Abstract: Two perennial legumes (hairy vetch and white clover) and two perennial grasses(ryegrass and bluegrass) were sown in inter-rows of apple orchard in Weibei dryland. Soil samples were taken from 0-100 cm soil layers to study the effects of planting grasses on various soil organic carbon fractions and soil microbial community with clean tillage as control. Results showed that planting grasses could significantly increase soil total organic carbon contents, particulate organic carbon contents, light fraction organic carbon contents, readily oxidizable organic carbon contents, dissolved organic carbon contents and microbial biomass carbon contents in 0-40 cm soil layers. The contents of soil organic carbon fractions in perennial legume were mostly higher than perennial grass. Soil total organic carbon contents of perennial legume and perennial grass increased 1.2 g/kg and 0.9 g /kg per year in 0-20 cm soil layers, respectively. The AWCD, Shannon index (H) and Richness index (S) in the planting grass treatments were higher than the clean tillage, in which the microbial activity of perennial legume was more higher. Therefore, growing grasses could improve soil organic carbon contents, diversities of soil microbial community, the utilization rate of carbon source and richness of soil microbial community, in which perennial legumes (hairy vetch and white clover) increased more significantly.

摘要：在渭北旱地苹果园行间播种毛苕子（Vicia villosa）、白三叶（Trifolium repens）、黑麦草（Lolium perenne）和早熟禾（Poa pratensis），以清耕为对照，对0-100cm土层的土壤有机碳各组分及微生物群落功能多样性进行研究。结果表明，行间生草可显著增加0—40 cm土层土壤的总有机碳（TOC）、颗粒有机碳（POC）、轻质有机碳（LFOC）、易氧化有机碳（ROC）、可溶性有机碳（DOC）和微生物量碳（MBC），豆科牧草毛苕子和白三叶的各有机碳含量总体上高于禾本科牧草黑麦草和早熟禾。其中在0-20cm土层中，豆科牧草的TOC含量每年增加约1.2 g/kg，禾本科牧草每年增加约0.9 g/kg。生草处理的微生物群落碳源利用率（AWCD）、微生物群落Shannon 指数（H）和微生物群落丰富度指数（S）均高于清耕处理，其中豆科牧草的微生物活性更高。因此，生草可以提高土壤有机碳各组分的含量、土壤微生物群落碳源利用率、微生物群落的丰富度和功能多样性。豆科牧草毛苕子和白三叶提高效应更加明显。

The interplanting grass in orchard, planting the grasses between the fruit trees or in the all orchard, is a method of orchard management. It affects the orchard microclimate, soil property and fruit quality. The research progress in this field in China was reviewed and the suggests on the grass cultivation management, the selection of the proper grasses, the effects of the grasses on the trees were provided in order to serve as theoretical base for the further research and practice.

果园生草栽培是在果树行间或全园种植草本植物作为覆盖物的一种果园管理方法，我国果园生草研究起步较晚。果园生草栽培对果园小气候、土壤、果实品质等都有很大影响。对我国果园生草的研究现状作一综述，指出：草种的管理技术、草种与果树的配套研究、草种对果树根系影响的研究还不够完善。由此提出了今后研究需要解决的问题，为我国果园生草的进一步研究及应用提供一定的理论基础。

The influence of three different management patterns (planting white clover, interplanting apple seedlings and bare land) on soil physical and chemical characteristics was determined in the experiment. The results showed that planting white clover significantly increased the nitrate nitrogen and ammonium nitrogen concentrations of 0-20 cm soil layer, and was 1.73 and 1.93 times of the bare land (CK), respectively. Available potassium and organic matters were also increased by 35.08% and 52.38%. Interplanting apple seedlings had no significant influence on concentrations of nitrate nitrogen and ammonium nitrogen in topsoil, while it made available potassium concentration increase by 48.61% compared to CK. However, the soil water content under planting white clover treatment decreased 25.27%, and the competition for water between grass and trees appeared. Thus, we suggested that the span of growing grass in cherry orchards in Tianshui area should be less than 3 years and then the soil should be cultivated and mulched for water retention.

