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应用生态学报 ›› 2019, Vol. 30 ›› Issue (5): 1651-1658.doi: 10.13287/j.1001-9332.201905.020

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抚育间伐对长白落叶松人工林土壤碳、氮及其组分的影响

周焘, 王传宽, 周正虎*, 孙志虎   

  1. 东北林业大学生态研究中心, 哈尔滨 150040
  • 收稿日期:2019-01-18 修回日期:2019-01-18 出版日期:2019-05-15 发布日期:2019-05-15
  • 通讯作者: E-mail: zzhou@nefu.edu.cn
  • 作者简介:周 焘,男,1997年生,本科生.主要从事森林生态学研究.E-mail: ZT97NEFU@163.com
  • 基金资助:
    国家科技支撑计划项目(2011BAD37B01)、长江学者和创新团队发展计划项目(IRT_15R09)和国家自然科学基金项目

Effects of thinning on soil carbon and nitrogen fractions in a Larix olgensis plantation.

ZHOU Tao, WANG Chuan-kuan, ZHOU Zheng-hu*, SUN Zhi-hu   

  1. Center for Ecological Research, Northeast Forestry University, Harbin 150040, China
  • Received:2019-01-18 Revised:2019-01-18 Online:2019-05-15 Published:2019-05-15
  • Supported by:
    This work was supported by the National Key Science and Technology Research and Development Program of of China (2011BAD37B01), the Program for Changjiang Scholars and Innovative Research Team (IRT_15R09) and the National Natural Science Foundation of China (31770670).

摘要: 抚育间伐作为重要的森林经营措施之一,能够改变林分结构和稳定性,进而影响森林生态系统的生物地球化学循环.然而,抚育间伐对森林土壤碳、氮循环的影响程度如何尚不明确,尤其缺少长期试验结果报道.本研究以黑龙江省孟家岗林场经过4种不同强度和频度的抚育间伐处理后的60年生长白落叶松人工林为研究对象(4次低强度的间伐,LT4;3次中等强度的间伐,MT3;2次高强度间伐,HT2;不进行间伐的对照,CK),从酸水解法划分土壤碳、氮库(活性碳、氮库Ⅰ,活性碳、氮库Ⅱ和惰性碳、氮库)的角度研究了抚育间伐对长白落叶松人工林土壤总有机碳、全氮的影响机制.结果表明: 抚育间伐显著增加了土壤有机碳和全氮含量,增幅分别高达48.7%~50.3%和28.9%~42.7%.抚育间伐均增加了3种碳、氮组分的含量,而增加的程度因碳、氮组分和抚育间伐措施的不同而异.与活性碳库Ⅰ和活性碳库Ⅱ的增加程度相比,惰性碳库的增加程度最大,LT4、MT3和HT2处理下惰性碳库分别增加71%、69%和75%.此外,抚育间伐也显著增加了惰性碳占土壤总有机碳的比例.LT4显著提高了土壤微生物生物量碳、氮含量和微生物熵,而MT3和HT2对微生物生物量碳、氮和微生物熵却无显著影响.抚育间伐可能通过产生较多的粗木质残体于土体中,增加土壤木栓质和木质素等顽固组分的输入,进而导致土壤惰性碳含量增加,降低有机质的分解,最终导致土壤有机碳增加.

关键词: 落叶松人工林, 碳组分, 氮组分, 微生物生物量, 间伐

Abstract: Thinning, an important forest management strategy, can alter forest structure and stability, and consequently affect ecosystem biogeochemical cycles. The effects of thinning on soil carbon and nitrogen is far from conclusive especially due to the lack of long-term experiments. Here, we investigated soil carbon and nitrogen in Larix olgensis plantations in Mengjiagang Forest Farm, Heilongjiang Province, with four thinning treatments (i.e., 4 times low-intensity thinning, LT4; 3 times medium-intensity thinning, MT3; 2 times high-intensity thinning, HT2; and un-thinned control). The effects of thinning on soil total organic carbon and total nitrogen were examined from the perspective of the composition of labile and recalcitrant pools (labile carbon or nitrogen pool I; labile carbon or nitrogen pool II; and recalcitrant carbon or nitrogen pool) by an acid hydrolysis approach. The results showed that thinning significantly increased soil total organic carbon and nitrogen by 48.7%-50.3% and 28.9%-42.7%, respectively. The carbon and nitrogen contents in all the labile I, labile II, and recalcitrant pools were increased by thinning, with the magnitudes varying across different pools and thinning types. LT4, MT3, and HT2 improved the recalcitrant carbon by 71%, 69% and 75%, respectively, which was significantly higher than the increment of two labile carbon pools. In addition, the percentage of recalcitrant carbon in total organic carbon was increased by thinning. LT4 significantly increased microbial biomass and microbial quotient, but no significant change was found in MT3 and HT2 treatments. Overall, our results indicated that thinning might increase the input of soil recalcitrant carbon components such as suberin and lignin by producing more coarse woody residues, thus leading to decline of organic matter decomposition and ultimately enhancement of soil organic carbon.

Key words: larch plantation, microbial biomass., carbon fraction, thinning, nitrogen fraction