Soil Stoichiometry Research Articles

Plant diversity and soil stoichiometry regulates the changes in multifunctionality during pine temperate forest secondary succession

The shift in ecosystem multifunctionality during ecosystem succession (years to decades) remains largely unexplored. In this study, we used a 120-year-old pine temperate forest chronosequence (1: 1–19 years, stage 2: 20–39 years, stage 3: 40–59 years, stage 4: 60–79 years, stage 5: 80–99 years, stage 6: 100–120 years) to evaluate the role that time plays in shaping ecosystem multifunctionality (nutrient cycling, carbon stocks, water regulation, decomposition and wood production), and found that, over the first century, ecosystem functioning gradually increased every ~50 years. Such a result was maintained for individual groups of ecosystem functions and services including nutrient cycling, carbon stocks, decomposition and wood production. Plant diversity and soil stoichiometry (C:N ratio) were the major environmental predictors for the changes in ecosystem multifunctionality during forest secondary succession. Plant diversity increased during ecosystem succession and was positively related to ecosystem multifunctionality. The soil C:N ratio decreased during ecosystem succession and was negatively related to multifunctionality. Our results suggest that increases in aboveground resource heterogeneity (higher plant diversity) and organic matter quality (lower soil C:N ratios) could help explain the increases in multifunctionality over a century of forest development. Our work illustrates the importance of time in shaping multifunctionality during the first century of ecosystem succession, and further provide important insights for the management of temperate forest ecosystems.

Understory Plant Functional Types Alter Stoichiometry Correlations between Litter and Soil in Chinese Fir Plantations with N and P Addition

Research Highlights: This study identifies the effect of nitrogen (N) and phosphorus (P) addition on stoichiometry correlations between understory plants and soil in subtropical Chinese fir plantations. Background and Objectives: Nitrogen and P are two nutrients limiting forest ecosystem production. To obtain more wood production, N and P are usually applied in plantation management. Changes in soil N and P will generally alter the stoichiometric characteristics of understory plants, which control carbon (C) and nutrient cycles between plants and soil. However, different correlations between plant and soil stoichiometry among functional groups of understory plants have not been investigated, which also impacted element cycling between plants and soil. Materials and Methods: Subtropical Chinese fir plantations were selected for N (100 kg ha−1 year−1) and P (50 kg ha−1 year−1) addition study. We collected fresh litter and the corresponding soil of four understory plants (Lophatherum gracile Brongn., Woodwardia japonica (L.f.) Sm., Dryopteris atrata (Kunze) Ching and Dicranopteris dichotoma (Thunb.) Berhn.) for study of C, N, and P stoichiometric ratios. Results: Nitrogen and P addition affected C, N, and P concentrations and stoichiometric ratios in litter and soil as well as correlations between litter and soil stoichiometric ratios. Understory plant species with different functional types impacted the correlations between plants and soil in C, N, and P stoichiometric ratios, especially correlations between litter C and soil C and N. Conclusions: Changes in soil N and P affect the stoichiometric ratios of understory plants. Functional groups impacted the correlation in C, N, and P stoichiometric ratios between plants and soil, indicating functional groups varied in their impacts on element cycling between plants and soil in plantations with exogenous nutrient addition, which should be considered in future management of plantations with intensive fertilization practice.

Different responses of soil element contents and their stoichiometry (C:N:P) to yak grazing and Tibetan sheep grazing in an alpine grassland on the eastern Qinghai – Tibetan Plateau’

The alpine grassland of the Qinghai–Tibetan Plateau has long been subjected to grazing by local livestock, yak and Tibetan sheep. Although there is plenty of evidence that grazing influences the vegetation community structure and functions, researches on how grazing of different livestock affects element contents in soil and their stoichiometry and how they relate to plant community remain inadequate in the region. We quantified the concentration and distribution of carbon (C), nitrogen (N) and phosphorus (P), and investigated the robustness of soil stoichiometry (C:N:P) under yak grazing and Tibetan sheep grazing through a manipulated grazing experiment on an alpine grassland. Our results showed that: (1) Yak grazing increased the soil total carbon content (STC) but decreased the soil total phosphorus content (STP), whereas Tibetan sheep grazing decreased STC but increased STP. Neither of the two livestock species had impact on the soil total nitrogen content (STN). (2) Yak grazing and sheep grazing had no impact on soil stoichiometry except for C:P. (3) Only STP and C:P were affected by the mixing ratio of yak to sheep. The plant biomass loss and the shifts in plant community structure may account for the opposite responses of STC and STP to yak grazing and sheep grazing, whereas the dung chemical property of different livestock species might also contribute to the response of STP. The higher soil C:N and lower soil N:P ratios indicated that plant growth may be limited more by N than by P in the region.

