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Advisor(s)
Abstract(s)
Avaliou-se a concentração e os fluxos
de nutrientes no gotejo e no escorrimento
do tronco de freixo (Fraxinus angustifolia
Vahl), num lameiro do Nordeste de Portugal.
A precipitação bruta, a precipitação sob
coberto (throughfall) e o escorrimento do
tronco (stemflow) foram objecto de monitorização
e amostras foram colhidas periodicamente
para determinação do pH, dos teores
de carbono (COD) e azoto (NOD) orgânicos
dissolvidos e de nutrientes. Os fluxos anuais
de COD, NOD, Cl, K, Na, Ca, Mg e P na
precipitação bruta foram, respectivamente,
3.93, 0.92, 0.20, 0.06, 1.81, 2.40, 1.11, 1.16,
0.29 e 0.06 g m-2, enquanto no gotejo foram
de 4,42, 0,20, 1,82, 1,82, 0,31, 0,54, 0,62,
0.20 g m-2; o fluxo de N-NH4
+ foi nulo e o de
N-NO-
3 foi negativo (-0,03 g m-2). A expressão
dos fluxos devido ao escorrimento do
tronco variará com a área influenciada por
esta solução. A restituição de nutrientes ao
solo pelo gotejo e pelo escorrimento do tronco
poderá contribuir para diferenciar as características
do solo sob a copa das árvores.
The effect of the ash-tree (Fraxinus angustifolia Vahl) crown on characteristics of throughfall and stemflow solutions was assessed in wet pastures located in north eastern Portugal. The amounts de gross rainfall, throughfall and stemflow were measured continuously and samples were periodically collected to determine pH, dissolved organic C (DOC) and N (DON), and nutrients. The annual fluxes of DOC, DON, Cl, K, Na, Ca, Mg and P in gross rainfall were, respectively, 3.93, 0.92, 0.20, 0.06, 1.81, 2.40, 1.11, 1.16, 0.29 and 0.06 g m-2, while those regarding throughfall were 4.42, 0.20, 1.82, 1.82, 0.31, 0.54, 0.62 and 0.20 g m-2; the flux of N-NH4 + was nil and that of N-NO- 3 was negative (-0.03 g m-2). The fluxes in relation with stemflow were small if expressed on a tree crown projection area basis, but can be much greater if the actual area affected is considered. The amounts and distribution of nutrients turned to the soil by throughfall and stemflow may lead to soil chemical characteristics differentiation beneath tree crowns.
The effect of the ash-tree (Fraxinus angustifolia Vahl) crown on characteristics of throughfall and stemflow solutions was assessed in wet pastures located in north eastern Portugal. The amounts de gross rainfall, throughfall and stemflow were measured continuously and samples were periodically collected to determine pH, dissolved organic C (DOC) and N (DON), and nutrients. The annual fluxes of DOC, DON, Cl, K, Na, Ca, Mg and P in gross rainfall were, respectively, 3.93, 0.92, 0.20, 0.06, 1.81, 2.40, 1.11, 1.16, 0.29 and 0.06 g m-2, while those regarding throughfall were 4.42, 0.20, 1.82, 1.82, 0.31, 0.54, 0.62 and 0.20 g m-2; the flux of N-NH4 + was nil and that of N-NO- 3 was negative (-0.03 g m-2). The fluxes in relation with stemflow were small if expressed on a tree crown projection area basis, but can be much greater if the actual area affected is considered. The amounts and distribution of nutrients turned to the soil by throughfall and stemflow may lead to soil chemical characteristics differentiation beneath tree crowns.
Description
Keywords
Freixo Gotejo Nutrientes Precipitação bruta Solo
Pedagogical Context
Citation
Pereira, Ermelinda; Madeira, Manuel; Abreu , Francisco Gonçalves de (2009). Concentrações e fluxos de nutrientes no gotejo e escorrimento do tronco de Fraxinus angustifolia Vahl. Revista de Ciências Agrárias. ISSN 0871-018X. 32:2, p.123-134
Publisher
Sociedade de Ciências Agrárias de Portugal