落叶松人工林土壤微生物含量的研究

通过土壤和凋落物层微生物含量的测定探讨了华北落叶松人工纯林，间伐抚育，混交林和二代连栽林地土壤细菌，真菌和放线菌的含量变化以及微生物在凋落物层，土层间的垂直分布状况，为研究落叶松人工纯林的潜在地力衰退问题提供了重要的科学依据。     

毛竹凋落物对阔叶林土壤微生物群落功能多样性的影响

林地凋落物分解在森林生态系统物质能量循环中有着重要地位,它是森林土壤养分的主要来源之一(蒋有绪,1981;曹群根等,1996).土壤微生物作为森林凋落物的主要分解者,其群落结构和功能以及微生物活性受到凋落物的影响(赵吉等,2002;Paul et al.,2005;Bragazza et al.,2006).     

三峡库区兰陵溪小流域3种林分类型土壤呼吸特征

In this study, the trenching method and infrared gas exchange analyzer were used to research the characteristics of soil respiration in 3 different types of stands including coniferous forest,broad-lea...     

杉木凋落物对土壤物理性质的影响

杉木凋落物归还林地供其再度吸收和利用是杉木人工林生态系统物质循环和能量流动的重要途径。虽然前人对杉木人工林、混交林凋落物的特性和养分循环进行了大量的实验与研究,并取得了一定的成果,对凋落物的特性与土壤养分循环有了较深的了解,但杉木凋落物对土壤各项物理性质影响的相关综合论述类文献较少。文章通过分析近年大量的研究成果和数据,运用对比、举例说明的方法阐述了杉木凋落物对土壤容重、孔隙度、通气性、水分、温度、团聚体等物理性质的影响,并对改善杉木人工林地的土壤性质进行了探讨。     

浅谈杉木人工林土壤微生物群落结构特征

指出了杉木人工林土壤微生物群落结构特征对杉木人工林的种植有着重要意义。基于此,分析了杉木人工林与土壤微生物群落结构特征的相关理论,从数量分布、垂直分布、季节性变化等不同角度论述了杉木人工林土壤微生物群落结构特征,为以后的研究工作奠定了理论基础。     

南亚热带不同树种人工林对土壤细菌群落多样性的影响

目的 探讨我国南亚热带地区不同树种人工林对土壤细菌群落多样性的影响,为该地区实施人工林生态系统适应性经营策略的树种选择提供土壤微生物生态学方面的科学依据。 方法 采用PCR-DGGE技术,比较分析位于广西凭祥市中国林业科学研究院热带林业实验中心的4个乡土树种（马尾松、红锥、米老排和火力楠）人工林和外来树种尾巨桉人工林土壤（0～20 cm）细菌群落的丰富度、多样性和均匀度,并探讨了土壤细菌群落多样性与土壤理化性质因子之间的相互关系。 结果 5种不同树种人工林土壤细菌群落多样性之间无显著差异（p > 0.05）,其土壤细菌群落多样性与土壤全氮和全磷呈显著正相关（p < 0.05）。 结论 从土壤细菌群落多样性看,在该地区营建乡土树种人工林与外来桉树人工林的效果无明显差异。     

微生物菌剂对小叶杨复垦区土壤理化性质和酶活性的影响

目的 探索不同微生物菌剂及配施方式对土壤理化性质和酶活性的影响,明确小叶杨与不同菌剂联合复垦技术对土壤的改良效果,为“植物 + 微生物菌剂”联合复垦技术应用提供理论参考。 方法 本研究采用丛枝菌根真菌（AMF）、哈茨木霉菌（TH）和胶质芽孢杆菌（BM）作为修复菌剂,并以小叶杨为复垦植被,设置单施、混施处理进行土壤复垦。通过测定土壤理化性质和酶活性来明确菌剂配施技术对该类型区土壤的改良效果。 结果 土壤含水量和有机质含量分别在BM单施与AMF单施处理组最高;pH值和电导率均以AMF + BM混施组最高;土壤酶活性与菌剂种类和配施方式密切相关,各菌剂处理组的酶活性得到了显著提高,AMF + BM处理的土壤酶综合指数最高,为0.84。菌剂配施促进了土壤养分和酶活性恢复,其中,AMF + BM处理的效果最佳,酶恢复指数为238.89%,养分恢复指数为178.15%。冗余分析显示,AMF + BM处理改善了土壤pH值、全P、过氧化氢酶、脲酶和土壤呼吸等指标。 结论 AMF与植物根际促生菌(PGPR)的配施在不同程度上改善了风蚀水蚀交错区的土壤理化性质,提高土壤酶活性;其中,AMF + BM处理效果最显著。     

