丁 波,丁贵杰,赵熙州,杨永彰
(1.贵州大学林学院/贵州省森林资源与环境研究中心, 贵州 贵阳 550025;2.贵州省林业科技推广总站,贵州 贵阳 550001; 3.榕江县营林总站,贵州 榕江 557200)
无刷直流电机控制系统仿真比较
丁 波1,2,丁贵杰1*,赵熙州1,杨永彰3
(1.贵州大学林学院/贵州省森林资源与环境研究中心, 贵州 贵阳 550025;2.贵州省林业科技推广总站,贵州 贵阳 550001; 3.榕江县营林总站,贵州 榕江 557200)
目的研究间伐对杉木人工林土壤微生物数量、酶活性及关系的影响,试图了解不同间伐强度作用下土壤恢复的过程和机制,为人工林经营提供理论依据。方法以18年生杉木人工林为研究对象,采用随机区组试验设计,分析4种间伐强度TS0(未间伐(0.0%),1 800株·hm-2)、TS1(轻度(16.7%),1 500株·hm-2)、TS2(中度(33.3%),1 200株·hm-2)和TS3(重度(50.0%),900株·hm-2)下杉木人工林土壤微生物数量及土壤酶活性特点,探讨土壤微生物数量与酶活性的相关性。结果表明:间伐3年后,林下土壤层酶活性和微生物数量显著提高,不同土层间土壤微生物数量和酶活性均差异显著;间伐显著提高了土壤过氧化氢酶、碱性磷酸酶、脲酶和蔗糖酶的活性,除过氧化氢酶(1530、3045 cm)、碱性磷酸酶(015、3045 cm)以及脲酶(3045 cm)以TS3处理的酶活性最高外,其他酶活性在各土层和不同间伐强度下均以TS2处理的酶活性最高;土壤各层微生物以细菌数量最多,其次是放线菌,硝化细菌最少,且TS2处理的微生物数量最多。土壤过氧化氢酶和脲酶活性均与细菌、真菌和硝化细菌数量呈极显著正相关,与放线菌数量呈极显著负相关,氨化细菌数量与过氧化氢酶活性呈负相关,而与脲酶活性呈正相关;碱性磷酸酶活性与细菌、真菌和硝化细菌数量呈正相关,与氨化细菌数量呈极显著负相关,与放线菌数量呈负相关;蔗糖酶活性与细菌、真菌和氨化细菌数量呈极显著正相关,与硝化细菌数量呈正相关,与放线菌数量呈负相关。结论间伐改善了林分环境、光照、温度以及林下植被的发育,提高了林下土壤酶活性并增加了微生物数量。间伐3年后的综合表现表明,中度间伐最利于杉木人工中、近熟林阶段的经营,对于改善土壤性质较好。
杉木;人工林;间伐强度;土壤微生物;土壤酶活性
杉木(Cunninghamialanceolata(Lamb.) Hook.)是我国最主要用材树种之一,由于人工林普遍密度较大、树种单一、林分结构简单等原因,杉木人工林出现了地力衰退[1]和生产力下降[2]的情况。前人针对地力衰退对杉木人工林理化性质的影响进行了大量研究[3-5],而间伐对土壤生物学特征(土壤酶、土壤微生物等)的影响研究相对较少,土壤养分和土壤生物学特征共同推动土壤质量的变化[6]。
土壤酶在土壤中参与许多物质循环和生物化学过程,其活性可作为土壤生态胁迫或土壤生态恢复等早期的敏感性指标[7],用作土壤养分及养分循环的指示物[6-8],在森林生态系统的生化过程中起关键的调节作用,土壤酶活性的高低可以反映土壤养分转化的强弱[9]。土壤微生物在土壤养分转化过程和植被生态系统中发挥着重要作用,因此,一直是研究热点内容之一[10]。国内研究表明,适宜间伐强度能改善林分水热状况,提高林下植物多样性,增强土壤微生物[3,7,11]和酶活性[12]。前人的研究主要集中在间伐对人工林生态系统单方面影响,如间伐对人工林林下植被[13]发育、生物量[14]、生长和出材量[15]、土壤酶演变[16-17]、土壤理化性质变化[5]的影响,而对人工林间伐后土壤微生物数量和土壤酶活性之间的关系少见报道。因此,探讨间伐后土壤酶活性与土壤微生物数量之间的关系,对了解森林生态系统过程具有深远意义,为科学制定杉木人工林经营技术措施和掌握间伐对土壤微生物及酶活性的影响提供参考。
过氧化氢酶采用高锰酸钾滴定法测定,碱性磷酸酶采用pH=10的硼酸盐缓冲液比色法测定,蔗糖酶采用3,5-二硝基水杨酸比色法测定,脲酶活性采用苯酚钠比色法测定。土壤细菌和氨化细菌采用牛肉膏蛋白胨培养基法测定,真菌采用马丁式培养基法测定,放线菌采用改良高氏Ⅰ号培养基法测定,硝化细菌采用改良的斯蒂芬森培养基法测定。
采用SPSS21.0软件对数据进行分析处理,单因素方差(one-way ANOVA)分析不同间伐强度下土壤酶和土壤微生物数量的显著差异性,用皮尔森(Pearson)法分析土壤酶和土壤微生物数量之间的相关性,采用origin8.6作图。
