Current Location:home > Browse

Institution

1. chinaXiv:202110.00019 [pdf]

Effects of different ridge-furrow mulching systems on yield and water use efficiency of summer maize in the Loess Plateau of China

CHEN Pengpeng; GU Xiaobo; LI Yuannong; QIAO Linran; LI Yupeng; FANG Heng; YIN Minhua; ZHOU Changming
Subjects: Geosciences >> Geography

Ridge-furrow film mulching has been proven to be an effective water-saving and yield-improving planting pattern in arid and semi-arid regions. Drought is the main factor limiting the local agricultural production in the Loess Plateau of China. In this study, we tried to select a suitable ridge-furrow mulching system to improve this situation. A two-year field experiment of summer maize (Zea mays L.) during the growing seasons of 2017 and 2018 was conducted to systematically analyze the effects of flat planting with no film mulching (CK), ridge-furrow with ridges mulching and furrows bare (RFM), and double ridges and furrows full mulching (DRFFM) on soil temperature, soil water storage (SWS), root growth, aboveground dry matter, water use efficiency (WUE), and grain yield. Both RFM and DRFFM significantly increased soil temperature in ridges, while soil temperature in furrows for RFM and DRFFM was similar to that for CK. The largest SWS was observed in DRFFM, followed by RFM and CK, with significant differences among them. SWS was lower in ridges than in furrows for RFM. DRFFM treatment kept soil water in ridges, resulting in higher SWS in ridges than in furrows after a period of no water input. Across the two growing seasons, compared with CK, RFM increased root mass by 10.2% and 19.3% at the jointing and filling stages, respectively, and DRFFM increased root mass by 7.9% at the jointing stage but decreased root mass by 6.0% at the filling stage. Over the two growing seasons, root length at the jointing and filling stages was respectively increased by 75.4% and 58.7% in DRFFM, and 20.6% and 30.2% in RFM. Relative to the jointing stage, the increased proportions of root mass and length at the filling stage were respectively 42.8% and 94.9% in DRFFM, 63.2% and 115.1% in CK, and 76.7% and 132.1% in RFM, over the two growing seasons, showing that DRFFM slowed down root growth while RFM promoted root growth at the later growth stages. DRFFM treatment increased root mass and root length in ridges and decreased them in 0–30 cm soil layer, while RFM increased them in 0–30 cm soil layer. Compared with CK, DRFFM decreased aboveground dry matter while RFM increased it. Evapotranspiration was reduced by 9.8% and 7.1% in DRFFM and RFM, respectively, across the two growing seasons. Grain yield was decreased by 14.3% in DRFFM and increased by 13.6% in RFM compared with CK over the two growing seasons. WUE in CK was non-significantly 6.8% higher than that in DRFFM and significantly 22.5% lower than that in RFM across the two growing seasons. Thus, RFM planting pattern is recommended as a viable water-saving option for summer maize in the Loess Plateau of China.

submitted time 2021-10-11 From cooperative journals:《Journal of Arid Land》 Hits5422Downloads219 Comment 0

2. chinaXiv:202110.00031 [pdf]

基于稳定同位素示踪的黄河兰州段河漫滩土壤水特征分析

王家鑫
Subjects: Geosciences >> Hydrology

以兰州市安宁区金牛街码头附近距黄河约 10 m 的河漫滩为研究对象,对河漫滩土壤水的 氢氧稳定同位素进行分析并结合不同水体 lc-excess(Line-conditioned excess),研究了河漫滩土壤剖 面不同深度土壤水氢氧稳定同位素与土壤含水量的变化特征以及降水以活塞流、优先流模式对土 壤水的补给过程。研究表明:(1)兰州当地大气降水线(Local meteoric water line,LMWL):δD=7.00 δ18O+3.81(R2=0.95,P<0.001)与全球大气降水线(Global meteoric water line,GMWL)有明显差异,受蒸 发的影响斜率小于 GMWL。(2)土壤垂直剖面中浅层土壤水δD 变幅较大,越往深层变幅越小并逐 渐趋于稳定,且δD 值随深度先减小、后增大、最后趋于稳定,而浅层土壤含水量较小,随着深度的增 加逐渐增大,河水对深层(>80 cm)土壤水存在补给。(3)4、6、10 月观察到降水以活塞流模式对土壤 水进行了补给,5、9 月观察到降水以优先流模式对土壤水进行补给,即降水对河漫滩土壤水以 2 种 入渗模式共同补给。明晰土壤水特征对于准确分析降水在土壤中的入渗量、深入认识其补给过 程、准确评价地下水补给资源以及地下水污染分析具有重要意义。

submitted time 2021-10-10 From cooperative journals:《干旱区地理》 Hits2824Downloads116 Comment 0

