柳树人工林土壤生物学性状研究

发布时间：2018-08-22 20:42

【摘要】：人工林对缓解我国木材紧张状况和促进林业生产建设起着巨大作用。然而,随着杉木、马尾松、杨树等人工林的不断发展,特别是连栽导致各地不同程度地出现了诸如“林木生长趋缓”、“林地土壤肥力下降甚至衰退”等一系列问题,给林业生产带来严重影响,因此,多年来,有关人工林地力变化的研究一直为人们所重视。柳树人工林作为近年来发展较快的人工林,其发展规模和面积日益增大,而有关其土壤性状或肥力变化方面的研究却鲜有报道,为此,以连云港市柳树人工林为研究对象,通过野外调查采样和室内分析测定,分析不同林龄柳树人工林土壤磷酸酶、蔗糖酶、脲酶、过氧化氢酶等酶活性的变化特征,研究土壤微生物量碳、氮的变化状况,阐明柳树人工林土壤生物学性质与理化性质间的关系,揭示柳树人工林土壤生物学性质状况,为土壤肥力维护和人工林可持续发展提供依据。主要研究结果如下:1.土壤碱性磷酸酶、蔗糖酶、脲酶、过氧化氢酶活性及土壤微生物量碳、微生物量氮在总体上都随人工林林龄增加而逐渐增加。1a生柳树人工林的土壤碱性磷酸酶、蔗糖酶、脲酶、过氧化氢酶分别为2.60mg/g、83.47mg/g、1.87mg/g、3.78ml/g,4a生的分别为3.16mg/g、106.42mg/g、2.49mg/g、3.82ml/g;1a生的土壤微生物量碳、微生物量氮分别为120.75mg/kg、33.51 mg/kg,4a生的分别为179.05mg/kg、43.98mg/kg。2.不同土层的林地土壤酶活性差异较大,土壤碱性磷酸酶、蔗糖酶、脲酶、过氧化氢酶活性的垂直变化总体规律为上层(0~20cm)中层(20~40cm)下层(40~60cm),土壤酶活性随土层加深而不断减小;不同林龄相同土层的土壤酶活性总体上随林龄增加而增大,即土壤酶活性4a3a2a1a。研究得出:1a生的上、中、下层土壤碱性磷酸酶分别为2.63 mg/g、1.66 mg/g、0.91 mg/g,2a生的分别为2.56 mg/g、1.87 mg/g、1.14 mg/g,3a生的分别为2.53 mg/g、2.23 mg/g、1.28 mg/g,4a生的分别为2.80 mg/g、1.95 mg/g、1.57 mg/g;1a生的蔗糖酶分别为88.72 mg/g、56.26 mg/g、21.97 mg/g,2a生的分别为88.58 mg/g、71.65mg/g、25.76 mg/g,3a生的分别为94.29 mg/g、70.79 mg/g、25.80 mg/g,4a生的分别为92.11mg/g、81.01 mg/g、39.73 mg/g;1a生的脲酶分别为2.27 mg/g、0.98 mg/g、0.48 mg/g,2a生的分别为2.23 mg/g、1.27 mg/g、0.62 mg/g,3a生的分别为1.64 mg/g、1.14 mg/g、0.74 mg/g,4a生的分别为2.19 mg/g、1.74 mg/g、1.05 mg/g;过氧化氢酶活性的变化相对较小,1a生的上、中、下层土壤过氧化氢酶分别为2.56 ml/g、2.57 ml/g、2.43 ml/g,2a生的分别为2.56ml/g、2.58 ml/g、2.4 ml/g,3a生的分别为2.5 ml/g、2.57 ml/g、2.47 ml/g,4a生的分别为2.57 ml/g、2.5 ml/g、2.51 ml/g。3.不同土层的土壤微生物量碳的大小顺序为0~20cm20~40cm40~60cm,土壤微生物量氮也表现为上层和中层较高,下层较低,因此,总体上它们都随土层加深而呈减少趋势。不同林龄相同土层的土壤微生物量碳总体均为4a生的最大、1a生的最小,4a生的上、中、下层土壤微生物量碳总体分别为171.03mg/kg、111.25mg/kg、75.82mg/kg,比对照分别增加了87.59%、171.70%、171.72%,1a生的分别为126.39mg/kg、79.11mg/kg、36.00mg/kg,比对照分别增加了38.63%、93.20%、29.01%。不同林龄的土壤微生物量氮的变化不尽相同,上层土壤的变化存在波动性,无明显变化规律,而中层和下层土壤微生物量氮的变化规律则与微生物量碳相似,即随林龄增加而逐渐增加。4.不同季节的土壤酶活性存在较大差异,土壤碱性磷酸酶、蔗糖酶及脲酶活性总体均表现为夏季相对较高、春季和冬季相对较低;过氧化氢酶活性则以春季最大、夏季其次、冬季最小。相同季节1a~4a生的土壤过氧化氢酶活性变化不大,而土壤碱性磷酸酶、蔗糖酶及脲酶活性总体随林龄增加而呈升高的趋势,例如:夏季4a生的土壤碱性磷酸酶活性为2.65 mg/g,比对照增加了20.87%,蔗糖酶活性为76.65mg/g,较对照增加38.41%,土壤脲酶活性为2.76mg/g,较对照增了110.43%。5.不同季节的土壤微生物量碳、氮变化规律不尽相同,微生物量碳为夏季最高、春季其次、冬季最低,而土壤微生物量氮则以夏季最大、冬季其次、春季最低;同一季节不同林龄人工林的土壤微生物量碳、微生物量氮均随林龄增加而不断增加。
[Abstract]:Plantation plays an important role in alleviating timber tension and promoting forestry production and construction in China. However, with the continuous development of Chinese fir, masson pine and poplar plantations, especially continuous planting, a series of problems have appeared in various places, such as "slow growth of trees", "decline or even decline of soil fertility of forest land". Forestry production has brought about serious impact, therefore, for many years, people have been paying attention to the research on the change of soil fertility of artificial forest. As a fast-growing artificial forest in recent years, the development scale and area of willow plantation are increasing day by day, but the research on the change of soil properties or fertility is seldom reported. Through field investigation, sampling and laboratory analysis, the characteristics of soil phosphatase, sucrase, urease and catalase activities in willow plantations at different ages were analyzed, and the changes of soil microbial biomass carbon and nitrogen were studied. The main results are as follows: 1. Soil alkaline phosphatase, sucrase, urease, catalase activity, soil microbial biomass carbon and microbial