swamptrees {nnspat}

Tree Species in a Swamp Forest

Description

Locations and species classification of trees in a plot in the Savannah River, SC, USA. Locations are given in meters, rounded to the nearest 0.1 decimal. The data come from a one-hectare (200-by-50m) plot in the Savannah River Site. The 734 mapped stems included 156 Carolina ashes (Fraxinus caroliniana), 215 water tupelos (Nyssa aquatica), 205 swamp tupelos (Nyssa sylvatica), 98 bald cypresses (Taxodium distichum) and 60 stems from 8 additional three species (labeled as Others (OT)). The plots were set up by Bill Good and their spatial patterns described in (Good and Whipple (1982)), the plots have been maintained and resampled by Rebecca Sharitz and her colleagues of the Savannah River Ecology Laboratory. The data and some of its description are borrowed from the swamp data entry in the dixon package in the CRAN repository.

See also (Good and Whipple (1982); Jones et al. (1994); Dixon (2002)).

Usage

data(swamptrees)

Format

A data frame with 734 rows and 4 variables

Details

Text describing the variable (i.e., column) names in the data set.

• x,y: x and y (i.e., Cartesian) coordinates of the trees

• live: a categorical variable that indicates the tree is alive (labeled as 1) or dead (labeled as 0)

• sp: species label of the trees:

  FX:

  Carolina ash (Fraxinus caroliniana)

  NS:

  Swamp tupelo (Nyssa sylvatica)

  NX:

  Water tupelo (Nyssa aquatica)

  TD:

  Bald cypress (Taxodium distichum)

  OT:

  Other species

Source

Prof. Philip Dixon's website

References

Dixon PM (2002). “Nearest-neighbor contingency table analysis of spatial segregation for several species.” Ecoscience, 9(2), 142-151.

Good BJ, Whipple SA (1982). “Tree spatial patterns: South Carolina bottomland and swamp forests.” Bulletin of the Torrey Botanical Club, 109(4), 529-536.

Jones RH, Sharitz RR, James SM, Dixon PM (1994). “Tree population dynamics in seven South Carolina mixed-species forests.” Bulletin of the Torrey Botanical Club, 121(4), 360-368.

Examples

data(swamptrees)
plot(swamptrees$x,swamptrees$y, col=as.numeric(swamptrees$sp),pch=19,
xlab='',ylab='',main='Swamp Trees')