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Forest disturbance
- 1. A term paperon A Review About Various Types Of Forest Disturbances (Term Paper on Advance Forest Ecology“SFB 702”) Presenter Anand Jha Roll: 04 M.Sc. forestry,1st yr.1st semester Institute of Forestry, Hetauda Campus, Hetauda Nepal 1 Submitted to Yogendra Yadav Module Co-ordinater, Advance Forest Ecology Assistant professor, Institute of Forestry, Hetauda Campus, Hetauda, Nepal
- 2. Presentation Outline • Introduction •Objective of the study • Methodology • Discussions and results • Recommendations • References 2
- 3. Forest Disturbance • Eventsthat cause change in forest structure and composition of forest ecosystem. Types of Forest Disturbances • Natural • Anthropogenic 3
- 4. Examples of ForestDisturbances • Fire • Flooding • Wind • Large mammals • Insect damage and diseases Disturbances can be described by : • Frequency • Distribution • Return Interval • Area covered • Magnitude 4
- 5. Major disturbance (Stand-replacingdisturbance): Removal/Killing of all the existing trees above the forest floor vegetation Minor Disturbance: Leave pre-disturbance trees alive Forest development after minor disturbance is more complicated than after major disturbance. 5
- 6. Objective of theStudy 6 • General Objective • To review about various types of disturbances present in the forest .
- 7. Methodology 7 • Secondary datacollection • Various published and unpublished articles. • Newspapers • Webpage • Etc…
- 8. Forest Disturbance • Adisturbance is defined as a temporary change in average environmental conditions that cause a pronounced change in an ecosystem. (DFRS, 2014) • Nearly two-thirds of the total forest area in the country was affected by grazing. Tree cutting, bush cutting, lahra cutting, lopping and forest fire were also common. Other anthropogenic disturbances, such as bark removal from the base of a tree, snaring, foot trails, forest roads, etc were observed in about one- quarter of the surveyed forest areas .(DFRS, 2018) 8
- 9. Characteristics of DifferentDisturbance Agents Forest Fires: 9 •Fires often occur in years and seasons of low humidity . •A lack of snow on the ground •Available fuel load
- 10. Damages due toFire • Damage the habitat of the environment—which depends on the soil type and the fire’s intensity • Affect the species population and distribution after an incident • Incur costly evacuations and destruction • Create heavy smog that is harmful to living things • Take animal and human lives (chandler et al. 1983) The coverage and number of native grass species were higher in controlled fire plot than in manual cutting and control plots. The study concludes that controlled fire is better than manual cutting and control treatments for the management of grassland.(U Aryal et al. 2018) 10
- 11. Damage to forestby wild animals: • The damage caused by wild animals varies with animals and the size of the plants. • While some animals cause only mechanical damage, others browse on the foliage, destroy the seeds or fruits, strip the bark or kill the plants by gnawing at the collar or cutting the roots. • The younger the plant, the greater are the chances of its being damaged. 11
- 12. Plant diseases: Plant diseasescan be defined as the series of invisible and visible responses of plants cells and tissues to a pathogenic organism or environmental factor that result in adverse changes in the form, function, or integrity of the plant and may lead to partial impairment or death of the entire plant. Due to disease at least six vital processes can be affected; • Food storage in the form of seed, roots, stems and bud. • Juvenile growth as either seedling or shoot development. • Root extension in the procurement of water and included minerals. • Water transport. • Food manufacture or photosynthesis. • Translocation of photosynthetic to sites of cell utilization .12
- 13. Insects: Insects are causingdamage to seeds, nurseries, plantations, natural forests and stored timber in various ways: • Defoliation, skeletonisation, Phloem and wood boring, Seed feeding, Sap-sucking, Shoot-boring, Root feeding, etc. Birds The major damages caused by birds are : • Nursery seed feeding • Damage to fruits and seeds. 13
- 14. Control Measures fromForest Fire • Direct preventive measure (Clearing camping sites and areas along paths and roads, Early burnings, Burning of grassy blanks etc) • Indirect preventive measure(Goodwill of the local people , education, legislative measures, putting up notices prohibiting kindling, keeping and carrying of fire in forest areas in fire season) • Remedial measure ( Detection, quick communication about occurrence of fire, quick action for suppression of fire, arrangement of labour, arrangement for tools, food, water, lighting etc, arrangement for transport of men and material. 14
- 15. Control Measures againstwild animals • The only way to prevent damage by other animals is to fence the area by appropriate fencing device. But it can be done only in nursery or a small regeneration area. Control Measures against Birds The incidence of birds damage particularly in nurseries can be reduced considerably by; • Keeping nursery beds covered by wire netting. • Putting up scare-crows. • Firing up blank cartridge. • Coating seeds with red-lead. 15
- 16. Control Measures againstDiseases • Disease detection , damage appraisal, , disease management strategies, ,Integrated Forest protection, Development of a pest/pathogen management system. 16 Control Measures against Pests Integrated pest management: “Integrated Pest Management (IPM) means the careful consideration of all available pest control techniques and subsequent integration of appropriate measures that discourage the development of pest populations and keep pesticides and other interventions to levels that are economically justified and reduce or minimize risks to human and animal health and the environment. IPM emphasizes the growth of a healthy crop with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms.” (FAO, 2007)
- 17. Conclusions • Thus themajor disturbances found in forest are Fire, Pest attacks, Diseases, Wild animals, Birds, etc . • Not all disturbances are destructive or negative to the overall forest ecosystem. Many natural disturbances allow for renewal and growth and often release necessary nutrients. 17
- 18. Recommendations • Various scientifictools and techniques should be applied to decrease the damage to forest due to various forest disturbances . • Anthropogenic forest disturbances that is harmful should me minimized. 18
- 19. References • Aryal, Upendra& Wagle, Bishnu & Lamichhane, B & Parajuli, Ashok & Thapa, Parbati. (2018). Effectiveness of control measures of Mikania micrantha on grassland: a case study from grassland in Sauraha area of Chitwan National Park. Banko Janakari. 27. 144. 10.3126/banko.v27i3.20559. • Chandler, C., Cheney, P., Thomas, P., Trabaud, L., & Williams, D. (1983). Fire in forestry. Volume 1. Forest fire behavior and effects. Volume 2. Forest fire management and organization. John Wiley & Sons, Inc.. • DFRS, 2015. State of Nepal's Forests. Forest Resource Assessment (FRA) Nepal, Department of Forest Research and Survey (DFRS). Kathmandu, Nepal. • Vreysen, M. J. B., Gerardo-Abaya, J., & Cayol, J. P. (2007). Lessons from Area-Wide Integrated Pest Management (AW-IPM) Programmes with an SIT Component: an FAO//IAEA Perspective. In Area-wide control of insect pests (pp. 723-744). Springer, Dordrecht 19
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Editor's Notes
- #4 Disturbance kill the vegetation and release the growing space making available for other plants to occupy. Individuals and species which first occupy growing space during forest development have an advantage in maintaining it and excluding other plants.
- #5 One disturbance can increase the predisposition of a forest to another disturbance. Very heavy grazing or fire can make some soils more susceptible to erosion. Dead, dry wood after a windstorm makes the area more susceptible to fires.
- #6 Following a major disturbance, newly regenerating trees compete only with other trees also regenerating after the disturbance. Following a minor disturbance, newly regenerating trees compete for growing space with previously established, large trees which survived the disturbance as well as with trees regenerating after the disturbance.