Plotless Sampling to Determine Cover
Cover estimated by plotless methods has the advantage of integrating large areas within a single sampling point. Early range assessments relied on the ocular reconnaissance method to estimate cover, where observers traversed the site before subjectively assigning a cover value. This technique generally provided consistent results when practiced by experienced observers, and large areas were surveyed in one day; but extensive training is required and personal bias is difficult to quantify.
A more objective plotless approach is the Variable Plot Method, where cover is assessed using a geometric gauge. This technique has been successfully used in USA rangelands, and is discussed in greater detail as a plotless method to determine cover.
References and Further Reading
Bonham, C.D. 1989. Measurements for terrestrial vegetation. John Wiley Sons, New York, NY. pp 27-31.
Daubenmire, R. 1968. Plant communities: A textbook on plant synecology. Harper Row, New York, NY. pp 86-87.
Mueller-Dombois, D., and H. Ellenburg. 1974. Aims and methods of vegetation ecology. John Wiley Sons, New York, NY. pp 101-106.