| As a part of the environment, the forest has the obvious effect in cleaning atmosphere,water conservation, dust absorption and noise reduction. So it played an important role inimproving the circumstance. Now, the indexes such as "the cover rate of forest" and "forestarea of each people" were used to assess the forest environment. But these indexes can'tembodiment the above function of the forest. How to import the fix quantify index of theenvironment inspect to the assessment of the forest environment quality and to indicate thebenefit and its health and cure function of forest environment has become one of theformer problems of the scientific research at present.The aero-anion level, dust absorption and noise reduction effect of Chinese Pine,Black Locust and Sawtooth Oak in Qinhuangdao Lianfengshan Park were observed andstudied systemically between May and October in 2006. The spatio-temporal variety rulewas determined and gained the following results:First, the aero-anion contributes of broadleaf forest were bigger than conifer forest.The incorporate was that: (1) Aero-anion concentration of summer was higher than springand autumn. From the arisen circs of the extremum, the extremum of Sawtooth Oak wasthe highest and arised in July. Aero-anion concentration was 1008 num/ cm3. Theextremum of Chinese Pine was the lowest and the aero-anion concentration was 698 num/cm3. Black Locust was placed in the middle and the aero-anion concentration was 698num/cm3. (2) There was the altemant phenomenon of apex and paddy of the aero-anionconcentration in one day. The peak value arised from 7:00 to 9:00 and from 16:00 to 17:00.The paddy value arised from 11:00 to 12:00 and around 0:00. The aero-anion concentrationchange extent of Chinese Pine was the least and the Sawtooth Oak was the biggest. (3) Theaero-anion concentration of edge was lower than the center of the forest. From the edge tothe center it rised 233 num/cm3 in Chinese Pine, 173 num/cm3 in Sawtooth Oak and 137num/cm3 in Black Locust. (4) It indicated that the aero-anion concentration was correlatednegatively with temperature, and correlated positively with relative humidity. That is to say,if the temperature declined, or the relative humidity arised, the aero-anion concentrationarised also.Second, the atmosphere dustfall was degressive in the six months. The amount ofatmosphere dustfall in Black Locust, Sawtooth Oak and Chinese Pine were separately12.36 t·km-2·month-1, 13.20t·km-2·month-1 and 12.67t·km-2·month-1 in May and 9.97t·km-2·month-1, 10.02t·km-2·month-1 and 11.23t·km-2·month-1 in October. From Mayto October, the amount of atmosphere dustfall separately decreased 19.3%, 24.1% and11.4% in above three forests. For the six mouths, the experiment indicated that the amountof atmosphere dustfall in Chinese Pine was the most, in Sawtooth Oak was the least and in Black Locust was in the middle. That is to say, the order of the dust absorption effect isSawtooth Oak, Black Locust, Chinese Pine.Third, this experiment also measured the noise attenuation, and it indicated that theorder of the noise reduction effect was Sawtooth Oak, Black Locust and Chinese Pine.Noise attenuated rapidly in the first 5 meters, and then noise attenuated steadily in 10-20miters, but foliage has faint influence to the noise attenuation when the spread distanceincreasing. In addition, this experiment also measured the environment noise. The resultsindicated that the environment noise level in forest was evidently lower than that with noforest. The noise of Chinese Pine, Black Locust and Sawtooth Oak were separately 54.8dB,51.4dB and 50.9dB, and which were separately 20.7%, 20.0% and 14.2% lower than theantitheses.Integrating the results, aero-anion level in the Sawtooth Oak forest was high, the dustabsorption and noise reduction effect were strong. So the Sawtooth Oak forest had thebiggest contributes to the forest environment. Chinese Pine had the least contributes, andBlack Locust was placed in the middle. |
