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间伐是人工林培育的重要措施之一,其在促进林分地上生长的同时,也对土壤产生重要影响,尤其是对土壤微生物与土壤酶活性等产生影响。为了明确间伐对日本落叶松人工林土壤酶活性的影响规律,本文以辽宁东部山区不同土壤肥力日本落叶松(Larix kaempferi)人工林为研究对象,通过设置不同强度的间伐试验(对照:未间伐,中度间伐:25%,强度间伐:50%),分析间伐2年后土壤酶活性的动态变化。结果表明:(1)不同肥力日本落叶松人工林的酚氧化酶活性在秋季最高,外切葡萄糖苷酶(PNC)、β-葡萄糖苷酶(PNG)、N-乙酰-β-氨基葡萄糖苷酶(NAG)和酸性磷酸酶活性在春季最高;(2)中度间伐显著提高肥力较差日本落叶松人工林表层酚氧化酶和NAG活性,中度和强度间伐显著降低该林分的亚表层PNG、NAG和酸性磷酸酶活性;(3)日本落叶松人工林土壤5种酶与全碳、全氮和无机氮均呈显著正相关,与p H值呈显著负相关。中度间伐显著降低了肥力较差日本落叶松人工林土壤酶与无机氮的相关性,而强度间伐却显著降低了土壤酶与全碳、有效磷的相关性;强度间伐只显著提高了肥力较好日本落叶松人工林土壤酶与全磷的相关性。综上,从提高土壤酶活性的角度,土壤肥力较差的日本落叶松人工林适合中度间伐,而土壤肥力较好的日本落叶松人工林更适合强度间伐。
Thinning is one of the important measures for plantation cultivation. It also plays an important role in soil growth while promoting the growth of forest stand, especially on soil microorganisms and soil enzyme activities. In order to clarify the effect of thinning on the activity of soil enzymes in Larix kaempferi plantations, we selected Larix kaempferi plantations with different soil fertility in the eastern mountainous area of Liaoning Province as the research object. By setting thinning experiments with different intensities (control: Moderate thinning: 25%, thinning: 50%). The dynamic changes of soil enzyme activities after 2 years of thinning were analyzed. The results showed as follows: (1) The activities of phenoloxidase in different fertility plants were the highest in autumn, the activities of PNC, PNG, N-acetyl-β-glucosaminidase (NAG) and acid phosphatase activity were the highest in spring. (2) Moderate thinning significantly increased the phenolic oxidase and NAG activity in the surface layer of fertilized Japanese larch plantation, and the middle and thinning significantly reduced the sub-surface PNG , NAG and acid phosphatase activities. (3) There was a significant positive correlation between five kinds of enzymes and total carbon, total nitrogen and inorganic nitrogen in the Japanese larch plantation soil, and negatively correlated with the p H value. Moderate thinning significantly reduced the correlation between soil enzyme and inorganic nitrogen in poorly fertilized Japanese larch plantations, while the intensity thinning significantly reduced the correlation between soil enzymes and total carbon and available phosphorus. Intensity thinning only significantly improved the soil fertility Correlation between soil enzyme and total phosphorus in the Japanese larch plantation. In summary, from the perspective of improving soil enzyme activity, Japanese larch plantation with poor soil fertility is suitable for moderate thinning, while Japanese larch plantation with better soil fertility is more suitable for thinning.