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森环森保所研究揭示间伐和林下植被去除对三峡库区马尾松人工林土壤微生物群落的影响

时间:2021年05月06日 16:12 来源:  作者:雷蕾

森环森保所气候变化与生态系统管理学科组在农林科学类二区期刊Applied Soil EcologyIF=3.178)上发表了题为“Effects of thinning intensity and understory removal on soil microbial community in Pinus massoniana plantations of subtropical China” doi:10.1016/j.apsoil.2021.104055)的研究论文。

土壤微生物群落在森林生产力维持、土壤养分循环以及土壤碳排放过程中起着重要的作用,因此,对于营林处理后土壤微生物群落进行长期连续的监测十分必要。本研究以未处理(对照)、轻度间伐、重度间伐和林下植被去除后的三峡库区马尾松人工林为研究对象,采用磷脂脂肪酸的方法研究了处理后3个生长季节和3个非生长季节的土壤微生物群落生物量和结构。研究发现(1)调查时间而非处理对土壤微生物群落结构以及生物量起着显著的影响;(2)间伐和林下植被去除的土壤微生物生物量在非生长季节呈现降低的趋势,而在第2和第3个生长季节呈现增加的趋势;(3)土壤水分、土壤碳氮比以及氮含量(全氮和无机氮)是调控土壤微生物群落主要因子;(4)处理后第2年,低土壤水分以及高土壤氮含量造成了土壤微生物生物量的显著增加;(5)间伐显著增加了土壤微生物真菌细菌比值,该比值与土壤异养呼吸呈显著正相关关系。

Fig. 2. Mean values (±SE; n =3) of total PLFAs, fungi PLFAs, bacterial PLFAs, FB ratio and soil heterotrophic respiration in control (CK), understory removal (UR), light thinned (LT) and heavily thinned (HT) plots across observation period. Asterisks represent p-values for main effects of treatment, year and their interactions on soil microbial PLFAs (* p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001). In case of significant interaction, letters above bars were added to indicate significant differences among levels of treatment in each year (p ≤ 0.05). In case of significant treatment or time effects only, results of post hoc test were inserted as small figures.

 

Fig. 4. Non-metric multidimensional scaling (NMDS) ordination of soil microbial PLFA biomarkers in control (CK), understory removal (UR), light thinned (LT) and heavily thinned (HT) plots across observation period. Significant environmental factors are represented as blue vectors in the figure (p < 0.05), marginally significant environmental factors are represented as grey vectors (0.05 < p < 0.06). 1st GS, 2nd GS and 3rd GS indicate growing season in the 1st, the 2nd and the 3rd year after treatment, and 1st NGS, 2nd NGS and 3rd NGS non-growing season in the 1st, the 2nd and the 3rd year after treatment.SM: soil moisture; TN: soil total nitrogen; SOC: soil organic carbon; pH: pH value of soil; MN: mineral nitrogen; CN: soil carbon to nitrogen ratio.

 

该研究表明森林管理措施如间伐和林下植被去除对环境因子(如土壤温湿度和养分可利用性)的显著影响,会直接改变土壤微生物群落的真菌细菌比,进而可能会影响土壤碳循环以及森林生产力。论文第一作者是森环森保所雷蕾助理研究员,通讯作者为森环森保所曾立雄副研究员。该工作得到了“十三五”国家重点研发计划项目(2016YFD0600205)和中央级公益性科研院所基本科研业务项目(CAFYBB2016SY013CAFYBB2016SY015)共同资助。(雷蕾/森环森保所)