Concept:Natural vegetation in a habitat is controlled mainly by environmental conditions such as climate, soil and water availability, not by human land use.
Explanation:The amount of rainfall determines the broad vegetation zone, whether forest, grassland or desert.
The nature of the soil particles (sand, silt or clay) influences how much water and nutrients the soil can hold for plant growth.
The depth of the water-table affects the availability of underground moisture to plant roots, especially in wetland and semi-arid areas.
These physical conditions together decide the type of natural vegetation a habitat can support.
Farming activities only modify or replace natural vegetation through clearing, planting and cultivation; they are not a natural determinant of what the habitat itself can support.
Therefore, farming activities is the exception among the listed factors.
Answer:C: farming activities.