Data/hora: 17/06/2024 08:03:52

Biblioteca(s): 	Embrapa Pantanal.	
Data corrente: 	19/01/1996	
Data da última atualização: 	19/01/1996	
Autoria: 	SIMS, P. L.; SINGH, J. S.	
Título: 	The structure and function of ten Western North American grasslands. II. Intra-seasonal dynamics in primary producer compartments.	
Ano de publicação: 	1978	
Fonte/Imprenta: 	Journal of Ecology, v.66, n.2, p.547-572, 1978.	
Idioma: 	Inglês	
Conteúdo: 	(1) Intra-seasonal dynamics of the various above-ground and below-groud primary produ-
cer compartments for ten central and western North American grassland sites are presen-
ted.
(2) The seasonal peak values of the primary producer compartments are examined, as in-
dicative of the net accumulation of organic material, and the relationships of these peak
values to various abiotic regimes at the sites are investigated.
(3) Seasonal live biomass followed either a unimodal or a bimodal growth pattern. In gene-
ral, grassland with only cool-season or only warm-season plants showed a unimodal pat-
tern, while grassland dominated by both cool- and warm-season species had a bimodal 
seasonal growth pattern. There were no significant sifferences between grazed and un-
grazed treatments in soasonal live biomass, although there was a significant site x treat-
ment interactions.
(4) Peak live biomass ranged from 84 to 336 g m-2, and showed a linear increase with in-
creasing amounts of growing-season precipitation up to 450 mm; at higher values of pre-
cipitation increases in live biomass tendend to level out. 
(5) Maximum rates of accumulation of live biomass ranged from 0.4 to 6.5 g m-2 day-1.
Ungrazed grassland had a peak rate of 4.2 g m-2 day-1 compared with 3.2 g m-2 day-1 for 
grazed grassland.
(6) Generally the recent-dead compartment showed maximum values soon after the peak 
in the live compartment. Material in the old-dead compartment, however, was at a maxi-
mum early in the growing season, and a general decline in the standing crop of old dead
material followed as material was transferred to the litter compartment.
(7) Litter dynamics responded closely to precipitation events, and showed a rather erratic
pattern.
(8) Root biomass generally reached a maximum about midway through the growing sea-
son. On the cooler grassland, grazed treatments typically had a larger peak in root bio-
mass; in contrast, the warmer grassland did not show a marked response in root biomass
to grazing.	
Palavras-Chave: 	Estrutura; Funcao; Function; Grassland; Structure.	
Thesagro: 	Biomassa; Pastagem.	
Thesaurus Nal: 	biomass.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Pantanal (CPAP)	
Exemplares: 	CPAP - (30288-1) - ADD - SP - -- - SP1461 -  - 1461 - DIS