Biochar Fertilization Significantly Increases Nutrient Levels in Plants and Soil but Has No Effect on Biomass of Pinus massoniana (Lamb.) and Cunninghamia lanceolata (Lamb.) Hook Saplings During the First Growing Season

Previous studies have shown that biochar fertilization has profound effects on plant and fine root growth, but there is a lack of studies on how changes in plant and soil stoichiometry by biochar fertilization influence plant growth and root morphology. We investigated the effects of biochar fertilization on biomass, root morphology, plant nutrient concentrations, and the stoichiometry of plants and soil in a greenhouse experiment with Pinus massoniana (Lamb.) (PM) and Cunninghamia lanceolata (Lamb.) Hook. (CL) throughout the 2017 growing season immediately following biochar fertilization application. Four levels of biochar treatment were used, i.e., addition rates of 0 (control), 5 (low biochar), 10 (medium biochar), and 20 t ha−1 (high biochar). Biochar fertilization had no effect on biomass, fine root length, or fine root surface area. Biochar treatment, however, had significant effects on nutrient levels and their stoichiometry in both plants and soil. Detrended correspondence analysis suggested that increases in soil C:N, soil C:P, and soil N:P were associated with increases in plant nutrient levels, especially P concentration. Our results indicate that biochar fertilization prioritizes enhancing plant and soil nutrients over increasing height and diameter in the first growing season. A higher biochar fertilization dosage has a major influence on root morphology for PM and on P concentrations in the plant and soil for CL, probably through different growth characteristics and nutrient resorption rates. Further studies, particularly those considering long-term effects, are necessary before general recommendations regarding biochar application should be given.

Moss patch size and microhabitats influence stoichiometry of moss crusts in a temperate desert, Central Asia

Desert mosses, which are important stabilizers in desert ecosystems, are distributed patchily as biological soil crusts in arid lands. Patch size and microhabitats of moss are affected by human activities in deserts, such as grazing, oil exploration, and reclamation. Moss patches as a microecosystem, is a functional unit. It is not clear how patch size of moss influences the stoichiometry of moss and soil. We examined the effects of moss patches of different sizes on moss and soil stoichiometry, and moss growth strategies in different microhabitats. The dominant moss (Syntrichia caninervis Mitt.) of biological soil crusts in the Gurbantunggut Desert was selected to study carbon (C), nitrogen (N), and phosphorus (P) contents in moss patches. Soil inside and under the moss patches was analyzed from open areas and under the canopy of living shrubs. The C, N, and P stoichiometry of the moss and soil, and soil enzyme activities were measured. The effects of patch size on C, N, and P characteristics were microhabitat dependent. Moss N content in above-ground parts, moss C, N, and P contents in below-ground parts, and sucrase activity in soil under moss patches significantly increased with increase in patch size in open areas. Under the canopy of living shrubs, patch size had no significant influence on moss C, N, and P contents, soil nutrient contents, and soil enzyme activities. Patch size effects were stronger for moss and soil C, N, and P characteristics in open areas than those under the canopy of living shrubs. Moss N and P contents in above-ground parts were significantly higher than those in below-ground parts, whereas moss C:N and C:P ratios in above-ground parts were significantly lower than those in below-ground parts. Moss C, N, and P stoichiometry was weakly correlated with soil nutrient contents and enzyme activities. Structural equation modeling showed that the models for C, N, and P cycling differed between open areas and under the canopy of living shrubs. The effects of patch size on the multifunctionality of the moss microecosystem were regulated by microhabitats. Increase in patch size benefits moss growth more in open areas than under the canopy of living shrubs. Shrubs provide a protected environment for moss plants and drive moss growth. Above-ground parts of mosses host more functions essential for growth and photosynthesis than below-ground parts of moss patches in a temperate desert. Patch size accounted for positive effects of moss stoichiometry in open areas. Patch size may influence the ecological function of moss patches. Shrubs dominantly drive moss growth compared with patch size effects.

The Role of Field-Scale Management on Soil and Surface Runoff C/N/P Stoichiometry.