赣西油茶人工林土壤微生物群落的多样性

为了解油茶林土壤微生物群落结构特征,揭示油茶林土壤微生物群落结构多样性变化特征对林龄和季节等环境因素的响应机制,为油茶林合理经营管理提供理论依据,以赣西地区新余市渝水区不同林龄油茶林24个土壤样品为研究对象,采用变性梯度凝胶电泳(PCR-DGGE)技术分析油茶林土壤细菌群落多样性。DGGE指纹图谱分析结果表明,油茶林土壤微生物类群的细菌多样性较丰富,各个样品的条带数目稳定分布在13~36条。10年龄油茶人工林细菌基因多样性较为丰富,集约经营10年龄油茶林的细菌物种数量多。细菌丰富度和Shannon-Wiener多样性指数在林龄变化上均表现为中龄林(2个10年龄)成熟林(30年龄、50年龄)幼龄林(1年龄、6年龄);其在季节变化上均呈一致的变化规律,为夏季秋、冬季春季。细菌16S rDNA的系统发育分析结果表明,大多数序列与未培养细菌的同源性较高,所有序列与数据库中16S rDNA序列的相似性在84%~99%。遗传关系研究得到主要的优势菌为泛菌属Pantoea sp.、肠杆菌属Enterobacter sp.。     

喀斯特原生乔木林和次生林土壤呼吸研究

研究喀斯特森林土壤呼吸对探索陆地生态系统碳循环有重要意义。对喀斯特原生乔木林和次生林土壤呼吸速率的非生长季动态变化及对温度变化的响应和不同凋落物处理下土壤呼吸的变化进行了研究,结果表明:喀斯特次生林和原生乔木林土壤呼吸速率非生长季动态变化与土壤温度、林内温度变化总体一致;两演替群落土壤温度能解释95.1%~96.8%,91.3%~92.8%的土壤呼吸变化。去除、添加凋落物处理对土壤呼吸影响有显著差异(P<0.05),分别使土壤呼吸降低了21.29%~54.03%和增加了13.79%~98.41%。不同土壤深度土壤呼吸的Q10值次生林为4.62~4.71、原生林为4.01~4.31。随着土壤深度的增加而增加,去除和添加凋落物处理引起土壤呼吸的Q10值不同,从大到小均表现为去除、对照、添加。两演替群落比较,土壤呼吸因小生境、森林植被不同而存在差异,次生林土壤呼吸速率高于原生乔木林,次生林呼吸速率与土壤温度的相关程度略高于原生乔木林,次生林土壤呼吸对温度的敏感性更强。     

林分组成对林下土壤pH及有机质含量变化的影响

以阜新地区油松+樟子松混交林和油松纯林的林下土壤为研究对象,通过研究不同林分组成下对土壤pH和有机质含量指标的变化,来探讨当地混交林林地土壤的特点。试验结果表明:土壤的pH随着土层的深度的增加而增加,但是还呈酸性;混交林各层土壤的pH显著高于纯林,对于土壤酸化有改善作用;土壤有机质含量变化是随着土层的深度的增加而降低,混交林各层土壤的有机质含量显著高于纯林,混交林有机质含量的提高能改善林地土壤质量。     

Effects of continuous nitrogen addition on microbial properties and soil organic matter in a Larix gmelinii plantation in China