本研究比较了樱桃（Cerasus pseudocerasus）园生三叶草（Trifolium repens)、间种苹果（Malus domestica)苗及清耕3种管理模式对土壤理化性质的影响，结果表明，生三叶草能显著提高0~20 cm土层硝态氮、铵态氮含量，分别为清耕的1.73、1.93倍；速效钾、有机质含量比清耕分别提高了35.08%、52.38%。而间种苹果苗对表层土壤硝态氮、铵态氮、有机质含量无显著影响，仅速效钾含量比清耕提高了48.61%。但生三叶草处理使20~40 cm土层土壤含水量降低25.27%，出现与果树争水的矛盾，因此在天水地区樱桃园的管理中建议生草时间最长为3年，之后便实行清耕覆盖保墒。

本文对近年土壤微生物、土壤酶活性和土壤动物等土壤质量生物学指标研究成果进行了综合评述.土壤微生物是土壤有机组分和生态系统中最活跃的部分,被认为是最敏感的土壤质量生物学指标:微生物生物量代表参与调控土壤中能量和养分循环及有机物质转化所对应微生物的数量,但须结合多样性研究以弥补其无法反映土壤微生物组成和区系变化的缺陷;微生物群落组成和多样性动态反映土壤中生物类群的多变性和土壤质量在微生物数量和功能上的差异;土壤微生物活性体现在土壤微生物商、微生物呼吸和代谢商等方面,应考虑生物量大小与微生物种群活性间的相关关系以反映微生物种群内的差异.土壤酶活性具有极高时效性,在较短时间内就能反映出土壤质量的变化.土壤动物通常以种类的组成和数量,土壤动物区系的相对丰度、多样性或活性作为评价土壤生物质量的敏感指标.与土壤理化指标相比,土壤生物学指标更能对土壤质量的变化做出灵敏迅速的响应,因而被广泛地用于评价土壤质量.

Litters are the important component of forest ecosystem and play a key role in plant growth and ecosystem nutrient cycle. Soil microbial communities, as one of the driving factors of forest litter decomposition, can significantly influenced by composition of litters. To understand the responses of carbon metabolism diversity of soil microbial communities to the leaf litter composition plays a key role in the sustainable management of plantations. We designed a simulation experiment with flowerpots at the Ecological Benefit Monitoring Station of the Yangtze River Protection Forest, which is located in Hengyang County of southern Hunan Province, to determine the impacts of litter composition on carbon metabolism diversity of soil microbial communities. The litters of masson pine ( Pinus massoniana ), slash pine ( Pinus elliottii ), white oak ( Quercus fabri ) and blue Japanese oak ( Cyclobalanopsis glauca ), which are all the typical species of the southern China, were chosen as study species. With the BIOLOG method, the carbon metabolism diversity of soil microbial communities were studied during the decomposition of different leaf litters, including two single coniferous leaf litter treatments (masson pine and slash pine) and four coniferous and broadleaf mixed litter treatments (masson pine+ white oak, masson pine+ blue Japanese oak, slash pine+ white oak and slash pine+ blue Japanese oak). The results showed that: (1) the decomposition of coniferous and broadleaf mixed litter increased the carbon metabolic intensity, richness and diversity of soil microbial communities in comparison with the decomposition of single coniferous leaf litter. Soil microbial communities under the coniferous and broadleaf mixed litters had significantly different carbon metabolic patterns in comparison with those of the single coniferous leaf litter treatment. In comparison with those of single coniferous leaf litter treatment, soil microbial communities under the coniferous and broadleaf mixed litters had higher utilization ability for the following carbohydrates: Tween 80, Phenylethylamine, 4-hydroxy benzoic acid, D-mannitol, N-acetyl-D-glucosamine, D-galacturonic acid, γ-hydroxy butyric acid, D-glucosaminic acid and D, L-α-Glycerol phosphate. (2) At the early stage of litter decomposition carbon metabolic intensity, richness and diversity of soil microbial communities showed significantly negative correlation with the initial carbon-nitrogen ratio of litters. However, at the latter stage of litter decomposition carbon metabolic intensity of soil microbial communities correlated with the initial lignin-nitrogen ratio of litters negatively ( P P <0.05). (3) The species composition changes of litter significantly altered the intensity and diversity of carbon metabolism of soil microbial communities due to different carbon-nitrogen ratio, lignin-nitrogen ratio and phosphorus concentration. The coniferous and broadleaf mixed litter strengthened the carbon metabolic function of soil microbial communities in comparison with single coniferous leaf litter in hilly red soil region of southern China.

