按提交时间
按主题分类
按作者
按机构
  • Leaf morpho-physiology and phytochemistry of olive trees as affected by cultivar type and increasing aridity

    分类: 生物学 >> 生态学 提交时间: 2022-11-08 合作期刊: 《干旱区科学》

    摘要:

  • Competition, spatial pattern, and regeneration of Haloxylon ammodendron and Haloxylon persicum communities in the Gurbantunggut Desert, Northwest China

    分类: 生物学 >> 生态学 提交时间: 2022-11-08 合作期刊: 《干旱区科学》

    摘要:

  • Leaf stoichiometry of Leontopodium lentopodioides at high altitudes on the northeastern Qinghai-Tibetan Plateau, China

    分类: 生物学 >> 生态学 提交时间: 2022-11-08 合作期刊: 《干旱区科学》

    摘要:

  • Manipulated precipitation regulated carbon and phosphorus limitations of microbial metabolisms in a temperate grassland on the Loess Plateau, China

    分类: 生物学 >> 生态学 提交时间: 2022-11-08 合作期刊: 《干旱区科学》

    摘要:

  • Effects of native and invasive Prosopis species on topsoil physiochemical properties in an arid riparian forest of Hormozgan Province, Iran

    分类: 生物学 >> 生态学 提交时间: 2022-11-08 合作期刊: 《干旱区科学》

    摘要:

  • 免灌人工梭梭林生长与土壤水分变化的耦合关系

    分类: 生物学 >> 生态学 提交时间: 2022-10-21 合作期刊: 《干旱区地理》

    摘要:为了研究古尔班通古特沙漠荒漠-绿洲过渡带区域龟裂土立地条件下免灌人工梭梭林生
    态特征,探讨林分的最佳建植密度,对莫索湾1983—2021年38 a集水造林地初始种植梭梭、梭梭自
    然更新苗及不同坡位的土壤水分进行了调查,研究了梭梭生长对密度差异的响应,同时分析了各
    林地土壤水分的变化特征,探讨了梭梭生长与土壤水分的关系,以期为人工梭梭林的营建与可持
    续性提供科学依据。结果表明:(1)当梭梭造林密度为6 m×3.5 m时(480 株·hm-2),母树存活率最
    高。随造林密度增大,母树保存率与梭梭自然更新比逐渐下降;母树保留密度越大的林地,其长势
    越差、生物量越低;盖度、郁闭度越高的林地,阻碍浅层土壤水分的补给,导致梭梭更新苗长势及生
    物量越差。(2)梭梭母树的林木生长与其根部140~280 cm深度土壤含水量之间均呈显著负相关
    (P<0.05),且主要利用根部140~240 cm土壤水分,对比3个林地可知该层土壤水分含量越高的林
    地,其母树的长势越好、生物量越高。(3)当母树保留密度为360株·hm-2(株行距4 m×7 m)时,梭梭
    长势较好、整体生物量最高,林下植被更为丰富,林地土壤水分条件相对较好。综上所述,在该地
    区进行集水造林时,保持该密度更有利于免灌人工梭梭林结构稳定、持续发挥防风固沙效益。

  • 腾格里沙漠不同类型沙丘土壤水分含量与地形-植被因子 关系研究

    分类: 生物学 >> 生态学 提交时间: 2022-10-21 合作期刊: 《干旱区地理》

    摘要:土壤水分是沙区主要的生态限制因子,其分布受气候、地形和植被等众多因素的影响。以
    腾格里沙漠沙坡头地区3种类型的沙丘(固定沙丘、半固定沙丘和流动沙丘)为研究对象,利用方差
    分析和冗余分析(RDA)等方法对沙丘不同部位和不同深度土壤水分的分布特征及其与地形-植被
    因子之间的关系进行了综合分析。结果表明:(1)不同类型沙丘上0~300 cm的土壤水分随着深度
    的增加而增加,表层土壤水分的波动程度大于中层和深层。(2)固定沙丘不同部位及不同深度的土
    壤水分之间没有明显的差异,半固定沙丘和流动沙丘迎风坡与丘底的土壤水分高于背风坡和丘
    顶。(3)固定沙丘上的土壤水分受地形-植被因子的影响较半固定沙丘和流动沙丘小,影响固定沙
    丘土壤水分的主要因子有坡向、高差和灌木多度。(4)地形-植被因子与研究区绝大多数半固定沙
    丘和流动沙丘的土壤水分均有负相关关系。研究揭示了腾格里沙漠土壤水分的分布规律及其与
    地形-植被因子的关系,对制定相应的防风固沙措施以及建立科学合理的植物固沙模式有积极的
    指导作用。

