Print PageTallgrass prairie restoration is an important tool for returning functional ecosystems to the Midwest. The objective of this study was to determine whether grass seed population source (i.e., cultivar or locally collected) and restoration seed mix (dominance of grasses seeded) differentially affect aboveground net primary productivity (ANPP) and root biomass in prairie restoration. This study was conducted in previously established restoration experiments in Kansas and Illinois. Each restoration contained whole plots seeded to either cultivar or locally collected grass sources and each whole plot contained five subplot treatments of seeded grass dominance. All plots were also seeded with 13 forb species. In 2010, we removed two soil cores from the 20% and 97% seeded grass dominance subplot treatments. Roots were manually separated from cores, washed, dried (55°C), and weighed to determine root biomass. ANPP was measured by drying (55°C) plant biomass clipped from 0.1 m2 frames.
Results/Conclusions
In Kansas, root biomass was greater in cultivar plots than non-cultivar plots (P=0.002), but similar in the 20 and 97% grass dominance treatments (P=0.203). In Illinois, root biomass was similar in cultivar and non-cultivar plots (P=0.465), but root biomass was greater in the 97% grass treatment than in the 20% grass dominance treatment (P=0.070). In Kansas and Illinois, ANPP was similar in both source and dominance treatments (P>0.199). Different responses of root biomass to the two factors (source and dominance) in the two locations may be due to variation in the effect of climate on abiotic filters in restoration. From 2005 to 2010, establishment and cover of dominant grasses was lower in Kansas non-cultivar plots, which likely explains the lower root biomass in non-cultivar plots in Kansas. In Illinois, the wetter climate likely enabled similar establishment of dominant species regardless of source, but resulted in greater root biomass in higher grass dominance treatments.
