%20--%3e%3csvg%20version='1.1'%20id='Layer_1'%20xmlns='http://www.w3.org/2000/svg'%20xmlns:xlink='http://www.w3.org/1999/xlink'%20x='0px'%20y='0px'%20viewBox='0%200%20100.6%2073.7'%20style='enable-background:new%200%200%20100.6%2073.7;'%20xml:space='preserve'%3e%3cstyle%20type='text/css'%3e%20.st0{fill:%23AF001E;}%20.st1{fill:%23FFFFFF;}%20%3c/style%3e%3cg%3e%3crect%20class='st0'%20width='100.6'%20height='73.7'/%3e%3cpath%20class='st1'%20d='M25.2,36.3l-0.5,2.3c-0.2,0.7-0.2,1-0.2,1.2c0,0.5,0.2,1,0.5,1.6L31.5,53c0.5,0.9,1,1.3,2.3,1.3h5.9%20c0.8,0,1.7-0.5,0.8-1.8l-7.9-13.1c2.7-1.7,5.6-4.1,5.6-9.3c0-6.8-3.8-10.6-12.2-10.6H13.9c-1.1,0-1.4,0.4-1.4,1.5v32%20c0,1.1,0.3,1.5,1.4,1.5h5c1.1,0,1.4-0.4,1.4-1.5V26h5.2c3.3,0,4.8,1.2,4.8,4.2c0,2.8-1.2,3.6-2.5,4.2C26.3,35,25.7,34.3,25.2,36.3z%20'/%3e%3cpath%20class='st1'%20d='M45.9,48.8L45.3,53c-0.1,0.8,0.3,1.1,1,1.2c1.6,0.2,5.5,0.5,9.4,0.5c8.6,0,14.9-2.8,14.9-10.9%20c0-4.7-2.1-8.3-9.2-10.1l-4-1c-2.7-0.7-4-1.6-4-3.6c0-2.8,2.6-3.4,5.1-3.4c3.4,0,6.8,0.3,8.1,0.4c1.4,0.1,1.8-0.1,2-1.2l0.7-4.1%20c0.1-0.8-0.3-1.1-1-1.2c-1.6-0.2-5-0.5-9.4-0.5c-9,0-13.3,3.9-13.3,10.1c0,5.6,3,8.9,8.3,10.3l4,1c3.3,0.9,4.7,1.8,4.7,3.9%20c0,3-2.1,3.6-7.1,3.6c-2.3,0-6.2-0.3-7.6-0.4C46.5,47.4,46.1,47.6,45.9,48.8z'/%3e%3cpath%20class='st1'%20d='M79.4,52.9c0,1.1,0.3,1.5,1.4,1.5h5c1.1,0,1.4-0.4,1.4-1.5v-32c0-1.1-0.3-1.5-1.4-1.5h-5%20c-1.1,0-1.4,0.4-1.4,1.5V52.9z'/%3e%3c/g%3e%3c/svg%3e)
Le misure decise a livello europeo in seguito al dibattito sulle piogge acide hanno migliorato le condizioni del suolo delle foreste europee, ma l'inquinamento da azoto rimane un problema in Ticino. Lo dice uno studio al quale ha preso parte l'Istituto federale di ricerca per la foresta, la neve e il paesaggio (WSL).
Le piogge acide sono state negli anni '80 una delle questioni ambientali più rilevanti in Europa. Le preoccupazioni relative ai danni a boschi, corsi d'acqua e laghi hanno portato ad accordi internazionali che hanno posto un freno alle emissioni di zolfo e di azoti, gli inquinanti atmosferici che provocano l'acidificazione della pioggia.
Studi europei sul periodo 1996-2012 hanno dimostrato che il tenore di solfati nell'acqua contenuta nel suolo è diminuito. Al contempo però "l'inquinamento da azoto prodotto dal traffico motorizzato e dall'agricoltura rimane comunque un problema di primaria importanza per le foreste e per il suolo di molte aree d'Europa", afferma Elisabeth Graf Pannatier del WSL; un problema che in Svizzera riguarda Ticino e Altipiano.
ats/joe.p.
