Geography Environment :: essays research papers

GEOGRAPHY NOTESSince European settlement amongst 78 & 100 plant species fix become are extinct. 150-200 infra threat. GENETIC DIVERSITY - safeguard species diversity. Large range of genetic forms deep down each species. Genetic variations. Extinct- disappearance of species after thorough searching (some liquidation is natural) At risk- in danger of becoming extinct Endangered- close to defunctness in the wild unless something is done the species could disappear altogether Vulnerable- The step onward endangered Rare- few of a particular species remain , less respectable category than endangeredExtinction can occur naturally because of climatical change which affects the vegetation on which animals depend.MEGAFAUNA-large Australian mammals from the ice ageAborigines 50000 yrs agone modified asia Australia bridge vegetation through burning it out resulting in dry arid landscapes. This also could have made extinct the megafauna.In Aus since 1788 only 30% of the vegetation rem ains unmodified to osme degree. Cultural flora means exotic or introduced species, such as those found in ornamental gardens or pine plantations.The murray darling was dammed affecting surrounding habitatsIntroduced species have had a 3 fold solvent on environments 1. Grazing2. disputation between native and introduced species 3. introduced species can introduce formerly unknown diseases.In recent years large amounts of insecticide and weedicide have been used and effect the food chain Homozygosity- breeding of the same species of animals Hybridise- mixed breeding of plantsWildlife is harmed by recreation practisesOldest nat. park in Australia is Witches Falls in QLD founded 1908.Rachel Carsons tacit SPRING showed the impact that pesticides could have in areas far outside where they were applied.We are using up our renewable resources faster than we can replace them remarkable plant and animal speciesLast remaining rainforest in Aus is between Townsville and Cooktown, it is on t he world heritage list