Desert Steppe In China Research Articles

Effects of Precipitation Changes on Plant Community Diversity and Soil C:N:P Ecological Stoichiometric Characteristics in a Desert Steppe of China

Studying the influence of precipitation patterns on plant community diversity, soil C:N:P ecological stoichiometric characteristics, and the relationships between key soil factors and plant community diversity is of great significance for the protection of plant community diversity in desert grasslands. This paper was studied in the desert steppe of the west of Loess Plateau using a three-year precipitation manipulation experiment (40% reduction in precipitation, 20% reduction in precipitation, natural precipitation, 20% increase in precipitation, and 40% increase in precipitation), explored the influence of changes in precipitation in dry and wet years on the diversity of plant community and soil C:N:P ecological stoichiometric characteristics. And we also explored the relationship between soil C:N:P ecological stoichiometric characteristics and the key soil factors and the diversity of plant community under changes in precipitation. The results showed that in a normal year and the drier year (2013 and 2015), Patrick richness and Shannon-Wiener diversity index were significantly low under the 20% reduction treatment compared with the control and 40% increase treatments, respectively. During the wetter year, Patrick richness and Shannon-Wiener diversity index were no different between any of the precipitation treatments. In the normal year and the drier year, the soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) contents and the carbon-nitrogen ratio (C:N), carbon-phosphorus ratio (C:P), and nitrogen-phosphorus ratio (N:P) all decreased with an increase in precipitation (the decrease in the C:N ratio was statistically significant). During the wetter year, SOC, TN, C:P, and N:P increased with an increase in precipitation. During the normal year, precipitation treatments had no significant influence on soil water content, having a limited influence on the plant community. TN, N:P, SOC, C:N, and microbial biomass nitrogen (MBN) had a more prominent influence on plant community diversity. In the wetter year, precipitation was abundant leading to a rise in soil nutrients. Water was not the most important factor limiting to plant growth whereas soil water content, soil nutrients, and ecological stoichiometric characteristics jointly regulate plant community diversity. In the drier years, precipitation treatments had a significant impact on soil water content, whereby an increase in precipitation led to high losses of soil nutrients. Therefore, soil water content was the most important factor affecting plant community diversity during drier years. These observations indicate that under dry and wet years, plant community diversity and soil C:N:P ecological stoichiometric characteristics have variable responses to precipitation and soil C:N:P effect on plant community were also different. These results provide a theoretical basis for the protection and management of desert steppe systems under future projected changes in precipitation.

Potential geographical distribution and changes of Artemisia ordosica in China under future climate change

Artemisia ordosica is a forerunner species of wind-break and sand-fixation in desert steppe in China, which plays an important role in ecosystem restoration and reconstruction. How-ever, it could influence human health. Based on 89 valid data of current distribution of A. ordosica in China and 19 typical climatic factors, the MaxEnt model was used to simulate the potential distribution of A. ordosica in China under current and two scenarios (RCP 4.5 and RCP 8.5; 2050s and 2070s). The SDM toolbox of ArcGIS software was used to analyze the potential distribution range of A. ordosica and its changes in China. The importance of key climatic factors was evaluated by comprehensive contribution rate, Jackknife method, and response curve of environmental variables. The accuracy of model was tested and evaluated by area under the curve (AUC) of the test subject working characteristic (ROC). The results showed that the MaxEnt model worked well (AUC=0.980). which predicted that A. ordosica was mainly concentrated in and around Mu Us Sandy Land, consistent with the current actual distribution range. The distribution area of A. ordosica of potential high fitness under the future two scenarios decreased by 5.2%-26.8%, which was negatively affected by future climate change. Seasonal variation of temperature, mean precipitation in the coldest season, and mean annual temperature had the greatest impact. The core area of future potential distribution of A. ordosica in China was located in Mu Us Sandy Land, with a tendency for spreading to northeast (Jilin, Heilongjiang, Liaoning and some parts of Hebei).

Effect of different grazing intensities on bacterial community composition and diversity in rhizosphere and non-rhizosphere soils in desert steppe of China

Effect of different grazing intensities on bacterial community composition and diversity in rhizosphere and non-rhizosphere soils in desert steppe of China

Soil respiration response to alterations in precipitation and nitrogen addition in a desert steppe in northern China