大写字母表示同一间伐强度不同土层的显著性(P<0.05),小写字母表示不同间伐强度下同一土层的显著性(P<0.05)。Different capital letters meant significant difference at 0.05 level in different soil layers under the same thinning intensity,lowercase letters meant significant difference at 0.05 level under different thinning intensities in the same soil layer.图1 间伐对杉木人工林土壤酶活性的影响Fig.1 Effects of soil enzymes activity with thinning on C. lanceoolata plantation
表1 杉木人工林土壤微生物数量(平均值±标准误)
注:大写字母表示同一间伐强度不同土层的显著性,小写字母表示不同间伐强度下同一土层的显著性。
Note: Different capital letters meant significant difference at 0.05 level in different soil layers under the same thinning intensity,lowercase letters meant significant difference at 0.05 level under different thinning intensities in the same soil layer .
从表2可看出:间伐3 a后,土壤脲酶与过氧化氢酶、蔗糖酶呈极显著正相关,过氧化氢酶与碱性磷酸酶呈显著正相关,过氧化氢酶与蔗糖酶、碱性磷酸酶与脲酶呈正相关,蔗糖酶与碱性磷酸酶呈负相关。土壤过氧化氢酶和脲酶均与细菌、真菌和硝化细菌呈极显著正相关,与放线菌呈极显著负相关;氨化细菌与过氧化氢酶呈负相关,而与脲酶呈正相关;碱性磷酸酶与细菌、真菌和硝化细菌呈正相关,与氨化细菌呈极显著负相关、与放线菌呈负相关,蔗糖酶与细菌、放线菌和氨化细菌呈极显著正相关,与硝化细菌呈正相关,与放线菌呈负相关。土壤微生物数量之间也有较强的相关性,细菌、真菌和硝化细菌三者间均呈极显著正相关,氨化细菌与细菌、放线菌、真菌以及硝化细菌呈正相关,放线菌与细菌、真菌和硝化细菌呈极显著负相关。
Note:The B1-B9 represent of hydrogen peroxide enzyme, phosphate enzyme , urease, sucrase, bacteria, actinomycosis, fungi, ammonifying bacteria and nitrifying bacteria. * correlation meant significant difference at theP<0.05, * * correlation meant very significant difference at theP< 0.01.
前人研究认为,间伐后,一方面林下植被生物多样性提高,土壤养分循环加速,使土壤微生物多样性和数量提高[3,24];另一方面改变林下微环境,加速根系分泌,促进凋落物分解,影响土壤中的有机质数量与质量[25-26],最终影响微生物群落。本研究结果与张鼎华等[3]、郑伟等[27]的研究结果相似。本研究中,土壤微生物数量均以TS2处理的最多,可能由于中度间伐后林分环境最有利于土壤微生物的发育,从而数量最多。
前人研究得出,酶活性与土壤微生物数量的相关性较高[28-29],本研究亦得出相似的结论。过氧化氢酶、脲酶与真菌、细菌及硝化细菌呈极显著相关性,与王笛等[29]的研究结论基本一致,但与陈军军等[30]等研究间伐对松栎混交林所得的结果有所不同;碱性磷酸酶与细菌、真菌和硝化细菌呈正相关,与氨化细菌呈极显著负相关、与放线菌呈负相关,这与陈军军等[30]的研究结果略有不同,这可能与二者的研究地域、林分类型、立地、干扰措施及环境等不同有关。
(2)间伐显著增加了杉木人工林土壤微生物的数量,不同土层间差异显著。土壤各层微生物数量以细菌最多,其次是放线菌,硝化细菌最少,中度间伐微生物数量最多。
(3)土壤过氧化氢酶和脲酶均与细菌、真菌和硝化细菌呈极显著正相关,与放线菌呈极显著负相关,氨化细菌与过氧化氢酶呈负相关,而与脲酶呈正相关;碱性磷酸酶与细菌、真菌和硝化细菌呈正相关,与氨化细菌呈极显著负相关,与放线菌呈负相关;蔗糖酶与细菌、真菌和氨化细菌呈极显著正相关,与硝化细菌呈正相关,与放线菌呈负相关。
(4)中度间伐可以促进杉木对林地养分的吸收和利用,就土壤微生物数量和酶活性而言,对18年生杉木人工林采用中度间伐(保留密度1 200株·hm-2)比较合适。
[1] 方 奇.杉木连栽对土壤肥力及其林木生长的影响[J].林业科学,1987,23(4):289-297.
