2.7 Measuring changes in the system The Ecosystem 2.7 Measuring changes in the system

Assessment Statements 2.7.1 Describe and evaluate methods for measuring changes in abiotic and biotic components of an ecosystem along an environmental gradient. 2.7.2 Describe and evaluate methods for measuring changes in abiotic and biotic components of an ecosystem due to a specific human activity. 2.7.3 Describe and evaluate the use of Environmental Impact Assessments (EIAs).

2.7.1 Describe and evaluate methods for measuring changes in abiotic and biotic components of an ecosystem along an environmental gradient. Ecological gradient – where two ecosystems meet or where an ecosystem suddenly ends. This causes both biotic and abiotic factors to vary with distance and form gradients in which trends can be recorded.

2.7.1 Describe and evaluate methods for measuring changes in abiotic and biotic components of an ecosystem along an environmental gradient. Line transect – tape measure laid out perpendicular to the gradient – only those touching tape counted Belt transect – band (0.5 to 1 m) laid out perpendicular to the gradient – all those within area

Need to be taken as far out as possible, and at the same time of day. 2.7.1 Describe and evaluate methods for measuring changes in abiotic and biotic components of an ecosystem along an environmental gradient. Can sample whole transect (continuous) or samples at equal points along transect (interrupted) Need to be taken as far out as possible, and at the same time of day. Should be repeated at least three times. Use random number to determine where to place transects.

2.7.2 Describe and evaluate methods for measuring changes in abiotic and biotic components of an ecosystem due to a specific human activity. Nuclear Contamination – Dosimeters are used to measure radiation with measurements in microroentgens per hour at ground level.

2.7.2 Describe and evaluate methods for measuring changes in abiotic and biotic components of an ecosystem due to a specific human activity. Satellite imagery – Very reliable, covers a large area, and allows us to see change over time. Excavations and mining – size of landforms created or destroyed can be determined by measuring the lowering of the surface (mm/yr) or volume carried by river tons/m3yr

2.7.3 Describe and evaluate the use of Environmental Impact Assessments (EIAs). Environmental Impact Assessment – designed to establish the impact of a project on the environment. Should provide a non-technical summary so that lay- people and the media can understand the implications of the study. Ranges from being part of legal framework, as help for policy decision, to be often ignored.

2.7.3 Describe and evaluate the use of Environmental Impact Assessments (EIAs). Requires a baseline study to understand what area is like before the project. Study includes: Habitat type and abundance Species list Species diversity Endangered species Land use Hydrology Human population Soil

It is often speculative, with few concrete answers. 2.7.3 Describe and evaluate the use of Environmental Impact Assessments (EIAs). Difficult for it to be complete due to lack of data. The EIA is directly limited by the quality of the baseline study. It is often speculative, with few concrete answers. Can potentially lead to changes in a development, avoiding negative environmental impact.