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1. chinaXiv:201906.00046 [pdf]

Multi-scale spatial relationships between soil total nitrogen and influencing factors in a basin landscape based on multivariate empirical mode decomposition

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

The relationships between soil total nitrogen (STN) and influencing factors are scale-dependent. The objective of this study was to identify the multi-scale spatial relationships of STN with selected environmental factors (elevation, slope and topographic wetness index), intrinsic soil factors (soil bulk density, sand content, silt content, and clay content) and combined environmental factors (including the first two principal components (PC1 and PC2) of the Vis-NIR soil spectra) along three sampling transects located at the upstream, midstream and downstream of Taiyuan Basin on the Chinese Loess Plateau. We separated the multivariate data series of STN and influencing factors at each transect into six intrinsic mode functions (IMFs) and one residue by multivariate empirical mode decomposition (MEMD). Meanwhile, we obtained the predicted equations of STN based on MEMD by stepwise multiple linear regression (SMLR). The results indicated that the dominant scales of explained variance in STN were at scale 995 m for transect 1, at scales 956 and 8852 m for transect 2, and at scales 972, 5716 and 12,317 m for transect 3. Multi-scale correlation coefficients between STN and influencing factors were less significant in transect 3 than in transects 1 and 2. The goodness of fit root mean square error (RMSE), normalized root mean square error (NRMSE), and coefficient of determination (R2) indicated that the prediction of STN at the sampling scale by summing all of the predicted IMFs and residue was more accurate than that by SMLR directly. Therefore, the multi-scale method of MEMD has a good potential in characterizing the multi-scale spatial relationships between STN and influencing factors at the basin landscape scale.

submitted time 2019-06-20 From cooperative journals:《Journal of Arid Land》 Hits1095, Downloads144, Comment 0

2. chinaXiv:201903.00234 [pdf]

Effects of spring fire and slope on the aboveground biomass, and organic C and N dynamics in a semi-arid grassland of northern China

ZHAO Xiang; HU Shuya
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science

The aboveground primary production is a major source of carbon (C) and nitrogen (N) pool and plays an important role in regulating the response of ecosystem and nutrient cycling to natural and anthropogenic disturbances. To explore the mechanisms underlying the effect of spring fire and topography on the aboveground biomass (AGB) and the soil C and N pool, we conducted a field experiment between April 2014 and August 2016 in a semi-arid grassland of northern China to examine the effects of slope and spring fire, and their potential interactions on the AGB and organic C and total N contents in different plant functional groups (C3 grasses, C4 grasses, forbs, Artemisia frigida plants, total grasses and total plants). The dynamics of AGB and the contents of organic C and N in the plants were examined in the burned and unburned plots on different slope positions (upper and lower). There were differences in the total AGB of all plants between the two slope positions. The AGB of grasses was higher on the lower slope than on the upper slope in July. On the lower slope, spring fire marginally or significantly increased the AGB of C3 grasses, forbs, total grasses and total plants in June and August, but decreased the AGB of C4 grasses and A. frigida plants from June to August. On the upper slope, however, spring fire significantly increased the AGB of forbs in June, the AGB of C3 grasses and total grasses in July, and the AGB of forbs and C4 grasses in August. Spring fire exhibited no significant effect on the total AGB of all plants on the lower and upper slopes in 2014 and 2015. In 2016, the total AGB in the burned plots showed a decreasing trend after fire burning compared with the unburned plots. The different plant functional groups had different responses to slope positions in terms of organic C and N contents in the plants. The lower and upper slopes differed with respect to the organic C and N contents of C3 grasses, C4 grasses, total grasses, forbs, A. frigida plants and total plants in different growing months. Slope position and spring fire significantly interacted to affect the AGB and organic C and N contents of C4 grasses and A. frigida plants. We observed the AGB and organic C and N contents in the plants in a temporal synchronized pattern. Spring fire affected the functional AGB on different slope positions, likely by altering the organic C and N contents and, therefore, it is an important process for C and N cycling in the semi-arid natural grasslands. The findings of this study would facilitate the simulation of ecosystem C and N cycling in the semi-arid grasslands in northern China.

submitted time 2019-03-28 From cooperative journals:《Journal of Arid Land》 Hits1233, Downloads206, Comment 0

3. chinaXiv:201903.00236 [pdf]

Distribution of soil aggregates and organic carbon in deep soil under long-term conservation tillage with residual retention in dryland

WANG Bisheng; GAO Lili; WEI Xueqin
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science

