For the tie-back and litter-removal experiment, we tested the combined effects of herbivore reduction, light, and litter on percentage change of the following quantities: total density, total cover, species richness, and flower production of Hieracium pratense. To test these effects, we used a split- split plot design, with three treatment factors (modified from Lenter and Bishop 1986:373).
Insecticide treatment did not reduce damage on Hieracium pratense in any year (Fig.
12, we found a highly significant positive linear relationship between light availability in the understory and both the flowering of Hieracium pratense (n = 30; [r.sup.2] = 0.42, P [less than] 0.0001) and the flowering of a group of understory forbs (n = 15, [r.sup.2] = 0.44, P [less than] 0.0001).
16; P-0.004; Hieracium pratense, Fragaria virginiana, Taraxacum officinale, Daucus carota, Chrysanthemum leucanthamum, Potentilla simplex, and Carlina vulgaris).