空气负离子(negative air ion,NAI)浓度是衡量空气清洁度的重要指标之一,不同时间尺度下NAI浓度的分析结果可能存在差异。从多时间尺度(时、天、月、季、年)视角出发,通过Mann-Kendall检验探究福州国家森林公园2017-2020年NAI浓度的变...空气负离子(negative air ion,NAI)浓度是衡量空气清洁度的重要指标之一,不同时间尺度下NAI浓度的分析结果可能存在差异。从多时间尺度(时、天、月、季、年)视角出发,通过Mann-Kendall检验探究福州国家森林公园2017-2020年NAI浓度的变化趋势,采用小波分析探究NAI浓度变化周期性,应用灰色关联厘清多时间尺度下NAI浓度与温湿度的关系变化。结果表明,1)NAI浓度在春夏季变化不显著,秋冬季显著下降。2)NAI时平均浓度峰值和谷值分别在4:00和11:00,冬春季低且平稳,夏秋季较高且波动强。3)月尺度NAI浓度存在6、11、17、52个月的主周期,日尺度具有6、12、18、40 d的主周期,时尺度存在12、19、51 h的主周期,分钟尺度存在25、40 min主周期。4)NAI浓度与温度灰色相关性低于浓度与湿度灰色相关性,二者在时和日尺度上较低,在月和季尺度上较高。研究结果从多时间尺度揭示NAI浓度变动特征及其与温湿度关系,并给出高效康养出行时间建议,即在5、10月的6、12、18、24、30日的8:00、16:00进行游园较为适宜。展开更多
Slash Pine(Pinus elliottii) is an introduced tree species that can adapt different site types. Since 1970s, in order to enrich the tree species resource, Slash Pine was planted on the cut_over area of Casuarina equise...Slash Pine(Pinus elliottii) is an introduced tree species that can adapt different site types. Since 1970s, in order to enrich the tree species resource, Slash Pine was planted on the cut_over area of Casuarina equisetifolia protection forest in Chishan Protection Forest Farm of Dongshan County, Fujian Province. It could prevent soil fertility from degeneration, improve forest productivity and provide fundamental data for soil ecological management to study the soil nutrient content and enzyme activities of different age stands of Slash Pine. The effect of Slash Pine on fertility of coastal sandy land was studied in this paper. The results showed that it would make the soil acid to plant Slash Pine on the cut_over area of C.equisetifolia protection forest Compared, because the pH value was declined as the growth of Slash Pine stand, and it declined to 3.96(0～20*!cm) and 3.87(20～40*!cm) when Slash Pine stand was 26*!a; Compared with the second generation coastal protection forest of C.equisetifolia the nutrients content in the soil of 26*!a Slash Pine stand were lower than that in the soil of the second generation forest, especially for available P, available K, and total N. The CEC in soil layer of 0～20*!cm was obviously effected by Slash Pine. In this soil layer, the CEC was increased as the growth of Slash Pine stands, and it was as 1.22 times as the content in the soil of the second generation forest. There was no obvious effect on urease activity, but the activities of phosphataese, polyphenol oxidase, and peroxidase were declined by planted Shash Pine on the cut_over area of Casuarina protection forest.展开更多
文摘Slash Pine(Pinus elliottii) is an introduced tree species that can adapt different site types. Since 1970s, in order to enrich the tree species resource, Slash Pine was planted on the cut_over area of Casuarina equisetifolia protection forest in Chishan Protection Forest Farm of Dongshan County, Fujian Province. It could prevent soil fertility from degeneration, improve forest productivity and provide fundamental data for soil ecological management to study the soil nutrient content and enzyme activities of different age stands of Slash Pine. The effect of Slash Pine on fertility of coastal sandy land was studied in this paper. The results showed that it would make the soil acid to plant Slash Pine on the cut_over area of C.equisetifolia protection forest Compared, because the pH value was declined as the growth of Slash Pine stand, and it declined to 3.96(0～20*!cm) and 3.87(20～40*!cm) when Slash Pine stand was 26*!a; Compared with the second generation coastal protection forest of C.equisetifolia the nutrients content in the soil of 26*!a Slash Pine stand were lower than that in the soil of the second generation forest, especially for available P, available K, and total N. The CEC in soil layer of 0～20*!cm was obviously effected by Slash Pine. In this soil layer, the CEC was increased as the growth of Slash Pine stands, and it was as 1.22 times as the content in the soil of the second generation forest. There was no obvious effect on urease activity, but the activities of phosphataese, polyphenol oxidase, and peroxidase were declined by planted Shash Pine on the cut_over area of Casuarina protection forest.
文摘通过滨海木麻黄基干防护林带的小气候效应及梯度变化规律的定位观测研究,结果表明:林带内的月平均温度与空旷地相比平均降低0.7℃,年平均气温的垂直梯度变化为林冠上部最高,1.5m 处次之,林冠中部最低,变化梯度为0.4℃;空旷地空气的绝对湿度均高于带内。林带内外平均相对湿度相差甚微,仅为0.8%,湿度的垂直梯度变化为林冠中部最大,林冠上部次之,而以林内近地层为最小,绝对湿度的变化梯度为0.6 mb,相对湿度的变化梯度为3.1%。林带土壤的年平均温度随土壤深度的增加而降低,冬春季节土壤温度随深度的增加而降低,至10 cm 后土壤温度又随深度而增加,夏秋季节土壤温度随深度的增加而一直降低。晴天照度均明显高于阴天,晴天空旷地的照度是阴天的2.6倍,照度在林带内呈明显的梯度变化,林冠层中部最小,林带下部次之,而在林冠上部照度最大。
