共查询到20条相似文献，搜索用时 15 毫秒
1.
外源氮输入对土壤有机碳矿化和凋落物分解的影响 总被引：3，自引：0，他引：3
目前,由人类活动造成的陆地生态系统氮输入量已经远远超过了其自身的生物固氮,外源氮输入的增多已经并将继续对土壤有机碳矿化和凋落物分解产生影响。本文分析了国内外有关氮输入增多对土壤有机碳矿化和凋落物分解的影响及其机理:由于研究点环境状况不同,凋落物性质的差异和分解阶段的不同等原因,氮输入对土壤有机碳矿化的结果主要表现为抑制或促进作用;对凋落物分解的影响表现为促进、无影响和抑制三种效果,有关其作用机理还有待进一步深入研究。着重指出对于作为大气CO2"汇"的沼泽湿地,氮输入的增多能够对其碳"汇"功能产生影响,因此进行氮输入对湿地土壤有机碳矿化和凋落物分解方面的研究,对于探讨湿地碳循环对外源氮输入的响应及其机理非常重要。 相似文献
2.
Yiting He Yong Wang Yi Jiang Guoping Yin Shunping Cao Xiongsheng Liu Renjie Wang Zijian Wu Fengfan Chen 《Soil Use and Management》2023,39(1):92-103
Leaf litter decomposition transfers elements from litter to soils that are essential for regulating nutrient cycles in plantation ecosystems, especially carbon and nitrogen. However, soil carbon and nitrogen dynamics in response to tree litter management remains insufficiently researched. We conducted a one-year field experiment at a fast-growing sweetgum tree plantation to evaluate the effects of leaf litter management on soil available nutrients, respiration rate and nitrogen mineralization rate. Three leaf litter treatments were applied, which were: (1) natural input (control); (2) double input and (3) non-input. It was found that the double input treatment increased soil inorganic nitrogen and microbial biomass nitrogen, but had little effect on microbial biomass carbon, dissolved organic carbon or dissolved organic nitrogen compared with natural input. The non-input treatment caused dissolved organic carbon to decrease compared with natural input. The respiration rate increased in the double input treatment, with a positive priming effect observed. Soil net ammonification, nitrification and mineralization rates also increased in the double input treatment in specific seasons. Meanwhile, positive linear relationships between respiration rate and all nitrogen transformation rates were observed for all treatments. Soil temperature was found to be an important prediction factor for predicting the respiration rate and mineralization as seasonal variations, but not for litter-induced fluctuations. Soil water content and mineral nitrogen were the primary drivers of litter-induced change to the respiration rate, whereas mineral nitrogen and microbial biomass were primary drivers of mineralization change. These results suggest that changes in soil nitrogen mineralization rate are strongly associated with the soil respiratory process, resulting in a potentially strong plant–soil feedback mechanism. 相似文献
3.
Astrid Rita Taylor Anne Pflug Dagmar Schröter Volkmar Wolters 《European Journal of Soil Biology》2010,46(2):80-86
The effect of soil organisms on ecosystem processes strongly depends on the composition of the overall community. Community composition however undergoes constant shifts due to pronounced spatio-temporal patterns in biomass and abundance of individual fauna groups. On this background the present experiment aimed to assess the potential impacts of shifts in the biomass of a dominant soil fauna group (microarthropods) on total community composition and on ecosystem processes mediated by fauna or microbes (e.g. decomposition, nitrogen mineralization).Microcosms, filled with spruce litter, hosted soil fauna communities that either contained ambient microarthropod biomass (control) or two elevated levels of microarthropod biomass (1.5 and 2 fold increase), while initial microbial biomass and that of other faunal groups remained unaltered. After an incubation period of 2 months, the biomass of microorganisms and fauna groups as well as ecosystem process variables were determined.The increase in microarthropod biomass at the investigated levels induced changes in the faunal community; mainly via negative or positive feeding interactions between microarthropods and the affected animal groups (Enchytraeidae, Nematoda). The abundance and activity of microorganisms at lower trophic levels however remained unaffected by these alterations; buffering the effect of shifts in the community structure on ecosystem processes. 相似文献
4.
