Ecological Stoichiometry Characteristics Research Articles

[Nutrients and Ecological Stoichiometry Characteristics of Typical Wetland Soils in the Lower Yellow River].

Carbon, nitrogen, phosphorus, and potassium in the soil are the necessary nutrient elements for plant growth, and their contents and ecological stoichiometry can reflect the status of soil quality and nutrient limitation. The Huayuankou Yellow River Floating Bridge Wetland in the lower Yellow River was selected as the research object. The methods of ANOVA, redundancy analysis, and linear regression fitting were used to study the contents of organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), alkaline nitrogen (AN), available phosphorus (AP), available potassium (AK), and their ecological stoichiometric ratios as well as the limiting elements of soil nutrients, and the key physicochemical properties that affect soil nutrients and their ecological stoichiometry in the wetland were revealed. The results showed that the mean values of ω(SOC), ω(TN), ω(TP), ω(TK), ω(AN), ω(AP), and ω(AK) in wetland soil were 5.46 g·kg-1, 0.60 g·kg-1, 0.28 g·kg-1, 17.06 g·kg-1, 13.75 mg·kg-1, 6.54 mg·kg-1, and 158.56 mg·kg-1, respectively, which showed an increasing trend from the river bank to the shoaly land and were generally higher at the high vegetation coverage areas than at the low vegetation coverage areas. There were significant correlations among SOC, TN, TP, and TK. Soil C/P, C/K, N/P, and N/K showed a consistent trend with soil nutrients, whereas C/N showed the opposite. The coefficients of variation of SOC, TN, AN, N/P, and N/K in the soil exceeded 50.00%, with significant spatial differences. The average value of C/N in wetland soil was 11.882, which was close to the average level of soils in China, whereas the average values of C/P and N/P were 49.119 and 4.516, respectively, both of which were lower than the average level of soils in China, and the N/P of soil was far less than 14, which indicated that N was limited in the soil. The proportion of clay and electrical conductivity combined to explain 61.4% and 43.9% of the variation in the soil nutrients and their ecological stoichiometry, respectively, which were the dominant soil physicochemical properties affecting the soil nutrients and their ecological stoichiometry of Huayuankou Yellow River Floating Bridge Wetland. The research results are helpful to improve our knowledge of nutrients and their influencing factors in the wetland soil of the lower Yellow River and provide an important scientific basis for the ecological restoration and management of the wetland in the lower Yellow River.

Biocrusts impact soil properties and ecological stoichiometry characteristics in frozen ground regions on the Qinghai-Tibet Plateau

Biocrusts impact soil properties and ecological stoichiometry characteristics in frozen ground regions on the Qinghai-Tibet Plateau

Does the fertile island effect in tamarisk nebkhas enhance in the northern Tarim Basin in the context of global warming?

AbstractWith the intensification of global warming, uncertainty regarding ecosystem evolution trends in drylands has increased. The objective of this article was to test whether the desertification process of tamarisk shrubland was intensified by comparing fertile island effects and soil ecological stoichiometry characteristics at different time periods. The tamarisk shrubland in the “shrubland” and “shrub duneland” stages in the northern Tarim Basin was selected, and soil samples were collected from the tamarisk nabkhas and from the interspaces between tamarisk nebkhas at the 0‐ to 30‐cm soil layers in 2009 and 2018. Soil carbon (C), nitrogen (N), and phosphorous (P) were analyzed, and the C/N, C/P, and N/P ratios were calculated. In comparison with 2009, fertile island effects were completely collapsed in the shrub duneland stage, with no obvious changes in the shrubland stage in 2018. The average soil C/N ratio decreased from a value greater than 25 in both stages. The average value of soil C/P ratio was below 200 in the shrubland and shrub duneland stages, with almost no marked change after nine years. The soil N/P ratio in our study significantly increased in 2018 than in 2009, but the soil N/P ratio was still much less than 11.9. Significantly positive correlations were observed between the relative interaction index (RII) of soil organic carbon (SOC) and soil total nitrogen (TN) and the soil C/P and N/P ratios in the tamarisk nebkhas. These results suggested that (1) fertile island effects were positive in relation to soil stoichiometry in tamarisk nebkhas in most cases; (2) the desertification process was accelerated in the shrub duneland stage, with no obvious progress during the shrubland stage; and (3) the loss of soil C from the collapsed fertile islands could therefore accelerate global warming.

Water and Nitrogen Coupling on the Regulation of Soil Nutrient-Microbial Biomass Balance and Its Effect on the Yield of Wolfberry (Lycium barbarum L.).