  • 东祁连山高寒草甸土壤理化性质对海拔和坡向的响应及 其与植被特征的关系

    分类: 生物学 >> 生态学 提交时间: 2022-10-21 合作期刊: 《干旱区地理》

    摘要:为了探索高寒草甸土壤理化性质对海拔和坡向的响应及其与植被的关系,以东祁连山高寒
    草甸为研究对象,分析了7个海拔和2个坡向高寒草甸的土壤养分含量和生态化学计量比变化规
    律及其与植被的关系。结果表明:(1)土壤含水量、电导率、有机碳、全氮、全钾、碱解氮、速效磷、速
    效钾含量、碳磷比(C/P)和氮磷比(N/P)随海拔的升高呈先升高后降低的趋势,土壤容重、全磷和碳
    氮比(C/N)呈先降低后升高的趋势。(2)同一海拔,大部分海拔梯度阳坡的土壤土壤容重、速效钾、
    电导率和全磷高于阴坡,阳坡的土壤含水量、速效磷、C/P和N/P低于阴坡,海拔3200 m梯度以下阳
    坡的土壤有机碳、全氮、碱解氮和C/N低于阴坡。(3)不同海拔和坡向的高寒草甸土壤C/N、C/P和N/P
    处于14.55~38.13、12.61~87.94和0.27~5.01之间。(4)冗余分析(RDA)发现,土壤容重、全氮和速效
    磷是影响高寒草甸植被的关键土壤因子,聚类分析发现海拔3200~3400 m的阴坡和阳坡聚为一
    类。综上所述,东祁连山高寒草甸土壤养分和生态化学计量比随海拔和坡向的变化呈规律性变
    化,基于对N/P比的分析发现,该区域高寒草甸类草原的初级生产力主要受土壤氮限制且低海拔和
    高海拔区域尤为明显,基于聚类分析发现,海拔3000 m和3400 m是该区域草地植被和土壤特征发
    生变化的临界线。建议在高寒草甸类草原的管理过程中,应该充分考虑海拔和坡向的分异性特征。

  • 宁夏河东沙地不同坡度柠条绵鸡儿(Caragana korshinskii)水分利用策略差异

    分类: 生物学 >> 生态学 提交时间: 2022-08-09 合作期刊: 《干旱区地理》

    摘要:为探讨全球气候变化背景下多元线性混合模型(IsoSource)和贝叶斯混合模型(MixSIAR)解析宁夏河东沙地柠条绵鸡儿(Caragana korshinskii)水分利用策略差异及适用性,利用氢氧稳定同位素技术,结合直接对比法、IsoSource模型和MixSIAR模型对比分析不同坡度(6°、10°、16°和24°)样地柠条绵鸡儿在生长季不同时期对各潜在水源的利用率,并评估两种模型的植物水分溯源效果。结果表明:柠条绵鸡儿对不同土层深度土壤水的利用存在明显的季节性差异,生长季初期,随着坡度的增大,柠条绵鸡儿对中层土壤水的利用率呈现出先增大后减小的趋势;生长季中期,随坡度增大,柠条绵鸡儿主要水分来源由深层土壤转移至浅层土壤;生长季后期,柠条绵鸡儿主要水分来源随着坡度的增大由浅层土壤转移至深层土壤。基于直接对比法的定性判断结果,IsoSource模型和MixSIAR模型计算坡度6°、10°和16°样地柠条锦鸡儿主要水分来源利用率的适用性均较高;而Mix⁃SIAR模型计算坡度24°样地柠条绵鸡儿主要的水分来源以及其贡献率具有更高的可靠性。Iso⁃Source模型更适合解析较小坡度(6°和16°)样地柠条绵鸡儿的水分利用策略;而MixSIAR模型解析较大坡度(10°和24°)样地柠条绵鸡儿水分利用策略的适用性更好。研究结果可为我国干旱区植物水分来源鉴别方法的选择提供科学参考。

