Question

Brainstorm to create a list of 4 human activities that interfere with ecosystems, food chains and food webs . For each explain how it happens,why we do it, and mention short and long-term effects

Answer 1

One activity would be logging of trees, which could be selective or clear cut. It is done to provide wood for building houses and for pulp for paper primarily. A short term effect would be loss of habitat for forest wildlife and removal of vegetation and it could result in increased erosion if in a mountainous area. Loss of old growth forest possible too. Long term effect if re-forested could be partial restoration of habitat. Another activity is open pit mining whereby the land where the orebody is is cleared and mining creates sometimes large holes in the ground and removes old lake habitats for migratory birds and fish in the short term.The purpose of the mining is partly to provide metals to society.  The long term, if adequate reclamation of waste dumps is undertaken, can lead to extensive new grasslands on the dumps and forage for deer and moose and sometimes cattle. Oil production and transport on oceans can lead to oil spills such as occurred off Valdez in the 1980's or in the Gulf of Mexico recently  and the short term is soaking marine animals with oil and killing many of them and contaminating beaches and shorelines. Some clean-up can be done but the long term effects of this activity may still be unknown. The oil is for fossil fuel for internal combustion engines but it will need to be replaced by say, electric cars for the future ie to clean energy. Another general effect of this time, the use of fossil fuels is from global warming is creating more and more intense hurricanes such as occurred in the Caribbean this fall in Cuba, Florida, Dominca and Puerto Rico in particular with the result of widespread damage or destruction of people's houses, flooding, loss of power and costly repairs  and loss of life. Only by limiting the production of greehouse gases by mankind will there be a chance to reduce the incidence and intensity of such events.