Due to the problems of relatively fragile stability, the quality of soil in the drip-irrigated agricultural ecosystem has high spatial heterogeneity and experiences significant degradation. We conducted a two-year field plot study (2021-2022) in a typical region of the arid zone with the "wolfberry" crop as the research object, with three irrigation and three nitrogen application levels, and the local conventional management as the control (CK). Soil quality under experimental conditioning was comprehensively evaluated based on Principal Component Analysis (PCA) and Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), and regression analyses were carried out between the soil quality evaluation results and wolfberry yield. The results showed that short-term water and nitrogen regulation enhanced the soil nutrient content in the root zone of wolfberry to some extent, but it did not significantly affect soil carbon:soil nitrogen (Csoil:Nsoil), soil carbon:soil phosphorus (Csoil:Psoil), and soil nitrogen:soil phosphorus (Nsoil:Psoil). When the irrigation quota was increased from I1 to I2, the soil microbial biomass carbon, nitrogen, and phosphorus (Cmic, Nmic, and Pmic) tended to increase with the increase in N application, but the microbial biomass carbon:nitrogen (Cmic:Nmic), microbial biomass carbon:phosphorus (Cmic:Pmic), and microbial biomass nitrogen:phosphorus (Nmic:Pmic) did not change significantly. The comprehensive evaluation of the principal components and TOPSIS showed that the combined soil nutrient-microbial biomass and its ecological stoichiometry characteristics were better under the coupled treatments of I2, I3, N2, and N3, and the overall soil quality under these treatment conditions was significantly better than that under the CK treatment. Under I1 irrigation, nitrogen application significantly increased the yield of wolfberry, while under I2 and I3 irrigation, the wolfberry yield showed a parabolic trend with the increase in nitrogen application. The highest yield was recorded in the I2N2 treatment in the first and second years, with yields of 9967 kg hm-2 and 10,604 kg hm-2, respectively. The coefficient of determination (explained quantity) of the soil quality based on soil nutrient-microbial biomass and the characteristics of its ecological stoichiometry for wolfberry yield ranged from 0.295 to 0.573. These findings indicated a limited positive effect of these indicators of soil on wolfberry yield. The short-term water and nitrogen regulation partly influenced the soil and soil microbial biomass in agroecosystems, but the effect on elemental balance was not significant. Our findings might provide theoretical support for managing the health of agricultural ecosystems.

[Soil Stoichiometry Characterization in the Oasis-desert Transition Zone of Linze, Zhangye].

To investigate the changes in C, N, P, and K contents and ecological stoichiometry of desert oasis soils and to elucidate their ecological responses to environmental factors, 10 sample plots were selected in the Zhangye Linze desert oasis in the middle part of the Hexi Corridor, and surface soil samples were collected to determine the C, N, P and K contents of soils and to reveal the distribution characteristics of soil nutrient contents and stoichiometric ratios in different habitats and the correlation with other environmental factors. The results showed that:① the distribution of soil carbon was uneven and heterogeneous across sites (R=0.761, P=0.06). The highest mean value was 12.85 g·kg-1 in the oasis, followed by 8.65 g·kg-1 in the transition zone and 4.1 g·kg-1 in the desert. ② The content of total soil potassium did not vary significantly and was high among deserts, transition zones, and oases and low in saline areas. ③ The mean soil C:N value was 12.92, the mean C:P value was 11.69, and the mean N:P value was 0.9, all of which were lower than the global average soil content (13.33, 72.0, and 5.9) and the Chinese soil average (12, 52.7, and 3.9). ④ Soil water content was the most influential factor affecting C, N, P, K, and ecological stoichiometry characteristics of desert oasis soils, with a contribution of 86.9%, followed by soil pH and soil porosity, with contributions of 9.2% and 3.9%, respectively. The results of this study provide basic information for the restoration and conservation of desert and oasis ecosystems and establish a basis for future study of the biodiversity maintenance mechanism in the region and its correlation with the environment.

Altitudinal Gradients Modify the Ecological Stoichiometry and Enzyme Activities of Soil in a Natural Secondary Quercus spp. Forest of the Dabie Mountains