Global climate change is expected to significantly influence soil respiration. When limited, rainfall and nitrogen (N) deposition strongly modify soil respiration in a broad range of biomes, but uncertainty remains with regards to the influence of the interactions of seasonal rainfall distribution and N deposition on soil respiration in an arid steppe. In the present study, we manipulated precipitation using V-shaped plexiglass gutters (minus 50%, control, and plus 50% treatments) and tested various N additions (control and plus 35 kg N ha−1 yr−1) to evaluate their impact on soil respiration, measured using a Li-Cor 8100, in a desert steppe in China. Increased precipitation stimulated soil respiration by 26.1%, while decreased precipitation significantly reduced soil respiration by 10.8%. There was a significant increase in soil respiration under N addition at 11.5%. Statistical assessment of their interactions demonstrated that N supplementation strengthened the stimulation of soil respiration under increased precipitation, whereas decreased precipitation offset the positive impact of N addition and led to a reduction in soil respiration. Contrasting interannual precipitation patterns strongly influenced the temporal changes in soil respiration as well as its response to N addition, indicating that the desert steppe plant community was co-limited by water and N. Net primary productivity (aboveground and belowground) predominantly drove soil respiration under altered precipitation and N addition. As grasses are better equipped for water deficit due to their previous exposure to long periods without water, there could be a shift from forb to grass communities under drier conditions. These findings highlight the importance of assessing the differential impacts of plant traits and soil physiochemical properties on soil respiration under altered precipitation and N addition.

异质生境对荒漠草原植物群落组成和种群生态位的影响

异质生境对荒漠草原植物群落组成和种群生态位的影响

荒漠草原土壤相对湿度对猪毛蒿表型可塑性的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 荒漠草原土壤相对湿度对猪毛蒿表型可塑性的影响 DOI: 10.5846/stxb201803150512 作者: 作者单位: 宁夏大学 西北退化生态系统恢复与重建教育部重点实验室,宁夏大学 西北退化生态系统恢复与重建教育部重点实验室,宁夏大学 西北退化生态系统恢复与重建教育部重点实验室,宁夏大学 西北退化生态系统恢复与重建教育部重点实验室,宁夏大学 西北退化生态系统恢复与重建教育部重点实验室,宁夏大学 西北退化生态系统恢复与重建教育部重点实验室,宁夏大学 农学院;宁夏大学 农学院,宁夏大学 西北退化生态系统恢复与重建教育部重点实验室 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（2016YFC0500709）；宁夏高等学校一流学科建设（生态学）资助项目（NXYLXK2017B06）；宁夏自然科学基金（2018AAC03037，NZ17005）；宁夏青年科技人才托举工程（2018） Effects of heterogeneous habitats on phenotypic plasticity of Artemisia scoparia in the desert steppe of China Author: Affiliation: Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China,Ningxia University,Yinchuan,Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China,Ningxia University,Yinchuan,Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China,Ningxia University,Yinchuan,Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China,Ningxia University,Yinchuan,Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China,Ningxia University,Yinchuan,Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China,Ningxia University,Yinchuan,School of agriculture,Ningxia University,Yinchuan,Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China,Ningxia University,Yinchuan 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:猪毛蒿（Artemisia scoparia）为菊科蒿属草本植物，是一种适应性较强的广幅种。研究荒漠草原不同土壤相对湿度条件下猪毛蒿的表型可塑性，对认识异质生境下猪毛蒿的生存适应策略具有重要的生态学意义。结果表明：株高、茎粗、根长、根重和单株生物量均表现出随土壤相对湿度的增大而增加的趋势，对异质生境具有较强的可塑性，而根冠比则表现出相对的稳定性。植株不同部位生物量大小排序为：上部 < 中部 < 下部，且植株下部显著大于上部生物量（P < 0.05）。土壤相对湿度 > 40%生境下的头状花序数量和重量显著高于土壤相对湿度 < 30%和30%-40%生境。繁殖器官绝对投入量（lg R）随着个体大小（lg V）的增大呈极显著的增加（P < 0.001），繁殖阈值介于1.868-2.006 g。随着土壤相对湿度的增加，繁殖分配比例极显著增大（P < 0.001）。营养器官和繁殖器官生物量、头状花序重量和数量、地下生物量和地上生物量均呈极显著线性正相关关系（P < 0.001），存在正向权衡。单个头状花序重量并不随个体大小和头状花序数量的增加而发生显著变化（P > 0.05），且在不同土壤相对湿度和不同部位间均无显著差异（P > 0.05）。由此可见，猪毛蒿在异质生境下产生的可塑性是其生存繁殖的重要反应机制之一。 Abstract:Artemisia scoparia is a herbaceous plant of the composite family and a widely distributed species with a high degree of adaptability. The phenotypic plasticity of A. scoparia in different levels of relative soil humidity was addressed in this paper, which has important ecological significance for revealing survival adaptation strategies of A. scoparia in heterogeneous habitats. The results showed that plant height, stem diameter, root length, root weight, and biomass all showed an increasing trend with an increase in soil relative humidity; these factors exhibited strong plasticity across the soil water heterogeneous habitat, whereas the root/shoot ratio showed no change. The order of the biomass of different parts was:upper part < middle part < lower part, and the lower part was significantly heavier than the upper part (P < 0.05). The number and weight of the head inflorescence in the high soil relative humidity (> 40%) habitat were significantly greater than that in the lower soil relative humidity (< 30% and 30%-40%) habitats. The absolute input of reproductive organs (lg R) increased with the increase of individual size (lg V) and showed a significant positive correlation (P < 0.001). The reproductive threshold was between 1.868-2.006 g. With the increase of soil relative humidity, the proportion of reproductive allocation was significantly increased (P < 0.001). There were significant positive linear correlations between vegetative organs and reproductive organs, weight, number of the head inflorescences, and underground and aboveground biomass (P < 0.001). This indicated that there were positive trade-offs between each pair. However, the weight of a single head inflorescence did not change significantly with the increase of individual size or the number of head inflorescences (P > 0.05), and there were no significant differences in the different soil relative humidity habitats and for the different parts of the plant (P > 0.05). The phenotypic plasticity of A. scoparia in the heterogeneous environment of soil water is one of the important mechanisms for its survival and reproduction. 参考文献 相似文献 引证文献