Agricultural runoff is an important contributor to water quality impairment. This study was conducted to evaluate the potential role of field-scale management on carbon (C), nitrogen (N), and phosphorus (P) stoichiometry in soils and runoff from agricultural fields. Cultivated and pasture fields at the Riesel watersheds in central Texas were used for this analysis, and nutrients were transformed to evaluate relative to the Redfield ratio (106 C/16 N/1 P). Using the Redfield ratio, all soil samples were P depleted relative to C and N. The majority of stormflow and baseflow runoff samples contained 9 to 19% Redfield N relative to C and P. Shifting from inorganic fertilizer application to poultry litter as a fertilizer source resulted in increased absolute C, N, and P concentrations in stormflow and baseflow runoff. Increasing rates of poultry litter application increased the Redfield P relative to Redfield C, whereas Redfield N remained relatively constant at roughly 9 to 11% in stormflow runoff from cultivated fields. This study shows how land use and management can affect C/N/P stoichiometry in stormflow and baseflow runoff.

Impact of desertification on soil and plant nutrient stoichiometry in a desert grassland

Grassland degradation resulting from desertification often alters the carbon (C), nitrogen (N) and phosphorus (P) cycles within grassland ecosystems. To estimate the effects of desertification on the C, N, and P concentrations and C:N:P stoichiometry of plants and soil, we examined C, N, and P concentrations in plant tissues (leaves, roots and litter) and soil across five degrees of desertification in the desert grassland of Ningxia, China (control, light, moderate, severe and very severe desertification stages). The C, N, and P concentrations and C:N:P stoichiometry of the leaves, roots and litter differed among the different desertification stages. Desertification resulted in opposing trends between the leaf N concentration and leaf C:N ratio. With the exception of the very severe desertification stage, the leaf N:P ratio decreased over the process of grassland desertification. The soil C, N, and P concentrations and soil N:P and C:P ratios decreased significantly along the grassland desertification gradient. In contrast, the soil C:N ratio remained relatively stable during desertification (10.85 to 11.48). The results indicate that desertification is unfavourable to C and N fixation and has a negative effect on the ecosystem structure and function of desert grassland.

Shrub modulates the stoichiometry of moss and soil in desert ecosystems, China

Desert mosses, which are important stabilizers in desert ecosystems, are distributed patchily under and between shrubs. Mosses differ from vascular plants in the ways they take up nutrients. Clarifying their distribution with ecological stoichiometry may be useful in explaining their mechanisms of living in different microhabitats. In this study, Syntrichia caninervis, the dominant moss species of moss crusts in the Gurbantunggut Desert, China, was selected to examine the study of stoichiometric characteristics in three microhabitats (under living shrubs, under dead shrubs and in exposed ground). The stoichiometry and enzyme activity of rhizosphere soil were analyzed. The plant function in the above-ground and below-ground parts of S. caninervis is significantly different, so the stoichiometry of the above-ground and below-ground parts might also be different. Results showed that carbon (C), nitrogen (N) and phosphorus (P) contents in the below-ground parts of S. caninervis were significantly lower than those in the above-ground parts. The highest N and P contents of the two parts were found under living shrubs and the lowest under dead shrubs. The C contents of the two parts did not differ significantly among the three microhabitats. In contrast, the ratios of C:N and C:P in the below-ground parts were higher than those in the above-ground parts in all microhabitats, with significant differences in the microhabitats of exposed ground and under living shrubs. There was an increasing trend in soil organic carbon (SOC), soil total nitrogen (STN), soil available phosphorous (SAP), and C:P and N:P ratios from exposed ground to under living shrubs and to under dead shrubs. No significant differences were found in soil total phosphorous (STP) and soil available nitrogen (SAN), or in ratios of C:N and SAN:SAP. Higher soil urease (SUE) and soil nitrate reductase (SNR) activities were found in soil under dead shrubs, while higher soil sucrase (STC) and soil β-glucosidase (SBG) activities were respectively found in exposed ground and under living shrubs. Soil alkaline phosphatase (AKP) activity reached its lowest value under dead shrubs, and there was no significant difference between the microhabitats of exposed ground and under living shrubs. Results indicated that the photosynthesis-related C of S. caninervis remained stable under the three microhabitats while N and P were mediated by the microhabitats. The growth strategy of S. caninervis varied in different microhabitats because of the different energy cycles and nutrient balances. The changes of stoichiometry in soil were not mirrored in the moss. We conclude that microhabitat could change the growth strategy of moss and nutrients cycling of moss patches.