[2] 黄成标,曹继钊,吴庆标,等.秃杉林与杉木连栽林的土壤理化性质及林木生长量比较[J].林业科学,2010,46(4):1-7.
[3] 张鼎华,叶章发,范必有,等.抚育间伐对人工林土壤肥力的影响[J].应用生态学报,2001,12(5):672-676.
[4] 吴蔚东,张桃林,孙 波,等.人工杉木林地有机物和养分库的退化与调控[J].土壤学报,2000,37(1):41-49.
[5] 孙启武,杨承栋,焦如珍.江西大岗山连栽杉木人工林土壤性质的变化[J].林业科学,2003,39(3):1-5.
[6] 牛小云,孙晓梅, 陈东升,等.日本落叶松人工林枯落物土壤酶活性[J].林业科学,2015,51(4):16-25.
[7] 郭 蓓,刘 勇,李国雷,等.飞播油松林地土壤酶活性对间伐强度的响应[J].林业科学,2007,43(7):128-133.
[8] 杨 涛,徐 慧,方德华,等.樟子松林下土壤养分、微生物及酶活性的研究[J].土壤通报,2005,37(2):253-257.
[9] 陈立新.落叶松人工林施肥对土壤酶和微生物的影响[J].应用生态学报,2004,15(6):1000-1004.
[10] 杨万勤,王开运.森林土壤酶的研究进展[J].林业科学,2004,40(2):152-159.
[11] 郝俊鹏,凌 宁,李瑞霞,等.间伐对马尾松人工林土壤酶活性的影响[J].南京林业大学学报:自然科学版,2013,37(4): 51-56.
[12] 成向荣, 徐金良,刘 佳,等.间伐对杉木人工林林下植被多样性及其营养元素现存量影响[J].中国农学通报,2014,30(4):17-22.
[13] 龚固堂,牛 牧,慕长龙,等.间伐强度对柏木人工林生长及林下植物的影响[J].林业科学,2015,51(4):8-15.
[14] 熊有强,盛炜彤,曾满生.不同间伐强度杉木林下植被发育及生物量研究[J].林业科学研究,1995,8 (4): 408-412.
[15] 徐金良,毛玉明,郑成忠,等.抚育间伐对杉木人工林生长及出材量的影响[J].林业科学研究,2014,27 (1): 99-107.
[16] 方 晰,田大伦,秦国宣,等.杉木林采伐迹地连栽和撂荒对林地土壤养分与酶活性的影响[J].林业科学,2009,45(12):65-71.
[17] 张 超,刘国彬,薛 萐,等.黄土丘陵区不同林龄人工刺槐林土壤酶演变特征[J].林业科学,2010,46(12):24-29.
[18] 李振高,骆永明,腾 应.土壤与环境微生物研究法[M].北京:科学出版社,2008.
[19] Singh S K,Rai J P N,Singh A.Influence of prevailing disturbances on soil biology and biochemistry of montane habitats at Nanda Devi Biosphere Reserve(NDBR). India during wet and dry seasons[J]. Geoderma,2011,162(3/4):296-302.
[20] Jimenez M D,de la Horra A M,Pruzzo L,etal. Soil quality;a new index based on microbiological and biochemical parameters[J]. Biology and Fertility of Soils,2002,35(4):302-306.
[21] 于海群,刘 勇,李国雷,等.油松幼龄人工林土壤质量对间伐强度的响应[J].水土保持通报,2008,28(3):65-70.
[22] 李国雷,刘 勇,甘 敬,等.飞播油松林地土壤酶活性对间伐强度的季节响应[J].北京林业大学学报,2008,30(2):82-88.
[23] 万忠梅,吴景贵.土壤酶活性影响因子研究进展[J]. 西北农林科技大学学报: 自然科学版,2005,33(6):87-92.
[24] 殷鸣放,周立君,毕刚蕊,等.带状间伐对长白落叶松人工纯林诱导复层林效果评价[J].东北林业大学学报,2013,41(5):20-24.
[25] Blanco J A,Imbert J B,Castillo F J. Nutrient return via litterfall in two contrastingPinussylvestrisforests in the Pyrenees under different thinning intensities[J]. Forest Ecology and Management,2008,256(11):1840-1852.
