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测定CO_2释放率,可确定云杉林下土壤有机层的生物活动。在实验室条件下,生物活动的最适温度是20—35℃,含水量是40—60%。微酸性至中性的有机物质可促进微生物形成CO_2,过酸(pH<2.4)则抑制了这个过程。在pH<2.4时,CO_2释放率较低,故在有机物中有耐酸性强的微生物群体。O_L层的潜在碳矿化占总量的50%,而下面的O_F和O_H层各占25%。在模拟“酸雨”试验中,据对渗透过有机层的水的分析,表明pH在3—6.6的范围内,酸雨可引起阳离子的不断淋溶。在这方面,O_L层起了缓冲作用。可以假设,由于酸雨对云杉林下土壤有机物的酸化,抑制了碳矿化,降低了矿质养分的释放。长期下去,将会影响到森林生态系中矿质养分的转化。
The CO 2 release rate was determined to determine the biological activity of soil organic layer under spruce forest. Under laboratory conditions, the optimum temperature for biological activity is 20-35 ° C and the water content is 40-60%. Slightly acidic to neutral organic substances promote microbial formation of CO 2, and peracid (pH <2.4) suppresses this process. At pH <2.4, CO 2 release rate is low, so there is a strong acid-resistant microorganisms in the organic compounds. The potential carbon mineralization in the O_L layer accounts for 50% of the total, while the O_F and O_H layers below each account for 25%. In a simulated “acid rain” test, an analysis of water that permeated the organic layer showed that the pH ranged from 3 to 6.6, and acid rain caused constant leaching of the cations. In this regard, O_L plays a buffer role. It can be assumed that the acidification of soil organic matter under the spruce forest inhibits carbon mineralization and reduces the release of mineral nutrients. In the long run, it will affect the conversion of mineral nutrients in forest ecosystems.