A Mechanistic Model of Microbially Mediated Soil Biogeochemical Processes: A Reality Check

Present gaps in the representation of key soil biogeochemical processes such as the partitioning of soil organic carbon among functional components, microbial biomass and diversity, and the coupling of carbon and nutrient cycles present a challenge to improving the reliability of projected soil carbon dynamics. We introduce a new soil biogeochemistry module linked with a well‐tested terrestrial biosphere model T&C. The module explicitly distinguishes functional soil organic carbon components. Extracellular enzymes and microbial pools are differentiated based on the functional roles of bacteria, saprotrophic, and mycorrhizal fungi. Soil macrofauna is also represented. The model resolves the cycles of nitrogen, phosphorus, and potassium. Model simulations for 20 sites compared favorably with global patterns of litter and soil stoichiometry, microbial and macrofaunal biomass relations with soil organic carbon, soil respiration, and nutrient mineralization rates. Long‐term responses to bare fallow and nitrogen addition experiments were also in agreement with observations. Some discrepancies between predictions and observations are appreciable in the response to litter manipulation. Upon successful model reproduction of observed general trends, we assessed patterns associated with the carbon cycle that were challenging to address empirically. Despite large site‐to‐site variability, fine root, fungal, bacteria, and macrofaunal respiration account for 33%, 40%, 24%, and 3% on average of total belowground respiration, respectively. Simulated root exudation and carbon export to mycorrhizal fungi represent on average about 13% of plant net primary productivity. These results offer mechanistic and general estimates of microbial biomass and its contribution to respiration fluxes and to soil organic matter dynamics.

Spatial distribution and stoichiometry of soil carbon, nitrogen and phosphorus along an elevation gradient in a wetland in China

AbstractDespite extensive studies on how environmental factors influence plant nutrient distribution and stoichiometry, it remains unclear how elevation affects soil distribution and stoichiometry. Here, patterns of the spatial distribution and stoichiometry of soil carbon (C), nitrogen (N) and phosphorus (P) were studied (with 123 soil samples) along a small‐scale elevation gradient in the wetland of East Dongting Lake, China. Plant nutrient concentrations (C, N and P), soil stoichiometry (C:N, C:P and N:P ratios) and their relations with other soil properties were analysed. In addition, the spatial distributions of plant nutrient concentrations and stoichiometry were evaluated geostatistically with regression kriging, entailing estimation of regression parameters by generalized least squares and ordinary kriging of the residuals. Soil C, N and P concentrations and stoichiometry had moderate to strong spatial dependence, and the ratios of C:P and N:P had similar patterns of distribution to soil organic carbon (SOC) and total nitrogen (TN). The SOC, TN, C:N, C:P and N:P ratios increased with increasing elevation, whereas total phosphorus (TP) showed no marked change. Furthermore, SOC, TN, C:N, C:P and N:P decreased considerably with increasing duration of submergence, soil moisture and pH. Therefore, elevation appeared to influence the distribution of plant nutrients and stoichiometry as a result of changing soil moisture and duration of submergence.Highlights Study showed how elevation influences plant nutrient distribution and stoichiometry. Regression kriging was used to map soil properties. Plant nutrients and stoichiometry decreased with increasing duration of submergence. Elevation affected nutrient distribution because of soil moisture and water regime.

Soil structural degradation and nutrient limitations across land use categories and climatic zones in Southern Africa

AbstractAlthough soil degradation is a major threat to food security and carbon sequestration, our knowledge of the spatial extent of the problem and its drivers is very limited in Southern Africa. Therefore, this study aimed to quantify the risk of soil structural degradation and determine the variation in soil stoichiometry and nutrient limitations with land use categories (LUCs) and climatic zones. Using data on soil clay, silt, organic carbon (SOC), total nitrogen (N), available phosphorus (P), and sulfur (S) concentrations collected from 4,468 plots on 29 sites across Angola, Botswana, Malawi, Mozambique, Zambia and Zimbabwe, this study presents novel insights into the variations in soil structural degradation and nutrient limitations. The analysis revealed strikingly consistent stoichiometric coupling of total N, P, and S concentrations with SOC across LUCs. The only exception was on crop land where available P was decoupled from SOC. Across sample plots, the probability (φ) of severe soil structural degradation was 0.52. The probability of SOC concentrations falling below the critical value of 1.5% was 0.49. The probabilities of soil total N, available P, and S concentrations falling below their critical values were 0.95, 0.70, and 0.83, respectively. N limitation occurred with greater probability in woodland (φ = .99) and forestland (φ = .97) than in cropland (φ = .92) and grassland (φ = .90) soils. It is concluded that soil structural degradation, low SOC concentrations, and N and S limitations are widespread across Southern Africa. Therefore, significant changes in policies and practices in land management are needed to reverse the rate of soil structural degradation and increase soil carbon storage.