  • 基于Cubist 模型的天山北坡草地鼠群密度时空分布特征

    分类: 生物学 >> 生态学 提交时间: 2022-08-09 合作期刊: 《干旱区地理》

    摘要:鼠害是影响草原生态健康的重要因素,了解小型啮齿动物种群密度时空分布特征,对精准的鼠害综合防治具有重要意义。以往对小型啮齿动物时空分布的研究多局限于静态的站点分布或小范围的种群密度时间变化分析,缺乏对较大时空尺度小型啮齿动物种群密度变化的分析。从已发表的文献中收集了天山北坡草地1982—2015年小尺度的有效洞口密度实地调查信息,同时结合环境因子数据,再根据海拔将研究区划分为≤900 m和>900 m 2类,运用Cubist模型和随机森林模型,分析有效洞口密度时空分布。结果表明:(1)1982—2015年天山北坡海拔≤900 m地区的有效洞口密度总体呈增加趋势,而海拔>900 m的地区总体呈减少趋势。基于Cubist模型构建有效洞口密度与环境因子的模型拟合精度明显优于随机森林模型。(2)植被状况、气象因子和放牧强度是天山北坡有效洞口密度时空分布主要的环境驱动因素。在天山北坡内海拔≤900 m和>900 m的地区中,有效洞口密度的驱动机制存在着显著差异。(3)在海拔≤900 m地区,影响有效洞口密度时空分布主要是叶面积指数,而对于海拔>900 m地区为归一化植被指数。这可能是受到大沙鼠(Rhom⁃bomys opimus)和黄兔尾鼠(Eolagurus luteus)消耗不同类型植被的影响。

  • Tree-ring δ15N of Qinghai spruce in the central Qilian Mountains of China: Is pre-treatment of wood samples necessary?

    分类: 生物学 >> 生态学 提交时间: 2022-06-20 合作期刊: 《干旱区科学》

    摘要:Abstract: A knowledge of the tree-ring stable nitrogen isotope ratio (δ15N) can deepen our understanding of forest ecosystem dynamics by indicating the long-term availability, cycling and sources of nitrogen (N). However, the radial mobility of N blurs the interannual variations in the long-term N records. Previous studies of the chemical extraction of tree rings before analysis had produced inconsistent results and it is still unclear whether it is necessary to pre-treat wood samples from specific tree species to remove soluble N compounds before determining the δ15N values. We compared the effects of pre-treatment with organic solvents and hot ultrapure water on the N concentration and δ15N of tree rings from endemic Qinghai spruce (Picea crassifolia) growing in the interior of the central Qilian Mountains, China, during the last 60 a. We assessed the effects of different preparation protocols on the removal of the labile N compounds and investigated the need to pre-treat wood samples before determining the δ15N values of tree rings. Increasing trends of the tree-ring N concentration were consistently observed in both the extracted and unextracted wood samples. The total N removed by extraction with organic solvents was about 17.60%, with a significantly higher amount in the sapwood section (P<0.01). The δ15N values of tree rings decreased consistently from 1960 to 2019 in both the extracted and unextracted wood samples. Extraction with organic solvents increased the δ15N values markedly by about 5.2‰ and reduced the variations in the δ15N series. However, extraction with hot ultrapure water had little effect, with only a slight decrease in the δ15N values of about 0.5‰. Our results showed that the radial pattern in the inter-ring movement of N in Qinghai spruce was not minimized by extraction with either organic solvents or hot ultrapure water. It is unnecessary to conduct hot ultrapure water extraction for the wood samples from Qinghai spruce because of its negligible effect on the removal of the labile N. The δ15N variation trend of tree rings in the unextracted wood samples was not influenced by the heartwood–sapwood transition zone. We suggest that the δ15N values of the unextracted wood samples of the climate-sensitive Qinghai spruce could be used to explore the ecophysiological dynamics while focusing on the long-term variations.

