| Popis: |
Successional trends in herbaceous plant production and diversity were studied in an age sequence of sites, i.e. chronosequence, inferred to represent a meadow to aspen to fir to spruce-fir sere. Primary production was observed to decrease in a linear fashion with successional development. Three components of diversity; richness, heterogeneity, and equitability or evenness, each had low early successional values, reaching maximum diversity in mid-succession, and declining to intermediate levels with maturity. The magnitude of these trends varied greatly, depending on the methods used to determine plant dominance. Characteristics of various dominance indices and their applicability to this study were examined. Mean daily photosynthetic biomass was found to be an especially appropriate index of dominance for studying these seasonally dynamic communities. A checklist of 141 vascular plant taxa encountered in the study is included. The flora was determined to be exceedingly species rich, with values of the calculated diversity indices among the highest reported in the literature reviewed. The limitations of diversity indices to sampled data is discussed. |