Litter-, soil- and C:N-stoichiometry-associated shifts in fungal communities along a subtropical forest succession

Suites of fungal adaptation to nutrient acquisition and allocation of vegetations are observed along forest succession gradients. However, the mechanisms behind seral shifts in plant-associated fungi need to be uncovered. To bridge this knowledge gap, the current study investigated the litter and soil chemical variables as well as the fungal community using high-throughput Illumina MiSeq sequencing along a 30a-100a succession gradient of a subtropical forest ecosystem in Xishuangbanna, southwestern China. Litter nitrogen (N) content changed consistently with fungal alpha-diversity and the relative abundances of functional guilds, such as saprotrophs and arbuscular mycorrhizal (AM) fungi. However, this trend was opposite to that observed for ectomycorrhizal (EcM) fungi and litter carbon (C) content. The total and water-soluble C and N contents as well as the C/N ratios in soil decreased with stand age, while the relative abundances of Rozellomycota, Chytridiomycota and lichens as well as the microbial C and N use efficiencies exhibited increasing trends across succession stages. Multivariate analysis and multiple linear regression showed that the seral shifts in fungal diversity and composition were closely related to the C:N stoichiometry of soil and litter. Specifically, the litter C content either negatively explained the alpha-diversity and saprotroph abundance or positively explained the abundance of EcM fungi. In contrast, the litter N content presented opposite trends. Further, the variances in the abundances of Rozellomycota and AM fungi were negatively explained by water-soluble C content but positively explained by water-soluble N content in the soil. These findings confirm that the replenishment and reduction of available nutrients are determined by plant-fungus interactions via the C:N stoichiometry of litter and soil along the forest chronosequence.

A comparison of C:N:P stoichiometry in soil and deadwood at an advanced decomposition stage

The aim of this study is to compare the C/N/P stoichiometry of deadwood among four tree species at different stages of decomposition. The way in which the relative concentrations of these elements in the soil are directly impacted by deadwood decomposition is also explored. First, hornbeam, alder, aspen and fir logs in different decomposition stages (III, IV and V) were selected and sampled. Second, the concentration and stoichiometry of carbon, nitrogen and phosphorous were established. Marked differences in C/N/P stoichiometry were observed between deadwood in an advanced decomposition stage and the soil immediately under the log. The average C/N/P ratio of soil under the influence of deadwood was narrower compared to the C/N/P ratio of deadwood. The C/N/P ratio of studied soils was similar to the expected C/N/P ratio of organic soils or humus. The results indicate that stage of decomposition and tree species have an impact on the elemental stoichiometry of the soil. Thus, C/N/P stoichiometry is a useful indicator of the intensity of nutrient flux from deadwood to the soil.

The Latitudinal Patterns of Leaf and Soil C:N:P Stoichiometry in the Loess Plateau of China.

Understanding the spatial patterns and the driving factors of plant leaf and soil stoichiometry are critical for improving the parameterization of future ecological models and to predict the responses of ecosystems to environmental changes. This study aimed to determine how the latitudinal patterns of leaf and soil C:N:P stoichiometry are affected by climate and vegetation types in the dryland ecosystems. The concentrations of leaf C, N, and P in herb community as well as soil nutrient concentrations along a 500–km–long latitudinal gradient in Northern Shaanxi of the Loess Plateau, were measured. The results showed that the soil C, N, P and C:N:P ratios at all three depths (0–10, 10–20, and 20–40 cm) showed significant latitudinal trends (except for soil C:N ratios) (P < 0.01). In general, the soil C, N and C:N:P ratios decreased exponentially while soil P increased first and then decreased with the latitude. The soil C, N, C:P, and N:P ratios at all three depths (0–10, 10–20 and 20–40 cm) were positively correlated with MAT and MAP (P < 0.05), while soil P and C:N ratios at all three depths were weakly correlated with MAT and MAP (P > 0.05). In addition, leaf C:N:P stoichiometry was significantly correlated with the latitude, MAT, and MAP (except for N:P ratios) (P < 0.01), such that, leaf C, C:N, and C:P ratios decreased as the latitude increased and MAT and MAP decreased, and leaf N, P concentrations increased as the latitude increased and MAT and MAP decreased, while leaf N:P ratios were weakly correlated with the latitude, MAT, and MAP (P > 0.05). Furthermore, the leaf C:N:P stoichiometry of herbaceous communities was related to the soil properties (except for soil P), and we found that the C:P ratios between the soil and leaves were strongly correlated. Compared with the global scale, the relatively high N:P ratios indicated that the vegetation growth of the herb community in the dryland of the Loess Plateau was more susceptible to P limitation.