Reproductive characteristics of Artemisia scoparia and the analysis of the underlying soil drivers in a desert steppe of China

Reproductive characteristics of Artemisia scoparia and the analysis of the underlying soil drivers in a desert steppe of China

Effects of nitrogen addition on plant community composition and microbial biomass ecological stoichiometry in a desert steppe in China

Effects of nitrogen addition on plant community composition and microbial biomass ecological stoichiometry in a desert steppe in China

Large herbivore‐induced changes in phytogenic hillocks: links to soil and windblown sediment on the desert steppe in China

AbstractPhytogenic hillocks are a type of wind‐deposited biological micro‐topography exhibiting a bulging shape under plant clusters in arid regions. In this study, we quantitatively measured the phenotypic characteristics of phytogenic hillocks, the soil particle size distribution in phytogenic hillocks and bare surfaces, and the sediment particle size distribution in hillocks of three heights under different grazing treatments. The results showed that the proportion of dense cluster phytogenic hillocks in the no grazing treatment was higher than in the moderate grazing treatment, and the proportion of scattered cluster phytogenic hillocks under moderate grazing was higher than under no grazing. The total area of dense cluster phytogenic hillocks under no grazing was higher than under heavy grazing and under moderate grazing. For the scattered cluster phytogenic hillocks, the total area was greatest under moderate grazing, followed by heavy grazing and, finally, no grazing. For single hillocks, grazing had a significant impact on the width of dense cluster phytogenic hillocks, while the heavy grazing treatment had a significant impact on the height of scattered cluster phytogenic hillocks. The results for windblown sediment showed that the only significant difference among grazing treatments occurred at a height of 2–8 cm. Grazing changed the relationships among the phenotypic characteristics of phytogenic hillocks, the soil particle size of phytogenic hillocks, and the particle size of wind‐deposited sediments. Our results suggested that grazing increased the proportion of scattered cluster phytogenic hillocks and caused the relationship between somewhat bare land and phytogenic hillocks to change from symbiosis to competition.

Effect of Stocking Rate on Soil-Atmosphere CH4 Flux during Spring Freeze-Thaw Cycles in a Northern Desert Steppe, China

BackgroundMethane (CH4) uptake by steppe soils is affected by a range of specific factors and is a complex process. Increased stocking rate promotes steppe degradation, with unclear consequences for gas exchanges. To assess the effects of grazing management on CH4 uptake in desert steppes, we investigated soil-atmosphere CH4 exchange during the winter-spring transition period.Methodology/Main FindingThe experiment was conducted at twelve grazing plots denoting four treatments defined along a grazing gradient with three replications: non-grazing (0 sheep/ha, NG), light grazing (0.75 sheep/ha, LG), moderate grazing (1.50 sheep/ha, MG) and heavy grazing (2.25 sheep/ha, HG). Using an automatic cavity ring-down spectrophotometer, we measured CH4 fluxes from March 1 to April 29 in 2010 and March 2 to April 27 in 2011. According to the status of soil freeze-thaw cycles (positive and negative soil temperatures occurred in alternation), the experiment was divided into periods I and II. Results indicate that mean CH4 uptake in period I (7.51 µg CH4–C m−2 h−1) was significantly lower than uptake in period II (83.07 µg CH4–C m−2 h−1). Averaged over 2 years, CH4 fluxes during the freeze-thaw period were −84.76 µg CH4–C m−2 h−1 (NG), −88.76 µg CH4–C m−2 h−1 (LG), −64.77 µg CH4–C m−2 h−1 (MG) and −28.80 µg CH4–C m−2 h−1 (HG).Conclusions/SignificanceCH4 uptake activity is affected by freeze-thaw cycles and stocking rates. CH4 uptake is correlated with the moisture content and temperature of soil. MG and HG decreases CH4 uptake while LG exerts a considerable positive impact on CH4 uptake during spring freeze-thaw cycles in the northern desert steppe in China.