biomass nitrogen increased gradually with the increase of plantation age. Soil alkaline phosphatase, sucrase, urease and catalase in willow plantation were 2.60 mg/g, 83.47 mg/g, 1.87 mg/g, 3.78 ml/g, 3.16 mg/g, 106.42 mg/g, 2.49 mg/g, 3.82 ml/g, respectively, and soil microbial biomass carbon, microbial biomass nitrogen and microbial biomass nitrogen were 120.75 mg/kg, 33.51 mg/kg, 179.05 mg/kg, 43.98 mg/kg, and 2.2.8 mg/kg, respectively. The activity of soil alkaline phosphatase, invertase, urease and catalase in the upper layer (0-20cm) and the lower layer (20-40cm) were different in the soil layer, and the activity of soil enzyme decreased with the soil layer deepening. The results showed that the activities of alkaline phosphatase in the upper, middle and lower layers of soil were 2.63 mg/g, 1.66 mg/g, 0.91 mg/g, 2.56 mg/g, 1.87 mg/g, 1.14 mg/g, 2.53 mg/g, 2.23 mg/g, 1.28 mg/g, 4-year-old were 2.80 mg/g, 1.95 mg/g, 1.57 mg/g, respectively. The three-year-born ureases were 94.29 mg/g, 70.79 mg/g, 25.80 mg/g, 25.80 mg/g, respectively, 94.29 mg/g, 70.79 mg/g, 56.26 mg/g, 56.26 mg/g, 56.26 mg/g, 21.97 mg/g, 21.97 mg/g, and 21.97 mg/g at 2a-born were 88.58.58 mg/g, 71.65 mg/g, 71.65 mg/g, 71.65 mg/g, 25.76mg/g, 94.29 mg/g, 70.79 mg/g, 25.79.79 mg/g, 25.80 mg/g, 92.11 mg/g, 81.01 mg/g, 81.01 mg/g, 81.01 mg/g, 39.01 mg/g, 1.14 mg/g, 0.74 mg/g, 4-year-old were 2.19 mg/g, 1.74 mg/g, 1.05 mg/g, catalase activity was relatively small, the catalase activity of 1-year-old upper, middle, lower soil were 2.56 ml/g, 2.57 ml/g, 2.43 ml/g, 2.56 ml/g, 2.58 ml/g, 2.4 ml/g, 3-year-old were 2.5 ml/g, 2.57 ml/g, 2.47 ml/g, 4-year-old respectively. Soil microbial biomass carbon in different soil layers ranged from 0 to 20 cm 20 to 40 cm 40 to 60 cm. Soil microbial biomass nitrogen was also higher in the upper and middle layers and lower in the lower layers. Therefore, they all showed a decreasing trend with the deepening of soil layers. The total soil microbial biomass carbon in the upper, middle and lower layers were 171.03 mg/kg, 111.25 mg/kg, 75.82 mg/kg, 87.59%, 171.70%, 171.72%, 126.39 mg/kg, 79.11 mg/kg, 36.00 mg/kg, respectively, which increased by 38.63%, 93.20% and 29.01% compared with the control. The change of soil microbial biomass nitrogen was similar to that of microbial biomass carbon (MBC). 4. Soil enzyme activities in different seasons were quite different, and soil alkaline phosphatase, sucrase and urease activities were different. The activities of catalase were the highest in spring, the second in summer and the smallest in winter. The activities of catalase in soils grown in the same season for 1A ~ 4A had little change, while the activities of alkaline phosphatase, invertase and urease increased with the increase of forest age, for example, in summer. Soil alkaline phosphatase activity increased by 20.87%, sucrase activity by 76.65 mg/g, 38.41% and urease activity by 2.76mg/g, 110.43% respectively. 5. Soil microbial biomass carbon and nitrogen varied in different seasons. Microbial biomass carbon was the highest in summer, the second in spring and the lowest in winter. Soil microbial biomass carbon and microbial biomass nitrogen increased with the increase of forest age in the same season.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S714;S792.12

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