Extensive studies have been conducted to evaluate the effect of soil fauna on plant litter decomposition in terrestrial ecosystems. However, scholars have reported inconsistent results on the direction and magnitude of the soil fauna effect. We present a global synthesis of 75 papers that cover 197 plant species with 543 cases of plant litter decomposition experiments and soil fauna effects on plant litter decomposition. By using a boosted regression tree model (BRT), we aim to provide a synthesis of existing data that comprehensively and quantitatively evaluates how climate, plant litter quality, and study methods interact with soil fauna in affecting plant litter decomposition. Global average effect size (ES) is −0.426, which indicates a 35% lower decomposition rate when soil fauna is excluded by physical or chemical exclusion techniques. The final model explains 32.3% of the variation in ES. The predictors that substantially account for the explained variation include mean annual temperature (MAT, 37.1%), mean annual precipitation (MAP, 9.7%), phosphorus (12.4%), nitrogen (5.6%), and lignin content (5.5%). By contrast, the heterogeneity of the study duration and soil fauna exclusion technique have negligible contributions (each <5%). Log effect size strongly decreases with both MAT and MAP. Plant litters with high quality have stronger soil fauna effect because the log effect size is negatively related to nitrogen and phosphorus content and positively related to lignin content. Our analysis demonstrates the critical role of climate and plant litter quality in determining the soil fauna effect on plant litter decomposition in terrestrial ecosystems. However, the large unexplained variation (67.7%) in ES in the BRT model indicates undiscovered mechanisms underlying the soil fauna effect in our analysis. We call for further studies on this topic in the future. 相似文献
5.
Increasing plant species richness generally enhances plant biomass production, which may enhance accumulation of carbon (C) in soil. However, the net change in soil C also depends on the effect of plant diversity on C loss through decomposition of organic matter. Plant diversity can affect organic matter decomposition via changes in litter species diversity and composition, and via alteration of abiotic and/or biotic attributes of the soil (soil legacy effect). Previous studies examined the two effects on decomposition rates separately, and do therefore not elucidate the relative importance of the two effects, and their potential interaction. Here we separated the effects of litter mixing and litter identity from the soil legacy effect by conducting a factorial laboratory experiment where two fresh single root litters and their mixture were mixed with soils previously cultivated with single plant species or mixtures of two or four species. We found no evidence for litter-mixing effects. In contrast, root litter-induced CO2 production was greater in soils from high diversity plots than in soils from monocultures, regardless of the type of root litter added. Soil microbial PLFA biomass and composition at the onset of the experiment was unaffected by plant species richness, whereas soil potential nitrogen (N) mineralization rate increased with plant species richness. Our results indicate that the soil legacy effect may be explained by changes in soil N availability. There was no effect of plant species richness on decomposition of a recalcitrant substrate (compost). This suggests that the soil legacy effect predominantly acted on the decomposition of labile organic matter. We thus demonstrated that plant species richness enhances root litter-induced soil respiration via a soil legacy effect but not via a litter-mixing effect. This implies that the positive impacts of species richness on soil C sequestration may be weakened by accelerated organic matter decomposition. 相似文献
6.
The dominant pools of C and N in the terrestrial biosphere are in soils, and understanding what factors control the rates at which these pools cycle is essential in understanding soil CO2 production and N availability. Many previous studies have examined large scale patterns in decomposition of C and N in plant litter and organic soils, but few have done so in mineral soils, and fewer have looked beyond ecosystem specific, regional, or gradient-specific drivers. In this study, we examined the rates of microbial respiration and net N mineralization in 84 distinct mineral soils in static laboratory incubations. We examined patterns in C and N pool sizes, microbial biomass, and process rates by vegetation type (grassland, shrubland, coniferous forest, and deciduous/broadleaf forest). We also modeled microbial respiration and net N mineralization in relation to soil and site characteristics using structural equation modeling to identify potential process drivers across soils. While we did not explicitly investigate the influence of soil organic matter quality, microbial community composition, or clay mineralogy on microbial process rates in this study, our models allow us to put boundaries on the unique explanatory power these characteristics could potentially provide in predicting respiration and net N mineralization. Mean annual temperature and precipitation, soil C concentration, microbial biomass, and clay content predicted 78% of the variance in microbial respiration, with 61% explained by microbial biomass alone. For net N mineralization, only 33% of the variance was explained, with mean annual precipitation, soil C and N concentration, and clay content as the potential drivers. We suggest that the high R2 for respiration suggests that soil organic matter quality, microbial community composition, and clay mineralogy explain at most 22% of the variance in respiration, while they could explain up to 67% of the variance in net N mineralization. 相似文献
7.