Understanding the vertical distribution and driving mechanisms behind soil carbon (C), nitrogen (N), and phosphorus (P) contents and enzyme activities along elevation gradients is of great significance for the healthy and sustainable management of forest ecosystems. For this study, the 0–20 cm soil-layer samples of different natural Quercus spp. secondary forests from eight altitude gradients (ranging from 250 to 950 m) were investigated to quantify their physicochemical properties, ecological stoichiometry characteristics, and enzyme activities. The results indicated that the soil nutrient content of natural secondary Quercus spp. forests in the Dabie Mountains was low, with average soil organic carbon (SOC) and total phosphorus (TP) contents of 19.86 ± 3.56 g·kg−1 and 0.68 ± 0.10 g·kg−1, respectively, which were 19.14% and 12.82% lower, respectively, than the Chinese average. In terms of vertical spatial distribution, the SOC, total nitrogen (TN), and TP contents of the soil at high altitudes (≥750 m) were greater than those at middle- and low-altitude areas and reached the maximum value at or near the top of the mountain (850–950 m). The stoichiometric attributes of the soil ecosystem fluctuated with the higher altitudes in vertical space; however, the fluctuation range was not significant. The C:N, N:P, and C:P ratios reached their maximum values at altitudes of 250, 750, and 850 m, respectively. However, the overall average value remained generally lower than the national average; thus, in forest management, attention should be paid to the supplementation of the soil with C and P. The activities of soil sucrase, urease, acid phosphatase, and catalase were interconnected across the overall space, and increased with altitude. The SOC, TP, and pH were the main factors that influenced the changes in soil enzyme activities.

Ecological strategy of Phyllostachys heteroclada oliver in the riparian zone based on ecological stoichiometry.

The abnormality of seasonal water level fluctuation in the riparian zone causes various ecological and environmental problems, such as vegetation degradation, biodiversity reduction, soil erosion, and landscape transformation, thereby critically modifying the ecosystem structure and functions. This necessitates the development of a dominant vegetation zone with competitive potential. In this study, we investigated the content and distribution pattern of nutrient elements in each organ of the dominant bamboo species, Phyllostachys heteroclada, in the riparian zone. We also analyzed the morphological characteristics, root aeration tissue structure, root oxygen exchange capacity, ATP supply situation, and leaf PSII photosynthetic mechanism of two bamboo species (P. heteroclada and P. nigra) in the riparian zone. Compared with P. nigra, the roots of P. heteroclada formed well-developed oxygen storage and transport structure, i.e., aeration tissue, and exhibited root oxygen secretion in the waterlogging environment of the riparian zone, whereas the roots maintained a high ATP content through energy metabolism, thus benefiting mineral absorption and transport. Moreover, the accumulation of N, P, Ca, Mg, and Fe in the leaves of P. heteroclada was greater under waterlogging conditions than under non-waterlogging conditions, which is the basis for the efficient operation of the photosynthetic mechanism of the leaves. Compared with waterlogged P. nigra, the PSII electron acceptor QA of P. heteroclada leaves had a vigorous reducing ability and showed higher efficiency of light uptake energy as well as higher quantum yield indexes ϕ(Eo) and ϕ(Po). This study demonstrates that the ecological adaptive regulation strategies of P. heteroclada in the riparian zone are intrinsic driving factors affecting their stoichiometric characteristics, including changes in the absorption and transport of minerals caused by root aeration structure and energy metabolism. Moreover, carbon production and allocation may be caused by the stable photosynthetic mechanism and source-sink relationship of leaves. Through the synergistic regulation of different organs realizing their roles and functions, P. heteroclada developed ecological stoichiometry characteristics adapted to the riparian zone.

Spatial distribution patterns and influencing factors of soil carbon, phosphorus, and C:P ratio on farmlands in southeastern China

Soil organic carbon (SOC), total phosphorus (STP), and the carbon-to-phosphorus ratio (C:P) are important indicators of soil fertility. Knowledge regarding the spatial patterns of SOC, STP, and C:P and their influencing factors are of great significance for precise fertilization, soil management, food security, environmental protection, and global climate change. A total of 16,582 topsoil samples (0–20 cm depth) were collected from farmland in Jiangxi Province, southeastern China. The spatial variability and driving factors of SOC, STP, and C:P were characterized using classical statistics, geostatistical analysis, and random forest (RF) methods. The results showed that the mean values of SOC, STP, and C:P were 17.90 g kg−1, 0.52 g kg−1, and 38.29, and their coefficients of variation were 30.98%, 33.49%, and 45.08%, respectively, indicating a moderate degree of variability. The RF model contained 47 explanatory variables related to parent materials, soil types, soil physicochemical properties, environmental variables, climate, farmland use types, straw returning methods, and fertilizer application rates, which accounted for 72.70%, 60.89%, and 63.71% of the spatial variability in SOC, STP, and C:P, respectively. Soil physicochemical properties had the most significant influence on SOC, STP, and C:P, with contributions of 45.83%, 50.93%, and 51.06%, respectively. Of all the factors, soil total nitrogen was identified as mostly driving the spatial distributions of SOC, STP, and C:P (variable importance of 29.39%, 11.72%, and 23.95%, respectively), followed by the nitrogen application rate (variable importance of 20.90%, 11.37%, 12.79%, respectively). Therefore, conservation tillage, crop rotation, straw return, combined application of nitrogen and phosphorus, and green manure application are the most effective measures for improving carbon sequestration and phosphorus availability. According to the ecological stoichiometry characteristics of carbon, nitrogen, and phosphorus and their temporal variation trends, the farmland soils in Jiangxi Province are typical carbon sink systems that are likely to be limited by phosphorus. The results of this study provide important insights for assessing soil carbon and phosphorus pools and sustainable agricultural development.