通过小盆模拟试验,用BIOLOG微平板培养的方法研究了南方红壤丘陵区典型物种马尾松和湿地松的凋落物分别与白栎和青冈的凋落物混合,与单一针叶凋落物分解时相比,针阔混合凋落物分解过程中土壤微生物群落功能多样性的差异。结果表明:(1)针叶和阔叶混合分解提高了土壤微生物群落碳代谢的强度、丰富度以及多样性,针阔混合凋落物分解时土壤微生物群落的碳源代谢方式与单一针叶分解时差异显著;(2)凋落物分解前期土壤微生物群落碳代谢强度、丰富度和多样性与凋落物初始C/N呈显著负相关, 分解后期土壤微生物群落碳代谢强度与凋落物初始木质素/N比呈显著负相关,碳代谢多样性与初始P含量呈显著正相关;(3)通过改变凋落物物种组成,进而改变凋落物元素组成(C/N、木质素/N和P),能显著影响土壤微生物群落的碳代谢强度和代谢多样性。在南方红壤丘陵区,针-阔叶混合的凋落物比单一针叶凋落物更有利于提高土壤微生物群落的功能。

Aims Soil microbes play a key role in material recycling and energy conversion in forest ecosystems. We studied the functional diversity of microbial communities and soil physical-chemical properties in order to illustrate variations of soil microbial community diversity along an elevational gradient in the Wuyi Mountains of China and influencing factors. Methods Evergreen broad-leaved forest (EBF), coniferous forest (CF), dwarf forest (DF) and alpine meadow (AM) were chosen as experimental sites along an elevation gradient in the National Natural Reserve of the Wuyi Mountains. We used Biolog EcoPlate analysis to study the functional diversity of microbial communities. Important findings There were significant differences in functional diversity of microbial communities in different soil elevations. The average well color development ( AWCD ), which directly reflected microbial activity and functional diversity, increased over time, while AWCD at the same soil depth gradually decreased along with increasing altitude and in the order of EBF > CF > DF > AM. The AWCD of different soil depths for the same vegetation type was in the order of 0–10 cm > 10–25 cm > 25–40 cm. The Simpson index, Shannon-Wiener index, richness index and McIntosh index of EBF were all higher than AM. There was variation among substrates used by soil microbial communities in different soil elevations. The substrate used in EBF was significantly higher than the substrate used in AM. The carbon sources mostly used by soil microbes were carbohydrates and carboxylic acids, followed by amino acids, phenolic acids and polymers; the lowest was amines. Principal component analysis (PCA) identified two factors in relation to carbon sources; they explained 75.27% and 16.14% of the variation. The carbon sources used by soil microbial communities were different among different vegetation types. Amino acids and amides were the two main carbon sources separating the two principal component factors. Soil microbial community diversity decreased along the elevation gradient and with soil thickness, and vegetative biomass, forest litter, soil nutrient, microzoon and plant roots might be the major factors controlling this diversity.

运用Biolog EcoPlate技术, 对武夷山不同海拔植被带(常绿阔叶林(EBF)、针叶林(CF)、亚高山矮林(DF)、高山草甸(AM))土壤微生物群落多样性差异进行了研究。结果表明: 不同海拔植被带土壤微生物群落功能多样性差异显著。土壤平均颜色变化率( AWCD )随培养时间延长而逐渐增加, 同一深度土层的 AWCD 值随海拔升高而逐渐降低, 大小顺序依次为EFB > CF > DF > AM。同一海拔植被带, 不同深度土层的 AWCD 值总体趋势依次为0–10 cm > 10–25 cm > 25–40 cm。土壤微生物群落Simpson指数、Shannon-Wiener指数、丰富度指数和McIntosh指数的总体趋势为EBF最高, CF和DF次之, AM最低。不同海拔植被带土壤微生物对不同碳源利用强度存在较大差异, 其中EBF利用率最高, AM利用率最低, 碳水化合物和羧酸类碳源是各海拔植被带土壤微生物的主要碳源。主成分分析结果表明, 从31个因素中提取的与碳源利用相关的主成分1、主成分2分别能解释变量方差的75.27%和16.14%, 在主成分分离中起主要贡献作用的是胺类和氨基酸类碳源。土壤微生物群落多样性随着海拔上升、土层加深而逐渐下降的原因, 可能是生物量、林分凋落物、土壤养分、微小动物、植物根系等多种因素共同作用的结果。

