normally upward branches to attain more sun light.
Use:
- These are only used for firewood.
2- Coniferous Forests:
Areas of growing:
- These are grown from 1000m to 4000m above sea level.
- These abundantly found in the northern mountain areas of KPK and in Baluchistan
- In KPK (Abottabad, Swat, Kohistan, Shangla)
- Murree, Islamabad
- Balochistan (Quetta, Kalat)
Description / appearance / natural characteristics:
- These are having evergreen leaves so, not need to shed their leaves during autumn.
- Having high trunk to catch more sunlight.
- Small, thick and needle shaped leaves to minimize loss of water through transpiration
- Sloping branches which prevent snow accumulation.
- Conical in shape to stand firmly against fast winds.
- Spread roots to absorb water and nutrients more ground and have firm grip on land.
- Thick bark to protect from cold weather.
- These trees are conical in shape to stand against fast winds.
- Seeds are covered in cone to protect them from harsh climate and forest fire.
- Distance between whirls indicates 1 year growth.
Importance / use of Coniferous:
- Use as a fuel wood
- Timber used to make furniture and paper
- Increase the scenic beauty of the area which attract tourists
- Clean the environment by absorbing carbon dioxide gas
- Forest on foothills protect the area from floods
- Roots capture the soil which decrease soil erosion
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Effects of deforestation of Alpine & Coniferous in mountainous areas:
- More chances of flood in by deforestation of mountain slopes
- Soil become soft so it leads to the soil erosion
- Soil erosion will causes siltation in the dams
- Habitat for the wild life will be finished
- Increase in global warming
- Decrease in annual rainfall
- More pollution in the area
- Decrease in tourism in northern areas
- More chances of land sliding due to loose soil contact.
3- Sub-Tropical scrub Forests:
Areas of growing:
- Growing on the foothills of Himalayas and western mountains (Sufaid Koh, Wziristan, Suleman Range)
Description / appearance / natural characteristics:
- These are the low and medium height bushes grown on the foothills
- These are having hardwood
- Broad leaves to catch more sunlight
- Deep roots to search for water
- Shed their leaves during dry season
Use:
- Use as a firewood
- Protect the water sheds and regulate the supply of water
- Leaves are used as fodder for animals
-
4- Sub-Tropical Thorny Forests:
Areas of growing:
- Plain areas of Punjab
- Plain areas of Sindh
- Southern and western Balochistan
Description / appearance / natural characteristics:
- Low height (6-10m)
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- Thorny bushes
- Deep roots to search for water
- Small leaves to prevent water loss
- Scanty vegetation due to water shortage
Importance/ Use:
- Use as a fire wood.
- Use for grazing purposes
5- Riverain/ Bela Forests:
Areas of growing:
- Grown along the banks of River Indus and its tributaries in Punjab and Sindh Plain.
Description / appearance / natural characteristics:
- Strong stems to withstand against floods.
- Linear plantation along the banks of rivers.
- High yielding commercial hardwood species (shishum and Babul)
- They can tolerate arid conditions with high temperature.
Importance/ Use:
- Provide valuable timber from the species of Shishum and Babul.
- Used to make furniture and agricultural implements.
6- Irrigated Forests:
Areas of growing:
- Plain areas of Punjab mainly along rivers (Changa Manga near Lahore, Wan Buchran in Thal Desert,
Sahiwal)
- Plain areas of Sindh (Guddu Barrage)
Description / appearance / natural characteristics:
- Linear plantation with same distance
- Large blocks of same species are planted at same time.
- They have the same height as these are planted at same time.
- These are having irrigation facilities (canals, tube wells)
- Shisum, Babul and Eucalyptus are normally planted.
Importance/ Use:
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- Important source of timber
- Use as firewood
- Provide shade and reduce air pollution
- Used to make matchsticks.
- Used to make furniture, sports and railway sleepers. (sleepers are planks laid beneath the track)
Advantages and disadvantages of irrigated plantation in Pakistan:
Advantages Disadvantages
1 Provide source of timber for construction, High initial investment is required.
firewood,
2 Leaves provide food for animals Do not give quick returns or profits
3 Leaf fall lead to humus formation that increases Maintenance and take-care of forests need money
fertility of soil on regular basis
4 High transpiration brings more rainfall Need continues irrigation, problem for
agriculture sector
5 Provide shade and habitat for people and animals Loss of land for industrialization and settlements
and other infrastructure
6 Clean the environment Illegal cutting of trees is difficult to stop
7 Increase the scenic beauty of the area and Forest fire causing damage to the environment
promote tourism
8 Control the surface run off and soil erosion
9 Provide employment opportunities to people in
forest related jobs
10 Eucalyptus trees reduce water logging and
salinity.
7- Mangroves Forests:
Areas of growing:
- Mangroves forests grown in the deltaic region
- Coastal areas of Sindh (Indus Delta)
- Coastal areas of Balochistan (Makran Coast) (Hub Delta)
Description / appearance / natural characteristics:
- These trees having broad leaves with drip tips so salty water can slide down.
- Leathery texture on leaves to minimize transpiration.
- These are having external roots (knees) to extract oxygen from the air.
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- Roots have special tissues which work as filter to separate the salt from the water they absorb. (excess
salt is carried to the leaves and extracted on their surface.)
