7-Forest-and-Wildlife (1) PDF

CE SCI 1 FOREST AND WILDLIFE  Forest The earth’s total land area is about 144.8 million sq. kilometers, or about 29% of the surface of the globe. Forests - areas where trees are the dominant vegetation - extensive tract of land covered...

CE SCI 1 FOREST AND WILDLIFE  Forest The earth’s total land area is about 144.8 million sq. kilometers, or about 29% of the surface of the globe. Forests - areas where trees are the dominant vegetation - extensive tract of land covered with trees and undergrowth, sometimes intermingled with open spaces  Forests include closed canopy forests (leaves and twigs of adjacent trees touch and) and open canopy forest and woodlands Closed Canopy Forest (some leaves and twigs of adjacent trees overlap). About 2/3 of the forest is classified as closed canopy and the rest is open canopy forest (Cunningham and Saigo, 1995). Open Canopy Forest  Layers of a Forest Forest floor - All trees in the rain forest start their lives here in this layer. On the damp ground, we see lots of fallen leaves and fruits, decaying trees, and fungi. They are food sources for many animals. They also help enrich the soil and provide nutrition for young plants to grow. Tapirs, termites, and scorpions are among many of the animals that we can find here. Understory - Immediately above the forest floor is the understory. The understory consists of tree trunks, saplings, small ground plants (such as dwarf palms), and vines. Residents here include bees, snakes, frogs, and leopards. Canopy - Moving up from the understory, we are now in the third layer, the canopy. Treetops in rain forests have leaves so densely packed that they form a "green blanket" in mid-air. We call this "green blanket" the canopy. The canopy shields sunlight from reaching the forest floor and the understory, making both layers very shady. Most of the rain forest animals live here, including several familiar faces - toucans, parrots, sloths, and monkeys. Emergent - When we ride in a helicopter above a rain forest, we first notice the canopy extending for miles and miles. Then, we also notice some trees standing high above the canopy layer. These tall trees, towering more than 200 feet and scattered throughout the rain forest, are emergents. They make up the highest layer of the rain forest. Birds of paradise, eagles, and macaws all live here. Table 1. World Land Use (Data from World Resources 1990- 1991 taken from Cunningham and Saigo, 1995) LAND USE % TOTAL LAND AREA Forest and woodlands 28 Pasture and grazing land 22 Arable cropland 10 Other lands (tundra, desert, 40 wetland urban) Table 2. General Land Use in the Philippines, 1987 (taken from DENR, 1997) LAND USE AREA (000 ha.) PERCENTAGE OF CATEGORY TOTAL AREA Agriculture 9,728.80 33.0000 Forestry 19,062.60 64.0000 Settlement 131.40 0.0040 Mining and Quarrying 8.70 0.0003 Inland Fisheries 595.70 2.0000 Open Land 11.00 0.0008  Classifications of Forest a. Old-growth forests – virgin forest and old second-growth forest that have not been seriously disturbed for several hundreds or thousand of years old, large number of standing dead trees and fallen logs b. Second-growth forests – stands of trees resulting from secondary ecological succession after cutting. About 40% of tropical forests are second-growth forests (Miller, 1994). Countries differ greatly in forest resources depending on the potential of the land and climate for the tree growth and on the history of land use and deforestation (Botkin and Keller, 1995). Table 3 shows the distribution of forest by continent.  Second-Growth Forest Old-Growth Forest Table 3. Forested Areas if the World by Continent (Percentage of Total World Forests, taken from Cunningham and Saigo, 1995) CONTINENTS PERCENT OF TOTAL WORLD FORESTS Africa 22.6 South America 21.4 Former USSR 18.4 North America 17.7 Asia 13.2 Europe 3.5 Oceania 3.1 The total area of forest in the Philippines is 62,768 sq. km. but only 2,250 sq. km. are protected by the government.  The Philippines shows a diversity in forest ecosystems. The existence of diverse natural forest formation in the Philippines could be due to the strong influence of varying physical and climatic factors such as soil type, rainfall and altitude. Classifications of Forest Types (devised by Madulid, 1994) a. Lowland evergreen rainforest – most widespread type found all over the country from 0 – 1000 meters above sea level (masl); dominated by dipterocarps, palms, legumes, and orchids. b. Lower montane forest – found in the Central Cordillera, Benguet, and Mt. Province at 1000 – 1500 masl; dominated by Lithocarpus and Liliaceous species. Lowland Evergreen Forest Lower Montane Forest c. Upper mountain forest – found on Mt. Pulag, Mt. Apo, Mt. Halcon, and Mt. Kitanglad at altitudes 1500 – 2400 masl. d. Sub-alpine forest – type found at altitudes over 2400 masl. e. Pine forest – having a pure stand of Pinus insularis and Pinus merkussi; may be found at 1000 masl in Benguet, Central Cordillera, Zambales, and Mindoro. f. Forest over limestone – distinct type of vegetation found over karst or calcareous limestone substrates; exhibits high endemism because of specific adaptability to soil type, poor