Variations in Ecological Stoichiometry Characteristics of C, N and P in Soils Beneath an <i>Abies fanjingshanensis</i> Forest

Variations in Ecological Stoichiometry Characteristics of C, N and P in Soils Beneath an <i>Abies fanjingshanensis</i> Forest

西南喀斯特区坡耕地秸秆覆盖对土壤生态化学计量特征及产量的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 西南喀斯特区坡耕地秸秆覆盖对土壤生态化学计量特征及产量的影响 DOI: 10.5846/stxb202104030867 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31760243，32060372）；贵州省科技计划项目（黔科合支撑[2021]一般462号） Effects of straw mulching on soil ecological stoichiometry characteristics and yield on sloping farmland in karst area, Southwestern China 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:土壤养分亏缺是限制作物生长的关键因素，同时也是制约作物产量的重要影响因子。为提高西南喀斯特区坡耕地土壤肥力和作物产量，于2018-2019年连续两年在贵州省黔西县开展了野外原位径流小区观测试验。通过该试验探讨不同秸秆覆盖率下土壤碳（C）、氮（N）、磷（P）、钾（K）含量及其生态化学计量特征，揭示不同秸秆覆盖率下土壤养分状况及土壤改良效果。共设6个秸秆覆盖梯度，玉米单作＋秸秆覆盖（SM0-SM5，0，1111、2222、3889、5556，6944 kg/hm2），其中SM0为对照组（CK）。结果表明：（1）秸秆覆盖不同程度增加了土壤有机碳（SOC）、全氮（TN）及全磷（TP）含量，总体上随覆盖量的增加而增加，尤其是覆盖量较多的情况下（SM4，SM5），均显著高于对照（P<0.05），但两者之间差异不显著（P > 0.05），而全钾（TK）则随着覆盖量的增加而减少。（2）在高秸秆覆盖条件下（SM4，SM5），除了N ： P外，两年各土壤养分元素的化学计量比均显著高于对照（P<0.05），但SM4和SM5之间差异不显著（P > 0.05）。（3）秸秆覆盖条件下土壤C ： N、C ： P较低，加速了土壤有机质矿化分解，同时也说明P的有效性较高。（4）高秸秆覆盖率条件下对作物增产较为显著，其中SM4处理作物产量最高。研究表明覆盖于地表的秸秆作为土壤营养元素的重要来源，可将其作为一种补充手段以补给土壤中被作物吸收和随水土流失而流失的土壤养分。综合主成分、灰色关联度及差异显著性分析，同时结合作物产量，建议在西南喀斯特坡耕地覆盖6000 kg/hm2左右的秸秆以促进农田生态系统的恢复，从而达到较好的土壤增肥、作物增产效果。 Abstract:Soil nutrient deficiency is a key factor limiting crop growth and yield, but also threatens the survival of crops. In order to improve soil fertility and crop yield of sloping farmland in karst area of Southwestern China, the experiments were carried out in Qianxi county, Guizhou province for two consecutive years from 2018 to 2019. We explored the contents and the ecological stoichiometry characteristics of soil carbon, nitrogen, phosphorus, potassium and revealed the soil nutrient status and soil improvement effect under different straw mulching application rates through this experiment. There were six straw mulching gradients of maize monoculture+straw mulching (SM0-SM5, 0, 1111, 2222, 3889, 5556, 6944 kg/hm2), in which SM0 was the control cheak (CK). The results showed that:(1) straw mulching increased the contents of soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) in different degrees, and generally increased with the increase of mulching rate. Especially in SM4 and SM5, which were significantly higher than those of the CK (P<0.05), but there was no significant difference between them (P > 0.05), while total potassium (TK) decreased with the increase of mulching rate. (2) Under the condition of high straw mulching (SM4, SM5), the stoichiometry ratio of soil nutrient elements in two years was significantly higher than that of the CK (P<0.05), except for N:P, but there was no significant difference between SM4 and SM5 (P>0.05). (3) Under the condition of straw mulching, the C:N and C:P in soil were lower, which accelerated the mineralization and decomposition of soil organic matter, and also showed that the availability of P was higher. (4) The crop yield of each mulching treatment was significantly higher than that of the CK (P<0.05), especially under the condition of high straw mulching, the yield of crop increased significantly, and the yield of SM4 was the highest. The research showed that straw mulch on the ground is an important source of soil nutrients, which can be used as a supplementary means to supplement the soil nutrients absorbed by crops and lost with soil erosion. Based on the crop yield, the principal component analysis, grey correlation analysis, difference significance, it is suggested that straw mulching in about 6000 kg/hm2 should be adopted for sloping farmland in the karst area of Southwestern China to promote the restoration of farmland ecosystem and achieve better effect of soil fertility and crop yield. 参考文献 相似文献 引证文献

