Friday, September 30, 2011

DEFORESTATION RELATED TO ENVIRONMENTAL ISSUES

Deforestation, Bangladesh
Deforestation in Bangladesh

Tropical forests of the world are degrading at an alarming rate because of population growth and human poverty, acute shortage of fuelwood, fodder and timber and a continuous decline in the amount of per capita cultivable land. 
Bangladesh, a South Asian least developed country, has been experiencing severe deforestation over the last 3 to 4 decades. During the period 2000-2005, deforestation rate in Bangladesh has been estimated at 3.3% per year. In Bangladesh, deforestation results mainly clearing agriculture land, principally shifting or jhum cultivation. About 85,000 hectares of the hill forests reserves under the practice of shifting cultivation and about 60,000 families engaged there. Of the three major forest categories (hill, inland Shorea robusta, Gaerten. f., and mangrove forests), the hill forests (48%) are the most important watershed areas of the country and are composed of tropical evergreen and semi-evergreen tree species. 
A rapid deforestation not only diminishes vegetative cover and species diversity; it may accelerate surface runoff, increase soil compaction and deteriorate soil biochemical properties, and often affects climate by releasing stored soil carbon as CO2 into the troposphere. 
The natures in which the tropical hill forest ecosystems are being deforested and degraded are becoming an ecological concern. Under regular protection, allow for natural regeneration and improvement of soil quality in the degraded forest ecosystems can be achieved over time.

Wednesday, September 28, 2011

FOREST FIRE AND CHANGING CLIMATE

Climate change, Fire
Forest fire in China
China is a country with serious forest fires, large burnt forest areas and tremendous fire losses. Forest fires have been long frequenting overall China and from 1950 to 2000, recurrent disturbance events considered in Sanming City, Fujian Province due to its regular distribution throughout the whole year. It affects the replacement of forest plants, site conditions, lowers the forest protection on water and soils, losing its function of conserving water sources, and regulating soil temperature. More combustible species such as Cunninghamia lanceolata and Pinus massoniana those comprise 76% of the total area also increasing challenge to the ecological health of the Sanming forests. Recently due to climate change of China, structure and composition of Sanming forest ecosystem are affected by dry and warm weather. Changing weather parameters such as rising temperature, high wind speed, low precipitation and humidity makes the forest environment unfavuorable for native plant and animal species. The ecosystem of the Sanming forest are severely disturbed by these causes, and it is somehow difficult to keep the ecosystem intact without applying sound ecological principle. So, the ability to predict and understand forest fire occurrences in Sanming is essential to implement necessary measures to mitigate these impacts.

CARBON STOCK CAPACITY OF PLANTATION FORESTS

Carbon stock, Plantation Forest
Plantation Forests in Bangladesh
The large portions of natural forests in Bangladesh have already been significantly degraded and fragmented, leaving the country with only a small percentage of forest cover. Plantations have high annual carbon sequestration rates and establishing plantations on degraded land has been proposed as an effective carbon management approach. Through the Clean Development Mechanism (CDM), carbon management approach can be achieved by plantation program in developing countries such as Bangladesh. Developing countries are mostly affected by the consequences of the “global warming”. The global warming issue focuses on the increasing accumulation of greenhouse gases, mainly CO2 in the atmosphere due to emissions caused by industrial activities and deforestation. Creating and maintaining carbon stocks in the tropical forests is an important response option for global warming in tropical developing countries such as Bangladesh. Among three plantations of 18-year old, the total (above- and below-ground) carbon stocks were found highest in Acacia auriculiformis (110.25 and 100.84 ton•ha−1, respectively), followed by Tectona grandis (91.28 and 80.33 ton•ha−1) and Anthocephalus chinensis (63.70 and 85.26 ton•ha−1) plantations. The capacity of plantations of Acacia auriculiformis, Anthocephalus chinensis and Tectona grandis to sequester atmospheric carbon and that reforestation makes a significant contribution to carbon sequestration and generating carbon credits in Bangladesh. The carbon stock of three plantation species indicates that Bangladesh has a capacity for carbon sequestration. To overcome the problem of global warming and climate change, sustainable forest management is the best way to achieve optimum carbon sequestration; and more easy, applicable and fast scientific methods are required to estimate the carbon stock in plantation forest.