Data/hora: 23/06/2024 20:54:37

Biblioteca(s): | Embrapa Pantanal.
Data corrente: | 06/08/1997
Data da última atualização: | 03/04/2017
Autoria: | GIBBENS, R. P.; BECK, R. F.
Título: | Changes in grass basal area and forb densities over a 64 year period on grassland types of the Jornada Experimental Range.
Ano de publicação: | 1988
Fonte/Imprenta: | Journal of Range Management, v.41, n.3, p.186-192, May, 1988.
Idioma: | Inglês
Conteúdo: | Between 1915 and 1932, permanent 1x1-m quadrats were established on grasslands of the Jornada Experimental range in southern New Mexico. Quadrat records accumulated from 1915 to 1979 on grassland dominated by black grama [Bouteloua eriopoda (Torr.) Torr.], poverty threeawn (Aristida divaricata Willd.), tobosa [Hilaria mutica (Buckl.) Benth.], and burrograss (Scleropogon brevifolius Phil.) were used to examine changes in perennial grass basal area and forb densities. Quadrats originally dominated by black grama had large reductions in basal area during droughts, and basal area increased slowly following droughts. By 1979, black grama no longer occurred on 77% of the quadrats. Quadrats originally dominated by poverty threeawn changed to a mesquite (Proposis glandulosa Torr. var. glandulosa) type. Perennial grass basal area on quadrats dominated by tobosa and burrograss decreased during droughts, but recovery was relatively rapid. Antecedent precipitation was associated with only 10 to 38% of the variation in perennial grass basal area. Perennial forb densities were low and fluctuated among yeras in all types. Annual forbs and grasses displayed large fluctuations in densities among yeras. The necessity of basing management of Chihuahuan Desert ranges on the perennial grass components is borne out by the low densities of palatable perennial forbs, and the extreme fluctuations and unpredictability in densities of annual forbs and grasses.
Palavras-Chave: | Arid rangeland; Black grama; Burrograss; Management; Pasture; Perennial grass; Planta perene; Poverty threeawn; Tobosa.
Thesagro: | Manejo; Pastagem.
Categoria do assunto: | --
Registro original: | Embrapa Pantanal (CPAP)
Exemplares: | CPAP - (34643-1) - ADD - SP - PP - SP15300 -  - 15300 - DIS