To ascertain the effects of long-term conservation tillage and residue retention on soil organic carbon (SOC) content and aggregate distribution in a deep soil (>20-cm depth) in a dryland environment, this paper analyzed the SOC and aggregate distribution in soil, and the aggregate-associated organic carbon (OC) and SOC physical fractions. Conservation tillage (reduced tillage with residue incorporated (RT) and no-tillage with residue mulch (NT)) significantly increased SOC sequestration and soil aggregation in deep soil compared with conventional tillage with residue removal (CT). Compared with CT, RT significantly increased the proportion of small macroaggregates by 23%–81% in the 10–80 cm layer, and the OC content in small macroaggregates by 1%–58% in the 0–80 cm layer. RT significantly increased (by 24%–90%) the OC content in mineral-SOC within small macroaggregates in the 0–60 cm layer, while there was a 23%–80% increase in the 0–40 cm layer with NT. These results indicated that: (1) conservation tillage treatments are beneficial for soil aggregation and SOC sequestration in a deep soil in a dryland environment; and (2) the SOC in mineral-associated OC plays important roles in soil aggregation and SOC sequestration. In conclusion, RT with NT is recommended as an agricultural management tool in dryland soils because of its role in improving soil aggregation and SOC sequestration.

submitted time 2019-03-28 From cooperative journals:《Journal of Arid Land》 Hits1594, Downloads238, Comment 0

4. chinaXiv:201811.00103 [pdf]

Changes in soil microbial community response to precipitation events in a semi-arid steppe of the Xilin River Basin, China

ZHANG Hui; LIU Wenjun; KANG Xiaoming; CUI Xiaoyong; WANG Yanfen; ZHAO Haitao; QIAN Xiaoqing; HAO Yanbin
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science

In the context of climate change, precipitation is predicted to become more intense at the global scale. Such change may alter soil microbial communities and the microbially mediated carbon and nitrogen dynamics. In this study, we experimentally repackaged precipitation patterns during the growing season (from June to September) of 2012 in a semi-arid temperate steppe of the Xilin River Basin in Inner Mongolia of China, based on the 60-year growing season precipitation data. Specifically, we manipulated a total amount of 240 mm precipitation to experimental plots by taking the following treatments: (1) P6 (6 extreme precipitation events, near the 1st percentile); (2) P10 (10 extreme precipitation events, near the 5th percentile); (3) P16 (16 moderate precipitation events, near the 50th percentile); and (4) P24 (24 events, 60-year average precipitation, near the 50th percentile). At the end of the growing season, we analyzed soil microbial community structure and biomass, bacterial abundance, fungal abundance and bacterial composition, by using phospholipid fatty acid (PLFA), real-time quantitative polymerase chain reaction (RT-qPCR) and 16S rRNA gene clone library methods. The extreme precipitation events did not change soil microbial community structure (represented by the ratio of PLFA concentration in fungi to PLFA concentration in bacteria, and the ratio of PLFA concentration in gram-positive bacterial biomass to PLFA concentration in gram-negative bacterial biomass). However, the extreme precipitation events significantly increased soil microbial activity (represented by soil microbial biomass nitrogen and soil bacterial 16S rRNA gene copy numbers). Soil fungal community showed no significant response to precipitation events. According to the redundancy analysis, both soil microbial biomass nitrogen and soil ammonium nitrogen (NH4-N) were found to be significant in shaping soil microbial community. Acidobacteria, Actinobacteria and Proteobacteria were the dominant phyla in soil bacterial composition, and responded differently to the extreme precipitation events. Based on the results, we concluded that the extreme precipitation events altered the overall soil microbial activity, but did not impact how the processes would occur, since soil microbial community structure remained unchanged.

submitted time 2018-11-23 From cooperative journals:《Journal of Arid Land》 Hits1917, Downloads349, Comment 0

5. chinaXiv:201807.00075 [pdf]

根据SCI文献计量分析的土电动修复研究.docx.docx

袁立竹; 盛宇平; 盛春蕾; 郭书海
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science

土电动修复是同种新兴的土修复技术。本文为1972-2017土电动修复SCI文献为分析对象,通过定量统计和文件挖掘对过去45年土电动修复发展过程和研究态势进行了描述。根据对关键词的整理和分析,察觉土壤电动修复研究重点围绕电动修复机理、共同修复技术和场所应用等3单方面,重要修复对象主要是重金属、有机污染物、盐及其他离子以及复合污染物等。付出便捷高效的自动修复场地应用技术将是今后的研究重点之一;机动修复技术和其他修复技术的有机结合,共同修复已成为电动修复研究的热门。

submitted time 2018-07-26 Hits1325, Downloads593, Comment 2

6. chinaXiv:201808.00151 [pdf]

