Biosphere Contents

5. Development

Stress and disturbance affect the physiological health of plants

From time to time a plant will suffer disturbances such as direct loss of tissue through such agencies as grazing. It may even suffer the removal of its substrate through erosion by windblow or surface water runoff. Stress and disturbance together comprise the environmental pressures which a plant must tolerate. Clearly these pressures operate at a variety of scales and might affect a whole community or a single individual.

Environmental and biological factors that can affect plant health

Periodic stress or disturbance can be accommodated more easily if plants have acclimatised to this stress over a period of time. They may also have been selected over generations for the ability to cope with these conditions. This is the basis of the provenance selection that is undertaken by foresters when selecting seedlings for new plantations. Having selected a particular species, the forester then selects seed from a particular area or provenance that matches most closely the conditions at the site at which planting is to be undertaken.

How do stress and disturbance affect plants?