%20--%3e%3csvg%20version='1.1'%20id='Layer_1'%20xmlns='http://www.w3.org/2000/svg'%20xmlns:xlink='http://www.w3.org/1999/xlink'%20x='0px'%20y='0px'%20viewBox='0%200%20138.2%2048'%20style='enable-background:new%200%200%20138.2%2048;'%20xml:space='preserve'%3e%3cstyle%20type='text/css'%3e%20.st0{fill-rule:evenodd;clip-rule:evenodd;fill:%23AF001E;}%20.st1{fill-rule:evenodd;clip-rule:evenodd;fill:%23FFFFFF;}%20%3c/style%3e%3cpath%20class='st0'%20d='M0,48h138V0H0V48z'/%3e%3cpath%20class='st1'%20d='M9.3,31.7l-0.4,2.7C8.8,35,9,35.2,9.5,35.3c2,0.2,4,0.3,6.1,0.3c5.6,0,9.7-1.8,9.7-7.1c0-3.1-1.3-5.4-6-6.6%20l-2.6-0.7c-1.8-0.5-2.6-1-2.6-2.3c0-1.9,1.7-2.2,3.3-2.2c2.2,0,4.4,0.2,5.3,0.2c0.9,0.1,1.2,0,1.3-0.8l0.4-2.6c0-0.1,0-0.2,0-0.3%20c0-0.1-0.1-0.2-0.1-0.3s-0.1-0.1-0.2-0.2c-0.1,0-0.2-0.1-0.3-0.1c-2-0.2-4.1-0.3-6.1-0.3C11.8,12.4,9,14.9,9,19c0,3.6,2,5.8,5.4,6.7%20l2.6,0.7c2.1,0.6,3,1.2,3,2.5c0,2-1.3,2.3-4.6,2.3c-1.5,0-4-0.2-4.9-0.3C9.6,30.9,9.4,31,9.3,31.7'/%3e%3cpath%20class='st1'%20d='M36.4,23.6l-0.3,1.5C36,25.4,36,25.6,36,25.9c0,0.4,0.1,0.8,0.4,1.1l4.2,7.6c0.1,0.3,0.3,0.5,0.6,0.7%20c0.3,0.2,0.6,0.2,0.9,0.2h3.8c0.5,0,1.1-0.3,0.5-1.2l-5.1-8.6c1.7-1.1,3.6-2.6,3.6-6.1c0-4.4-2.5-6.9-7.9-6.9h-7.8%20c-0.7,0-0.9,0.2-0.9,1v20.8c0,0.7,0.2,1,0.9,1h3.2c0.7,0,0.9-0.2,0.9-1V16.8h3.3c2.1,0,3.1,0.8,3.1,2.8c0.1,0.6,0,1.2-0.3,1.6%20c-0.3,0.5-0.7,0.9-1.3,1.1C37.1,22.7,36.8,22.3,36.4,23.6z'/%3e%3cpath%20class='st1'%20d='M66.1,34V22.7c0-0.7-0.2-1-0.9-1h-5.8c-0.7,0-0.9,0.2-0.9,1v2.5c0,0.7,0.2,0.9,0.9,0.9h1.7v5%20c-0.6,0.1-1.1,0.1-1.7,0.1c-4.8,0-6-3.1-6-7.4c0-5.4,2-6.8,6.5-6.8c1.3,0,3.1,0.1,4.1,0.2c1,0.1,1.2,0,1.3-0.8l0.4-2.5%20c0.1-0.7,0-1-0.8-1.1c-1.8-0.2-3.6-0.3-5.4-0.2c-8.2,0-11.6,4.3-11.6,11.3s2.7,11.9,11.3,11.9c2,0.1,4,0,6-0.4%20C65.9,35.2,66.2,34.9,66.1,34'/%3e%3cpath%20class='st1'%20d='M74.9,31.7l-0.4,2.7c-0.1,0.5,0.2,0.7,0.6,0.8c2,0.2,4,0.3,6.1,0.3c5.6,0,9.7-1.8,9.7-7.1c0-3.1-1.3-5.4-6-6.6%20l-2.6-0.7c-1.8-0.5-2.6-1-2.6-2.3c0-1.9,1.7-2.2,3.3-2.2c2.2,0,4.4,0.2,5.3,0.2c0.9,0.1,1.2,0,1.3-0.8l0.4-2.6c0-0.1,0-0.2,0-0.3%20c0-0.1-0.1-0.2-0.1-0.3s-0.1-0.1-0.2-0.2c-0.1,0-0.2-0.1-0.3-0.1c-2-0.2-4.1-0.3-6.1-0.3c-5.8,0-8.6,2.6-8.6,6.6%20c0,3.6,2,5.8,5.4,6.7l2.6,0.7c2.1,0.6,3,1.2,3,2.6c0,2-1.3,2.3-4.6,2.3c-1.5,0-4-0.2-4.9-0.3C75.3,30.8,75,30.9,74.9,31.7'/%3e%3cpath%20class='st1'%20d='M93.1,31.7l-0.4,2.7c-0.1,0.5,0.2,0.7,0.6,0.8c2,0.2,4,0.3,6.1,0.3c5.6,0,9.7-1.8,9.7-7.1c0-3.1-1.3-5.4-6-6.6%20l-2.6-0.7c-1.8-0.5-2.6-1-2.6-2.3c0-1.9,1.7-2.2,3.3-2.2c2.2,0,4.4,0.2,5.3,0.2c0.9,0.1,1.2,0,1.3-0.8l0.4-2.6c0-0.1,0-0.2,0-0.3%20c0-0.1-0.1-0.2-0.1-0.3c-0.1-0.1-0.1-0.1-0.2-0.2c-0.1,0-0.2-0.1-0.3-0.1c-2-0.2-4.1-0.3-6.1-0.3c-5.8,0-8.6,2.6-8.6,6.6%20c0,3.6,2,5.8,5.4,6.7l2.6,0.7c2.1,0.6,3,1.2,3,2.6c0,2-1.3,2.3-4.6,2.3c-1.5,0-4-0.2-4.9-0.3S93.1,30.9,93.1,31.7'/%3e%3cpath%20class='st1'%20d='M120.2,23.6l-0.3,1.5c-0.1,0.3-0.1,0.5-0.1,0.8c0,0.4,0.1,0.8,0.3,1.1l4.2,7.6c0.1,0.3,0.3,0.5,0.6,0.7%20c0.3,0.2,0.6,0.2,0.9,0.2h3.8c0.5,0,1.1-0.3,0.5-1.2l-5.1-8.6c1.7-1.1,3.7-2.7,3.7-6.1c0-4.4-2.5-6.9-7.9-6.9H113%20c-0.7,0-0.9,0.2-0.9,1v20.8c0,0.7,0.2,1,0.9,1h3.2c0.7,0,0.9-0.2,0.9-1V16.8h3.3c2.1,0,3.1,0.8,3.1,2.8c0.1,0.6,0,1.2-0.3,1.6%20c-0.3,0.5-0.7,0.9-1.3,1.1C120.9,22.7,120.6,22.3,120.2,23.6'/%3e%3c/svg%3e)