Effects of interspecific interactions on the growth and vertical distribution of both apple and white clover roots in apple-white clover intercropping system were studied from Mar.2009 to Sep.2010 by surveys of root biomass density,root length density and root surface area density using rhizobox methods.Results showed that interspecific interaction caused a positive effect on the growth of apple roots and a negative effect on the growth of white clover roots in apple-white clover intercropping system.Compared to sole cropping systems,the fine roots of both apple and white clover showed significant flexibility for apple-white clover intercropping system,and the amount of apple tree fine roots increased while the amount of white clover fine roots decreased.Vertical distribution patterns of both apple and white clover roots were not significantly influenced for apple-white clover intercropping systems compared with sole cropping system;however,there was obvious influence on its distribution proportion of different soil layers.Apple roots extended more into deep soil layers,while fine roots extended more deeply into soil layers than did thick roots.White clover fine roots extended more into surface soil layers and the vertical distribution of its thick roots had no significant affect in apple-white clover intercropping system.Conclusions were that the growth and vertical distribution of both apple and white clover roots were influenced due to interspecific interaction in apple-white clover intercropping system and the influences were different between fine roots and thick roots.

设置苹果( Malus demestica Borkh)和白三叶( Trifolium repens L.)单作与间作栽培处理,通过根箱试验研究种间互作对苹果、白三叶根系生长及其分布的影响。结果表明:种间互作导致苹果根系生长发育的正效应和白三叶根系生长发育的负效应;苹果、白三叶不同径级根系对种间互作的响应能力不同,细根比粗根表现出较强的可塑性;苹果细根占总根中的比例提高,而白三叶细根占总根中的比例则降低;种间互作对苹果、白三叶不同径级根垂直分布格局影响不明显,但对不同径级根在各土层中的分布比例产生了明显影响,苹果粗根和细根均有下移的趋势,细根下移的趋势更明显,而白三叶细根分布有上移的趋势,粗根则无明显变化。总之,种间互作对苹果、白三叶根系生长发育及其垂直分布产生了一定的影响,对不同径级根生长及其垂直分布的影响不同。

应国家苹果产业技术体系病虫害防控研究室要求,2011年初,我们选取陕西乾县梁山乡官地村一组赵上利的双矮苹果园,作为病虫害综合防治试验示范园,进行了为期1年的病虫害防治试验示范.

The effects of long-term fertilization on soil microbial communities of tea plantation were investigated by using BIOLOG techniques. Based on AWCD and community diversity index, the treatments with fertilizers resulted in increasing the abundance and diversity of soil microorganisms compared to the non-fertilizing treatment, the combination of inorganic and organic fertilizers showed the greatest effect followed by the application of organic matter while inorganic fertilizer had less effect. Long-term fertilization exhibited little influence on the common species of soil microorganisms according to the analysis of multiple indexes; however, application of organic fertilizer caused unevenly distribution of microbial communities in soil. After analyzing the principle components, it was found that the differentiation of soil microbial communities was mainly caused by carbohydrate and carboxylic acid. The improvement of soil fertility of tea plantation enhanced the microbial activity.

利用BIOLOG研究长期施肥后茶园土壤微生物群落功能多样性变化，结果表明：与清耕（CK）相比，各长期施肥处理AWCD值的变化速度(斜率)和最终能达到的 AWCD 值均有不同程度提高，其大小顺序为：DWY>DY>W>CK，可见施肥能不同程度提高微生物整体活性和丰富度，以有机无机肥配施效果最好。分析多样性指数表明：各处理对土壤常见微生物种类影响并不大，施有机肥使微生物群落均匀度有所降低。对碳源利用主成分起分异作用的主要是糖类和羧酸类物质。对 AWCD 值、多样性指数与土壤养分因子的相关性分析表明，在红壤茶园中土壤肥力提高有利于土壤微生物活性的提高。

