ESTIMATES OF ATMOSPHERIC DEPOSITION AND CANOPY EXCHANGE FOR 3 COMMON TREE SPECIES IN THE NETHERLANDS

Citation
R. Vanek et Gpj. Draaijers, ESTIMATES OF ATMOSPHERIC DEPOSITION AND CANOPY EXCHANGE FOR 3 COMMON TREE SPECIES IN THE NETHERLANDS, Water, air and soil pollution, 73(1-4), 1994, pp. 61-82
Citations number
38
Categorie Soggetti
Environmental Sciences","Water Resources
ISSN journal
00496979
Volume
73
Issue
1-4
Year of publication
1994
Pages
61 - 82
Database
ISI
SICI code
0049-6979(1994)73:1-4<61:EOADAC>2.0.ZU;2-Z
Abstract
During one year, dry and wet deposition onto thirty forest stands is s tudied by sampling throughfall and bulk precipitation. Nine measuremen t sites are situated in Douglas fir (Pseudotsuga menziesii Mirb. Franc o) stands, ten in Scotch pine (Pinus sylvestris L.) and eleven in Oak (Quercus robur L.) stands. Because the stands are situated in each oth er's proximity (i.e. within a radius of approximately 1.4 km) it is as sumed that they experience an approximately equal air pollution load. For the acidifying compounds SO42-, NO3- and NH3+ spatial variability in wet deposition was small within the area studied. Dry deposition, a s estimated by net throughfall, displayed a much higher spatial variab ility. Significant differences existed between tree species and growin g seasons. Douglas fir mostly displayed the highest, Oak the lowest an d Scotch pine intermediate values for net throughfall fluxes of acidif ying compounds. The annual net throughfall fluxes for nitrogen compoun ds were significantly higher for the coniferous tree species than the broadleaved tree species. For SO42-, however, Oak showed a relatively high throughfall flux during the summer. By comparing the temporal pat tern of net throughfall fluxes between the three tree species it was c oncluded that considerable canopy leaching occurred for SO42-, Mg2+, P O43-, HCO3- and K+ in Oak stands during the sprouting of leaves in spr ing. From surface wash experiments in the laboratory it is concluded t hat canopy leaching of these ions may also be enhanced when Oak leaves are infected by Oak mildew, a fungal disease caused by the fungus Mic roshaera aliphilitoides.