Klaus Birkhofer Tim Diekötter Markus Fischer Stephanie Socher 《Soil biology & biochemistry》2011,43(10):2200-2207
Edaphic fauna contributes to important ecosystem functions in grassland soils such as decomposition and nutrient mineralization. Since this functional role is likely to be altered by global change and associated shifts in plant communities, a thorough understanding of large scale drivers on below-ground processes independent of regional differences in soil type or climate is essential. We investigated the relationship between abiotic (soil properties, management practices) and biotic (plant functional group composition, vegetation characteristics, soil fauna abundance) predictors and feeding activity of soil fauna after accounting for sample year and study region. Our study was carried out over a period of two consecutive years in 92 agricultural grasslands in three regions of Germany, spanning a latitudinal gradient of more than 500 km. A structural equation model suggests that feeding activity of soil fauna as measured by the bait-lamina test was positively related to legume and grass species richness in both years. Most probably, a diverse vegetation promotes feeding activity of soil fauna via alterations of both microclimate and resource availability. Feeding activity of soil fauna also increased with earthworm biomass via a pathway over Collembola abundance. The effect of earthworms on the feeding activity in soil may be attributed to their important role as ecosystem engineers. As no additional effects of agricultural management such as fertilization, livestock density or number of cuts on bait consumption were observed, our results suggest that the positive effect of legume and grass species richness on the feeding activity in soil fauna is a general one that will not be overruled by regional differences in management or environmental conditions. We thus suggest that agri-environment schemes aiming at the protection of belowground activity and associated ecosystem functions in temperate grasslands may generally focus on maintaining plant diversity, especially with regard to the potential effects of climate change on future vegetation structure. 相似文献
8.
Yolima Carrillo Becky A. Ball Michael S. Strickland Mark A. Bradford 《Pedobiologia》2012,55(4):185-192
There is increasing awareness of the importance of ecological legacies in contemporary ecosystem processes. Decomposition is regulated by a set of interacting hierarchically organized factors. As spatial and temporal scales decrease, decomposition is largely dependent on the quality of resources and the decomposer community, but whether and how these factors manifest via historical legacy effects is not well understood. We tested whether the history of plant litter inputs had short-term legacy effects on contemporary litter and soil organic matter carbon (C) and nitrogen (N) mineralization. Using a field/laboratory microcosm approach, we exposed soils to two litters of contrasting chemistry and, after adding fresh substrates, we monitored C and N dynamics. In a parallel experiment, we manipulated the soil community to reduce litter-history impacts on its composition and size to investigate whether the soil community could be an important contributor to legacy effects We found strong short-term litter legacy effects on contemporary litter and soil N mineralization, the duration of which was dependent on the contemporary substrate for decomposition. These strong effects were not consistent with the home field advantage phenomenon, as exposure to a specific litter did not favor the decomposition of the same litter when it was applied as a contemporary substrate. Reduction of the litter-history effects on soil biota decreased the impact of litter history on N immobilization, suggesting that plant litter impacts on the soil community may be an important component of plant litter legacies on N decomposition. In contrast to N, litter legacies appeared to be much less important for C decomposition, suggesting that legacy effects might uncouple contemporary C and N dynamics. 相似文献
9.
Summary The effects of different litter input rates and of different types of litter on soil organic matter accumulation and net N mineralization were investigated in plant communities dominated by Erica tetralix L. or Molinia caerulea (L.) Moench. Plots in which the litter on the soil had repeatedly been removed were compared with plots in the same plant community in which litter had been added to the soil. In another treatment, litter was removed and replaced by litter from the other plant community. Net N mineralization was measured in situ after 5 years. Less soil organic matter and soil N was found in plots in which litter had been removed, compared with control plots, or plots to which litter had been added, but these differences were significant for the Erica sp. soils only. Plots in which litter had been replaced and control plots did not differ significantly in the amount of soil organic matter. However, in both plant communities, the differences agreed with the faster decomposition rate of Molinia sp. litter compared with Erica sp. litter. The gravimetric soil moisture content was correlated positively with the amount of soil organic matter, both in the Erica sp. soils and the Molinia sp. soils. Net N mineralization rates (g N m-2) differed significantly between treatments for Erica sp. soils but no for Molinia sp. soils. For Erica sp. soils, net N mineralization rates increased with increasing amounts of soil organic matter and soil N. Replacing the litter with Molinia sp. litter (which differs in chemical composition) had no clear additional effect on the net N mineralization rate. 相似文献
10.