  • Dependency of litter decomposition on litter quality, climate change, and grassland type in the alpine grassland of Tianshan Mountains, Northwest China

    分类: 生物学 >> 生态学 提交时间: 2022-06-17 合作期刊: 《干旱区科学》

    摘要:

    Abstract: Litter decomposition is an important component of the nutrient recycling process and is highly sensitive to climate change. However, the impacts of warming and increased precipitation on litter decomposition have not been well studied, especially in the alpine grassland of Tianshan Mountains. We conducted a manipulative warming and increased precipitation experiment combined with different grassland types to examine the impact of litter quality and climate change on the litter decomposition rate based on three dominant species (Astragalus mongholicus, Potentilla anserina, and Festuca ovina) in Tianshan Mountains from 2019 to 2021. The results of this study indicated there were significant differences in litter quality, specific leaf area, and leaf dry matter content. In addition, litter quality exerted significant effects on litter decomposition, and the litter decomposition rate varied in different grassland types. Increased precipitation significantly accelerated the litter decomposition of P. anserina; however, it had no significant effect on the litter decomposition of A. mongholicus and F. ovina. However, warming consistently decreased the litter decomposition rate, with the strongest impact on the litter decomposition of F. ovina. There was a significant interaction between increased precipitation and litter type, but there was no significant interaction between warming and litter type. These results indicated that warming and increased precipitation significantly influenced litter decomposition; however, the strength was dependent on litter quality. In addition, soil water content played a crucial role in regulating litter decomposition in different grassland types. Moreover, we found that the litter decomposition rate exhibited a hump-shaped or linear response to the increase of soil water content. Our study emphasizes that ongoing climate change significantly altered litter decomposition in the alpine grassland, which is of great significance for understanding the nutrient supply and turnover of litter.

  • Water use characteristics of different pioneer shrubs at different ages in western Chinese Loess Plateau: Evidence from δ2H offset correction

    分类: 生物学 >> 生态学 提交时间: 2022-06-17 合作期刊: 《干旱区科学》

    摘要:

    Abstract: Caragana korshinskii Kom. and Tamarix ramosissima Ledeb. are pioneer shrubs for water and soil conservation, and for windbreak and sand fixation in arid and semi-arid areas. Understanding the water use characteristics of different pioneer shrubs at different ages is of great importance for their survival when extreme rainfall occurs. In recent years, the stable isotope tracing technique has been used in exploring the water use strategies of plants. However, the widespread δ2H offsets of stem water from its potential sources result in conflicting interpretations of water utilization of plants in arid and semi-arid areas. In this study, we used three sets of hydrogen and oxygen stable isotope data (δ2H and δ18O, corrected δ2H_c1 based on SW-excess and δ18O, and corrected δ2H_c2 based on −8.1‰ and δ18O) as inputs for the MixSIAR model to explore the water use characteristics of C. korshinskii and T. ramosissima at different ages and in response to rainfall. The results showed that δ2H_c1 and δ18O have the best performance, and the contribution rate of deep soil water was underestimated because of δ2H offset. During the dry periods, C. korshinskii and T. ramosissima at different ages both obtained mostly water from deeper soil layers. After rainfall, the proportions of surface (0–10 cm) and shallow (10–40 cm) soil water for C. korshinskii and T. ramosissima at different ages both increased. Nevertheless, there were different response mechanisms of these two plants for rainfall. In addition, C. korshinskii absorbed various potential water sources, while T. ramosissima only used deep water. These flexible water use characteristics of C. korshinskii and T. ramosissima might facilitate the coexistence of plants once extreme rainfall occurs. Thus, reasonable allocation of different plants may be a good vegetation restoration program in western Chinese Loess Plateau.

