Tiller Dynamics of Two Grasses--Responses to Grazing, Density and Weather

Bullock, James M.; Hill, B. Clear; Silvertown, Jonathan

doi:10.2307/2261301

Cited by 75 publications

(58 citation statements)

References 29 publications

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“…It has been reported that tiller density in grass swards exhibits considerable response to the environment and management [10,18,21,22,[29][30][31]. It is therefore important to develop a model which can predict tiller density dynamics under varying environmental and management conditions.…”

Section: Discussionmentioning

confidence: 99%

Linking Management, Environment and Morphogenetic and Structural Components of a Sward for Simulating Tiller Density Dynamics in Bahiagrass (Paspalum notatum)

Hirata

2015

Agriculture

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Abstract:A model which describes tiller density dynamics in bahiagrass (Paspalum notatum Flügge) swards has been developed. The model incorporates interrelationships between various morphogenetic and structural components of the sward and uses the inverse of the self-thinning rule as the standard relationship between tiller density and tiller weight (a density-size equilibrium) toward which tiller density progressively changes over time under varying nitrogen (N) rates, air temperature and season. Water and nutrient limitations were not considered except partial consideration of N. The model was calibrated against data from swards subjected to different N rates and cutting intensities, and further validated against data from a grazed sward and swards under different cutting intensities. As the calibration and validation results were satisfactory, the model was used as a tool to investigate the responses of tiller density to various combinations of defoliation frequencies and intensities. Simulations identified defoliation regimes required for stabilizing tiller density at an arbitrary target level, i.e., sustainable use of the sward. For example, the model predicted that tiller density can be maintained at a medium level of about 4000 m −2 under conditions ranging from weekly cuttings to an 8 cm height to 8-weekly cuttings to 4 cm. More intense defoliation is needed for higher target tiller density and vice versa.

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Section: Discussionmentioning

confidence: 99%

Linking Management, Environment and Morphogenetic and Structural Components of a Sward for Simulating Tiller Density Dynamics in Bahiagrass (Paspalum notatum)

Hirata

2015

Agriculture

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“…Most perennial grasses have bimodal recruitment patterns with flushes of new tillers emerging during the spring and fall (Langer 1956, Briske and Butler 1989, Briske and Richards 1995 ) , o n l y produced 1 annual cohort. These established patterns of tiller recruitment may be affected by defoliation which extends the recruitment period (Butler and Briske 1988), promotes additional tiller cohorts (Olson and Richards 1988a), and changes the timing of peak recruitment (Bullock et al 1994). Tiller recruitment is also a major method of perennial grass persistence (Hendrickson and Briske 1997) and annual tiller replacement is necessary to maintain tiller density (Olson and Richards 1988b).…”

Section: Introductionmentioning

confidence: 99%

Tiller recruitment patterns and biennial tiller production in prairie sandreed

Hendrickson¹,

Moser²,

Reece³

2000

REM

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ResumenEl renuevo de las macollas (número de macollas que brotan durante todo el periodo de crecimiento) es un proceso esencial para asegurar la perennidad de los pastos. La regulación del tiempo, la cantidad de renovación de las macollas, y el papel de las macollas bienales deben ser documentados para las especies claves de las praderas. Prairie sandreed [Calamovilfa longifolia (Hook) Scribn.] es un pasto importante en las lomas arenosas (sandhills) al oeste de Nebraska, no solo por su contribución ecológica sino también como forraje. Los objetivos de este estudio han sido el de documentar el patrón de renuevo de las macollas, la ocurrencia y la contribución de las macollas durante el presente año y las macollas bienales del año anterior en la producción de la biomasa del pasto prairie sandreed en dos localidades de Nebraska. El renuevo de las macollas fué determinado cada dos semanas durante la época de crecimiento del pasto y por un período de dos años. A medida que las macollas iban brotando fueron clasificadas en intravaginadas (crecimiento desde adentro de la vaina de la hoja) y extravaginadas (penetración de la vaina de la hoja) o rizomas e identificadas con alambres de colores. El pasto prairie sandreed posee un patrón unimodal en su renovación de las macollas; durante el presente año mas del 50% de sus macollas, brotaron a mediados de Mayo y el 80% a mediados de Junio. La proporción de la brotación de las macollas y el número absoluto de las macollas que brotaron estuvo pobremente correlacionado (r < 0.3 P > 0.20) con la precipitación total a corto y a largo plazo. En el segundo año, las macollas bienales y las macollas que brotaron durante el presente año fueron contadas y cortadas para determinar la biomasa. Las macollas bienales representaron de un 6 al 20% del total de las macollas en las dos localidades , y fueron por lo general 30% tan grandes como las macollas nuevas. Las macollas extravaginadas formaron mas del 78% de la población de macollas bienales, debido a su caracter dominante para brotar y también a su alto porcentaje de sobrevivencia durante el invierno. Las macollas del presente año fueron las que mas contribuyeron a la producción del pasto forrajero sandreed, completando la mayor parte de su brotación a mediados de Junio. La carencia de relación entre el renuevo de las macollas y los patrones de la precipitación, combinado con resultados obtenidos en años anteriores, indican que el renuevo de las macollas está involucrado en un proceso el cual se inicia en el anterior período de crecimiento del pasto.

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“…Shoot natality and mortality have been explained in terms of densitydependent competition (Kays and Harper 1974;Mook and van der Toorn 1982;Lonsdale and Watkinson 1983;Bullock et al 1994) and physiological integration that moderates shoot competition (Hutchings and Barkham 1976;Hutchings 1979;Liddle et al 1982;Pitelka 1984;Hutchings and Bradbury 1986;Hara et al 1993;Suzuki 1994). However, these studies do not show how clonal shoot dynamics maintain the shoot population of the next generation, that is, they do not show how it contributes to the "persistence" of clones (genets) (sensu Eriksson and Jerling 1990).…”

Section: Introductionmentioning

confidence: 99%

Shoot population dynamics of persisting clones of Miscanthus sinensis in the warm-temperate region of Japan

Kobayashi

Yokoi

2003

Journal of Plant Research

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The population dynamics of annual shoots in four clonal patches of Miscanthus sinensis was surveyed in terms of clone persistence. Over a study period of 3 years, a stable net shoot number was attained through a balanced replacement of old shoots by tillering 2-3 times a year. The birth rate was significantly correlated with the average monthly temperature. This suggests that a warm climate advances the date of tillerings, and shoots become taller as they emerge earlier. Five cohorts were identified, corresponding to shoots that were born in spring, early summer, summer, autumn and early winter. The autumn cohorts were more numerous and had a greater longevity than the other cohorts; they were thus were best suited for overwintering and, consequently, maintaining the population from one generation to the next. The shoots of earlier cohorts grew too tall to survive the cold of winter, which might cause freezing injury, while later cohorts' shoots excelled in overwintering because of their shortness. However, if the delayed shoots are very short, they will also have difficulty in surviving the early season of growth. Therefore, M. sinensis shoots have an optimum size for survival.

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Tiller Dynamics of Two Grasses--Responses to Grazing, Density and Weather

Cited by 75 publications

References 29 publications

Linking Management, Environment and Morphogenetic and Structural Components of a Sward for Simulating Tiller Density Dynamics in Bahiagrass (Paspalum notatum)

Linking Management, Environment and Morphogenetic and Structural Components of a Sward for Simulating Tiller Density Dynamics in Bahiagrass (Paspalum notatum)

Tiller recruitment patterns and biennial tiller production in prairie sandreed

Shoot population dynamics of persisting clones of Miscanthus sinensis in the warm-temperate region of Japan

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