A field experiment was conducted in Qinling-Bashan Region of Shaanxi province to investigate the influence of different fertilization treatments on soil microbial community, enzymes activities and soil nutrients in walnut orchards. There were three treatments, control (CK), conventional fertilizer treatment (T1) and bio-organic fertilizer treatment (T2). The effect of bio-organic fertilizer addition on microbial community metabolic profiles was analyzed with the Biolog (ECO Microplate) method. The results show that the average well color development (AWCD), Shannon index and richness index (S) of microbial community of the T2 treatment are all significantly higher than those of the T1 treatment. Utilization of six carbon source types by soil microbial community shows that the soil microbial community of the bio-organic fertilizer treatment enhances consumption of all the six carbon source types, which indicates the soil microbial community function is changed to some extent. Principal components analysis demonstrates that there are larger differences on utilization of carbon substrates by soil microbial community between the T2 and CK treatment and between the T1 and control, which indicates that the function of soil microbial community is modified by fertilization regimes. The soil sucrase, acidic phosphatase and dehydrogenase activities are improved significantly, and soil urease activity is changed significantly after the application of bio-organic fertilizer in comparison with the control, while soil catalase activities are similar between the two treatments. The contents of total soil nitrogen, total phosphorus, total potassium and available phosphorus of  the T2 treatment are significantly higher than those of the CK. In addition, soil pH is increased in the T2 treatment, and decreased in the T1 treatment in comparison with CK treatment. It is concluded that application of bio-organic fertilizer could not only change the function of microbial community, improve the activities  of  soil sucrase, acidic phosphatase, urease and dehydrogenase, but also increase the contents of soil nutrients.

采用大田试验，探讨生物有机肥对秦巴山区核桃园土壤微生物群落结构及其代谢、 酶活性和土壤理化性质的影响。结果表明，施入生物有机肥可改变土壤微生物群落结构，改变微生物对各大类碳源的利用，提高微生物碳源利用率、物种多样性和丰富度，常规施肥对土壤微生物群落结构影响不显著。生物有机肥可显著提高土壤蔗糖酶、酸性磷酸酶和脱氢酶活性，但对过氧化氢酶的影响不显著；常规施肥可提高土壤脲酶和脱氢酶活性，对其他酶活性没有显著影响。生物有机肥可显著提高土壤有机质， 全量氮、磷、钾和速效磷含量，提高土壤pH值，使土壤理化性质得到改善；常规施肥也可在一定程度上提高土壤养分含量，但其效果不如生物有机肥。

In this paper,  we used DGGE and Biolog to study the composition and function of soil microbial flora. Based on the UPGMA analysis,  the results of the DGGE indicate that T1(CK) and T2(single inorganic fertilizer treatment) have a similarity of 41% in wheat season,  T4（conventional NPK+ straw）and T5(conventional NPK+ straw + straw decomposing inoculants) have a similarity of 52%,  and T3(70%  conventional NPK + organic fertilizer) is clustered into one group alone. In corn season,  the similarity between T1 and T2 is 68%,  which is grouped into the first category,  the similarity between T4 and T5 is  78%,   which is grouped into the second category,  and T3 as the third category. These results show that there are similarities between different fertilizer treatments. Through a series of experiments of gel cutting,  sequencing and BLAST comparison,  we find that most of bacteria in the tested soils is uncultured and the main cultured bacteria belong to Bacillus and Paenibacillus. Using principal component analysis,  the results of Biolog show that T1 and T2 have similar microbial functions,  and T4 and T5 also have similar functions,  while T3 has different functions. Carbon source utilization characteristics of microbial communities have different results,  T5 and T4 have the strongest metabolic function,  and then T3 treatment,  and T2 and T1 have the minimum. Our study suggests that the composition and function of soil bacteria have certain consistency under different fertilizer treatments.

