Data/hora: 14/06/2024 04:24:26

Biblioteca(s): 	Embrapa Pantanal.	
Data corrente: 	01/10/1997	
Data da última atualização: 	05/04/2017	
Autoria: 	LEE, C. A.; LAUENROTH, W. K.	
Título: 	Spatial distributions of grass and shrub root systems in the shortgrass steppe.	
Ano de publicação: 	1994	
Fonte/Imprenta: 	American Midland Naturalist, v.132, n.1, p.117-123, 1994.	
Idioma: 	Inglês	
Conteúdo: 	In water-limited ecosystem such as the shortgrass steppe of North America, the ability of plants to absorb sufficient water for growth and reproduction is dependent upon the characteristics of their root systems. Our objective was to evaluate the spatial distributions of roots of three plant life forms: a grass (Bouteloua gracilis) (H.B.K.) Lag., a dwarf shrub [Gutierrezia sarothrae (Push.) Britt. & Rusby] and a shrub [Atriplex canescens (Pursh.) Nutt.]. Our interests were in a quantitative evaluation of evidence that different life forms obtained water from different soil layers. Root systems were excavated and evaluated in terms of horizontal and vertical extension, and proportion of total root lenght in each 10-cm layer of the soil profile. Bouteloua gracilis had over 80% of its roots in the top 50 cm of the soil, whereas the depth at which Atriplex canescens had over 80% of its roots was 100 cm. The corresponding depth for Gutierrezia sarothrae was 80 cm. Both of the woody plants had deeper and more widely spreading root systems than the grass. The environment of the shortgrass steppe is characterized by low and variable water availability. These conditions lead to a contribution of available water that is biased toward the upper soil layers. The greater concentration of roots of Bouteloua gracilis in the soil layers near the surface compared to the two woody species provides a potential explanation for its dominance in the shortgrass steppe.	
Palavras-Chave: 	Distribuicao; Distribution; Growth; Plant; Shrub root system.	
Thesagro: 	Crescimento; Planta.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Pantanal (CPAP)	
Exemplares: 	CPAP - (35037-1) - ADD - SP - PP - SP15399 -  - 15399 - DIS