- These are low height (3m) shrubs grown in delta area due to salty water.
- In better areas (where fresh and silt is available) height may rise to 6-8 m.
- These are having stunting and limiting growth because industrial and domestic waste polluting deltaic
water.
Importance/ Use:
- Supply of firewood.
- Timber is used for construction by local people.
- Provide habitat and breeding area to fish and shrimps so helping fishermen.
- Fallen leaves provide nutrition to marine life.
- Leaves of mangroves used as fodder for livestock.
- Protect the coastline from erosion and high waves produce during cyclones.
- Act as a barrier against earthquake and tsunami by absorbing shock waves.
Reasons for cutting Mangroves / threat to mangroves:
- Low discharge of water and silt into rivers due to the construction of dams and barrages.
- Cutting of mangroves for firewood and fodder for animals.
- Sea-water pollution
- The removal of sand from the beaches.
- The reclamation of beaches for constructing buildings and roads.
- Chemicals releasing from industries and sewage water are poisons for mangroves.
Effects of cutting of Mangroves:
- Cutting of mangroves threat to the marine life.
- Coastal soil may be eroded by sea waves resulting loss of coast land.
- Destruction due to the tsunami and tropical cyclones.
Projects to restore Mangroves:
- World Wide Fund (WWF) Project
- International Union for the Conservation of Nature (IUCN)
Determinants / Factors to determine the type of forests:
- Altitude, e.g. high altitude = fir / spruce / alpine;
- Precipitation, e.g. dry areas = thorny bushes / scrub;
- Precipitation, e.g. high precipitation = coniferous / evergreen forests;
- Soil type / edaphic factors, e.g. salty areas = mangroves / fertile soil =
- high density;
- Temperature, e.g. low / cold = alpine;
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- Temperature, e.g. high / hot / warm = tropical scrub;
- Presence of rivers = riverain / bela;
- Presence of oases = individual trees / palms.
Causes of Deforestation:
- Growing population requires more land for settlements
- Increase in demand of timber for making furniture, sports goods, agricultural inputs etc.
- Increase in demand of food crops forests are cleared for agriculture.
- Development of infrastructure like construction of roads, buildings, railway lines and airports
- Forests are cleared for mining activities in the area.
- Use of timber as the fuel wood in the northern as well as rural areas.
- Overgrazing by livestock turns the forest area into barren land.
- Illegal cutting of trees by timber mafia or the corruption of forestry department.
Effects of Deforestation:
- Deforestation causes to expose the soil that can be run off easily.
- No roots to capture the soil firmly so soil is eroded away by winds and water easily.
- Upper layer of fertile soil is eroded which leaves behind the infertile soil.
- Land erosion causes land slide in the mountainous areas which causes a lot of destruction like blocking
of roads, railways and disrupt communication and supplies mostly to northern areas.
- Due to deforestation water carries a large amount of silt with it which accumulates in the dams which
causes to lower down the capacity to store water in dams.
- There will be more air pollution which will lead to the global warming.
- Natural habitat of various species destroyed which results in the extinction of valuable species.
- Deforestation lead to decrease in transpiration which causes to decrease in rainfall that may also leading
to drought conditions.
- End of scenic beauty of the area which also affect tourism.
Solution to deforestation:
- Afforestation (growing of trees at new areas)
- Reafforestation (growing of tress at same place where these were cut down earlier)
- Terracing (growing of trees on slope of mountains by making steps), it will prevent erosion of land by
wind and rainwater.
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- Contour ploughing (growing of trees on the slope of mountains) which will check the speed of water
and save the soil from runoff and eventually reduces soil erosion.
- Selective logging / cutting (cutting of only fully grown trees) technique should be used to make sure the
better growth of younger trees.
- Reserve the land for fuel wood plantation so the valuable species of trees could be saved.
- Creating awareness among the people by government and non-governmental organization and media to
save the trees and grow more new trees.
- The supply of natural gas or the alternate energy resources to the northern areas which will eventually
decrease in deforestation.
- Supply irrigation facilities to the deforested areas and commercial species of trees, which will grow
rapidly, should be planted.
- Strict enforcement of forest laws
- Restricting the use bulldozers and heavy machinery in the forests the save from damage.
- Urban forestry programs should be started in which trees should be planted along roads and open areas.
- Establishment of nurseries in the urban areas
Afforesation Projects in Pakistan:
- Tarbela / Mangla watershed Management Project
- Rachna Doab Afforestation Project
- Agha Khan Rural Support Program (AKRSP) in Baltistan area in 1995
- Billion tree project started in 2015.
Sustainable Forestry:
“Sustainable forestry means to meet the needs of the present without compromising the ability of
future generations to meet their own needs”.
In simple words sustainable forestry means that resources should be used in such a way that not only the
present generation benefits from them, but also future generations also continue to benefit from them.
- Trees must not be cut down at the faster than they can be replaced. (for example if tree grows fully in 30
years then no more than 1/30th of the forests should be cut down in a year.
- Every tree cut down should be replaced with a sapling.
- If an area new to be deforested for settlements, roads and railways then new areas of forests must be
planted to replace them.
- Selective logging technique should be used.
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