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Xa’an palm (Sabal yapa) has been used to thatch traditional Maya houses for over 3000 years. In the Yucatan Peninsula, this palm has been introduced to pasturelands, maize fields (milpas), and homegardens. These and other traditional management systems are usually believed to be sustainable, but there is as yet little evidence to support this hypothesis. Demographic models have been used for this purpose, mainly focusing on population growth rate (λ). So far, retrospective analysis has not been applied, even though it examines how changes in the the life cycle of a species, caused by different management regimes, affect its λ. In this study, we assess whether ecologically sustainable use of xa’an occurs in... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: Ethnoecology; LTRE; Mexico; NTFP; Sabal yapa; Traditional management; Xa’an palm; Yucatan.. |
Ano: 2005 |
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Vieira,Sidney Rosa; Guedes Filho,Osvaldo; Chiba,Márcio Koiti; Cantarella,Heitor. |
Assessing the spatial variability of soil chemical properties has become an important aspect of soil management strategies with a view to higher crop yields with minimal environmental degradation. This study was carried out at the Centro Experimental of the Instituto Agronomico, in Campinas, São Paulo, Brazil. The aim was to characterize the spatial variability of chemical properties of a Rhodic Hapludox on a recently bulldozer-cleaned area after over 30 years of coffee cultivation. Soil samples were collected in a 20 x 20 m grid with 36 sampling points across a 1 ha area in the layers 0.0-0.2 and 0.2-0.4 m to measure the following chemical properties: pH, organic matter, K+, P, Ca2+, Mg2+, potential acidity, NH4-N, and NO3-N. Descriptive statistics were... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Soil fertility; Traditional management; Semivariogram. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000500041 |
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