3. chinaXiv:202110.00033 [pdf]

祁连山典型灌丛群落结构特征及其多样性研究

马剑
Subjects: Biology >> Ecology

灌丛群落作为祁连山森林生态系统的重要组成部分,在维护西北地区生态安全方面扮演着 不可或缺的角色。系统地研究祁连山地区灌丛群落结构特征对阐明灌丛群落的更新、演替和稳定 具有十分重要的意义,可为祁连山区森林生态系统的保护、恢复与重建提供基础数据和科学依 据。选择分布在祁连山大野口流域的甘青锦鸡儿(Caragana tangutica)、鲜黄小檗(Berberis diapha? na)、金露梅(Potentilla fruticosa)、鬼箭锦鸡儿(Caragana jubata)和吉拉柳(Salix gilashanica)5 种典 型灌丛群落为研究对象,通过野外调查取样和室内分析,主要研究了 5 种典型灌丛群落的物种组 成、生活型组成和物种多样性的变化规律。结果表明:(1)祁连山大野口流域灌丛群落组成较为简 单,只出现了 48 种植物,隶属于 26 科,38 属,以蔷薇科、禾本科、菊科和豆科等西北干旱区优势科的 数量居多。(2)生活型谱均以地面芽植物所占比例最大,为 37.09%,地上芽植物所占比例最少,为 4.00%。(3)整体上看,灌丛群落的 Shannon-Wiener 多样性指数(H)变化范围为 1.12~2.26,Simpson 多样性指数(D)变化范围为 0.60~0.74,其物种多样性指数较低,物种组成较为简单,其中不同灌丛 群落 H 多样性指数表现为金露梅>鬼箭锦鸡儿>鲜黄小檗>甘青锦鸡儿>吉拉柳,D 多样性指数表现 为金露梅>鬼箭锦鸡儿>吉拉柳>鲜黄小檗>甘青锦鸡儿。(4)不同的生境条件导致群落多样性层间 结构存在差异,除鬼箭锦鸡儿群落,多样性指数均为草本层>灌木层,而鬼箭锦鸡儿群落中灌木层 和草本层的物种多样性指数较为接近,物种组成灌草均一。

submitted time 2021-10-10 From cooperative journals:《干旱区地理》 Hits5083Downloads486 Comment 0

4. chinaXiv:202110.00037 [pdf]

基于地理探测器模型的疏勒河流域景观生态风险评价及驱动因素分析

孙丽蓉
Subjects: Geosciences >> Geography

疏勒河流域地处河西走廊最西端,是典型的干旱内陆河流域,生态环境极其脆弱,也是我国 重要的生态屏障之一。借助 Fragstats 软件从斑块和景观 2 个尺度,结合 2000—2018 年土地利用数 据,评价分析疏勒河流域景观生态风险时空变化特征,利用地理探测器定量分析了该流域景观生 态风险驱动因素。结果表明:(1)疏勒河流域主要景观类型为未利用地和草地,其斑块个数(NP)、 景观形状指数(LSI)、最大斑块指数(LPI)和聚集度指数(AI)值均较高;2000—2018 年蔓延度指数(CONTAG)值下降、香农多样性指数(SHDI)和香农均匀度指数(SHEI)值缓慢上升,流域景观破碎 度严重。(2)疏勒河流域景观生态风险空间分布呈现北高南低,2000—2018 年呈现流域景观生态风 险逐渐下降趋势,其中较高风险和高风险地区面积下降明显。(3)人为干扰度是影响景观生态风险 空间分布的主要因子,归一化植被指数(NDVI)次之,人口密度影响最小;景观生态风险的影响均为 双因子增强或非线性增强,无显著差异大多表现在自然和自然因子间,自然和人为因子之间存在 显著性差异。因此,对流域进行景观生态风险指数评价和驱动因素分析至关重要。

submitted time 2021-10-10 From cooperative journals:《干旱区地理》 Hits2638Downloads68 Comment 0

5. chinaXiv:202110.00055 [pdf]

