利用混沉降物的收集以推估林木對空氣污染物的截留能力

Assessment the Ability of Trees to Intercept Pollutants by Using Bulk Deposition

本研究目的為利用混沉降物的分析以推估都會區不同種類的鄉土綠化樹種對空氣污染物的截留能力。在台中國立自然科學博物館的植物園內，選取海岸林區的水黃皮、季風雨林區的茄苳、南部低海拔區的苦楝及相思、中部低海拔區的台灣欒樹、無患子及楓香、北部低海拔區的紅楠及樟樹等九種樹種為標本木，分別在其樹幹及樹冠下架設幹流水及穿落水的取樣裝置，且於園區內的空曠地架設林外雨取樣裝置。雨水收集從2006年5月開始至2006年7月結束，以場雨為單元收集水樣。此試驗期間的穿落水分析結果顯示，相思樹及苦楝對空氣中NOx的截留量最高，分別為3.14kg ha^(-1)3months^(-1)及2.54kg ha^(-1)3months^(-1)，而台灣欒樹、紅楠、楓香則有淨吸收作用，吸收量分別為1.19、1.19及0.33kg ha^(-1)3months^(-1)，雖然樹冠對NOx不管是截留或者吸收都可以幫助降低空氣中污染物的濃度，然而以此試驗選擇的樹種而言，對空氣中NOx的總減量還是相思及苦楝較多。對大氣中SO2的截留量方面，則以水黃皮及無患子較佳，分別為3.08及2.73kg ha^(-1)3months^(-1)，較低則是楓香及紅楠，分別為0.94及0.38kg ha^(-1)3months^(-1)。 The objectives of this study were to compare the ability of trees to remove pollutants from the air. Bulk precipitation, throughfall, and stemflow were collected from March 2006 to October 2006 in the botanical garden of the Nationl Museum of Natural Science. Poonga-Oil free (Pongamia pinnata) of Coral Atoll, Red cedar (Bischofia javanica) of Monsoon Rainforeat, China Berry-tree (Melia azedarach), Taiwan Acacia (Acacta confusa) of Southern Lowlanda, Flamegold (Koelreuteria formosana), Chinese Soapberry (Sapindus mukorossi), Fragrant Maple (Liquidambar formosana) of Central Lowlands and Red Nanmu (Machilus thunbergii), Camphor tree (Cinnamomum camphora) of Northern Lowlands were selected as sampling trees. Taiwan Acacia and China Berry-tree had higher net NOx interception and were 3.14 and 2.54 kg ha^(-1) 3months^(-1), respectively. The net NOx absorption of Flamegold, Red Nanmu and Fragrant Maple were 1.19, 1.19 and 0.33 kg ha^(-1) 3monthc^(-1), respectively. We concluded that Taiwan Acacia and China Berry-tree had higher NOx reducing ability among the nine kinds of sampling trees. In terms of SO2 interception, Poonga-Oil tree and Chinese Soapberry had higher net SO2 interception and were 3.08 and 2.73 kg ha^(-1) 3months^(-1), respectively. However, Fragrant Maple and Red Nanmu had lower interception and were 0.94 and 0.83 kg ha^(-1) 3months^(-1), respectively.

The objectives of this study were to compare the ability of trees to remove pollutants from the air. Bulk precipitation, throughfall, and stemflow were collected from March 2006 to October 2006 in the botanical garden of the Nationl Museum of Natural Science. Poonga-Oil free (Pongamia pinnata) of Coral Atoll, Red cedar (Bischofia javanica) of Monsoon Rainforeat, China Berry-tree (Melia azedarach), Taiwan Acacia (Acacta confusa) of Southern Lowlanda, Flamegold (Koelreuteria formosana), Chinese Soapberry (Sapindus mukorossi), Fragrant Maple (Liquidambar formosana) of Central Lowlands and Red Nanmu (Machilus thunbergii), Camphor tree (Cinnamomum camphora) of Northern Lowlands were selected as sampling trees. Taiwan Acacia and China Berry-tree had higher net NOx interception and were 3.14 and 2.54 kg ha^(-1) 3months^(-1), respectively. The net NOx absorption of Flamegold, Red Nanmu and Fragrant Maple were 1.19, 1.19 and 0.33 kg ha^(-1) 3monthc^(-1), respectively. We concluded that Taiwan Acacia and China Berry-tree had higher NOx reducing ability among the nine kinds of sampling trees. In terms of SO2 interception, Poonga-Oil tree and Chinese Soapberry had higher net SO2 interception and were 3.08 and 2.73 kg ha^(-1) 3months^(-1), respectively. However, Fragrant Maple and Red Nanmu had lower interception and were 0.94 and 0.83 kg ha^(-1) 3months^(-1), respectively.