Gridded Pollen Percentages used in creation of maps shown in Figures 2, 3, GIF-animations.  
Number of Variables: 83
All variables are space-delimited

VARNAME	  VAR#	COMMENTS  
Row       01	RowID for gridpoint
Column    02	ColumnID for gridpoint
AgeCon    03	Age of pollen data
AgeTarg	  04	Age of basemap to which data is interpolated
C-space   05    # of spatial dimensions to search window (effectively a dummy field; should always=3: X,Y,elev)
Npoints   06    # of points in search window placed around grid center
WinDist   07    Weighted sum of distances between all pollen sites within search window and grid center
X         08    Albers X  (Projection: Albers equal area; parallels 33.33°N, 66.66°N; center=70°N,100°W; Radius=1)
Y         09    Albers Y  (Projection: Albers equal area; parallels 33.33°N, 66.66°N; center=70°N,100°W; Radius=1)
Elev      10    Elevation (m)
ChrnErr   11    Chronology Error or Rank -- See Williams et al. 2003 Ecol. Mon. for more information
PolErr    12    Pollen Error or Rank-- See Williams et al. 2003 Ecol. Mon. for more information
Abies     13    ** Percent pollen abundance (relative to these 61 pollen types)
Acer      14    ** Summary pollen variables (TPinus, TPicea, PForbs, PForbsAmb)
Alnus     15    ** not included in pollen sum
Ambros    16    see lines 13-15
Apiaec    17    see lines 13-15
Aquifo    18    see lines 13-15
Artemi    19    see lines 13-15
Astera    20    see lines 13-15
Betula    21    see lines 13-15
Brasen    22    see lines 13-15
Carya     23    see lines 13-15
Caryop    24    see lines 13-15
Castan    25    see lines 13-15
Ceanot    26    see lines 13-15
Celtis    27    see lines 13-15
Cephal    28    see lines 13-15
Cercoc    29    see lines 13-15
CheAma    30    see lines 13-15
Clethr    31    see lines 13-15
Corylu    32    see lines 13-15
CupTax    33    see lines 13-15
Cypera    34    see lines 13-15
Dry-t     35    see lines 13-15
Empetr    36    see lines 13-15
Ephedr    37    see lines 13-15
Ericac    38    see lines 13-15
Eriogo    39    see lines 13-15
Euphor    40    see lines 13-15
Fabace    41    see lines 13-15
Fagus     42    see lines 13-15
Fraxiu    43    see lines 13-15
Juglan    44    see lines 13-15
LarTsu    45    see lines 13-15
LiqAmb    46    see lines 13-15
Mim       47    see lines 13-15
Myrica    48    see lines 13-15
Nyssa     49    see lines 13-15
Ostrya    50    see lines 13-15
OxyDig    51    see lines 13-15
PForbs    52    see lines 13-15
PForbsAm  53    see lines 13-15
TPicea    54    see lines 13-15
Pic_gl    55    see lines 13-15
Pic_ma    56    see lines 13-15
PiceaUd   57    see lines 13-15
TPinus    58    see lines 13-15
Pin.St    59    see lines 13-15
PinusUd   60    see lines 13-15
Platan    61    see lines 13-15
Poacea    62    see lines 13-15
Populu    63    see lines 13-15
Quercu    64    see lines 13-15
Ranumc    65    see lines 13-15
Rubiac    66    see lines 13-15
Salix     67    see lines 13-15
SarVer    68    see lines 13-15
Saxifr    69    see lines 13-15
Selagi    70    see lines 13-15
SheCan    71    see lines 13-15
Sphaer    72    see lines 13-15
Taxodi    73    see lines 13-15
Thu       74    see lines 13-15
Tilia     75    see lines 13-15
Tsuga     76    see lines 13-15
Ulmus     77    see lines 13-15
SpAsBi    78    Spruce>20%, Ash>6%, Birch>10%          **Vars 78-83 are composite indices
SpSePi    79    Spruce>20%, Sedge>5%, Pine>20%         **used to create multi-taxon maps
HiOaEl    80    Hickory>5%, Oak>20%, Elm>5%            **0=none, 1=only taxon 3, 2=only taxon 2
HeBePi    81    Hemlock>10%, Beech>5%, Pine>30%        **2=taxa 2+3, 3=only taxon 1, 4=taxa 1+3
HeFiDF    82    Hemlock>10%, Fir>1%, Douglas Fir>1%    **5=taxa 1+2, 6=all taxa
PFOaSp    83    Prairie Forbs>5%, Oak>20%, Spruce>20%