"Vegetation Analysis in Upland and Highland Areas, Using the Quadrant method of Vegetation sampling"


Over the last few decades, the interpretation of the environment and itís relation to human has
undergone a radical transformation. The new understanding of the unity of the biosphere and the extent
and the scale of the processes within it make necessary not only incorporation of new data but also constant
reappraisal of data and theories of long standing.
Classification of vegetational communities by referencing the dominant tree species is a common
practice. Attempts to quantify that dominance has led to various methods of sampling. For practical reason,
all the members of a vegetational community cannot be counted or measured, and even if this were done (at
the expense of significant time and effort), the information gathered would be no more useful or significant
than the data acquired by proper sampling. The optimum sampling method must provide sufficient data to
establish an accurate assessment of a vegetational community with a minimum amount of time and effort.
Ecological research requires the sampling of many attributes of individuals, populations,
communities and ecosystems. Sampling data typically exhibit two features of major interest: a certain
central tendency and a certain pattern of variability. The central tendency is the value or condition that best
typifies the attribute examined. For example, most trees in the sample were scotch pine (Pinus sylvestris),
their average diameter was 10 inches. Variability is the spread of individual values about this central
tendency. For example, trees ranged from 4" to 24" in diameter, but 80% were within 14" of the average.
Ecologists use statistical techniques to describe the central tendency, express the variability within the
sample data, and state the degree of confidence that can be placed on estimates of central tendency.
The most widely sampling techniques for vegetation analysis involve; quadrats in which individuals
can be counted and measured, line transects along which the intercepted individuals are measured, and
points at which measurements are made of distance to and attributes of the nearest individuals. These
techniques can be adapted for almost all plants communities. And many communities of sessile or
sedentary animals.
The quadrat technique is easy to use in communities with a profile low enough that a frame can be
placed over the area to be sampled, or a radius line rotated a central point. It is also appropriate for forest
communities that are open enough to allow plot boundaries to be marked easily and accurately with a tape
measurement. The line transect technique is effective for low, dense communities in which quadrats are
difficult to place on the surface. It is also the easiest technique to use when individual organisms are
difficult to distinguish from one another, or are irregular in shape. Point-based techniques are best when
individuals are widely placed or when the dominant organisms are large and dense enough that quadrat
boundaries or straight transect lines are difficult to lay out.
Consideration of the size, shape, and number of sampling units, and whether they should be spaced
systematically, randomly, or in a stratified random manner. For any sampling procedure, it is usually most
convenient to establish a baseline along one side of the stand or through the stand center. Quadrats,
transects, or sampling points can be located randomly, in a stratified random manner, or systematically with
reference to the baseline. Quadrats or sampling points can be located randomly by drawing pairs of random
numbers to serve as coordinates of sampling locations, one number indicating the distance along the
baseline, the other, the distance into the area.
This paper is a study that compares the vegetation in two different habitat, upland and highland using
the point centered quartered sampling method, the study was conducted in the month of March, 1997.
The first habitat sampled was Millís Reservation, NJ, which is a habitat classified as upland represent
an idealized midpoint on the soil moisture gradient and referred to as mesic, no standing water appears on
such site, but it retains a good supply of rainwater for the use by plants. Mesic sites include land of flat or
undulating contour including gentle slopes and hilltops that are not excessively drained and valleys and
ravines that are not as wet as swampy