Degraded soil increases the performance of a dominant
grass, Andropogon gerardii (Big bluestem)
Drew A. Scott
Sara G. Baer
Received: 28 March 2018 / Accepted: 25 May 2018
Ó Springer Science+Business Media B.V., part of Springer Nature 2018
Abstract Dominant grasses can suppress subordi-
nate species in grassland restorations. Examining
factors that inﬂuence performance of a dominant grass
when interacting with subordinate forbs may provide
insights for maintaining plant community diversity.
The objective of our study was to determine how soils
of different restoration ages and functionally different
forbs inﬂuence the performance (using biomass and
tillering rate as proxies) of a dominant grass: Andro-
pogon gerardii. Sites included a cultivated ﬁeld and
two restored prairies (4 or 16 years after restoration) at
Konza Prairie (NE Kansas). We hypothesized A.
gerardii performance would be greater in more
degraded soils and when interacting with legumes.
Soil structure, nutrient status, and microbial biomass
were measured in soil that was used to conduct the
plant interaction study. Andropogon gerardii perfor-
mance was measured during an 18-week greenhouse
experiment using the relative yield index calculated
from net absolute tillering rate and ﬁnal biomass
measurements in three soil restoration age treatments
combined with four interacting forb treatments.
Restoration improved soil structure, reduced plant-
available nutrients, and increased microbial biomass.
Relative yield index values of A. gerardii were greater
with non-legumes than legumes. Andropogon gerardii
performed best in degraded soils, which may explain
the difﬁculty in restoring tallgrass prairie diversity in
long-term cultivated soil. Results from this study
suggest practices that promote soil aggregation and
fungal biomass, coupled with including a high abun-
dance of legumes in seed mixes could reduce domi-
nance of A. gerardii and likely increase plant diversity
in tallgrass prairie restorations.
Keywords Microbial biomass Á Nitrogen Á
Phosphorus Á Plant–soil interactions Á Phospholipid
fatty acids Á Prairie Á Restoration Á Soil structure
PLFA Phospholipid fatty acid
RY Relative yield
Only * 9% of the tallgrass prairie remains intact
(White et al. 2000), largely due to the conversion of
this ecosystem to row crop agriculture (Samson et al.
2004). Ecological restoration has become a common
practice to increase the extent and biodiversity of this
Communicated by E.T.F Witkowski.
D. A. Scott (&) Á S. G. Baer
Department of Plant Biology and Center for Ecology,
Southern Illinois University, Carbondale, 1125 Lincoln
Dr. Mailcode 6509, Carbondale, IL 62901, USA