  • Spatiotemporal variations and driving factors of habitat quality in the loess hilly area of the Yellow River Basin: A case study of Lanzhou City, China

    分类: 生物学 >> 生态学 提交时间: 2022-06-17 合作期刊: 《干旱区科学》

    摘要:

    Abstract: Rapid industrialization and urbanization have led to the most serious habitat degradation in China, especially in the loess hilly area of the Yellow River Basin, where the ecological environment is relatively fragile. The contradiction between economic development and ecological environment protection has aroused widespread concern. In this study, we used the habitat quality of Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST-HQ) model at different scales to evaluate the dynamic evolution characteristics of habitat quality in Lanzhou City, Gansu Province of China. The spatiotemporal variations of habitat quality were analyzed by spatial autocorrelation. A Geographical Detector (Geodetector) model was used to explore the driving factors that influencing the spatial differentiation of habitat quality, including natural factors, socio-economic factors, and ecological protection factors. The results showed that the habitat quality index of Lanzhou City decreased from 0.4638 to 0.4548 during 2000–2018. The areas with reduced the habitat quality index were mainly located in the Yellow River Basin and Qinwangchuan Basin, where are the main urban areas and the new economic development areas, respectively. The spatial distribution of habitat quality presented a trend of high in the surrounding areas and low in the middle, and showed a significant positive spatial autocorrelation. With the increase of study scale, the spatial distribution of habitat quality changed from concentrated to dispersed. The spatial differentiation of habitat quality in the study area was the result of multiple factors. Among them, topographic relief and slope were the key factors. The synergistic enhancement among these driving factors intensified the spatial differentiation of habitat quality. The findings of this study can provide a scientific basis for land resources utilization and ecosystem restoration in the arid and semi-arid land.

  • Changes in diversity, composition and assembly processes of soil microbial communities during Robinia pseudoacacia L. restoration on the Loess Plateau, China

    分类: 生物学 >> 生态学 提交时间: 2022-06-13 合作期刊: 《干旱区科学》

    摘要:

    Abstract: Robinia pseudoacacia L. (RP) restoration has increased vegetation cover in semi-arid regions on the Loess Plateau of China, but ecological problems have also occurred due to RP restoration, such as reduced soil moisture. Further, it is still uncertain how microbial diversity, composition and assembly processes change with RP restoration in semi-arid regions. Therefore, amplicon sequencing of small subunit ribosomal ribonucleic acid (16S rRNA) and internal transcribed spacer (ITS) genes was performed to study soil bacterial and fungal diversity, composition and assembly processes at four study sites with different stand ages of RP plantations (Y10, RP plantation with stand ages less than 10 a; Y15, RP plantation with stand ages approximately 15 a; Y25, RP plantation with stand ages approximately 25 a; and Y40, RP plantation with stand ages approximately 40 a) along a 40-a chronosequence on the Loess Plateau. The diversity of soil bacteria and fungi increased significantly during the restoration period from 10 to 15 a (P<0.05). However, compared with Y15, bacterial diversity was lower at Y25 and Y40, and fungal diversity remained stable during the restoration period between 25 and 40 a. The relative abundances of Proteobacteria and Ascomycota increased during the restoration period from 10 to 15 a. Conversely, after 15 a of restoration, they both decreased, whereas the relative abundances of Actinomycetes, Acidobacteria and Basidiomycota gradually increased. The variations in soil bacterial communities were mainly related to changes in soil total nitrogen, nitrate nitrogen and moisture contents, while soil fungal communities were mainly shaped by soil organic carbon and nitrate nitrogen contents. Bacterial communities were structured by the heterogeneous selection and stochastic process, while fungal communities were structured primarily by the stochastic process. The RP restoration induced an increase in the relative importance of heterogeneous selection on bacterial communities. Overall, this study reveals the changes in microbial diversity, community composition and assembly processes with RP restoration on the Loess Plateau and provides a new perspective on the effects of vegetation restoration on soil microbial communities in semi-arid regions.

  • 干旱区梨园不同覆盖条件下土壤环境因子综合性评价研究

    分类: 生物学 >> 生态学 提交时间: 2022-06-09 合作期刊: 《干旱区地理》

    摘要:

    在干旱沿黄灌区开展不同覆盖材料配合滴灌的灌溉保墒方式下,进一步研究了不同覆盖方
    式对梨园全生育期的土壤理化性状和养分含量变化影响,分析了土壤温度、水分、pH等和矿质营养
    元素间的相互关系,对覆盖后的土壤质量进行了综合性评价。试验处理分为无覆盖对照(T1)、园
    艺地布覆盖(T2)、玉米秸秆覆盖(T3)和黑地膜覆盖(T4)4个处理;试验设计为随机区组设计,每个
    处理小区均为167株梨树(约占地667 m2),重复3次;各小区土样分0~20 cm、20~40 cm、40~60 cm
    土层取样。结果表明:(1)园艺地布和黑地膜覆盖处理有一定的增温效应,而玉米秸秆覆盖有较好
    的降温和稳温效应,且增墒效应明显,土壤含水率比其他3种处理显著提高了1.0%~2.7%。(2)相较
    无覆盖处理,黑地膜覆盖可提升表层土壤pH,并加速表层土壤有机质的分解,有机质含量较无覆盖
    处理下降33.1%;玉米秸秆覆盖可显著降低各土层的土壤pH,降低范围为1.8%~4.6%,并促进0~20
    cm土层有机质的提升,土壤有机质含量增加12.2%;园艺地布覆盖下0~40 cm土层内土壤有机质含量
    和全盐量均有降低。(3)黑地膜覆盖下0~20 cm和20~40 cm土层的碱解氮含量分别为73.00 mg·g-1和
    64.53 mg·g-1,均显著地高于无覆盖处理,无覆盖条件下土壤碱解氮在深层(40~60 cm土层)积累较
    多,显著地高于玉米秸秆和黑地膜覆盖;各处理0~20 cm和20~40 cm土层速效磷含量差异显著,大
    小顺序均为T4>T3>T2>T1,玉米秸秆覆盖可提升土壤速效钾和速效铁的含量。(4)进行主成分分析
    表明不同覆盖方式对梨园浅层土壤环境因子的影响要明显大于深层土壤,在0~40 cm土层内各覆
    盖处理效果均好于无覆盖处理,其中玉米秸秆覆盖在0~20 cm和20~40 cm土层综合得分分别为
    1.189和0.326,覆盖效果最佳。

  • 胡麻生理生化代谢指标对干旱胁迫的 响应及其模拟模型的研究

    分类: 生物学 >> 生态学 提交时间: 2022-06-08 合作期刊: 《干旱区地理》

    摘要:

    为进一步研究胡麻生理生化代谢指标响应干旱胁迫时对胡麻产量的影响,采用盆栽控水法模拟胡麻干旱胁迫,依据2013—2014年甘肃省定西市西巩驿镇胡麻试验数据,建立并检验胡麻干旱胁迫模型,模拟干旱胁迫时对胡麻生理生化指标及产量影响,利用均方根误差(RMSE)和决定系数(R2)描述模型拟合度。结果表明:(1)模型产量模拟值的RMSE为41.3159~155.6685 kg·hm-2,平均值为80.1837 kg·hm-2;R2为0.8929~0.9894,平均值为0.9387,该模型具有较好的拟合度、可行性也较强。(2)在重度干旱胁迫下,抗氧化代谢指标——超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)中,CAT活性表现趋势为下降,终花期POD活性增幅(26.09%~28.00%)最大;渗透调节的3种物质含量均显著上升,其中脯氨酸增幅最大,达236.22%。(3)呈现出极显著相关性的各指标有3组,分别是脯氨酸与叶绿素、丙二醛和CAT活性;可溶性蛋白与丙二醛和CAT活性;POD活性与SOD活性。胡麻生理生化指标响应不同程度干旱胁迫与胡麻的产量有极强的关联,此模型的建立是对胡麻生理生化指标响应干旱胁迫的科学补充,进一步为胡麻的高效生产管理及农业生产系统提供理论依据和支持。

  • 华北一作区马铃薯生长发育及产量对干旱胁迫响应的模拟研究 ——以武川县为例

    分类: 生物学 >> 生态学 提交时间: 2022-06-08 合作期刊: 《干旱区地理》

    摘要:

    为探究不同程度干旱胁迫对华北一作区马铃薯生长发育及产量的影响,以内蒙古呼和浩特市武川县为例,基于多年马铃薯生长发育资料和气象资料,对APSIM-Potato模型进行调参与验证,评价模型在武川地区的适用性。利用验证后的模型模拟马铃薯叶面积指数(LAI)、地上部生物量和产量对不同发育阶段干旱胁迫的响应。结果表明:(1)各发育阶段天数的模拟值与实测值的均方根误差(RMSE)均在3 d内;LAI、地上部生物量和产量的模拟值与实测值的归一化均方根误差(NRMSE)分别为12.82%、17.35%和14.48%,均低于20%,表明APSIM-Potato模型在武川地区具有较好的适用性。(2)随着干旱胁迫时间和强度的增加,马铃薯LAI、地上部生物量和产量随之减小。模拟单一发育阶段干旱胁迫时,马铃薯LAI、地上部生物量和产量对分枝-开花期水分胁迫的响应最大;模拟连续发育阶段干旱胁迫时,LAI、地上部生物量和产量对全生育期水分胁迫的响应最大。