本研究采用DGGE和Biolog两种方法， 研究了五种不同施肥处理对土壤微生物区系组成和功能的影响。采用UPGMA对DGGE试验结果进行聚类分析得出，小麦季中不施肥对照（T1）和常规氮磷钾肥（T2）聚为一类，相似性为41%，常规氮磷钾肥+秸秆还田（T4）和常规氮磷钾肥+秸秆还田+秸秆腐熟剂（T5）聚为一类，相似性为52%，而70%常规氮磷钾肥+有机肥（T3）单独聚为一类；玉米季也得到类似的结果，只是T1和T2的相似性为68%，T4和T5相似性达78%，而T3依然归为一类，这说明不同施肥处理间土壤微生物区系存在相似性。经过切胶测序及BLAST比对，发现大多为不可培养细菌，可培养细菌中多为芽孢杆菌属和类芽孢杆菌属。Biolog试验采用主成份分析得出，T1和T2土壤微生物功能类似，T4和T5土壤微生物也具有相似的功能，而T3则单独分为一类。其中，T5和T4的土壤细菌群落对底物碳源的代谢活性最强，T3处理次之，T2和T1最低。通过这两种不同试验方法的分析可以看出，不同施肥处理对土壤微生物区系和功能的影响存在关联性。

【Objectives】As soil fertility in apple orchards is declined continuously and livestock waste organic manure sources are seriously inadequate, application of plant-derived organic manure is becoming one of important measures to improve orchard soil conditions. Effects of plant-derived organic matter and driving forces on soil microbial functional diversity in pot planted apple rootstock seedlings were studied by using the BIOLOG microplate technique. The functions of glucose, urea and earthworm in the plant-derived organic matter transformation process to soil carbon pool were explored, which could provide a reference for revealing evolution mechanism of orchard soil quality.【Methods】2a Malus baccata (L.) Borkh seedlings were planted in apple orchard soils (0-20 cm) mixed with chopped apple branches, corn stalks and orchard weeds. The urea, glucose and earthworms were added into the pots. The soil microbial community diversities were analyzed by the BIOLOG technique. Soil extracts of different treatments were cultured in BIOLOG ecological test plates. The diversity indexes were calculated using microplate optical density values at 96 h. Substrate richness (S) is the number of different substrates used by the community (counting all positive OD readings). Shannon’s diversity index is the ratio of the corrected absorbance value of each well to the sum of absorbance value of all wells. Substrate evenness (E) is a measure of the uniformity of activities across all substrates. Simpson’s Dominance indicates the dominance of certain species. The carbon substrate utilization differences of microbe were obtained by principal components analysis (PCA) of six carbon sources (carbohydrates, amino acids, carboxylic acids, polymers, aromatic and amines) in the BIOLOG microplates.【Results】The results show that the average well color development(AWCD) values are significantly affected by organic material types, small molecular organic compounds and numbers of earthworms. The AWCD values of the corn straw+ glucose+ 12 earthworms（T4）and the orchard weed with glucose（T9）are obviously higher than those of other treatments in the first 24 hour culture, and the activities of microbial communities are also higher and carbon sources are used earlier. The AWCD values show an exponential growth in the 24-96 hour culture, and then become flat after 120 hours. The treatments of the corn straw+ glucose+ 12 earthworms（T4）, the apple branches+ glucose+ 6 earthworm （T2）and the orchard weed with glucose（T9） have the steepest slopes and the highest microbial activities, and secondly for the corn straw+ urea+ 6 earthworm（T6）and the apple branches with urea（T1） treatments. The small molecular organic compounds have significant effects on the microbial community substrate richness（S） and Simpson’s dominance （Ds）, and the substrate richness （S） is the highest under the apple branches+ glucose+ 6 earthworm（T2）, while the Simpson’s dominance（Ds） is the highest under the corn straw+ glucose+12 earthworms（T4）. The Shannon index（H） and Substrate evenness （E）between different treatments are not significantly different. It is found that the differentiations of soil microbial communities are mainly caused by carbohydrate and polymers carbon. 【Conclusions】Compared with the straw and weeds treatments, the microbial diversity of the branches treatments is high. The glucose provides  carbon sources which can be used rapidly by microbe, and the microbial functional diversity is significantly increased. The effect of earthworm activity on the microbial functional diversity is less  compared with the glucose. The urea has little effects on the microbial functional diversity, while the combination of urea and glucose could improve the microbial diversity.