Arbuscular Mycorrhizal Fungi Alter Plant and Soil C:N:P Stoichiometries Under Warming and Nitrogen Input in a Semiarid Meadow of China.

Ecological stoichiometry has been widely used to determine how plant-soil systems respond to global change and to reveal which factors limit plant growth. Arbuscular mycorrhizal fungi (AMF) can increase plants’ uptake of nutrients such as nitrogen (N) and phosphorus (P), thereby altering plant and soil stoichiometries. To understand the regulatory effect of AMF feedback on plants and soil stoichiometry under global change, a microcosm experiment was conducted with warming and N input. The C4 grass Setaria viridis, C3 grass Leymus chinensis, and Chenopodiaceae species Suaeda corniculata were studied. The results showed that the mycorrhizal benefits for the C4 grass S. viridis were greater than those for the C3 grass L. chinensis, whereas for the Chenopodiaceae species S. corniculata, AMF symbiosis was antagonistic. Under N input and a combination of warming and N input, AMF significantly decreased the N:P ratios of all three species. Under N input, the soil N content and the N:P ratio were decreased significantly in the presence of AMF, whereas the soil C:N ratio was increased. These results showed that AMF can reduce the P limitation caused by N input and improve the efficiency of nutrient utilization, slow the negative influence of global change on plant growth, and promote grassland sustainability.

氮磷添加对荒漠草原植物群落多样性和土壤C:N:P生态化学计量特征的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 氮磷添加对荒漠草原植物群落多样性和土壤C:N:P生态化学计量特征的影响 DOI: 10.5846/stxb201812022624 作者: 作者单位: 宁夏大学资源环境学院,宁夏大学,宁夏大学,宁夏大学,浙江农林大学省部共建亚热带森林培育国家重点实验室,杭州 311300,宁夏大学 作者简介: 通讯作者: 中图分类号: 基金项目: 宁夏高等学校科学研究项目（NGY2017003） Effects of nitrogen and phosphorus addition on plant community diversity and soil C: N: P ecological stoichiometry in a desert steppe of China Author: Affiliation: College of Recourses and Environment, Ningxia University,Ningxia University,Ningxia University,Ningxia University,,Ningxia University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了深入了解P添加是否有助于缓解N沉降增加引起的植物群落多样性降低等问题，以宁夏盐池县长期围封的荒漠草原为研究对象，探讨了连续两年（2015-2016年）5 g/m2/a的N水平下，P添加对植物生物量、群落多样性和土壤C：N：P生态化学计量特征的影响，分析了植物群落多样性与土壤C：N：P比及其他关键因子的关系。结果表明：少量N添加下，增施P肥促进了植物生物量积累，但中高量P添加抑制了多数植物生长，使牛枝子（Lespedeza potaninii）、草木樨状黄芪（Astragalus melilotoides）和苦豆子（Sophora alopecuroides）等物种重要值降低；随着P添加量增加，Shannon-Wiener多样性指数和Patrick丰富度指数先增加后降低，Simpson优势度指数逐渐增加，Pielou均匀度指数变化幅度较小；随着P添加量增加，土壤C：P和N：P比逐渐降低；土壤N：P比、C：P比、全P含量、速效P浓度以及微生物量C：P比与植物群落多样性关系密切，意味着N沉降增加下趋于解耦的土壤元素平衡关系可能会影响到植物群落组成。综合以上结果，适量P添加可以通过提高土壤P有效性、增加凋落物归还量和刺激微生物P释放等途径，调节土壤P供给和植物P需求间的压力，从而缓解N添加引起的植物群落多样性降低。 Abstract:In order to deeply understand whether P addition could alleviate the N deposition-induced decrease in plant community diversity, we explored the effects of P addition on plant biomass, community diversity, and soil C:N:P ecological stoichiometry under 2-year of 5 g/m2/a of N addition (2015-2016) in a long-term fenced desert steppe, located in Yanchi County, Ningxia, north-western China. We also analysed the relationships between plant community diversity indices and soil C:N:P ecological stoichiometry as well as other key soil factors. The results showed that combined with low N addition, low P addition promoted plant biomass accumulation, but moderate and high P addition inhibited the growth of most species, resulting in decreases in the importance values of Lespedeza potaninii, Astragalus melilotoides, and Sophora alopecuroides. With the increase of P addition, both Shannon-Wiener diversity index and Patrick richness index increased firstly and then decreased, while there were gradual increase in Simpson dominance index and little change in Pielou evenness index. Increasing P addition reduced soil C:P and N:P ratios; soil N:P ratio, C:P ratio, total P content, available P concentration, and microbial biomass C:P ratio were tightly related to plant diversity indices, indicating that the decoupling of elemental stoichiometry in soils will exert great impacts on plant community composition under increasing N deposition. Taken together, these results might suggest an appropriate amount of P addition could regulate the pressure between soil P supply and plant P demand through increasing soil availability, raising litter return amount, stimulating microbial P release, and other approaches, to further alleviate the N addition-induced decrease in plant community diversity. 参考文献 相似文献 引证文献