宁夏枸杞(LyciumbarbarumL.)花器官形态多样性和品系间识别研究

张益芝; 戴国礼; 秦垦; 马海军
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Plant Protection

依照研究为宁夏枸杞( L y c i u m b a r b a r u mL.)种内 42 单品系为实验材料,在对那花器官的 16 起性状的形态学指标进行赋值,测量的基础上,使用组间就元素在差分析、主成分分析和集纳类分析法对那形态学差异的大多状态性进行了研究。研究结果表明:同品系宁夏枸杞花器官形态学指标在不同时(实际观测时间为 2017 年 7 月、8 月、9 月)p<0.05,别不明显;并且,主成分分析显示花瓣外缘色泽、花瓣正-阴脉络、花瓣形状、花瓣背部色泽、花喉色泽、母雄蕊位置 6 单花部形象指标的积累贡献率达到 84.791%,啊宁夏枸杞不同品系花器官差异的主成分;聚拢类分析以欧式距离 7.5 啊阈值,以出席试的 42 单品系分成 6接近。通过本项研究明确了,同品系的宁夏枸杞花器官形态在不同时间表现出一定的安定,作为有别于宁夏枸杞种内不同品系的鉴别指标之一;并且,罗出了反映宁夏枸杞花器官形态差异的 6 单主成分并以 42卖宁夏枸杞分为六类,开始建立了宁夏枸杞种内品系间的形态学鉴别方法,但是为宁夏枸杞的形态学研究和品系鉴定等工作提供依据。

submitted time 2018-07-18 From cooperative journals:《广西植物》 Hits1904, Downloads442, Comment 0

7. chinaXiv:201808.00150 [pdf]

根据 OTCs 宪章增温方式探讨气候变暖对青藏高原草地生态系统的影响

张相锋; 彭阿辉; 宋凤仙; 陈冬勤
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Plant Protection

开始到式生长室(OTCs)增温实验是研究全球气候变化和陆地生态系统关系的重要方法有,已经普遍 应用于青藏高原地区。该文通过对近来国内外研究文献的回忆,分别从植物物候、群落结构、大发游戏网站量和 土方面综合分析青藏高原草地生态系统对 OTCs 宪章增温实验的响应。研究发现:增温使群落返青期提 前、黄期延迟,生季延长;造福禾本科植物的生长;天寒地冻草甸地下大发游戏网站量分配格局向深层转移;天寒地冻草地生态系统对模拟增温的响应存在不确定性,受到地域、群落类型和实验时间的影响;在增温条件下,降雨和冻土融化引起的土水分变化通过调控生态系统的物候、生产力、土等途径控制在生态系统对气 等变暖的响应。在并在这个基础上,提出了未来应主要研究的几乎只方面。

submitted time 2018-07-18 From cooperative journals:《广西植物》 Hits2273, Downloads443, Comment 0

8. chinaXiv:201808.00149 [pdf]

Cu 胁迫下基质中凹凸棒石粘土对当归幼苗的保护作用

张牡丹; 强出汪青; 冉瑞兰; 达到梦婷; 贾凌云; 孙坤; 冯汉青
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Plant Protection

在蕴不同比例凹凸棒石粘土的混合基质中(凹凸棒石粘土:基质的体积比分别为 0/1、1/100、1/70、1/50、1/20)培养当归幼苗,因为研究 Cu 胁迫对当归幼苗的生理学影响和凹凸棒石粘土对 Cu 胁迫下当归幼苗的保护作用。结果发现:(1)基质中不存在凹凸石棒石粘土时,乘 CuCl2拍卖浓度的上升,当归幼苗叶片的实际光化学效率[Y(II)]、PSII 电子传递速率(ETR)、光化学淬灭(qP)和叶绿素含量都逐渐下降;如果叶片的不光化学猝灭(qN)、可溶性蛋白含量、抗氧化酶活性(SOD、POD、CAT、APX)、过氧化氢含量和根和叶片中的 Cu 含量均显著性增加,标志 Cu 胁迫降低了当归幼苗的光化学效率、叶绿素的合成、增加了组织中 Cu 含量和氧化压力;(2)CuCl2胁迫下,当基质中存在不同比例的崎岖棒石粘土时,Cu 胁迫所导致的叶子 Y(II)、ETR、qP 和叶绿素含量的下降和叶片 qN、可溶性蛋白含量、抗氧化酶活性、过氧化氢含量、到底和叶片的 Cu 含量的上升均发生所缓解,立即是因为凹凸棒石粘土通过吸附或固定基质中游离的和可交换的 Cu 离子,调减了当归幼苗对中 Cu 离子的收取,所以解决了 Cu 离子对植物造成的生理学压力,还这种缓解作用依次为:1/70>1/50>1/20≧ 1/100>0/1,立即是由于基质中存在过多的崎岖棒石粘土时,那个在接受基质中 Cu 离子的同时为会影响基质的交接气性、现水性和酸碱度等。上述结果表明:凹凸棒石粘土在基质中的适当加入能够解决 Cu 胁迫对当归幼苗造成的的生理学压力。该实验结果为当归在无土化栽培中重金属污染的减少提供一定的借鉴和参考。

