Influence of plant community composition on biomass production in planted grasslands.

United States energy policy mandates increased use of renewable fuels. Restoring grasslands could contribute to a portion of this requirement through biomass harvest for bioenergy use. We investigated which plant community characteristics are associated with differences in biomass yield from a range of realistic native prairie plantings (n = 11; i.e., conservation planting, restoration, and wildlife cover). Our primary goal was to understand whether patterns in plant community composition and the Floristic Quality Index (FQI) were related to productivity as evidenced by dormant season biomass yield. FQI is an objective measure of how closely a plant community represents that of a pre-European settlement community. Our research was conducted in planted fields of native tallgrass prairie species, and provided a gradient in floristic quality index, species richness, species diversity, and species evenness in south-central Wisconsin during 2008 and 2009. We used a network of 15 randomly located 1 m2 plots within each field to characterize the plant community and estimate biomass yield by clipping the plots at the end of each growing season. While plant community composition and diversity varied significantly by planting type, biomass yield did not vary significantly among planting types (ANOVA; P >0.05). Biomass yield was positively correlated with plant community evenness, richness, C4 grass cover, and floristic quality index, but negatively correlated with plant species diversity in our multi-season multiple linear mixed effects models. Concordantly, plots with biomass yield in the lowest quartile (biomass yield < 3500 kh/ha) had 8% lower plant community evenness and 9% lower FQI scores than those in the upper quartile (biomass yield > 5800 kh/ha). Our results suggest that promoting the establishment of fields with high species evenness and floristic quality may increase biomass yield, while simultaneously supporting biodiversity

Indeks Pharmacy Vol. 13 No 1, Juli 2016 Dan Panduan Penulisan Pharmacy

Ndeks Pharmacy vol. 13 no 1, Juli 2016 dan Panduan Penulisan Pharmac

Analysis of similarities (ANOSIM) matrix for managed grassland plant communities among four planting types.

<p>Numbers below the diagonal are ANOSIM <i>R</i> values, those above are P-values. ANOSIM <i>R</i> values typically range from zero to one, where zero are completely dissimilar communities and one represents completely similar communities.</p><p>Analysis of similarities (ANOSIM) matrix for managed grassland plant communities among four planting types.</p

Box plots of vegetation characteristics by planting type and year.

<p>Letters indicate means that are significantly different (Tukey’s HSD, P < 0.05) for (A) biomass yield (kg/ha), (B) Floristic Quality Index (FQI), (C) Evenness (E′), (D) Shannon-Weaver Diversity Index (H′), (E) species richness (S), and (F) C4 grass cover among planting types and between years.</p

Nonmetric multi-dimensional scaling (NMS) biplots for vegetation in south-central Wisconsin prairies.

<p>A three axis solution best described the vegetation data: (A) axis 1 versus axis 2, (B) axis 1 versus axis 3, and (B) axis 2 versus axis 3. Ordination ellipses indicate planting type. Numbers under the environmental variable name represent the correlation with the horizontal and vertical axes of the respective plot. Purple gradients represent FQI scores.</p

Correlation of environmental variables with nonmetric multidimensional scaling axes.

<p>Bold indicates environmental variables with r² > 0.50, whose vectors are shown on nonmetric multidimensional scaling plots.</p><p>^†Variable definitions: S: plant species richness; H′: plant species Shannon-Weaver diversity index; FQI: Floristic Quality Index; E′: plant species evenness.</p><p>Correlation of environmental variables with nonmetric multidimensional scaling axes.</p