【目的】苹果园土壤肥力持续下降，禽畜废弃物肥源严重不足，施用植物源有机肥成为生产中改善果园土壤状况的重要措施之一。本试验利用BIOLOG微平板技术研究了盆栽条件下添加植物源有机物料及其腐殖化过程驱动因子对果园土壤微生物群落多样性的影响，探讨葡萄糖、 尿素和蚯蚓在植物源有机物料向土壤碳库转化中的作用，为揭示果园土壤质量的演变机制提供参考。【方法】取苹果园0—20 cm土层土壤，与苹果枝条、 玉米秸秆和果园杂草粉碎物混合，栽植2a生苹果砧木山定子幼苗，分别添加尿素、 葡萄糖和蚯蚓，利用BIOLOG微平板技术进行土壤微生物群落多样性分析。不同处理的土壤浸提液在 BIOLOG生态测试板中培养，取培养96 h时微平板光密度值进行多样性指数计算，分别用丰富度指数S 表示被微生物群落利用的基质数量，多样性指数表示反应孔与对照孔光密度值之差和整块板总差的比值，均匀度指数 E表示可培养微生物的种类均匀度，优势度指数Ds用于评估某些最常见种的优势度。对土壤微生物群落利用BIOLOG微平板中六类碳源（碳水化合物类、 氨基酸类、 羧酸类、 多聚物类、 芳香族类和胺类）的情况进行主成分分析，明确不同处理微生物对碳源利用能力的差异。【结果】有机物料种类、 小分子有机物和蚯蚓数量均对平均吸光值（AWCD值）有显著影响，在培养0~24 h，玉米秸秆+葡萄糖+12条蚯蚓（T4）和果园杂草+葡萄糖（T9）处理的AWCD值明显高于其他处理，微生物群落的活性较强，碳源开始利用较早。2496 h时，AWCD呈指数增长，120 h后趋于平缓，以玉米秸秆+葡萄糖+12条蚯蚓（T4）、 苹果枝条+葡萄糖+6条蚯蚓（T2）、 果园杂草+葡萄糖（T9）处理斜率最大，其次为玉米秸秆+尿素+6条蚯蚓（T6）和苹果枝条+尿素（T1）处理； 小分子有机物种类对微生物群落丰富度指数（S）和优势度指数（Ds）的影响显著，丰富度指数（S）以苹果枝条+葡萄糖+6条蚯蚓（T2）最大，优势度指数（Ds）以玉米秸秆+葡萄糖+12条蚯蚓（T4）最大，各处理的多样性指数（H）和均一度指数（E）差异不显著； 对碳源利用主成分起分异作用的主要是碳水化合物类和多聚物类。【结论】与秸秆和杂草处理相比，苹果枝条处理土壤微生物群落多样性较丰富，加入葡萄糖为土壤微生物提供可迅速利用的碳源，微生物功能多样性也显著增加； 蚯蚓活动对微生物群落多样性的影响比葡萄糖小，尿素对微生物群落多样性的影响也较小，但同时添加尿素和葡萄糖有助于微生物多样性的增加。

土壤微生物是土壤生态系统的主要组成部分,而且不同的土壤具有不同的土壤微生物群落.影响土壤微生物多样性的因素很多,主要可以分为自然因素和人为因素.本文将从土壤微生物多样性的影响因素的两个方面阐述目前国内外土壤微生物多样性的研究现状.

