Plant cover
The abundances of plant species are often measured by plant cover, which is the relative area covered by different plant species in a small plot. Plant cover is not biased by the size and distributions of individuals, and is an important and often measured characteristic of the composition of plant communities.[1][2]
Contents
1 Usage
2 Measurement
3 References
4 External links
Usage
Plant cover data may be used to classify the studied plant community into a vegetation type, to test different ecological hypothesis on plant abundance, and in gradient studies, where the effects of different environmental gradients on the abundance of specific plant species are investigated.[3]
Measurement
The most common way to measure plant cover in herbal plant communities, is to make a visual assessment of the relative area covered by the different species in a small plot (see quadrat). The visually assessed cover of a plant species is then recorded as a continuous variable between 0 and 1, or divided into interval classes as an ordinal variable.[4] An alternative methodology, called the pin-point method (or point-intercept method), has also been widely employed.
In a pin-point analysis, a frame with a fixed grid pattern is placed randomly above the vegetation, and a thin pin is inserted vertically through one of the grid points into the vegetation. The different species touched by the pin are recorded at each insertion. The cover of plant species k in a
plot, ck{displaystyle c_{k}}
ck=ykn{displaystyle c_{k}={frac {y_{k}}{n}}}
where yk{displaystyle y_{k}}
References
^ Coker, Kent A.; Coker, P. (1992). Vegetation Description and Analysis – A Practical Approach. John Wiley & Sons, New York..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output .citation q{quotes:"""""""'""'"}.mw-parser-output .citation .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/12px-Wikisource-logo.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-maint{display:none;color:#33aa33;margin-left:0.3em}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
^ Grant, S. A. (1993). Resource description: Vegetation and sward components. In A. Davies, R. D. Baker, S. A. Grant, & A. S. Laidlaw (Eds.), Sward measurement handbook (2nd ed., pp. 69–98). British Grassland Society, Reading.
^ Austin, M. (2009). "Species distribution models and ecological theory: a critical assessment and some possible approaches". Ecological Modelling. 200: 1–19. doi:10.1016/j.ecolmodel.2006.07.005.
^ Braun-Blanquet, J. (1964). Pflanzensoziologie. Springer, Wien.
^ Damgaard, Christian (2009). "On the distribution of plant abundance data". Ecological Informatics. 4 (2): 76–82. doi:10.1016/j.ecoinf.2009.02.002.
External links
PIN-POINT 1.0 is a Mathematica notebook for estimating plant cover from pin-point data using a generalised binomial distribution.