[26] Hynes H M,Germida J J. Relationship between ammonia oxidizing bacteria and bioavailable nitrogen in harvested forest soils of central lberta[J]. Soil Biology and Biochemistry,2012,46(1):18-25.
[27] 郑 伟,霍光华,骆昱春,等.马尾松低效林不同改造模式土壤微生物及土壤酶活性的研究[J].江西农业大学学报, 2010,32(4):743-751.
[28] 丁 菡,胡海波,王人潮.半干旱区土壤酶活性与其理化及微生物的关系[J],南京林业大学学报:自然科学版,2007,31(2):12-18.
[29] 王 笛,马风云,姚秀粉,等.黄河三角洲退化湿地土壤养分、微生物与土壤酶特性及其关系分析[J],中国水土保持科学,2012,10(5):94-98.
[30] 陈军军,侯 琳,李 银,等.秦岭松栎混交林土壤微生物及酶活性[J].东北林业大学学报,2014,42(3):103-106,111.
ImpactsofThinningonSoilEnzymesActivityandMicroorganismsinCunninghamialanceolataPlantation
DINGBo1,2,DINGGui-jie1,ZHAOXi-zhou1,YANGYong-zhang3
(1. College of Forestry/Institute for Forest Resources & Environment of Guizhou, Guizhou University, Guiyang 550025, Guizhou, China;2. General Station of Forestry Science and Technology Popularization of Guizhou Province, Guiyang 550001, Guizhou, China;3. Forestry Station of Rongjiang County, Rongjiang 557200, Guizhou, China)
ObjectiveIn order to understand the process and mechanism of soil restoration under different thinning intensities, and provide theoretical basis for management of plantation, the impact of thinning intensity on soil enzyme activity and microorganisms inCunninghamialanceolataplantation and the interaction between them were studied.Method18-year-oldC.lanceolataplantations in Rongjiang county of Guizhou province were studied with random block experiments. The soil enzyme activity and soil microorganisms under 4 different thinning intensities, TS0(no thinning (0.0%), 1 800 trees·hm-2), TS1(mild (16.7%), 1 500 trees·hm-2) and TS2(moderate (33.3%), 1 200 trees·hm-2) and TS3(severe (50.0%), 900 trees·hm-2) were analyzed, the correlation of soil microorganisms and soil enzyme activities were also revealed.ResultAfter 3 years’ thinning, both the enzyme activities and microorganism amounts in soil layer significantly increased, the differences in soil microbe amount and enzyme activity among different soil layers were significant, and the activities of soil catalase, phosphatase, urease and invertase significantly increased. The activities of catalase (15-30 cm and 30-45 cm), alkaline phosphatase (0-15 cm and 30-45 cm) and urease(30-45 cm)in treatment TS3were higher than that in other treatments, while the activities of the other enzymes in different soil layers and different intensities were higher in treatment TS2. The amount of bacteria was the most in each layer, followed by actinomyces and nitrifying bacteria. The amount of microorganisms in treatment TS2was more than that in other treatments. The activities of urease and catalase had very significantly positive correlation with the amounts of bacteria, fungi and digestion, while they were very significantly negative correlation with actinomycetes. The amount of ammonifying bacteria had negative correlation with hydrogen peroxide enzyme activity, and had positive correlation with urease activity. The activities of phosphatase had positive correlation with the amounts of bacteria, fungi and nitrifying bacteria, and had very significantly negative correlation with ammonifying bacteria amount, and had negative correlation with actinomycetes amount. The activities of invertase had very significantly positive correlation with the amount of bacteria, actinomyces, and ammonifying bacteria, and had positive correlation with amount of nitrifying bacteria, and had negative correlation with actinomycetes.ConclusionThe forest environment, light, temperature and the growth of vegetation were improved after thinning, and the soil enzyme activities and the amount of microorganisms increased. The general performances after 3 years’ thinning indicated that middle thinning intensity is the best in the management of near-matureC.lanceolataplantations and improvement of soil properties.
Cunninghamialanceolata; plantation; thinning intensity; soil microbes; soil enzyme
10.13275/j.cnki.lykxyj.2017.06.025
2016-08-16
贵州省重大专项(黔科合重大专项字[2012]6011号);贵州省林业重大专项(黔林科合[2011]重大0l号);贵州省农业科技攻关(黔科合NY字[2012]3027号)
丁 波(1981—),男,仡佬族,贵州凤冈人,博士研究生,高级工程师,主要从事人工林培育研究和林业科技推广工作.
* 通讯作者:丁贵杰(1960—),男,教授,博士生导师,主要从事人工林培育及生态学研究.
S791.27
A
1001-1498(2017)06-1059-07
徐玉秀)