Data/hora: 11/05/2024 10:10:14

Biblioteca(s): 	Embrapa Cerrados.	
Data corrente: 	31/05/1996	
Data da última atualização: 	31/05/1996	
Autoria: 	RIBEIRO, J. F.	
Título: 	Environmental heterogeneity in space and time and plant life history traits on zonation of five riparian woody species of the California Central Valley.	
Ano de publicação: 	1991	
Fonte/Imprenta: 	Davis : University of California, 1991.	
Páginas: 	121p.	
Idioma: 	Inglês	
Notas: 	PhD. Thesis.	
Conteúdo: 	Establishment of species on floodplains, and consequent zonal distribution and succession, are associated with allogenic factors as soil moisture holding capacity, and to autogenic elements such asw dispersion,germination, and seedling growth rate and shade tolerance. This investigation focused on the identification of how some of these allogenic and autogenic factors may be related withy woody riparian species zonal distribution. The species studied were the pioneers Salix hindsiana Benth., S. laevigata Bebb. and Populus fremontii S. Wats, and the late successional species Aacer negundo L. ssp. californicum (T & G) Wesmael and Jugalns hindsii Jepson. Results provided evidence that earlier and shorter reproductive period allows pioneer species to have mature seed dispersed during the sdame season. Earlier seed maturation and dispersion allows colonization of new areas at the edge creek created by spring flooding. Lack of water at establishment is not a major problem because it occurs at the edge of the creek. In contrast, the longer reproductive period and the dispersal and the dispersal time during early winter for the late successional species provides the necessary chilling to overcome dormancy. Germination generally occrs late in the mild winter of California Central Valley, where soil at a greater distance from the creek is stillmoist from wintewr rain and creek flooding. The germination requirements regarding light, temperature, and soil moisture shows general trends among seed characteristics. Similarities shared by pioneer species were very short seed very short seed longevity and absense of dormancy. In contrast, late successional species exhibited longer seed viability and winter dormancy. Initial growth and seed size in two of the selected species, P. fremontii (pioneer) and A. negundo (late-successional) were related to light availability. The pioneer species P. fremontii showed Small wind disperesd seeds, and seedling with faste growth rate and shade intolerance. These are trpical necessary characteristics of especies which colonize open areas mostly available at the creweks at the period of seed dispersal and germination. Incontrast, A. negundo had relatively bigger seeds with less dispersal mobility and earlier establishment during the growth season and seedlings showed a steady growth rate and good shade tolerance. The charcteristics of a seed dormancy requirement, seed germination early in the growing season and shade tolerance are advantageous for late successional species growing on relatively drier sites in riparian ecosystems.  	
Palavras-Chave: 	Distribuicao; Distribution; Environments; Estados Unidos; Riparian vegetation; Species; USA; Zoneamento.	
Thesagro: 	Espécie; Mata Ciliar; Planta Lenhosa.	
Thesaurus Nal: 	California; woody plants.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Cerrados (CPAC)	
Exemplares: 	CPAC - (13124-1) - UPC - TS - -- - T004/91 - RIB - T004/91 - DIS