Between 1915 and 1932, more than 100 1 m2 quadrats were established
across the Jornada Experimental Range to document vegetation dynamics
in the dominant grass species over time. Basal area of perennial
grasses, locations of annual grasses, forbs, shrubs, and canopy cover
of major shrubs were charted. Thirty-four quadrats were established in
1915, 8 in 1916, 14 in 1919, 3 in 1921, 2 in 1924, 17 in 1926, 21 in
1927, 2 in 1929, 1 in 1931, and 2 in 1932. Data was recorded as chart
quadrat maps, in which the locations and shapes of all living plants
located within the quadrat were mapped onto the data sheet. From
1915-1924 mapping was done by dividing the quadrat frame into a
decimeter grid using straps and reproducing locations of plants on
grid paper. From 1925-2016 mapping was done using a pantograph, a
device which allows for more accurate mapping of size and location of
plants (Hill, 1920). Perennial grasses were mapped as polygons
representing the boundary of each individual grass bunch at a point 1
inch above the soil surface (i.e. basal area); shrubs were mapped as
polygons representing the canopy cover of each individual; and forbs
were mapped as point locations only.