喀斯特山地不同微地貌下土壤碳氮磷空间异质性及生态化学计量特征

PDF HTML阅读 XML下载 导出引用 引用提醒 喀斯特山地不同微地貌下土壤碳氮磷空间异质性及生态化学计量特征 DOI: 10.5846/stxb202110232994 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 中国科学院战略性先导科技专项（XDB40000000，XDA23060100）；中国科学院"西部之光"交叉团队项目（人字〔2022〕4号）；国家自然科学基金（42077455） Spatial heterogeneity and ecological stoichiometry characteristics of soil carbon, nitrogen and phosphorus under different micro-geomorphology in karst mountains Author: Affiliation: Fund Project: Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB40000000 & No. XDA23060100)，Chinese Academy of Sciences "Western Light" Cross-team Program (No. Ren Zi 2022-4), Natural Science Foundation of China (No. 42077455) 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:喀斯特地区特殊地质背景造就复杂破碎的地形发育出多样的微地貌，这使得清晰地认识土壤碳氮磷的空间异质性及生态化学计量特征存在困难。基于实地调查、土壤采样、实验测试的结果数据，引入混合效应模型评估方法结合变异系数，分别从全量（土壤有机碳、全氮、全磷）及有效态（活性有机碳、碱解氮及速效磷）两方面，揭示不同微地貌类型下土壤碳氮磷空间异质性及其生态化学计量特征。结果显示：（1）不同微地貌类型下土壤有机碳、全氮、全磷对碳氮磷比值的耦合解释度为：土面（91.09%） > 石沟（91.02%） > 石坑（84.63%） > 石洞（80.17%） > 石缝（73.20%），土面的空间异质性最低而石缝最高。（2）有效态方面，活性有机碳、碱解氮和速效磷对碳氮磷比值的耦合解释度特征为：石缝（84%） > 石洞（58.15%） > 土面（47.80%） > 石坑（44.06%） > 石沟（32.18%），说明石缝微地貌的土壤活性有机碳、碱解氮及速效磷空间异质性最低。（3）不同微地貌类型下土壤全量碳氮磷生态化学计量的变异系数差异均在50%以上（C/N 80%、C/P 53.57%、N/P 69.33%）。通过揭示不同微地貌土壤全量及有效态碳氮磷空间异质性及生态化学计量特征，为喀斯特土壤系统管理方案及应对全球变化与碳中和提供数据和科学参考。 Abstract:The specially geological background of karst area has created complex and broken topography and developed various micro-geomorphology, which made it difficult for people to clearly understand the spatial heterogeneity and ecological stoichiometry characteristics of soil carbon, nitrogen and phosphorus. On the basis of field investigation, soil sampling and test results, the mixed effect model evaluation method combining coefficient of variation was introduced, and the spatial heterogeneity of soil carbon, nitrogen and phosphorus under different micro-geomorphic types and their eco-chemical measurement characteristics were revealed from two aspects:total amount (soil organic carbon, total nitrogen and total phosphorus) and effective amount (active organic carbon, available nitrogen and available phosphorus). The results show that:(1) The coupling interpretation degree of soil organic carbon, total nitrogen and total phosphorus to the ratio of carbon, nitrogen and phosphorus under different micro-geomorphic types is:earth flatland (91.09%) > gully (91.02%) > pit (84.63%) > stone cavern (80.17%) > crevice (73.20%), with the lowest spatial heterogeneity of soil surface and the highest stone crevice. (2) In terms of available state, the coupling explanation degree of active organic carbon, available nitrogen, available phosphorus and the ratio of carbon, nitrogen and phosphorus is characterized as followed:crevice (84%) > stone cavern (58.15%) > earth flatland (47.80%) > pit (44.06%) > gully (32.18%), which indicates that the spatial heterogeneity of soil active organic carbon, available nitrogen and available phosphorus in stone crevice micro-topography is the lowest. (3) The coefficient of variation of ecological stoichiometry of total soil carbon, nitrogen and phosphorus under different micro-geomorphic types are all above 50% (C/N 80%, C/P 53.57%, and N/P 69.33%). By revealing the spatial heterogeneity of total and available carbon, nitrogen and phosphorus in different micro-geomorphic soils and the characteristics of eco-chemistry, we can provide data and scientific reference for karst soil system management scheme and coping with global change and carbon neutralization. 参考文献 相似文献 引证文献

Research progress on the effects of forest fire on forest ecosystem C-N-P ecological stoichiometry characteristics

Research progress on the effects of forest fire on forest ecosystem C-N-P ecological stoichiometry characteristics

半干旱黄土小流域不同植被类型植物与土壤生态化学计量特征

半干旱黄土小流域不同植被类型植物与土壤生态化学计量特征

Ecological stoichiometry of plant leaves, litter and soils in a secondary forest on China's Loess Plateau.

