Responses of the Codominant Grassland Species Andropogon gerardii and Sorghastrum nutans to Long-term Manipulations of Nitrogen and Water

We examined the role of interspecific competition in the regulation of abundance and coexistence of the dominant grasses in tallgrass prairie using a removal experiment with Andropogon gerardii Vitman and Sorghastrum nutans L. Nash, two of the most abundant grasses in tallgrass prairie. Plant removal treatments (using foliar herbicide), applied to 0.3-m2 plots at the Konza Prairie Biological Station (northeast Kansas, USA), included removal of all A. gerardii, removal of all S. nutans, and no removal. To determine whether soil fertility altered the outcome, we included a fertilizer addition treatment (10 g N·m2) fully crossed with the removal treatments. Andropogon gerardii removal resulted in significantly increased net photosynthesis, stomatal conductance, and tiller mass in S. nutans. Sorghastrum nutans removal had little effect on A. gerardii, suggesting asymmetric competition. Fertilizer significantly increased tiller mass and flowering stalk production in S. nutans, but had little effect on A. gerardii. The ability of A. gerardii to suppress the performance of S. nutans is consistent with the greater abundance of A. gerardii over much of the tallgrass prairie, while the ability of S. nutans to take advantage of increased resources may be one mechanism by which it avoids competitive exclusion. Because of the greater variability in the performance of S. nutans than in that of A. gerardii, any natural or anthropogenic alterations to this grassland that lead to shifts in dominance between these species may affect ecosystem productivity and stability.Key words: Andropogon gerardii, competition, grassland, neighbour removal, photosynthesis, Sorghastrum nutans, tallgrass prairie.

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Influence of Antidotes on Forage Grass Seedling Response to Metolachlor and Butylate

Weed Science ◽

10.1017/s0043174500074713 ◽

1988 ◽

Vol 36 (2) ◽

pp. 202-206 ◽

Cited By ~ 7

Author(s):

Timothy S. Griffin ◽

Lowell E. Moser ◽

Alex R. Martin

Keyword(s):

Panicum Virgatum ◽

Field Studies ◽

Andropogon Gerardii ◽

Forage Grass ◽

Big Bluestem ◽

Sorghastrum Nutans ◽

Bouteloua Curtipendula ◽

Naphthalic Anhydride ◽

Intermediate Wheatgrass ◽

Sideoats Grama

Field studies were conducted for 3 yr near Mead, NE, to evaluate the effectiveness of seed safeners CGA-92194 [N-(1,3-dioxalon-2-yl-methoxy)iminobenzeneacetonitrile], NA (1,8-naphthalic anhydride), and R-29148 (2,2-dimethyl-5-methyldichloroacetyloxazolidine) to reduce herbicide injury to big bluestem (Andropogon gerardiiVitman), indiangrass[Sorghastrum nutans(L.) Nash], intermediate wheatgrass[Agropyron intermedium(Host.) Beauv.], sideoats grama[Bouteloua curtipendula(Michx.) Torr.], and switchgrass (Panicum virgatumL.) from preplant-incorporated butylate [5-ethyl bis-(2-methylpropyl)carbamothioate] and metolachlor [2-chloro-N- (2-ethyl-6-methylphenyl) -N- (2-methoxy-l-methylethyl)acetamide], applied at 4.5 and 2.2 kg ai/ha, respectively. Big bluestem stands were satisfactory, regardless of herbicide or safener treatment, although stands were reduced by NA treatment with either herbicide. Indiangrass stands varied by year, with protection from both herbicides by R-29148 in 1984 and by NA in 1985. All safeners reduced injury to intermediate wheatgrass from metolachlor and to a lesser extent from butylate; acceptable stands were obtained with metolachlor treatment when unsafened. Sideoats grama was nearly eliminated with either herbicide, regardless of safener. Switchgrass treated with NA produced stands two- to threefold higher than other safened or unsafened seed in metolachlor plots and equal to unsafened seed in the weeded control plots.

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Long-Term Effects of Scrub Clearance and Litter Removal on the Re-Establishment of Dry Alvar Grassland Species

Annales Botanici Fennici ◽

10.5735/085.049.0104 ◽

2012 ◽

Vol 49 (1-2) ◽

pp. 21-30 ◽

Cited By ~ 5

Author(s):

Jan P. Bakker ◽

Eje Rosén ◽

Wim A. Ozinga ◽

Mario Bretfeld ◽

Tobias Feldt ◽

...

Keyword(s):

Long Term Effects ◽

Grassland Species ◽

Litter Removal

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Long term development of a realistic and integrated socio-ecological system

10.1101/823294 ◽

2019 ◽

Author(s):

C. Gaucherel ◽

C. Carpentier ◽

I.R. Geijzendorffer ◽

F. Pommereau

Keyword(s):

Petri Nets ◽

Management Practice ◽

Management Strategies ◽

Interaction Network ◽

Grassland Species ◽

Extensive Grazing ◽

New Type ◽

Opening Up

AbstractWe developed a discrete and qualitative model of integrated socio-ecosystems, with the help of formal Petri nets. We illustrated such Petri nets in the case study of temporary marshes in the Mediterranean part of France, the Camargue delta, by integrating biotic, abiotic and human-related components along with their processes into the same interaction network. The model demonstrated that when marshes are exposed to extensive grazing the presence of marsh heritage species is facilitated by opening up the vegetation through various trajectories. This supports the commonly used management practice of extensive grazing to conserve certain protected habitats. With this Possibilistic approach, we identified all potential ecosystem trajectories and provided their differential (non-systematic) impacts on heritage species richness (number). Hence, we rigorously demonstrate with this new type of model that grazing benefits marsh species which are faced with competition from common grassland species. The detailed analysis of the explicit state space and trajectories allows exploring simultaneously the identification of a range of recommendations for management strategies.

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Sensitivity of temperate grassland species to elevated atmospheric CO2 and the interaction with temperature and water stress

Agricultural and Food Science ◽

10.23986/afsci.72746 ◽

1996 ◽

Vol 5 (3) ◽

pp. 271-283 ◽

Cited By ~ 13

Author(s):

Michael B. Jones ◽

Marjan Jongen

Keyword(s):

Community Structure ◽

Water Stress ◽

Atmospheric Concentration ◽

Temperate Grasslands ◽

Elevated Atmospheric Co2 ◽

Grassland Species ◽

Long Term Effect ◽

Intensively Managed ◽

Increasing Temperature

The annual cycle of growth of many temperate grasses is limited by low temperatures during the winter and spring and water stress during the summer. Climate change, induced by increase in the concentration of greenhouse gases in the atmosphere, can affect the growth and community structure of temperate grasslands in two ways. The first is directly through changes in atmospheric concentration of CO2 and the second is indirectly through changes in temperature and rainfall. At higher latitudes, where growth is largely temperature limited, it is probable that the direct effects of enhanced CO2 will be less than at low latitudes. However, interactions with increasing temperature and water stress are complex. Temperate grasslands range from intensively managed monocultures of sown species to species rich natural and semi-natural communities whose local distributions are controlled by variations in soil type and drainage. The different species can show marked differences in their responses to increasing CO2 concentrations, rising temperatures and water stress. This will probably result in major alterations in the community structure of temperate grasslands in the future. In addition to impacts on primary productivity and community structure, a long-term effect of elevated CO2 on grasslands is likely to be a significant increase in soil carbon storage. However, this may be counteracted by increases in temperature.

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