采用室内培养的方法研究杨-麦、杨-花生等不同复合经营模式下,杨树叶与农作物秸秆混合后对土壤碳、氮矿化及土壤微生物量的影响。结果表明:(1)单一模式中,花生叶处理的有机碳矿化累积量最大,花生茎秆、杨树叶处理次之,小麦秸秆处理最低。混合处理有机碳矿化累积量依次为杨树叶-花生叶>杨树叶-花生茎秆>杨树叶-小麦秸秆,且培养结束时,混合物表现出明显的促进作用;(2)土壤微生物量碳、氮与各残落物氮含量、C/N比存在显著的相关性;(3)杨树叶、小麦秸秆及其混合物处理的土壤矿质态氮含量均低于对照,而添加花生叶、花生茎秆以及它们与杨树叶的混合物使矿质态氮含量高于对照。试验说明杨-麦、杨-花生复合模式均能有效提高土壤微生物的生物量,调节碳的动态及氮的供应,而选择种植含氮量高的农作物更有利于促进残落物分解和养分归还,这对深入研究林-农复合系统的模式筛选、结构优化及可持续经营具有一定的现实意义。 相似文献
11.
12.
Interactions between plants, litter and microbes in cycling of nitrogen and phosphorus in the arctic
Estimated nutrient mineralization in northern nutrient-poor ecosystems, measured as differences in soil inorganic nutrients before and after a period of soil incubation in the absence of plants and litter, usually shows a discrepancy of much lower rates than plant nutrient uptake rates. In plots that had been pre-treated by 12 year of warming and fertilizer addition, we incubated soils together with litter and plants added and examined whether the absence of plants and litter in ‘traditional’ incubations could explain the discrepancy. The pre-treatment had no effect on nitrogen (N) mineralization but increased phosphorus (P) mineralization, while litter addition decreased N and increased P mineralization but without any effect on plant and microbial N and P sequestration. Incubations of soils with plants increased N mobilization to the soil inorganic plus plant pools several-fold as compared to the net mineralization in soils without plants. Hence, the presence of plants stimulated mobilization of the growth-limiting N. The growth-sufficient P was not affected by the presence of plants, however. Furthermore, increased plant and microbial N uptake correlated positively, which speaks against competition for plant available N from soil microbes in N-constrained ecosystems, at least during the time-span of 10 weeks the experiment lasted, and instead suggests facilitation. 相似文献
13.
The vertical distribution of soil macroarthropods has been poorly studied despite their importance in understanding the interrelationship between the surface litter and deeper soil layers. Analyzing macrofaunal assemblages in litter and mineral soil layers is especially relevant in soils of arid and semiarid areas, where the litter usually forms a discrete layer that remains separated from the mineral soil and supports a markedly different fauna. In order to analyze the degree of compartmentalization among litter and mineral soil communities, we studied the vertical distribution of macroinvertebrates in an arid area of Southeastern Spain. During 2 years, macroinvertebrates were sampled in the litter and mineral soil beneath shrubs, ant nest mounds and bare soil using cores to a depth of 50 cm. Results showed that macroinvertebrate richness, abundance and biomass decreased gradually with soil depth with small differences between microhabitats. Assemblage composition also varied with depth; an overall vertical stratification was observed, although effects of sampling period, especially in the winter, and microhabitats with higher litter accumulations on the similarity among assemblages were observed. Although the faunal assemblages of the litter and mineral soil habitats displayed some important differences in taxonomic and trophic composition, there were taxa inhabiting both habitats, acting as connectors between litter and the mineral soil. In addition, seasonal differences in the vertical distribution of detritivorous tenebrionid larvae indicate that this connection varies in time, emphasizing the importance of temporal variability in the connection between the surface layer and the below-ground soil. 相似文献
14.
土壤动物在土壤有机质形成中的作用 总被引：2，自引：1，他引：2
作为土壤生态系统重要组成部分的土壤动物,在土壤元素循环转化和迁移过程中发挥着重要的作用。土壤动物是凋落物分解的"微型粉碎机",通过体内"特殊转换器",影响土壤有机质的转化、腐殖质的形成。本文从土壤动物对地表枯落物分解入手,分析了影响土壤动物对凋落物分解的因素,土壤动物通过刺激土壤酶活性,与土壤微生物群落一起,加快土壤有机物的分解,促进土壤腐殖质的转化。旨在拓宽土壤动物生态功能,丰富土壤腐殖质形成机理学说,对保护土壤生物多样性、提高土壤地力、保障粮食安全具有重要的科学意义。 相似文献
15.
