Re: [R] Using XY location data to calculate ecological parameters

From: ONKELINX, Thierry <Thierry.ONKELINX_at_inbo.be>
Date: Tue 12 Sep 2006 - 14:05:14 GMT


Assuming you only use the X direction to split the data into 10 m cells.

table(list(Species, round(X, digits = -1)))

This will generate a table with the number of seedlings per species in each 10 m cell. Divide this by the area of each cell and you get the densities.

Cheers,

Thierry



ir. Thierry Onkelinx

Instituut voor natuur- en bosonderzoek / Reseach Institute for Nature and Forest

Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, methodology and quality assurance

Gaverstraat 4

9500 Geraardsbergen

Belgium

tel. + 32 54/436 185

Thierry.Onkelinx@inbo.be

www.inbo.be

-----Oorspronkelijk bericht-----
Van: r-help-bounces@stat.math.ethz.ch
[mailto:r-help-bounces@stat.math.ethz.ch] Namens James R. Milks Verzonden: dinsdag 12 september 2006 15:36 Aan: r-help@stat.math.ethz.ch
Onderwerp: [R] Using XY location data to calculate ecological parameters

Dear R gurus,

I have XY data giving the locations of tree seedlings that were surveyed during a 210 meter belt transect. This belt transect was taken by stretching a line across the field, then measuring all seedlings within 1 meter on either side of the line. The end result was XY coordinates and height for ~1,300 seedlings. I would like to use that data to calculate density of seedlings per 10 meters per species and relative species abundance in order to compare between this transect and other transects as well as to compare between segments of the same transect. Are there any R packages out there that will allow me make those calculations? To give an idea of my data, here's a fictional example:

Species				X (m)	Y(m)
Acer negundo		90.10	-.19
Acer negundo		90.14	-.90
Acer saccharinum	90.25	.54
Acer rubrum			90.89	.21
Acer negundo		91.25	.36
Acer negundo		91.46	-.65

etc.

Thanks.

Jim Milks



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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Wed Sep 13 00:16:16 2006

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