近 60 a 祁连山极端降水变化研究

温煜华
Subjects: Geosciences >> Atmospheric Sciences

利用祁连山 24 个气象台站 1961—2017 年逐日降水资料,选用 12 个极端降水指数,采用线 性趋势法、Pearson 相关性分析法等,分析了祁连山极端降水指数的时空变化特征,并分析了海拔、 大气环流指数对祁连山极端降水指数时空变化的影响机制。结果表明:(1)祁连山、河西内陆河流 域、柴达木内陆河流域、黄河流域(外流)连续干旱日数(CDD)呈显著减少趋势,连续湿润日数 (CWD)呈增加趋势,空间分布表现出东西差异;其他极端降水指数总体呈增加趋势,空间分布呈现 出祁连山中部增加幅度较大,向外围呈环状递减的趋势。(2)降水总量增加的主要原因在于雨日天 数显著增加,中雨日数的天数也显著增大,这种降水分配模式将增大极端降水事件发生的概率,进 一步证实祁连山降水活动增强,极端降水频度更高,持续时间更短,降水向降雨日数更多、时间更 集中的方向发展。极端降水空间分异表现在极端降水强度的降低幅度随海拔的升高而减少,高海 拔区降水量和降水日数增加更为明显,CDD 的减少主要发生在高海拔区。(3)在所选的 11 个大气环 流异常因子中,祁连山极端降水受北大西洋年代际振荡(AMO)指数影响最大,北极涛动(AO)指数与 祁连山极端降水的关系最为复杂,大西洋海平面表面温度指数越大、南海夏季风(SCSSMI)指数、南美 夏季风(SAMSMI)指数越低则流域发生多雨、洪涝现象的概率越大,反之发生少雨现象的概率越大。

submitted time 2021-10-10 From cooperative journals:《干旱区地理》 Hits85Downloads45 Comment 0

6. chinaXiv:202109.00028 [pdf]

基于多源遥感数据的温度-土壤湿度-降水干旱指数(TMPDI)的构建与应用

满元伟
Subjects: Geosciences >> Geography

干旱在全球范围内产生了深远的社会和经济影响,可靠的干旱监测对防旱抗旱工作具有重要指导意义。由于在植被覆盖度和农作物种植率较低区域使用植被状态或单因子进行干旱监测时精度较低,故本文采用地表温度(LST)、降水量(P)和土壤湿度(SM)数据,基于三维欧氏几何空间中欧氏距离方法构建了一种新的干旱指数:温度-土壤湿度-降水干旱指数(TMPDI)用于干旱监测。并以甘肃省为研究区,利用SPI、SPEI、遥感数据以及小麦单位面积单产对TMPDI进行验证。结果表明:TMPDI与SPI、SPEI高度相关(R2>0.64),且在干旱监测中兼顾降水量与气温影响的同时,降低了使用降水量或地表温度进行干旱监测的不确定性,提高了土壤湿度在农业干旱监测中的准确性与有效性,能准确地描述干旱事件的时空演变特征,同时也能较好地反映出干旱强度与干旱面积率的变化对小麦产量造成的影响,说明TMPDI在农业干旱监测中具有较高的有效性和可靠性。

submitted time 2021-09-14 From cooperative journals:《干旱区研究》 Hits926Downloads171 Comment 0

7. chinaXiv:202109.00036 [pdf]

水分胁迫对设施延迟栽培葡萄根际土壤 有机氮及土壤酶活性的影响

杨昌钰
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science

为探讨不同水分胁迫条件下设施栽培葡萄根际土壤基本理化性质与有机氮组分及土壤酶活性的变化规律,并分析三者之间的相关关系,为甘肃河西地区设施延迟栽培葡萄制定合理的胁迫灌溉模式提供一定的参考依据。采用水分胁迫单因素完全随机试验设计,运用Bremner法测定着色成熟期葡萄根际土层中有机氮组分含量及土壤基本理化性质、全生育期土壤酶活性在不同水分胁迫(中度W1、轻度W2、充分供水W3)下的变化特征。结果表明:(1)全生育期中度和轻度水分胁迫对设施延迟栽培葡萄根际土壤全氮、铵态氮、全磷、有机质以及有机碳无显著影响,却降低了葡萄根际土壤微生物生物量碳、氮含量;新梢生长期和果实膨大期土壤硝态氮和速效磷含量分别为12.06 mg·kg-1和28.88 mg·kg-1,显著低于充分供水处理。(2)中度和轻度水分胁迫对葡萄全生育期根际土壤过氧化氢酶活性无显著性影响,而对果实膨大期和着色成熟期的脲酶、蔗糖酶含量均呈现不同程度的抑制效果。(3)各处理有机氮组分的含量大小顺序为非酸解态氮>酸解氨基酸态氮>酸解铵态氮>酸解未知态氮>酸解氨基糖态氮;轻度和中度水分胁迫均有助于葡萄根际土壤酸解总氮的积累,比对照分别提高21.16%和10.34%。(4)相关分析表明,蔗糖酶与生物量碳呈显著正相关;RDA分析显示硝态氮、铵态氮为影响土壤有机氮组分变化的最主要环境因子,全氮次之。

submitted time 2021-09-14 From cooperative journals:《干旱区研究》 Hits203Downloads114 Comment 0