Lijbert Brussaard Mirjam M. Pulleman lise Oudraogo Abdoulaye Mando Johan Six 《Pedobiologia》2007,50(6):447-462
Over the last four decades, spanning David Coleman's career, and in no small measure thanks to him, soil ecologists have made tremendous progress in describing and understanding the overwhelming complexity of biological, biophysical and biochemical interactions in soil. These interactions shape the soil as a habitat for the soil food web and the vegetation and, thereby, regulate the two main life-supporting processes on Planet Earth: production and decomposition. Changes in decomposition and production processes are governed by (human-induced) changes in vegetation composition/cover, the amounts and quality of organic residues and (in)organic fertilizers entering the soil. Such modifications alter the physical environment and the soil biota. Hence, decomposition and production processes cannot be understood and/or manipulated without explicitly addressing the composition and activity of the soil food web. Using a conceptual model, we argue that quantitative understanding of biophysical interactions, in particular those between soil fauna and soil structure, are paramount to understanding biological and biochemical processes in soil and the availability of water and nutrients to plants. The need to increase the efficiency of crop production worldwide, to reverse soil degradation and to increase soil resilience will set the agenda for soil ecologists in the near future. 相似文献
16.
Minna-Liisa Rantalainen Leena Kontiola Hannu Fritze 《Soil biology & biochemistry》2004,36(12):1983-1996
The aim of this field experiment was to explore the combined effects of two factors potentially affecting the local composition of soil decomposer community: resource quality and habitat fragmentation. We created humus (habitat) patches with three different resource quality: (1) pure homogenised humus; (2) humus enriched with needle litter; and (3) humus enriched with needle and leaf litter. These patches were embedded either in a mineral soil matrix, thus representing fragmented habitat, or in natural forest soil, representing continuous (non-fragmented) habitat. The development of faunal (colonisations/extinctions of soil animal populations) and microbial communities in the patches was followed for 12 months. Our results partly supported the hypothesized strong influence of resource quality on the structure of local soil food webs: the abundances of practically all groups of soil fauna, together with biomass of fungi, were higher in the litter-enriched patches than in the pure humus patches. The manifestation and magnitude of the responses of fauna were, however, strongly affected by complex interactions between the characteristics (especially colonisation capacity) of the faunal group in question, habitat quality and time of sampling. In microarthropods and nematodes, the effect of resource quality cascaded up to the predatory level, rendering further support to the existence of strong bottom-up control in soil food webs. Contrary to our expectations, species richness of the communities was not unanimously affected by resource quality. Habitat fragmentation affected the communities only through different number and identity of patch-colonising species in the fragmented and continuous habitat: fragmentation induced no extinctions of species during the experiment at any resource quality level. Consequently, the results indicate that resource quality is more important factor than habitat fragmentation in determining the local structure of communities in soils. On the other hand, colonisation capacities of soil organisms appear to set limits to the exploitation of local resources. 相似文献
17.
Soil food webs cycle nutrients and regulate parasites and pathogens, services essential for both agricultural productivity and ecosystem health. Nematodes provide useful indicators of soil food web dynamics. This study was conducted to determine if nematode soil food web indicators and crop yield can be enhanced by combinations of cover crops in a conservation tillage system. The effects of three cover crop treatments (vetch/pea, oat/wheat and oat/wheat/pea/vetch) with low, medium and high C:N and a bare fallow control were investigated in Davis, CA. Nematode fauna, soil properties and plant productivity were measured. Soil food web indices, including the Enrichment Index (EI), Structure Index (SI), Basal Index (BI), and Channel Index (CI), based on the composition of nematode assemblages, were calculated to infer soil food web condition. Cover cropped tomato/corn rotations had twice the number of enrichment opportunist bacterial feeding nematodes, active participants in nitrogen mineralization, than fallowed tomato/corn rotations (opportunist bacterial feeders = 163 versus 98). In winter fallowed plots food webs were basal, common in disturbed, nutrient-poor conditions (BI = 37). Total number of enrichment opportunist nematodes, soil NH4-N levels, and inferred nitrogen mineralization, were higher in cover crop treatments with low to mid C:N ratios. Omnivore and predator nematodes were scarce, averaging less than 6 nematodes 100 g?1 in all treatments. In year one, plant productivity was highest after fallow. In contrast, in year two productivity was highest after cover crops with high nitrogen content and productivity significantly correlated with the structure of the soil fauna. Monitoring the abundance of enrichment opportunists may provide managers with a new tool to evaluate soil food web nitrogen mineralization and plant productivity. 相似文献
18.
