Trees are fundamental to life and the processes that maintain healthy soil, and clean air and water. There is evidence which shows that in regions where the trees are cleared to less than 30% of their original surface area, other sustainable life processes begin to collapse. Rivers silt up, soils wash away, and air quality declines. | TABLE OF CONTENT INTRODUCTION Unit 1 THE ROLE OF TREES. Page 1-3 Unit 2 THE DEVELOPMENT OF 4-6 Unit 3 IDENTIFICATION OF TREES I .Page 7-9 Unit 4 IDENTIFICATION OF TREES II . Page 10-12 Unit 5 TREE SIZE AND TYPE 13-16 Further Reading TREES AND 17-20 Unit 6 FOREST AND 21-24 Further Reading WINDBREAKS. Page 25-26 Unit 7 CREATING A NEW STAND. Page 27-31 Unit 8 DIFFERENT TYPE OF 32-36 Unit 9 FOREST MEASUREMENTS DEFINED. Page 37-39 Unit 10 FOREST HARVESTING. Page 40-42 Unit 11 FOREST TREE INSECTS AND HOW TO CONTROL 43-47 Further Reading TREES DISEASES. Page 48-53 Unit 12 PREVENTION AND CONTROL OF 54-57 REFERENCES. Page 58 Unit 1 THE ROLE OF TREES For hundreds of years people have planted trees to serve the needs of future generations for timber and tree products. In Europe and Asia forests were planted by rulers church leaders and farmers - for the people. By planting trees they particularly and symbolically showed faith and hope for the future. Trees are fundamental to life and the processes that maintain healthy soil and clean air and water. There is evidence which shows that in regions where the trees are cleared to less than 30 of their original surface area other sustainable life processes begin to collapse. Rivers silt up soils wash away and air quality declines. James Lovelock a renowned ecologist claimed these breakdowns in natural systems will in turn affect other word bio-areas continent or cyclones may occur more frequently. It will be sad if these things happen before we change from consumers to producers. I Comprehension 1. What do people plant trees for 2. What do European and Asian people want to show by planting trees 3. What are fundamental roles of trees 4. What will happen to the area when the trees are cut down II Grammar ADJECTIVE PREPOSITION Exercise 1 Complete these sentences with the correct preposition 1. It very to let me use your car.