黔中石漠化区不同海拔顶坛花椒人工林生态化学计量特征

PDF HTML阅读 XML下载 导出引用 引用提醒 黔中石漠化区不同海拔顶坛花椒人工林生态化学计量特征 DOI: 10.5846/stxb201810222279 作者: 作者单位: 贵州师范大学喀斯特研究院/国家喀斯特石漠化防治工程技术研究中心,贵州师范大学地理与环境科学学院,贵州师范大学地理与环境科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划课题（2016YFC0502603）；贵州省科技计划项目（黔科合支撑[2016]2610号） Ecological stoichiometry of Zanthoxylum planispinum var. dintanensis plantation at different altitudes in rocky desertification area of central Guizhou Author: Affiliation: School of Karst Science,Guizhou Normal University,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:了解黔中石漠化区不同海拔顶坛花椒（Zanthoxylum planispinum var. dintanensis）人工林的生态化学计量特征，有助于深入认识其养分循环规律和元素丰缺状况。对顶坛花椒人工林叶片、凋落物和土壤C、N、P、K含量进行了测定，分析了生态化学计量特征及之间的关系。结果表明：（1）顶坛花椒人工林叶片OC、TN、TP、TK分别为228.11-446.81、0.96-5.69、2.17-5.60、6.42-17.74 g/kg，凋落物OC、TN、TP、TK依次为239.19-415.25、1.70-4.62、1.83-2.63、1.80-4.26 g/kg，土壤OC、TN、TP、TK分别为29.69-53.17、2.99-6.41、0.18-1.52、15.01-21.14 g/kg，土壤养分呈现低N高P格局；（2）叶片、凋落物、土壤C、N、P、K生态化学计量随海拔的分异规律不完全一致，其变化特征能够表明C、N来源多样，P、K来源相对固定；（3）土壤养分含量与叶片养分含量、生态化学计量之间多表现出显著相关，表明叶片养分主要来自土壤；总体上，土壤养分含量及其生态化学计量与凋落物养分含量具有弱的相关性，与凋落物养分生态化学计量具有强的相关性，表明凋落物和土壤之间存在一定的养分转换强度但是并非完全继承。 Abstract:Understanding the ecological stoichiometry of Zanthoxylum planispinum var. dintanensis plantation at different altitudes in the rocky desertification area of central Guizhou is helpful to know the regularity of nutrient circulation and the status of element abundance and deficiency. In this study, the contents of C, N, P, and K in the leaves, litter and soil of the Zanthoxylum planispinum var. dintanensis plantation were determined. The ecological stoichiometry and the relationship between them were analyzed. The results showed that: (1) the organic carbon (OC), total nitrogen (TN), total phosphorus (TP), and total potassium (TK) of the leaves of Zanthoxylum planispinum var. dintanensis plantation were 228.11-446.81, 0.96-5.69, 2.17-5.60, 6.42-17.74 g/kg, respectively. The OC, TN, TP, and TK of litter were 239.19-415.25, 1.70-4.62, 1.83-2.63, 1.80-4.26 g/kg, respectively. The OC, TN, TP, and TK in the soil were 29.69-5.17, 2.99-6.41, 0.18-1.52, 15.01-2.14 g/kg, respectively. The soil nutrients showed the pattern of "low N and high P". (2) The differentiation of C, N, P, and K in leaves, litter, and soil was not exactly consistent with the difference of altitude. Its change characteristics showed that the sources of C and N were diverse, but the sources of P and K were relatively fixed. (3) There was a significant correlation between nutrient content and the ecological stoichiometry in soil and leaves, which indicated that the nutrients in the leaves were mainly from the soil. In general, soil nutrient content and its ecological stoichiometry had a weak correlation with litter nutrient content, but strongly correlated with litters nutrient ecological stoichiometry. It indicated that there was a certain nutrient conversion strength between litter and soil but not complete inheritance. 参考文献 相似文献 引证文献

