Discuss the factors that could lead to alternative stable states in an ecosystem. the link between ecosystem Discuss stability, succession, diversity and human activity. Distinguish the roles of r and K selected species in succession. Interpret models or graphs related to succession and zonation. 2.5: Investigating ecosystems Significant ideas: The description and investigation of ecosystems allows for comparisons to be made between different ecosystems and for them to be monitored, modelled and evaluated over time, measuring both natural change and human impacts. Ecosystems can be better understood through the investigation and quantification of their components. Knowledge and understanding: Guidance: The study of an ecosystem requires that When constructing identification keys, it be named and located; for example, students should be reminded that generic Deinikerwald in Baar, Switzerland—a terms such as or are not “big” “small” mixed deciduous–coniferous managed useful. Comparative, quantitative woodland. descriptors and simple identification of Organisms in an ecosystem can be the presence or absence of external identified using a variety of tools features are most useful in keys. including keys, comparison to herbarium The design of sampling strategies needs or specimen collections, technologies to be appropriate for its purpose and and scientific expertise. provide a valid representation of the Sampling strategies may be used to system being investigated. Suitable measure biotic and abiotic factors and sampling techniques include random or
Discuss the factors that could lead to alternative stable states in an ecosystem. Discuss the link between ecosystem stability, succession, diversity and human activity. Distinguish the roles of r and K selected species in succession. Interpret models or graphs related to succession and zonation. 2.5: Investigating ecosystems Significant ideas: The description and investigation of ecosystems allows for comparisons to be made between different ecosystems and for them to be monitored, modelled and evaluated over time, measuring both natural change and human impacts. Ecosystems can be better understood through the investigation and quantification of their components. Knowledge and understanding: The study of an ecosystem requires that it be named and located; for example, Deinikerwald in Baar, Switzerland—a mixed deciduous–coniferous managed woodland. Organisms in an ecosystem can be identified using a variety of tools including keys, comparison to herbarium or specimen collections, technologies and scientific expertise. Sampling strategies may be used to measure biotic and abiotic factors and Guidance: When constructing identification keys, students should be reminded that generic terms such as “big” or “small” are not useful. Comparative, quantitative descriptors and simple identification of the presence or absence of external features are most useful in keys. The design of sampling strategies needs to be appropriate for its purpose and provide a valid representation of the system being investigated. Suitable sampling techniques include random or
IB_Environmental_Systems_and_Societies_2016.docx