Continuous increases in anthropogenic nitrogen(N) deposition are likely to change soil microbial properties, and ultimately to affect soil carbon(C) storage.Temperate plantation forests play key roles in C sequestration, yet mechanisms underlying the influences of N deposition on soil organic matter accumulation are poorly understood. This study assessed the effect of N addition on soil microbial properties and soil organic matter distribution in a larch(Larix gmelinii) plantation. In a 9-year experiment in the plantation, N was applied at100 kg N ha~(-1) a~(-1) to study the effects on soil C and N mineralization, microbial biomass, enzyme activity, and C and N in soil organic matter density fractions, and organic matter chemistry. The results showed that N addition had no influence on C and N contents in whole soil. However,soil C in different fractions responded to N addition differently. Soil C in light fractions did not change with N addition, while soil C in heavy fractions increased significantly. These results suggested that more soil C in heavy fractions was stabilized in the N-treated soils. However,microbial biomass C and N and phenol oxidase activity decreased in the N-treated soils and thus soil C increased in heavy fractions. Although N addition reduced microbial biomass and phenol oxidase activity, it had little effect on soil C mineralization, hydrolytic enzyme activities, d13 C value in soil and C–H stretch, carboxylates and amides, and C–O stretch in soil organic matter chemistry measured by Fourier transform infrared spectra. We conclude that N addition(1) altered microbial biomass and activity without affecting soil C in light fractions and(2) resulted in an increase in soil C in heavy fractions and that this increase was controlled by phenol oxidase activity and soil N availability.     

氮磷钾不同比例对油茶幼林根际土壤细菌群落结构的影响

本研究以3年生油茶幼林为研究对象,采用高通量测序技术对有机肥、氮磷钾不同比例的有机无机复合肥以及不施肥处理下的油茶根际土壤细菌多样性及群落结构进行分析.研究结果表明:5个处理中Y1处理的OTU和特有微生物数量为最高;各个处理优势细菌有所不同,CK、Y1、Y2的优势菌种为绿弯菌门,而Y3、Y4的优势菌种为放线菌门;群落物种丰富度指数(Chao1指数和ACE指数)表明,施肥能提高土壤细菌的丰富度,其中Y1处理的Chao1指数、Y4的ace指数分别比对照提高了19.2％、20.3％;AN、AK、TK是油茶幼林根际土壤优势细菌的主要影响因子,Y1处理下土壤细菌的丰度为所有处理中最高.研究结果揭示了氮磷钾不同比例对油茶幼林根际土壤细菌的群落结构的和影响,为油茶幼林施肥提供了理论依据.     

氮磷钾不同比例对油茶幼林根际土壤细菌群落结构的影响

本研究以3年生油茶幼林为研究对象,采用高通量测序技术对有机肥、氮磷钾不同比例的有机无机复合肥以及不施肥处理下的油茶根际土壤细菌多样性及群落结构进行分析.研究结果表明:5个处理中Y1处理的OTU和特有微生物数量为最高;各个处理优势细菌有所不同,CK、Y1、Y2的优势菌种为绿弯菌门,而Y3、Y4的优势菌种为放线菌门;群落物种丰富度指数(Chao1指数和ACE指数)表明,施肥能提高土壤细菌的丰富度,其中Y1处理的Chao1指数、Y4的ace指数分别比对照提高了19.2％、20.3％;AN、AK、TK是油茶幼林根际土壤优势细菌的主要影响因子,Y1处理下土壤细菌的丰度为所有处理中最高.研究结果揭示了氮磷钾不同比例对油茶幼林根际土壤细菌的群落结构的和影响,为油茶幼林施肥提供了理论依据.     

米槠人工林土壤微生物群落组成对凋落物输入的响应

全球气候变化显著影响森林凋落物数量,进而会对土壤微生物群落造成影响。本研究以亚热带米槠人工林为研究对象,探究不同凋落物量输入处理(凋落物去除、凋落物加倍、对照)下,森林土壤微生物群落组成的变化。结果表明:与去除凋落物相比,凋落物加倍后0~10 cm土壤铵态氮(NH4^+-N)、硝态氮(NO3^--N)、全氮(TN)、有效磷(AP)含量分别显著增加了30.30%、49.66%、12.77%和13.90%。与对照相比,凋落物加倍与去除处理土壤微生物生物量碳(MBC)和氮(MBN)含量分别显著增加和下降(P<0.05),但凋落物加倍与去除处理间无显著差异。凋落物加倍处理下土壤丛枝菌根真菌(AMF)、革兰氏阳性菌[G(+)]、革兰氏阴性菌[G(-)]、放线菌(ACT)、真菌(F)丰度和总磷脂脂肪酸(TPLFA)含量分别比去除凋落物处理的土壤高68.35%、63.35%、82.65%、69.02%、40.56%和65.85%,而土壤革兰氏阳性菌与阴性菌比值、真菌与细菌比值则分别降低11.64%和26.67%。冗余度分析表明,铵态氮是影响该人工林土壤微生物群落组成的最主要环境因子。可见凋落物输入量变化改变了土壤养分有效性,进而显著影响了土壤微生物群落组成,这对进一步深入探究全球气候变化对亚热带森林土壤养分循环的影响具有重要意义。     

