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Eucalyptus, rapid growth, out of materials with high rates of resistance and barren, strong resistance and rotational felling period is short, etc, is used to alleviate the advantages of wood and forest products for the global natural need to reduce e over-exploitation of natural forests, maintain the balance of the ecosystem, currently eucalyptus has become our country and even the world tropical and subtropical region one of the main planting tree plantation. But eucalyptus is a controversial species, a lot of people think planting eucalypt will cause a series of ecological problems, and some even pointed out that the eucalyptus will destroy the environment, pollution of water sources, etc. Therefore, it is necessary to the ecological service function of eucalyptus plantation made scientific and objective evaluation and calculation, it has become the current Guangxi, even the world issues that need to be resolved.This study refers to a large variety of forest ecosystems at home and abroad service function evaluation methods, learn from the State Forestry Administration publication "Forest Ecosystem observation system" (LY/T 1606-2003), "Assessment of forest ecosystem services Specification "(LY/T 1721-2008) the correlation method and formula, according to its own characteristics Eucalyptus plantation, respectively, and the spatial distribution of age classes from two aspects, using seven indicators (water conservation, soil conservation, fixing carbon and releasing oxygen, the accumulation of nutrients, atmospheric environment purification, biodiversity conservation and forest recreation) and 12 sub-indicators (regulation of water and water purification, solid soil and fertilizer, fixing carbon and releasing oxygen, forest nutrient accumulation, providing negative ions, the absorption of pollutants and dust, species conservation, forest recreation) of eucalyptus plantations in Guangxi ecosystem services function of Material and value were estimated.Guangxi eucalyptus plantation water conservation capacity was 5.846 billion m3·a-1; In the conservation of soil function, solid soil amounted to 27,436,886 t·a-1, the amount of fertilizer was 1.05 million t·a-1, which reduce the amount of N loss was 28,260 t·a-1, to reduce P loss was 19,206 t·a-1, less K loss was 421,156 t·a-1, to reduce the amount of organic matter loss was 581,388 t·a-1; In the function of fixing carbon and releasing oxygen, fixing carbon was 10,643,598 t·a-1, converted into carbon dioxide absorption capacity was 39,030,432 t·a-1; releasing oxygen was 28,494,610 t·a-1; Accumulation function of the amount of forest nutrient reached 102,724 t·a-1, which trees accumulated N was 56,031 t·a-1, P was 5,028 t·a-1, K was 41,664 t·a-1; In the function of atmospheric environment purification, annually negative ions was 5.93×1025; Absorption of air pollutants amounted to 184,876 t·a-1, which absorbed sulfur dioxide was 146,015 t·a-1, absorption of fluoride was 20,412 t·a-1, absorption of nitrogen oxides was 18,450 t·a-1, the amount of dust was 74,412,820 t·a-1.The total value of eucalyptus plantation ecological service function in Guangxi was 1.52×1011 Yuan·a-1, the average magnitude of value per unit area was 9.25×104Yuan·hm-2·a-1. Eucalyptus plantation in the contribution of ecosystem services function in water conservation Value was 4.79×1010 Yuan·a-1, accounting for 31.47%; Soil conservation value was 3.06×109 Yuan·a-1, accounting for 2.01%; The value of fixing carbon and releasing oxygen was 7.53×1010 Yuan·a-1, accounting for 49.45%; The forest nutrient accumulation Value was 1.22×109 Yuan·a-1, accounting for 0.80%; The value of atmospheric environment purification was 1.17×1010 Yuan·a-1, accounting for 7.69%; Biodiversity conservation value was 1.29×1010 Yuan·a-1, accounting for 8.45%; Forest recreation value was 1.94×108 Yuan·a-1, accounting for 0.13%. By the descending order of magnitude of value was:fixing carbon and releasing oxygen >water conservation> biodiversity conservation> atmospheric environment purification> soil conservation> forest nutrient accumulation> forest recreation. The value of water conservation and fixing carbon and releasing oxygen was account 80.93% of the total value, showing that these two kinds of ecosystem services function in a dominant position in Guangxi Eucalyptus plantation, is the major service functions.
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