Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Polish Journal of Ecology

2 Kram K.

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: wytrącanie masy

Sortuj według:

Ogranicz wyniki do:

Modification of the atmospheric load of elements during passage through foliaged canopies of five tree species of temperate zone forests

Kram K.

Polish Journal of Ecology

2010

Vol. 58, nr 1

87-101

Atmospheric load is an important source of nutrients and pollutants to ecosystems. During the flux through forest canopies that deposition is intensively modified enriching in some elements and pooring in others. Both, atmospheric load and flux of elements through forest canopies, were investigated in the Kampinos National Park (central Poland) during vegetative seasons (April-October) of the years 1998 and 2000. Throughfall was compared with atmospheric deposition in five different forest ecosystems: pine, birch, locust tree, alder, and oak. Atmospheric deposition data was obtained from rain collectors equipped with artificial foliage of an area similar to the actual leaf surface area in a given ecosystem. Results showed that H[^+] and Pb[^2+] flowed passively through tree canopies. NO[3^-], PO[4^3-], SO[4^2-], NH[4^+], Na[^+], Cd[^2+], Zn[^2+] and Cu[^2+] were retained in the canopies (the process was the most intensive for ammonium - 58%, and phosphorus - 60% retained), whileCl[^-], Mg[^2+], K[^+] and Ca[^2+] were leached out of canopies (throughfall, in comparison to bulk precipitation, was enriched by up to 109% in case of potassium). These processes all occurred more vigorously in deciduous trees, like alder and oak, and less intensively or not at all in pine tree stands. Trees living in symbiosis with nitrogen-fixing microorganisms (alder and locust tree) were equally effective at trapping nitrogen from atmospheric loads, as at non-symbiotic tree species. The calendar day has no influence on the throughfall balance of elements with the only exception for calcium (only in alder forest also magnesium and chlorine), which was more intensively leached out during the autumn then on the beginning of vegetation season.

Nitrogen deposition and flux through three birch stands (Betula pubescens Ehrh.) in the Kampinos National Park (central Poland)

Kram K.

Polish Journal of Ecology

2008

Vol. 56, nr 4

605-612

Nitrogen flow through birch stand canopies was studied in the Kampinos National Park (large forested area with inland dunes and wetlands close to Warsaw) during the growing seasons (April-October) of 2005-2006. The amount of nitrogen deposition including main forms like NO[3], NH[4], organic N and the aerosolgaseous fraction of deposition were estimated as well as the influence of birch canopies on this process. Because a method of "artificial foliage" allows to measure an aerosol-gaseous fraction of deposition a gradient of rain collectors equipped with artificial foliage of known surfaces were used. The results were compared with amounts of nitrogen measured in the throughfall of three birch forests. All stands (age 20.50 years) were rather similar, but stand II has smaller LAI (Leaf Area Index = 2.5 m[^2] m[^-2]) than stands II and III (3.8 and 3.9 m[^2] m[-2]). It was found that nitrogen deposition in the Kampinos National Park is rather high - 1.6 kg ha[^-1] month[-1]. Ammoniumnitrogen made almost half of this value, organic nitrogen - over one third, and nitrate-nitrogen constituted the rest. Aerosol-gaseous input significantly made the deposition increased only in the case of nitrate-nitrogen, but deposition of ammonium- and organic nitrogen were similar and independent of catching leaf area. All fractions of nitrogen were effectively taken up during their passing through birch canopies (57% of nitrogen deposition was retained). Generally two thirds of deposited ammonium-nitrogen, more than half of organic N, and one third of nitratenitrogen were taken up by birch canopies. However, uptake efficiency of all N forms was lower for stand with smallest leaf area with no statistically significant retention of organic N.