8. chinaXiv:202109.00040 [pdf]

民勤绿洲边缘阻沙带表层土壤粒度空间分布特征

赵鹏
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science

土壤粒度是风沙活动的重要表征参数。通过野外调查与室内测试,分析了不同空间分布防风固沙林表层土壤粒度的空间分布特征,旨在评价民勤绿洲边缘阻沙带防风固沙功能。结果表明:(1)坝区梭梭-沙拐枣-沙蒿-沙米固沙林表层土壤粒度组成以细砂、中砂、极细砂为主,分别占33.47%、26.08%、18.18%;泉山区白刺+沙蒿+五星蒿固沙林表层土壤粒度组成以细砂、粉粒和极细砂为主,分别占29.62%、21.17%、18.87%;湖区白刺-芦苇-猪毛菜固沙林表层土壤粒度组成以细砂、粉粒和极细砂为主,分别占36.66%、27.98%、22.83%。(2)平均粒径,坝区(2.55Φ)>泉山区(3.5 Φ)>湖区(3.94 Φ),分选性,坝区(1.58 Φ)较差,湖区(2.10 Φ)和泉山区(2.29 Φ)很差。(3)泉山区、湖区表层土壤粒度频率曲线为双峰型,坝区为单峰型,偏度均为极正偏态,峰度表现为很窄。粒度累计分布曲线反映出坝区风沙活动较泉山区、湖区频繁、强烈。阻沙带荒漠植被群落物种组成决定着其防风固沙功能的大小,进而影响其表层土壤的粒度分布特征。建议阻沙带生态防护体系修复时应注重选择固沙能力强的造林树种。

submitted time 2021-09-14 From cooperative journals:《干旱区研究》 Hits205Downloads122 Comment 0

9. chinaXiv:202109.00042 [pdf]

腾格里沙漠南缘昌岭山1872 年以来干湿变化研究

祁京
Subjects: Geosciences >> Atmospheric Sciences

选取腾格里沙漠南缘对气候变化敏感的昌岭山为研究区,通过分析昌岭山优势树种青海云杉树轮宽度年表与气候因子的相关关系,得出5—7月PDSI(帕默尔干旱指数)与树轮宽度年表的相关性较强(r=0.621,P<0.001),干旱是影响树木径向生长的主控气候因子;通过建立树轮宽度年表和PDSI的线性回归方程,重建了研究区过去146 a以来的PDSI干旱变化;同时基于重建的PDSI的年际变化表明:研究区在过去146 a间共经历了4个干旱期(1882—1894年,1915—1936年,1966—1978年,1989—2015年)。周期分析结果显示重建序列存在2 a、2.6~3 a、11 a左右的变化周期,说明研究区气候变化主要受厄尔尼诺-南方涛动(ENSO)和太阳黑子活动的驱动。研究结论对于探讨中国西北干湿变化规律及预测未来气候变化条件下该区域亚高山森林生态系统的变化提供了科学依据。

submitted time 2021-09-14 From cooperative journals:《干旱区研究》 Hits914Downloads131 Comment 0

10. chinaXiv:202108.00012 [pdf]

Effects of climate change and land-use changes on spatiotemporal distributions of blue water and green water in Ningxia, Northwest China

WU Jun; DENG Guoning; ZHOU Dongmei; ZHU Xiaoyan; MA Jing; CEN Guozhang; JIN Yinli; ZHANG Jun
Subjects: Geosciences >> Geography

Water resources are a crucial factor that determines the health of ecosystems and socio-economic development; however, they are under threat due to climate change and human activities. The quantitative assessment of water resources using the concept of blue water and green water can improve regional water resources management. In this study, spatiotemporal distributions of blue water and green water were simulated and analyzed under scenarios of climate change and land-use changes using the Soil and Water Assessment Tool (SWAT) in Ningxia Hui Autonomous Region, Northwest China, between 2009 and 2014. Green water, a leading component of water resources, accounted for more than 69.00% of the total water resources in Ningxia. Blue water and green water showed a single peak trend on the monthly and annual scales during the study period. On the spatial scale, the southern region of Ningxia showed higher blue water and green water resources than the northern region. The spatiotemporal distribution features of blue water, green water, and green water flow had strong correlations with precipitation. Furthermore, the simulation identified the climate change in Ningxia to be more influential on blue water and green water than land-use changes. This study provides a specific scientific foundation to manage water resources in Ningxia when encountered with climate change together with human activities.

submitted time 2021-08-06 From cooperative journals:《Journal of Arid Land》 Hits1757Downloads238 Comment 0

12345678910  Last  Go  [17 Pages/ 169 Totals]