Effects of biochar and litter on carbon and nitrogen mineralization and soil microbial community structure in a China fir plantation

To investigate the effects of biochar addition(1 or 3%)to the soil of a China fir plantation with or without litter,we conducted a 90-day incubation experiment.We also studied the C and N dynamics and the microbial community structure of the soil.In soil without litter,the application of biochar at a rate of 3%significantly decreased CO2 emissions,while addition of 1%biochar had no effect.Biochar application did not affect the net N mineralization rate but significantly reduced the NH4?concentration after 90 days.In litter-enriched soil,biochar application had no significant effect on total CO2 emissions;however,application of 3%biochar significantly reduced the net N mineralization rate.Biochar application to soil with or without litter immediately reduced the dissolved organic carbon(DOC)concentration independent of the application rate,which was primarily due to sorption of DOC by the biochar.Phospholipid fatty acid analysis demonstrated that both concentrations of added biochar to soil(with or without litter)altered the soil microbial community structure at the end of incubation,although the effect of biochar was not as strong as the effect of time or litter application.The effect of biochar addition alone on microbial community structure was inconsistent over time.Litter added to soil significantly increased fungi and reduced Gram-positive bacteria.In the presence of litter,biochar applied at both 1%and 3%significantly increased(p<0.05)the proportion of actinomycete only at day 90.Our results indicate biochar as a potentially effective measure for C sequestration in the test soil of a China fir plantation,even in the presence of litter.     

间伐对侧柏人工林土壤微生物生物量碳、氮的影响

以徐州侧柏人工林为对象,研究了在弱度间伐（LIT,20％）、轻中度间伐（MIT1,40％）、中度间伐（MIT2,60％）和强度间伐（HIT,80％）下,林下土壤微生物生物量碳、氮在土壤表层（0 ～ 10 cm）和亚表层（10～20 cm）的变化.结果表明：不同间伐强度下,微生物生物量碳、氮含量均随着土层加深而减少.随着间伐强度增加,微生物生物量碳、氮总体变化趋势为先增加后降低,其中微生物生物量碳表现为MITl＞ LIT＞ HIT＞ MIT2,均与对照CK有显著差异（P＜0.05）;微生物生物量氮表现为MIT2＞ MITl＞ LIT＞ HIT,各处理间均表现出显著差异（P＜0.05）.间伐也使土壤微生物熵增加,尤以MIT2达到最大（2.63％）.研究表明,侧柏人工林经过2 a间伐,土壤微生物生物量碳、氮含量增加,在一定程度上使土壤碳库和氮库短期内出现不稳定趋势.     

Effects of elevated CO2 concentrations on soil microbial respiration and root/rhizosphere respiration in forest soils

The two main components of soil respiration, i.e., root/rhizosphere and microbial respiration, respond differently to elevated atmospheric CO₂ concentrations both in mechanism and sensitivity because they have different substrates derived from plant and soil organic matter, respectively. To model the carbon cycle and predict the carbon source/sink of forest ecosystems, we must first understand the relative contributions of root/rhizosphere and microbial respiration to total soil respiration under elevated CO₂ concentrations. Root/rhizosphere and soil microbial respiration have been shown to increase, decrease and remain unchanged under elevated CO₂ concentrations. A significantly positive relationship between root biomass and root/rhizosphere respiration has been found. Fine roots respond more strongly to elevated CO₂ concentrations than coarse roots. Evidence suggests that soil microbial respiration is highly variable and uncertain under elevated CO₂ concentrations. Microbial biomass and activity are related or unrelated to rates of microbial respiration. Because substrate availability drives microbial metabolism in soils, it is likely that much of the variability in microbial respiration results from differences in the response of root growth to elevated CO₂ concentrations and subsequent changes in substrate production. Biotic and abiotic factors affecting soil respiration were found to affect both root/rhizosphere and microbial respiration. __________ Translated from Journal of Plant Ecology, 2007, 31(3): 386–393 [译自: 植物生态学报]     

