Data/hora: 03/06/2024 08:55:04

Biblioteca(s): | Embrapa Pantanal.
Data corrente: | 26/08/1997
Data da última atualização: | 05/04/2017
Autoria: | OLSON, B. E.; RICHARDS, J. H.
Título: | Annual replacement of the tillers of Agropyron desertorum following grazing.
Ano de publicação: | 1988
Fonte/Imprenta: | Oecologia, v.76, p.1-6, 1988.
Idioma: | Inglês
Conteúdo: | The annual replacement of tillers of Agropyron desertorum (Fisch. ex Link) Schult., a grazing-tolerant, Eurasian tussok grass, was examined in the field following cattle grazing. Heavy grazing before internode (culm) elongation seldom affected tiller replacement. Heavy grazing during or after internode elongation, which elevates apical meristems, increased overwinter mortality of fall-produced tillers and reduced the number and heights of these replacement tillers. Unexpectedly, tussocks grazed twice within the spring growing season tended to have lower overwinter tiller mortality, greater tiller replacement, and larger replacement tillers than tussocks grazed only once in late spring. These responses of twice-grazed tussocks, however, were still less than those of ungrazed tussocks or tussocks grazed moderately in early spring. The presence of ungrazed tillers on partially grazed tussocks did not increase the replacement of associated grazed tillers relative to tillers on uniformly grazed plants. This result indicates that resource sharing among tillers, if present, is short-lived or ecologically unimportant in this species. Although A. desertorum is considered grazing-tolerant, tiller replacement on heavily grazed tussocks, particularly those grazed during or after internode elongation when apical meristems were removed, was usualy inadequate for tussock maintenance. Thse observations at the tiller (ramet) level of organization in individual tussocks (genet) may explain the often noted reduction in stand (population) longevity with consistent heavy grazing.
Palavras-Chave: | Annual tiller replacement; Efeito do pastejo; Grazing effect; Perfilhamento anual; Touceira de graminea; Tussok grass.
Thesaurus Nal: | Agropyron desertorum.
Categoria do assunto: | --
Registro original: | Embrapa Pantanal (CPAP)
Exemplares: | CPAP - (34738-1) - ADC - SP - PP - SP15349 -  - 15349 - DIS