Ecological stoichiometry can reveal nutrient cycles in soil and plant ecosystems and their interactions. However, the ecological stoichiometry characteristics of leaf-litter-soil system of dominant grasses, shrubs and trees are still unclear as are their intrinsic relationship during vegetation restoration. This study selected three dominant plant types of grasses (Imperata cylindrica (I. cylindrica) and Artemisiasacrorum (A.sacrorum)), shrubs (Sophora viciifolia (S. viciifolia) and Hippophae rhamnoides (H. rhamnoides)) and trees (Quercus liaotungensis (Q. liaotungensis) and Betula platyphylla (B. platyphylla)) in secondary forest areas of the Chinese Loess Plateau to investigate ecological stoichiometric characteristics and their intrinsic relationships in leaf-litter-soil systems. The results indicated that N concentration and N:P ratios in leaf and litter were highest in shrubland; leaf P concentration in grassland was highest and litter in forestland had the highest P concentration. Soil C, N and P concentrations were highest in forestland (P < 0.05) and declined with soil depth. Based on the theory that leaf N:P ratio indicates nutritional limitation of plant growth, this study concluded that grass and shrub growth was limited by N and P element, respectively, and forest growth was limited by both of N and P elements. The relationships between the N concentration in soil, leaf and litter was not significant (P >0.5), but the soil P concentration was significantly correlated with litter P concentration (P < 0.05). These finding enhance understanding of nutrient limitations in different plant communities during vegetation restoration and provide insights for better management of vegetation restoration.

围封对天山高寒草原4种植物叶片和土壤化学计量学特征的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 围封对天山高寒草原4种植物叶片和土壤化学计量学特征的影响 DOI: 10.5846/stxb201901130107 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 新疆维吾尔自治区自然科学基金项目（2016D01A076） Effects of enclosure on leaves of four plants and soil stoichiometry in an alpine grassland of Tianshan Mountains 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:以中国科学院巴音布鲁克草原生态系统研究站长期围栏内外的羊茅（Festuca ovina）、天山赖草（Leymus tiansecalinus）、二裂委陵菜（Potentilla bifurca）和鹅绒委陵菜（Potentilla anserine）4种植物叶片和土壤为研究对象，分析了放牧与围封对植物叶片和土壤C、N、P的化学计量特征的影响。结果表明，围封样地土壤养分浓度整体高于放牧样地（P<0.05），全氮（TN）浓度除外。围封显著增加羊茅叶片C、N浓度（P<0.05），对P浓度影响不显著；围封显著增加鹅绒委陵菜叶片的C浓度，但是显著降低叶片的N和P浓度（P<0.05），围封对天山赖草和二裂委陵菜养分含量影响不显著。围封显著增加鹅绒委陵菜C：N和C：P（P<0.05）；围封显著降低羊茅C：N、C：P和增加N：P（P<0.05）；围封显著降低二裂委陵菜C：N（P<0.05），对天山赖草的化学计量特征影响不显著。不同植物对围封的响应不同，意味着长期围封可能会改变天山高寒草原生态系统的结构。围封降低优势种（羊茅）的固碳能力，增加退化期出现的代表性植物（鹅绒委陵菜）的固碳能力，表明在长期围封下植物凋落物中的杂类草（鹅绒委陵菜）可能更多的为土壤提供碳来源，也能促进优势禾本科物种的氮含量和碳含量的增加。 Abstract:To determine effects of grazing and enclosure on the ecological stoichiometry characteristics, we evaluated the carbon(C),nitrogen(N),and phosphorus(P) contents in soil and leaves of four plants, which were Festuca ovina, Leymus tiansecalinus, Potentilla bifurca and Potentilla anserine, inside and outside the fence of the Bayinbuluk Grassland Ecological Research Station, Chinese Academy of Sciences. The results showed that soil nutrient content of enclosed grassland was significantly higher than that of grazing site, except total nitrogen (TN) content (P<0.05). The enclosure significantly increased the content of C and N in the leaves of Festuca ovina (P<0.05), but it did not significantly affect the content of P. The enclosure significantly increased the C content (P<0.05), but it significantly reduced the N and P content in the leaves of Potentilla anserine. Effects of the enclosure on the nutrient content of Leymus tiansecalinus and Potentilla bifurca were not significant. The enclosure significantly increased C:N and C:P of Potentilla anserine (P<0.05), while it significantly reduced C:N, C:P and increased N:P of Festuca ovina(P<0.05). The enclosure significantly reduced C:N of Potentilla bifurca(P<0.05), but it had no significant effect on the stoichiometric characteristics of Leymus tiansecalinus. The different species had different responses to the enclosure, meaning that long-term enclosure may change the structure of the Tianshan alpine grassland ecosystem. The enclosure reduced the carbon sequestration capacity of the dominant plant species (Festuca ovina) and increased the carbon sequestration capacity of the forb (Potentilla anserine) in the degradation stage. In long-term enclosure, Potentilla anserine may provide more carbon for the soil, and it also could promote nitrogen and carbon content of the dominant grass species. 参考文献 相似文献 引证文献