亚热带地区杉木人工林和阔叶林土壤活性有机质研究(英文)

土壤活性有机质对土壤养分如氮、磷、硫的生物化学循环具有作用,其含量和质量影响土壤的初级生产力。本试验在中国科学院会同森林生态实验站通过对第一代、第二代杉木纯林和地带性阔叶林土壤活性有机质组分的对比研究,发现杉木纯林土壤活性有机质的含量低于地带性阔叶林。第一代杉木纯林易氧化有机碳、微生物生物量碳、水溶性有机碳和水溶性碳水化合物的含量分别比第二代杉木纯林高35.9%、13.7%、87.8%和50.9%,比地带性阔叶林的低15.8%、47.3%、38.1%和30.2%。在调查的三种林地内,土壤微生物生物量碳和水溶性有机碳含量下降幅度较大,其次为水溶性碳水化合物,而易氧化有机碳的变化最小。同时,杉木纯林土壤养分等理化性质也比地带性阔叶林低。这表明在杉木纯林取代地带性阔叶林以及杉木纯林连栽后林地的土壤肥力降低。图3 表2参26。     

Effects of continuous nitrogen addition on microbial properties and soil organic matter in a <Emphasis Type="Italic">Larix gmelinii</Emphasis> plantation in China

Continuous increases in anthropogenic nitrogen (N) deposition are likely to change soil microbial properties, and ultimately to affect soil carbon (C) storage. Temperate plantation forests play key roles in C sequestration, yet mechanisms underlying the influences of N deposition on soil organic matter accumulation are poorly understood. This study assessed the effect of N addition on soil microbial properties and soil organic matter distribution in a larch (Larix gmelinii) plantation. In a 9-year experiment in the plantation, N was applied at 100 kg N ha^?1 a^?1 to study the effects on soil C and N mineralization, microbial biomass, enzyme activity, and C and N in soil organic matter density fractions, and organic matter chemistry. The results showed that N addition had no influence on C and N contents in whole soil. However, soil C in different fractions responded to N addition differently. Soil C in light fractions did not change with N addition, while soil C in heavy fractions increased significantly. These results suggested that more soil C in heavy fractions was stabilized in the N-treated soils. However, microbial biomass C and N and phenol oxidase activity decreased in the N-treated soils and thus soil C increased in heavy fractions. Although N addition reduced microbial biomass and phenol oxidase activity, it had little effect on soil C mineralization, hydrolytic enzyme activities, δ¹³C value in soil and C–H stretch, carboxylates and amides, and C–O stretch in soil organic matter chemistry measured by Fourier transform infrared spectra. We conclude that N addition (1) altered microbial biomass and activity without affecting soil C in light fractions and (2) resulted in an increase in soil C in heavy fractions and that this increase was controlled by phenol oxidase activity and soil N availability.     

洞庭湖区滩地杨树人工林土壤呼吸动态分析

采用LI-8100土壤呼吸仪对洞庭湖区滩地杨树人工林土壤呼吸日变化和季节变化进行野外测定,分析了土壤呼吸速率日变化和季节变化与温度和土壤含水量的相关性。结果表明：土壤呼吸速率的日变化和季节变化比较明显,其动态与地表温度和土壤温度（5cm）的变化大体一致,均表现为单峰型。夏季日变化最高出现在下午15：00—17：00,其它3个季节高峰值均出现在中午11：00—13：00,最低值都出现在凌晨5：00左右;季节变化呼吸速率大小依次是夏季〉春季〉秋季〉冬季。滩地杨树人工林地的土壤呼吸作用与地表温度和土壤温度（5cm）均有较好的指数关系,与土壤含水量呈线性关系,说明温度和水分是影响土壤CO2排放通量变化的关键因子。