submitted time 2018-07-18 From cooperative journals:《广西植物》 Hits2465, Downloads466, Comment 0

9. chinaXiv:201808.00148 [pdf]

西藏虎头兰高效植株再生体系的研究

袁芳; 宋凯杰; 蔡熙彤; 杨泽东; 王 武器; 兰小中
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Plant Protection

西藏虎头兰(Cymbidium tracyanum)啊兰科兰属于多年生草本植物,凡是同种最有观赏价值的野生花卉,目前有关西藏 虎头兰组培快繁的研究报道甚少。该研究为野生西藏虎头兰种子为他植体,通过分析不同基本培养基和植物激素配比对原球茎诱导、增殖和分化的影响,和光照时间和培养温度对试管苗生长的影响,罗出适宜西藏虎头兰植株高效再生的标准。 结果表明:适当西藏虎头兰生长的中心培养基为 1/2 MS;种子萌发和原球茎诱导的最适培养基为 1/2 MS+1.0 mg·L-1 6-BA +0.5 mg·L-1 NAA,培养 50 d 继,发生 95.00%的种子发育成原来球茎;本来球茎增殖的最适培养基为 1/2 MS+2.0 mg·L-1 NAA, 培养 30 d,增殖倍数为 4.25;本来球茎的最适分化培养基为 1/2 MS+2.0 mg·L-1 NAA+60 g·L-1土豆泥+0.5 g·L-1活性炭, 培养 10 d,乱芽发生率为 98.33%,培养至 40 d,幼苗生根率为 94.67%;试管苗在温度 20℃、光照时间 12 h·d-1、光照强度 2 000 lx 的标准下培养,苗长势好,叶片生理性焦尖发生率仅为 3.33%;因为腐殖土作为栽培基质,试管苗的移栽成活率为 97.78%。该研究结果为保护西藏虎头兰野生资源和工厂化育苗提供了正确依据和技术支持。

submitted time 2018-07-18 From cooperative journals:《广西植物》 Hits2784, Downloads513, Comment 0

10. chinaXiv:201808.00147 [pdf]

云南被子植物新材料

告知丁香; 杨锦超; 肖之强; 杜凡
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Plant Protection

植物资源调查是探讨系统发育、植物区系发展历史和亲缘关系的基础,凡是我国植物研究工作的重要职责之一。虽然我国在植物资源调查方面发出了丰富的积累,连为《华夏植物志》和各个地方植物志为表示,但是部分偏远地区的种植 物资源状况还缺乏数据。通过形态特征比较分析,察觉云南省被子植物新记录 3 种。柳叶黄肉楠 (ActinodaphnelecomteiAllen)本来分布四川、贵州、广东(低幼源)、广西,云南省丘北县为其新记录点;八角樟(Cinnamomum ilicioidesA.Chev.)本来分布广东、海南、广西,越南北部,云南省西双版纳傣族自治州勐腊县为其新记录点;贵州山 胡桃(CaryakweichowensisKuangA.M.Lu exChangetLu)本来分布贵州安龙、望谟、册亨、兴义等,云南省丘北县为 那个新记录点。柳叶黄肉楠和八角樟在云南的新分布点是针对本国樟科薄弱地带的增补,啊分析滇产旧种类对相关属的起源发生和中华樟科分类学研究提供了新材料;贵州山核桃在物种层面上对确定贵州山核桃与喙核桃 (Annamocaryasinensis)双方间的联系提供了新的案例,连为云南发展山核桃(C.cathayensis)生产提供了种质资源。

submitted time 2018-07-18 From cooperative journals:《广西植物》 Hits2290, Downloads469, Comment 0

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