Decomposition of forest litter and simultaneous release of bioelements is one of the fundamental pathway of the flow of nutrient and energy in forest ecosystems, and an important component of the global carbon budget. The aim of this review is to summarize the changes of nutrient and chemical components during the decomposition, the factors controlling litter decay rate and its measurement. Decomposition of plant litter refers to the physical and chemical processes involved in reducing litter to its elemental chemical constituents. It includes two stages. First, litter is broken down by detritivores to small pieces which can be chemically reduced. Second, through the activities of micro-organisms (bacteria and fungi) these small pieces of organic matter are further reduced and mineralized into basic inorganic molecules. Also the course of nutrient dynamics during decomposition often can occur in three sequential phases, including an initial nutrient release through leaching, a net immobilization of nutrients by decomposer microorganisms and nutrient release from the litter, usually at a rate paralleling mass loss. However, the pattern of immobilization and release varies among species and ecosystems, and any particular litter type may not show all three phases. Litter decomposition rates are controlled by climate, litter chemistry, and by soil organisms. Climate has a direct effect on litter decomposition due to the effects of temperature and moisture. However, as a result of the climatic control of soil formation and nutrient cycling, it is to be expected that climate also has an indirect effect through the climatic impact on litter chemistry. Actual evapotranspiration (AET) is used as an index for the climatic control on decomposition. Mean AET in the humid tropical region is higher than in both the temperate and the mediterranean region and this results in rapid decomposition of litter. Especially, decomposition of litter (including root litter) contributes about 70% to the total annual carbon flux. Thus, changes in AET due to global warming will affect the global carbon budget through effects on the decomposition pathway. At a global scale, litter chemistry is only of secondary importance in explaining variation in litter decomposition rates. N and P concentrations, C/N and C/P ratios, lignin concentration and lignin/N and lignin/P ratios are considered as primary litter chemistry parameters, of which the lignin/N ratio and P related parameters exert significant influence on litter decomposition rates in the tropics. However, there is no consistent chemical predictor of litter decomposability in the temperate region. Also, there are indications that the chemical control of litter decomposition depends on the phase of the decomposition process. Generally, readily decomposable carbohydrates are lost at the initial stage, subsequently the decay-resistant materials such as lignin and cellulose are accumulated. High initial N, P and K concentrations lead to high initial decay rates, but to low long-term litter decay. Thus, there is clearly a need for more long-term studies on the chemical control of litter decomposition rates in various climatic regions. In addition, physical and chemical properties of soils and microbial communities also affect litter decomposition. Litter bag represent the most standardized method for studying litter decomposition, but it has several limitations. Litter bag may alter decomposition rates by altering litter microclimate, hindering soil contact and excluding litter macrofauna. Nevertheless, litter bags allow comparisons among species and experimental manipulations. Currently, the three most widely used indices of litter decomposition rate in forest ecosystem are release rate of CO 2 , decay constant of k value and weight loss rate of litter. Despite intensive research in the last decade, uncertainties of litter decomposition in forest ecosystems still remain for further studies: long-term in situ observation; use of uniform methods to obtain comparable data; research on the mechanism of litter decay using models; the effects of global climatic changes on litter decomposition in forest ecosystems; and the assessment of management activities controls on the litter decay and nutrient release in forests.

系统评述森林凋落物的分解过程、凋落物分解及养分释放的影响因素、分解研究的方法等。森林凋落物的分解既有物理过程,又有生物化学过程,一般由淋溶、自然粉碎、代谢作用等共同完成。凋落物分解过程先后出现分解速率较快和较慢2个阶段,元素迁移一般呈现淋溶-富集-释放的模式。凋落物分解主要受气候、凋落物性质、微生物和土壤动物的影响,气候是最基本的影响因素,常用实际蒸散(actual evapotranspiration 简称AET)作为指标。凋落物分解速率呈明显的气候地带性,与温度、湿度等紧密相关。从全球尺度来讲,凋落物质量对分解速率的影响处于次要地位,但在同一气候带内因AET变化较小,则起了主导作用。N、P和木质素浓度、C/N、C/P、木质素与养分比值是常见的凋落物质量指标,其中C/N和木质素/N最能反映凋落物分解速率。凋落物化学性质对其分解的影响作用又与分解阶段有关。凋落叶中N、P、K初始浓度高使得初期分解较快,而后期分解放慢。土壤理化性质及微生物区系也将不同程度地影响凋落物分解。尼龙网袋法(litter bag method)操作简单,是野外测定森林凋落物分解速率最常用的方法。除此之外,缩微试验也得到了广泛应用。目前普遍采用的衡量凋落物分解速率大小的指标主要有CO 2 释放速率、凋落物分解系数( k 值)及质量损失率。在此基础上提出了指数衰减、线性回归等模型来模拟凋落物分解过程。尽管对凋落物分解在森林生态系统C、N、P循环、土壤肥力维持等方面已进行了较深入的研究,但未来研究应侧重以下方向:长期的定位观测;采用相对统一的研究方法,获得可比性强的数据进行综合;深化凋落物分解机理研究;探讨全球气候变化对森林凋落物分解的影响;评价营林措施(如林分皆伐、造林、施石灰和肥料等)对凋落物分解与养分释放的调节作用。