Effects of Nutrient-Deficient Soil on Gas-Exchange, Chlorophyll Fluorescence and C-Allocation in Young Picea abies (L.) Karst : Root - Soil Interactions in Trees

2000

7 Lit.Ang.

Artikel aus einer Zeitschrift

5943

200083854

We measured gas exchange, chlorophyll fluorescence and dry weight of 4-year-old potted spruce seedlings, half of which were fertilised, under field conditions. The soil was a nutrient deficient clacareous soil of a natural stand in the Northern Alps of Tyrol. All unfertilised seedlings (U) showed a strong N-deficiency leading to yellow-green needles while fertilised plants (F) were well supplied with all nutrients. In general, net photosynthetic rates were about twice as high in F, whereas leaf conductance was lower in F than in U, indicating than Pn differences was not caused by stomatal aperture. Effective quantum yield was also higher in F than in U. Gas-exchange and quantum yield were positively correlated to needle N content. It was mainly N deficiency which caused a biomass reduction in U, and an increase in the root / shoot ratio.