BIOLOGY 1P03 Lecture : Species
19 Jan 2013
School
Department
Course
Professor
Document Summary
Many species depend on particular patterns of disturbances on the landscape such as fires and windstorms. Conservation biologists work to assess whether reestablishment of historic disturbance patterns can help preserve biodiversity. Many plant species require periodic fires for successful establishment and survival but however controlled burning is a common forest management tool. Scars in the annual growth rings of trees preserve evidence of past fires that didn"t kill them researchers can determine when fires occurred, how severe they were and when fire patterns changed. Annual growth rings showed that low-intensity fires were common near l. a until. After that cattle and sheep grazing and fire suppression reduced the frequency of low-intensity fires. Since the species have been lost, it is not easy to reintroduce the species. Previous attempts to create wetlands have failed and so established a large field experiment to discover why found that experimental plots planted with species-rich mixtures developed a complex vegetation structure.
