Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 2

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  Cupressus lusitanica
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The input of rain water to the forest floor and the composition of rainfall and throughfall water were monitored between October 2001 and September 2002 in a natural and two plantation (Eucalyptus globulus and Cupressus lusitanica) forests at Munesa, southeastern highlands of Ethiopia. The proportions of throughfall to annual incident rainfall that passed through the different forest canopies were 53% under Cupressus and the natural forest and 82% under Eucalyptus. Annual nutrients deposition by rainfall varied from 0.08 kg ha-1 yr-1 for Mg to 3.79 kg ha-1 yr-1 for Na. Wash-off of materials deposited on the canopy surface and leaching of intracellular solutes from the canopy resulted in an enrichment of throughfall fluxes in K, Mg, Ca and Cl relative to rainfall and varied among forest types, being highest under natural and Eucalyptus forests and lowest under Cupressus. Sodium, NO3–N, NH4–N, SO4–S and PO4–P fluxes in throughfall were depleted relative to rainfall, but the magnitude of net depletion was different for the different elements; highest for Na (3.87 kg ha-1 yr-1) followed by NH4–N (2.85 kg ha-1 yr-1) and lowest for PO4–P (0.42 kg ha-1 yr-1). The amount of canopy uptake and leaching were generally low in the dry season and increased sharply towards the wet season.
The dynamics of nutrients in water passing through the forest floors of two plantation forests (Cupressus lusitanica and Eucalyptus globulus) and an adjacent natural forest were monitored over a one year period at Munesa, Ethiopia. The results showed that, in all forest types, after K, Ca and Cl were the most abundant nutrients leached from the forest floor to the mineral soil. The concentration of NO3–N in the natural forest was about 10 times higher than that of NH4–N, but 8 and 3 times higher than that of NH4–N under Eucalyptus and Cupressus, respectively. No significant differences in concentrations of most of the nutrients were observed among forest types, but magnesium and NO3–N were significantly higher under the natural forest and Eucalyptus than under Cupressus. Except for NH4–N, which was depleted in relation to throughfall in the natural forest, the concentrations of all other nutrients were enriched in litter leachate in relation to both rainfall and throughfall. However, with the exceptions of NO3–N in all forest types, Ca under Cupressus and PO4–P under Cupressus and Eucalyptus, all measured nutrient fluxes from the forest floor to the mineral soil decreased in relation to throughfall fluxes. Generally, the results show that despite the differences in tree species composition among the forest types the organic layer acted as a sink for most of the nutrients coming via throughfall.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.