[Effects of slope direction on soil nutrient and its ecological stoichiometry in bamboo forest].

We analyzed the effects of slope direction on soil nutrients and ecological stoichiometry by collecting soil samples from different slope directions (shady slope and sunny slope) of the bamboo forest in Longyou County, Zhejiang Province. The results showed that soil nutrients were affected by slope direction and soil depth. The nutrients level of soils in the sampling area showed the trends of shady slope > sunny slope, and surface soil > bottom soil. Compared to sunny slope, the cation exchange capacity (CEC), the contents of total organic carbon, total nitrogen, alkaline hydrolyzed nitrogen, available phosphorus, total potassium and available potassium of shady soils significantly increased by 43.7%, 103.8%, 92.0%, 75.5%, 22.4%, 89.4% and 240.7%, respectively. There was no significant difference in total phosphorus contents between shady slope and sunny slope. At all soil layers, there was no significant difference of C/N ratio between shady and sunny slopes. The average C/P ratio of shady slope was 180.8%, 42.0% and 54.3% higher than that of sunny slope at 0-20 cm, 20-40 cm and 40-60 cm, respectively. At each soil layer, the average C/K and N/K ratios between shady and sunny slopes had no significant difference. The average C/K and N/K ratios of shady slope and sunny slope were all significantly different among the three soil layers. In the shady slope, the contents of soil organic carbon showed significantly positive correlation with total nitrogen, total phosphorus, total potassium, and soil available nutrients. Overall, soil nutrients and ecological stoichiometry characteristics of shady slope of bamboo forest were superior to those of sunny slope.

[Soil ecological stoichiometry characteristics under different types of biological soil crusts in the hilly Loess Plateau region, China].

Biological soil crusts (biocrusts) play an important role in soil nutrient accumulation and cycling. We examined the relationship between soil nutrient characters and biocrusts types, with six typical types of biocrusts in the hilly Loess Plateau region, including light cyanobacterial crust, dark cyanobacterial crust, cyanobacterial with moss crust (mixed crusts), moss crust, Diploschistes spp. crust, and Nostoc commune crust. The variations of soil carbon (C), nitrogen (N), phospho-rus (P) concentrations and stoichiometric ratios of biocrustal layer and the subsoil under different types of biocrusts were investigated. The results showed that there were significant differences in C, N, P concentrations and stoichiometric ratio among different biocrusts types. The concentrations and stoichiometric ratios of C, N, P in the biocrustal layer were significantly higher than those of 0-10 cm soil beneath biocrusts. The concentrations of C and N significantly decreased with the increases of soil depth across all the biocrusts types. P content showed no variation between soil layers. The concentrations and stoichiometric ratios of C, N, P of moss crust were significantly higher than those of other biocrusts,with C, N, and P content of 27.07, 2.42 and 0.67 g·kg-1. In soil layer of 0-2 cm, the concentrations and stoichiometric ratios of C, N, P under N. commune crust were significantly higher than those of other biocrusts.

Decomposition dynamics and ecological stoichiometry of Quercus acutissima and Pinus densiflora litter in the Grain to Green Program Area of northern China

Litter decomposition and ecological stoichiometry of nutrient release is an important part of material cycling and energy flow in forest ecosystems. In a study of the ecological stoichiometry and nutrient release during litter decomposition in a pine–oak forest ecosystem of the Grain to Green Program (GTGP) area of northern China, a typical pine and oak species (PDS: Pinusdensiflora Sieb., QAC: Quercusacutissima Carr.) were selected in the Taiyi Mountain study area. The ecological stoichiometry characteristics of carbon (C), nitrogen (N) and phosphorus (P) and litter decomposition dynamics were studied by field sampling and quantitative analyses. The results showed the following. (1) The decomposition dynamics of both litters was slow-fast-slow. The most important climatic factor affecting the litter decomposition rate from May to October was precipitation and temperature from November to April of the following year. (2) Throughout the 300-day study, in both litters, C of the two litters was released, N first accumulated and was then released, and P exhibited a release-accumulate-release pattern. (3) C:P was significantly higher than C:N and N:P (p < 0.05); the C:N of PSD litter was higher than that of QAC (p < 0.05), but the N:P of QAC litter was higher than that of PSD litter (p < 0.05). The C:N of both litters was very high in the study area, indicating that the nutrient release ability during litter decomposition in the two typical pine–oak forest ecosystems was relatively weak; therefore, more attention should be paid to nitrogen-fixing species and mixed forests in the GTGP area of northern China.