  • 根系水分胁迫响应函数对土壤水及作物生长动态和产量模拟影响的研究

    分类: 生物学 >> 生态学 提交时间: 2022-04-16 合作期刊: 《干旱区地理》

    摘要:

    为探究根系水分胁迫响应函数对农田水分动态及产量模拟的影响,基于Richards方程和 PS123作物生长模型分别进行了土壤水分动态和小麦产量的模拟,对比分析了VGS型曲线)、MP (凹凸型曲线)及LSS型曲线)3种水分胁迫响应函数。采用山西省霍泉站(3 a)及潇河站(
    2 a)的试验资料对模型中的土壤水力特征参数、水分胁迫响应函数参数进行反演,确定最优的参数值,得到了土壤含水率、蒸散量及籽粒产量的模拟结果。结果表明:(1VGMPLS函数条件下的土壤水 R 分及产量模拟结果均较好,回归估计标准误差(RMSE)值在0.021~0.036之间,模拟值与实测值间的检验达到了极显著水平;对于霍泉站,VGMPLS函数条件下,土壤含水率模拟值与实测值的平均相对误差分别为6.37%8.26%7.18%,相关性系数值最小为0.7814,模拟产量的平均相对误差值分别为8.73%8.40%8.42%;对于潇河站,土壤含水率模拟值与实测值的平均相对误差结果普遍大于霍泉站,最大为12.47%。(2)土壤水分动态模拟,S型曲线的水分胁迫响应函数较凹凸型曲
    线的水分胁迫响应函数表现出了更好的效果,其中使用VG函数模拟的平均相对误差较小,模拟的蒸散量更接近于实测值。(3)产量模拟,
    3种水分胁迫响应函数差异不明显。综上,VG函数是一种精度较高的根系水分胁迫响应函数,且模型简洁、方便;改进的LS函数能够提高模拟精度,但模型的稳定性有待近一步研究。

  • 油莎豆(Cyperus esculentus)耕作区作物残茬对农田风蚀的影响

    分类: 生物学 >> 生态学 提交时间: 2022-04-16 合作期刊: 《干旱区地理》

    摘要:

    油莎豆(Cyperus esculentus)是一种油料作物,其对土壤养分要求低,因此适合在我国北方风沙区推广种植,以调整农业种植结构。然而在采收过程中对土地的扰动,会潜在增加农田风蚀的风险,因此需要对油莎豆残茬的生态效益进行探究与评估。基于野外集沙实验和风速廓线测定实验,对油莎豆与梭梭间作未采收、油莎豆纯作留4垄采6垄和油莎豆纯作留6垄采63种残茬类型的防风固沙能力进行了系统研究。结果表明:油莎豆与梭梭间作残茬类型中的输沙通量最低,总输沙通量显著小于其他2种模式(P<0.05),并且空气动力学粗糙度(0.553 cm1.156 cm)和摩阻速度(0.3040.332)也最高。留4垄采6垄模式输沙通量随时间增加,甚至超过全采收模式,空气动力学粗糙度接近于0,且摩阻速度最低。留6垄采6垄模式输沙通量则介于前两者之间,空气动力学粗糙度为0.100 cm0.137 cm,摩阻速度为0.2400.272。总体而言,单一的宽条带式油莎豆残茬削减风速的作用不如高低穿插搭配的作物残茬。油莎豆种植可以考虑选择合适的采收间距及搭配合适的直立植物进行间作,以在油莎豆采收后漫长的休耕期进行留茬以减轻风蚀保护农田。休耕期合理的作物留茬是减轻土壤风蚀的关键措施之一,这对于干旱区农田的可持续发展具有重要的生态价值。