swamp                 package:ecespa                 R Documentation

_T_r_e_e _S_p_e_c_i_e_s _i_n _a _S_w_a_m_p _F_o_r_e_s_t

_D_e_s_c_r_i_p_t_i_o_n:

     Locations and botanical classification of trees in a plot in the
     Savannah River. Locations are given in metres, rounded to the
     nearest 0.1 metre.  The data come from  a 1-ha (200 m x 50 m) plot
     in the Savannah River Site, South Carolina, USA.  The 734 mapped
     stems included 156 Carolina ash (_Fraxinus caroliniana_),  215
     Water tupelo (_Nyssa aquatica_), 205 Swamp tupelo (_Nyssa
     sylvatica_),  98 Bald cypress (_Taxodium distichum_) and 60 stems
     of 8 additional species. Although 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. There are slightly different versions of the Good plot
     data. Every time the plots are resampled, some errors are
     corrected. This is mostly a concern for the biologists. The
     different versions are very similar; they are all very good
     examples of a marked spatial point pattern.

_U_s_a_g_e:

     data(swamp)

_F_o_r_m_a_t:

     A data frame with 734 observations on the following 3 variables.

     '_x' Cartesian x-coordinate of tree

     '_y' Cartesian y-coordinate of tree

     '_s_p' a factor with levels indicating the species of each tree:

            'FX'  Carolina ash (_Fraxinus caroliniana_)
            'NS'  Swamp tupelo (_Nyssa sylvatica_)
            'NX'  Water tupelo (_Nyssa aquatica_)
            'TD'  Bald cypress (_Taxodium distichum_)
            'OT'  Other species


_S_o_u_r_c_e:

     Philip Dixon's personal web page <URL:
     http://www.public.iastate.edu/~pdixon/>

_R_e_f_e_r_e_n_c_e_s:

     Dixon, P.M. 2002. Nearest-neighbor contingency table analysis of
     spatial  segregation for several species. _Ecoscience_, *9*(2):
     142-151.

     Good, , B. J. & Whipple, S.A. 1982. Tree spatial patterns: South
     Carolina bottomland and swamp forest. _Bulletin of the Torrey
     Botanical Club_, *109*: 529-536.

     Jones et al. 1994. Tree population dynamics in seven South
     Carolina mixed-species forests. _Bulletin of the Torrey Botanical
     Club_, *121*:360-368.

_E_x_a_m_p_l_e_s:

     data(swamp)
     plot(swamp$x,swamp$y, col=as.numeric(swamp$sp),pch=19,
                      xlab="",ylab="",main="Swamp forest")

