Abstract
Competitive interactions were compared under field and greenhouse conditions for three representative tallgrass prairie species, Echinacea purpurea , Panicum virgatum and Ratibida pinnata . These were planted in monoculture and in mixtures of two species using a replacement series design with groups of four or eight plants. Competition was determined from shoot dry weight data collected during 120 days in the greenhouse and after 415 days in the field. Yields declined with increased density of a single species in the greenhouse from 40 days onward and in the field. Relative yields were up to 100% higher in mixtures than in monocultures for all species early on in the greenhouse experiment. Later in the experiment and in the field relative yields of E. purpurea decreased in the presence of P. virgatum and R. pinnata , whereas relative yields of these two species increased in the presence of E. purpurea . There were correlations in relative yield between the field and the greenhouse experiment at 80 and 120 days. In the greenhouse P. virgatum maintained higher net assimilation rates than the other species. Relative growth rates of all species were higher in monoculture and in mixtures up to 40 days, after which they declined, especially for E. purpurea in mixtures. In the field, higher light intensities occurred in pure stands of E. purpurea than in mixed stands with other species. The order of competitive ability that was apparent from these field and greenhouse studies, P. virgatum = R. pinnata > E. purpurea , could be partially explained by photosynthetic rates in relation to canopy light interception.
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Claims 11
Claim · model-written summary
Single-species density reduced yields in greenhouse and field.
- Taxon
- Echinacea purpurea
.jpg?width=60)
Echinacea purpureat0 - Outcome
- Yieldse0
- Direction
- declinede0
- Setting
- greenhousee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Yields declined with increased density of a single species in the greenhouse from 40 days onward and in the field.”
t0“Echinacea purpurea”
Claim · model-written summary
Early greenhouse mixture relative yields were up to 100% higher for all three species.
- Taxon
- Echinacea purpureaEchinacea purpureat0
- Outcome
- Relative yieldse0
- Direction
- highere0
- Value
- 100%e0
- Comparator
- monoculturese0
- Setting
- greenhousee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Relative yields were up to 100% higher in mixtures than in monocultures for all species early on in the greenhouse experiment.”
t0“Echinacea purpurea”
Claim · model-written summary
Echinacea relative yield declined with Panicum later and in the field.
- Taxon
- E. purpureaEchinacea purpureae0
- Interactor
- P. virgatum
Panicum virgatume0other - Outcome
- relative yields of E. purpureae0
- Direction
- decreasede0
- Setting
- fielde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Later in the experiment and in the field relative yields of E. purpurea decreased in the presence of P. virgatum and R. pinnata”
Claim · model-written summary
Echinacea relative yield declined with Ratibida later and in the field.
- Taxon
- E. purpureaEchinacea purpureae0
- Interactor
- R. pinnata
.jpg?width=60)
Ratibida pinnatae0other - Outcome
- relative yields of E. purpureae0
- Direction
- decreasede0
- Setting
- fielde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Later in the experiment and in the field relative yields of E. purpurea decreased in the presence of P. virgatum and R. pinnata”
Claim · model-written summary
Panicum relative yield increased in the presence of Echinacea.
- Taxon
- P. virgatumPanicum virgatume0
- Interactor
- E. purpureaEchinacea purpureae0other
- Outcome
- relative yieldse0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Later in the experiment and in the field relative yields of E. purpurea decreased in the presence of P. virgatum and R. pinnata , whereas relative yields of these two species increased in the presence of E. purpurea”
Claim · model-written summary
Ratibida relative yield increased in the presence of Echinacea.
- Taxon
- Ratibida pinnataRatibida pinnatat0
- Interactor
- E. purpureaEchinacea purpureae0other
- Outcome
- relative yieldse0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“relative yields of these two species increased in the presence of E. purpurea”
t0“Ratibida pinnata”
Claim · model-written summary
Relative yields correlated between field and greenhouse at 80 and 120 days.
- Taxon
- Echinacea purpureaEchinacea purpureat0
- Outcome
- relative yielde0
- Setting
- fielde0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There were correlations in relative yield between the field and the greenhouse experiment at 80 and 120 days.”
t0“Echinacea purpurea”
Claim · model-written summary
Panicum maintained higher net assimilation rates in the greenhouse.
- Taxon
- P. virgatumPanicum virgatume0
- Outcome
- net assimilation ratese0
- Direction
- highere0
- Comparator
- the other speciese0
- Setting
- greenhousee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the greenhouse P. virgatum maintained higher net assimilation rates than the other species.”
Claim · model-written summary
Relative growth rates declined after 40 days, especially for Echinacea in mixtures.
- Taxon
- E. purpureaEchinacea purpureae0
- Outcome
- Relative growth ratese0
- Direction
- declinede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Relative growth rates of all species were higher in monoculture and in mixtures up to 40 days, after which they declined, especially for E. purpurea in mixtures.”
Claim · model-written summary
Pure Echinacea stands had higher field light intensities than mixed stands.
- Taxon
- E. purpureaEchinacea purpureae0
- Outcome
- light intensitiese0
- Direction
- highere0
- Comparator
- mixed standse0
- Setting
- fielde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the field, higher light intensities occurred in pure stands of E. purpurea than in mixed stands with other species.”
Claim · model-written summary
Panicum and Ratibida were competitively stronger than Echinacea.
- Taxon
- P. virgatumPanicum virgatume0
- Outcome
- competitive abilitye0
- Setting
- fielde0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The order of competitive ability that was apparent from these field and greenhouse studies, P. virgatum = R. pinnata > E. purpurea , could be partially explained by photosynthetic rates in relation to canopy light interception.”