Ecological stoichiometry characteristics of the leaf–litter–soil continuum of Quercus acutissima Carr. and Pinus densiflora Sieb. in Northern China

To research the nutrient circulation laws of the pine-oak forest ecosystem, this paper studied the ecological stoichiometry characteristics of organic carbon (C), total nitrogen (N) and total phosphorus (P) in the two “leaf–litter–soil” continuums (QAC: Quercus acutissima Carr., PDS: Pinus densiflora Sieb.) in China and their intrinsic relationships. Results showed that (1) Contents of C, N and P in the two continuums were C > N > P, and total contents of the different components were leaf > litter > soil. (2) Ecological stoichiometry characteristics of C, N and P in the two continuums were C:P > C:N > N:P. For the different components, the C:N and C:P were litter > leaf > soil, and the N:P was leaf > litter > soil. (3) Content of C in leaves was higher than that of the global and Chinese values and indicated that their defense capabilities against outside environmental forces were very strong. While contents of N and P in soil were lower than that of the global and Chinese values. Therefore, attention should be paid to selecting nitrogen fixing species and strengthening the construction of a mixed forest in mountainous area of northern China and similar areas around the world.

Effects of water level and competition pattern on ecological stoichiometry characteristics of a typical wetland plant &lt;i&gt;Polygonum hydropiper&lt;/i&gt; in Lake Dongting

以洞庭湖典型湿地植物辣蓼为目标植物，短尖苔草为邻近植物，通过控制实验研究不同水位（30、0和-30 cm）和竞争（无竞争、全部竞争、地上竞争和地下竞争）模式下目标植物生长及生态化学计量特征的变化.结果表明：水位处理显著影响不同竞争模式下的生物量积累，辣蓼生物量随水位增加显著降低；-30 cm水位无竞争模式下生物量最大，为10.84±1.52 g.在30 cm和0 cm水位梯度下，不同竞争模式下的生物量间无显著差异.但-30 cm水位下，地下竞争模式下的辣蓼生物量积累较全竞争模式和地上竞争模式下显著增多，说明非胁迫条件下，辣蓼和苔草的竞争以地上竞争为主.水位处理对辣蓼叶片、茎和根的氮、磷含量影响显著，30 cm水位下，叶片氮、磷含量显著高于其他水位下的含量.在-30 cm水位下，叶片C：N和C：P显著高于其他水位下的比值，分别为48.08±3.85、590.3±43.4.相比于对照处理（无竞争），竞争作用下的辣蓼总氮含量降低，而C：N值增加，N：P值降低，这可能是因为竞争作用导致辣蓼对氮的吸收减少所致.;Taking Polygonum hydropiper as the target plant and Carex brevicuspis as the adjacent plant, the changes of growth and ecological stoichiometry characteristics of P. hydropiper under different water levels(30 cm, 0 cm and -30 cm)and competition patterns (no competition, full competition, above-ground competition and below-ground competition) were studied through outdoor control experiments. The results showed that:the biomass accumulation of P. hydropiper was significantly affected by water level under different competition patterns, and which decreased significantly with the increase of water level. The maximum biomass was 10.84±1.52 g in the no competition pattern with the -30 cm water level. Under 30 cm and 0 cm water levels, the biomass accumulation of P. hydropiper had insignificant difference under different competition patterns. However, at -30 cm water level, the biomass accumulation of P. hydropiper under the below-ground competition pattern was significantly higher than that under the full competition pattern and the above-ground competition pattern, which indicated that the competition between P. hydropiper and C. brevicuspis was dominated by the above-ground competition under the non-stress condition. The nitrogen and phosphorus contents in leaves, stems and roots of P. hydropiper were significantly affected by water level. The nitrogen and phosphorus contents of leaves were significantly higher at 30 cm water level than those at other water levels. At -30 cm water level, the ratio of C:N and C:P was significantly higher than those at other water levels, which was 48.08±3.85 and 590.3±43.4, respectively. Compared with the control treatment, competition decreased the total nitrogen content of P. hydropiper, while the C:N ratio increased and the N:P ratio decreased, which may be due to that the competition reduced the nitrogen absorption of P. hydropiper.