Phenol oxidase, peroxidase and organic matter dynamics of soil 总被引：2，自引：0，他引：2
Robert L. Sinsabaugh 《Soil biology & biochemistry》2010,42(3):391-404
Extracellular enzymes mediate the degradation, transformation and mineralization of soil organic matter. The activity of cellulases, phosphatases and other hydrolases has received extensive study and in many cases stoichiometric relationships and responses to disturbances are well established. In contrast, phenol oxidase and peroxidase activities, which are often uncorrelated with hydrolase activities, have been measured in only a small subset of soil enzyme studies. These enzymes are expressed for a variety of purposes including ontogeny, defense and the acquisition of carbon and nitrogen. Through excretion or lysis, these enzymes enter the environment where their aggegrate activity mediates key ecosystem functions of lignin degradation, humification, carbon mineralization and dissolved organic carbon export. Phenol oxidases and peroxidases are less stable in the environment than extracellular hydrolases, especially when associated with organic particles. Activities are also affected, positively and negatively, by interaction with mineral surfaces. High spatiotemporal variation obscures their relationships with environmental variables and ecological process. Across ecosystems, phenol oxidase and peroxidase activities generally increase with soil pH, a finding not predicted from the pH optima of purified enzymes. Activities associated with plant litter and particulate organic matter often correlate with decomposition rates and potential activities generally increase with the lignin and secondary compound content of the material. At the ecosystem scale, nitrogen amendment alters the expression of phenol oxidase and peroxidase enzymes more broadly than culture studies imply and these responses correlate with positive and negative changes in litter decomposition rates and soil organic matter content. At the global scale, N amendment of basidiomycete-dominated soils of temperate and boreal forest ecoystems often leads to losses of oxidative enzyme activity, while activities in grassland soils dominated by glomeromycota and ascomycetes show little net response. Land use that leads to loss of soil organic matter tends to increase oxidative activities. Across ecosystems, soil organic matter content is not correlated with mean potential phenol oxidase and peroxidase activities. A multiple regression model that includes soil pH, mean annual temperature, mean annual precipitation and potential phenol oxidase activity accounts for 37% of the variation in soil organic matter (SOM) content across ecosystems (n = 63); a similar model for peroxidase activity describes 32% of SOM variance (n = 43). Analysis of residual variation suggest that suites of interacting factors create both positive and negative feedbacks on soil organic matter storage. Soils with high oxygen availability, pH and mineral activity tend to be substrate limited: high in situ oxidative activities limit soil organic matter accumulation. Soils with opposing characteristics are activity limited: low in situ oxidative activities promote soil organic matter storage. 相似文献
19.
R. P. Griffiths E. R. Ingham B. A. Caldwell M. A. Castellano K. Cromack Jr 《Biology and Fertility of Soils》1991,11(3):196-202
Summary Specialized ectomycorrhizal fungi form dense mats in forest soils that have different enzyme levels, higher respiration rates, more biomass, different soil fauna, and different soil chemistry compared with adjacent soils not obviously colonized by these mats. In this study, mats formed by two genera of fungi collected in three locations were compared with a wide range of measurements. Per cent moisture, pH, chloroform fumigation-flush C, anaerobic N mineralization, exchangeable ammonium, and respiration, N2 fixation, and denitrification rates were compared between soils or litter colonized by ectomycorrhizal mat-forming fungi and adjacent non-mat material. Significant differences were observed between the two genera of mat-forming fungi and also between mats formed primarily in mineral soil and those formed in litter. These differences suggest that different mat-forming fungi perform different functions in forest soils and that these fungi function differently in mineral soil compared with litter.Published as Technical Paper 9496, Oregon Agricultural Experiment Station 相似文献
20.
湿地生态系统土壤氮素矿化过程研究动态 总被引：4，自引：2，他引：4
土壤氮素的矿化过程与土壤供氮能力及氮素损失密切相关,其对于氮素生物地球化学过程的生态意义重大。本文综述了当前湿地土壤氮素矿化过程的研究方法、模型表征以及影响因素的研究动态。氮素矿化过程的研究主要集中在净矿化作用方面,而其研究模型又主要包括矿化动力学模型、热力学模型和环境效应模型。影响湿地土壤氮素矿化过程的因素主要包括湿地气候条件、水文条件、土壤理化性质、枯落物性质、土壤生物区系及人类活动等。今后研究的重点应包括:(1)氮素矿化过程的驱动机制与驱动因素;(2)概念模型与应用模型的表征;(3)全球变暖、降水改变以及人为碳、氮输入对矿化过程的影响;(4)人类活动在湿地土壤氮素矿化过程中的作用。 相似文献