乌兰布和沙漠典型灌木群落土壤化学计量特征

乌兰布和沙漠典型灌木群落土壤化学计量特征

Carbon, nitrogen and phosphorus stoichiometry in leaf, litter and soil at different vegetation restoration stages in the mid-subtropical region of China

Carbon, nitrogen and phosphorus stoichiometry in leaf, litter and soil at different vegetation restoration stages in the mid-subtropical region of China

滇南喀斯特地区灌木群落和人工林土壤元素化学计量特征

PDF HTML阅读 XML下载 导出引用 引用提醒 滇南喀斯特地区灌木群落和人工林土壤元素化学计量特征 DOI: 10.5846/stxb201810072159 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划（2016YFC0502501） Characteristics of soil stoichiometry in native shrub and plantation communities in karst regions of Yunnan province Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在云南喀斯特地区，为提升退化灌木群落的生态系统服务功能，营造了不同树种的人工林分。这些人工林分如何影响土壤化学性质还未得到充分认识。以云南泸西县灌木群落及三种常见人工林（云南松（Pinus yunnanensis）、赤杨（Alnus japonica）和侧柏（Platycladus orientalis））土壤为研究对象探讨喀斯特地区在人工林建造后土壤的13种元素全量、可利用性含量和化学计量学特征变异格局，为喀斯特石漠化治理提供理论依据。结果表明，1）基于判别分析，四种群落土壤化学计量特征可以显著区分。土壤Fe、P、K、Mn全量及交换性Ca、交换性Mg和NH4+-N对区分四种群落土壤贡献最大。2）四种群落之间相比，侧柏林土壤C、N、S、Na全量和NO3--N含量均低于其他三种群落，土壤肥力较低；赤杨林铵态氮含量最高；云南松林有效Fe、有效Cu含量最高。而且，四个群落土壤全量C/N、C/K比值存在显著差异性。3）根据四种群落13种土壤元素和pH值相关性分析，35对元素具有显著相关性，占所有元素对数的38.5%，说明该地土壤元素积累的相互依赖性。与灌木群落相比，人工林土壤元素全量和可利用性含量相关性比例均更高。这些研究结果对今后基于适地适树人工林营造、生态系统服务功能提升和经营利用，均具有重要指导意义。 Abstract:The natural forest vegetation degraded to shrub-dominated plant communities in karst areas of Yunnan province, due to the geological conditions and long-term human disturbance. Plantation stands of different tree species have been established to raise ecosystem services across Yunnan province, such the karst shrub areas, during the last three decades. In this context, the elemental compositions of original soils could be influenced to a certain extent. In this study, we measured the total and available element concentrations of 13 elements (C, N, S, P, K, Ca, Mg, Na, Fe, Al, Cu, Zn, and Mn), and summarised the stoichiometric traits of soils in the shrub, Pinus yunnanensis, Alnus japonica, and Platycladus orientalis stands in Luxi county, Yunnan province. The results showed that firstly, soil stoichiometric traits of four communities were significantly distinguished based on canonical discriminant analysis. Furthermore, soil total Fe, P, K, Mn concentrations, and available Ca, Mg, and NH4+-N concentrations, contributed to the differences the most. Secondly, cypress stands showed lower total C, N, S, Na and NO3--N concentrations compared with the other three communities, suggesting that the soil fertility was reduced. The soil NH4+-N concentration was higher in alder stands compared with the other communities; the soil available Fe and Cu concentrations were highest in the Yunnan pine stand. Furthermore, there were also significant differences of C/N and C/K ratios among the four stands. Thirdly, based on a correlation analysis of the 13 elements and the pH value, 35 pair-elements showed a significant correlation, accounting for 38.5% of all elements, suggesting that there was strong inter-dependence accumulation of soil elements in these karst areas. Compared with the shrub community, the significant correlations between the total elements and available elements in plantation stands were higher. Our results have important implications for plantation establishment and management to increase ecosystem services in such karst areas. 参考文献 相似文献 引证文献