water holding capacity, and poor nutrient availability. Upper mountain Forest Pine Forest g. Forest over ultrabasic soils – yield unique species highly adapted to substrates high in minerals like chromite; their distribution coincide with major faultlines in the Philippines where ultrabasic soils were exuded out by past major events of diastrophism. h. Semi-deciduous forest – found in the eastern Sieera Madre Range and Palawan where distinct seasonally dry climate predominates. i. Beach forest – a strand of vegetation composed of species adapted to sandy soils; sand creeping plants like Ipomoea and Cyperus spp. Are found extending seaward. j. Mangrove/Nipa forest – mangrove and other associated species occur as dense stands or narrow belts on shorelines extending seaward and in months of rivers where fresh and saltwater mix. A transition to nipa (Nypa fruticans) forest stand is commonly found in estuarine to freshwater conditions. k. Freshwater swamp forest – inland to 200 masl vast swamp lands yield successional forest formations of varying species composition depending on the water level. Limestone Forest Mangrove Forest  Importance of Forest 1. Commercial Importance - Supply lumber for housing, biomass for fuelwood, pulp for paper,medicines, and many other products - Forest lands are also used for mining, grazing livestock, and recreation and are flooded to provide reservoirs for hydropower dams and flood control - More than half of the people in the world depend on firewood or charcoal as their principal source of heating and cooking fuel  Importance of Forest 2. Ecological Importance - Forested watersheds act as giant sponges, absorbing, holding, and gradually releasing water that recharges springs, streams, and aquifers - Regulate the flow of water from mountain highlands to croplands and urban areas - Help control soil erosion, the severity of flooding, and the amount of sediment washing into rivers, lakes, and artificial reservoirs - Play important role in the global carbon cycle and act as an important defense against global warming.  Importance of Forest 2. Ecological Importance - Trees help remove carbon dioxide from the air and add oxygen into it - Deforestation, especially wholesale clearing and burning of tropical forests contributes greatly to greenhouse effect - Provides habitats for a large number of wildlife species than any other land ecosystem - Planets major reservoir of biological diversity  Forest Management and Conservation Forest management – involves planning for sustainable harvest, with particular attention paid to forest regeneration (Cunningham and Saigo, 1995) Miller Classifies Forest Management Systems into: a. Even – aged management - in this case, trees in a given stand are maintained at about the same age and size, harvested all at once, and replenished naturally or artificially so that a new even-aged stand will grow. Example: tree farms  Forest Management and Conservation b. Uneven – aged management - trees in a given stand are maintained at many ages and sizes to foster continuous natural regeneration The goals of this kind of management are: » Biological diversity » Long-term production of high-quality timber » A reasonable economic return » Multiple use of land TREE HARVESTING METHOD  Tree Harvesting Method Depends on whether uneven-aged or even- aged forest management is being used Also depends on the tree species being harvested, the nature of the site, and the objectives and resources of the owner  1. Selective Cutting - Intermediate-aged or mature trees in an uneven-aged forest are cut singly or in small groups - Reduces crowding, encourages the growth of younger trees, maintain an uneven-aged stand with trees of different species - Also helps protect the site from soil erosion and wind damage - This is common in many tropical forests  2. Shelterwood Cutting - Removal of all mature trees in an area in a series of cuttings, typically over a period of 10 years - Can be applied to even-aged or uneven-aged stands - This cut opens up the forest floor to light and leaves the best trees to cast seed and provide shelter for growing seedlings  3. Seed-Tree Cutting - Harvest nearly all the trees on a site in one cutting, leaving a few uniformly distributed seed- producing trees to regenerate a new crop - After new trees have become established, the seed trees may be harvested  4. Clear Cutting - Removal of all trees from a given area in a single cutting to establish a new, even-aged stand or tree farm - It requires much skill and planning than other harvesting methods because it destroys wildlife habitats and thus, reduces biodiversity  5. Strip Logging - Alternative to clear cutting - Alows a sustainable timber yield from forests without the widespread destruction often associated with conventional clear- cutting  The Extinction of the Philippine Forest In years to come, the Philippine rainforest will likely have ceased to exist, not just in theory, but literally. Along with the rainforest, some 3,600 species of plants, fungi, and animals found only in the Philippines will be gone. Among the animals we can say farewell to: Tarsier Flying Lemurs Cockatoo Philippine Crocodile Green Turtle