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Spatial pattern and driving factors of biomass carbon density for natural and planted coniferous forests in mountainous terrain,eastern loess plateau of China

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Forest Ecosystems 2020年第2期 159-171页

作者： Lina Sun Mengben Wang Xiaohui Fan Institute of Loess Plateau Shanxi University

Background:Understanding the spatial pattern and driving factors of forest carbon density in mountainous terrain is of great importance for monitoring forest carbon in support of sustainable forest management for mitigating climate change.Methods:We collected the forest inventory data in 2015 in Shanxi Province,eastern loess plateau of China, to explore the spatial pattern and driving factors of biomass carbon density(BCD) for natural and planted coniferous forests using Anselin Local Moran’s I,Local Getis-Ord G~* and semivariogram analyses,and multi-group structural equation modeling,respectively.Results:The result of spatial pattern of BCDs for natural forests showed that the BCD was generally higher in the north but lower in the south of Shanxi.The spatial pattern for planted forests was substantially different from that for natural forests.The results of multi-group SEM suggested that elevation(or temperature as the alternative factor of elevation) and stand age were important driving factors of BCD for these two forest types.Compared with other factors,the effects of latitude and elevation on BCD showed much greater difference between these two forest types.The difference in indirect effect of latitude(mainly through affecting elevation and stand age) between natural and planted forests was to some extent a reflection of the difference between the spatial patterns of BCDs for natural and planted forests in Shanxi.Conclusions:The natural coniferous forests had a higher biomass carbon density,a stronger spatial dependency of biomass carbon density relative to planted coniferous forests in Shanxi.Elevation was the most important driving factor,and the effect on biomass carbon density was stronger for natural than planted coniferous forests.Besides,latitude presented only indirect effect on it for the two forest types.

关键词： Spatial pattern Spatial heterogeneity Multi-group structural equation modeling Stand age Elevation Mountainous terrain

Range-wide genetic diversity in natural populations of Larix principis-rupprechtii Mayr.

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Journal of Forestry Research 2021年第1期32卷 319-327页

作者： Xiaoyan Di Xiangxiang Meng Mengben Wang Institute of Loess Plateau Shanxi UniversityTaiyuan 030006People’s Republic of China

Prince Rupprecht’s larch(Larix principis-rupprechtii Mayr.),a deciduous conifer,widely grows in middle and high elevations of Northern China.Its natural distribution has sharply decreased and has become fragmented,which may have resulted in the loss of genetic variation.In this study,ten natural populations across the entire range of this species were analyzed using amplifi ed fragment length polymorphism markers.A total of 309 loci were detected from 225 individuals of these populations,of which 261(84.5%)were polymorphic.At the species level,the genetic diversity was high(average of the Nei’s genetic diversity H e=0.2602,and Shannon’s information index I=0.3967).The results of molecular variance analysis showed that 90.71%of the genetic diversity occurred within populations.The genetic diff erentiation among populations was moderate as a whole(F ST=0.0929,G ST=0.1510),which is consistent with the moderate level of gene fl ow among populations(N m=2.8116).Based on the unweighted pair group method with arithmetic mean and STRU CTU RE analysis,these populations were grouped into three genetically distinct clusters.The degree of inter-population diff erentiation(G ST=0.1338)for the south group was larger than that for the north group(G ST=0.0915).There was a signifi cant correlation between genetic distance and geographic distance across the species range(r=0.316,P<0.05).Genetic diversity was signifi-cantly associated with longitude but not elevation or climatic factors.The populations with high genetic diversity from each cluster are therefore recommended for future conservation and management of this species.

关键词： Larix principis-rupprechtii Amplifi ed fragment length polymorphism markers(AFLP) Genetic diversity Environmental factors

Fungi community characteristics and driving factors in Bothriochloa ischaemum litter in a copper mining area

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Fungi community characteristics and driving factors in Bothr...

Spatial pattern and driving factors of biomass carbon density for natural and planted coniferous forests in mountainous terrain,eastern loess plateau of China

第十二届现代生态学讲座暨林草与环境学科研究生学术论坛

作者： Yu Wang Jia Tong Institute of Loess Plateau Shanxi University

Among influencing biotic and abiotic factors,microorganisms predominate litter decomposition,playing an important role in maintaining the ecosystem material cycle. Because Bothriochloa ischaemum is the dominant plant species in China’s Eighteen River tailings dam,it was selected it as the research object. Here,we used amplicon sequencing to explore dynamic fungal community characteristics in B. ischaemum litter during different decomposition stages and investigated relevant driving factors affecting associative dynamic changes. Results showed significant fungal community composition differences in litter during the different decomposition stages. Among these differences,Ascomycetes and Basidiomycetes were the dominant phyla during litter decomposition. At a class level,the relative abundance of Dothideomycetes gradually decreased as litter decomposition progressed while Sordariomycetes gradually increased,ultimately becoming the dominant class. The community structure of the fungal community was mainly affected by litter pH,total carbon(TC),and copper(Cu) content. Comparably,the fungal community’s network structure was the most complex. Additionally,the fungal community’s modularity gradually increased,while the degree of functional differentiation also increased,strengthening fungal community stability after 200 days of litter decomposition. Moreover,unclassifiedordariomycetes and Curvularia were the dominant fungal community genera during the litter decomposition process. This study will help in our further understanding of microbial driving mechanisms during litter decomposition in contaminated non-ferrous metal mining areas. It also clarifies fungal community structure during litter decomposition in this copper tailings area. Finally,results from this study provide a scientific basis for further improving soil fertility and nutrient cycling in mining areas.

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Forest Ecosystems 2020年第1期7卷 104-116页

作者： Lina Sun Mengben Wang Xiaohui Fan Institute of Loess Plateau Shanxi UniversityWucheng Road 92Taiyuan 030006China

Background:Understanding the spatial pattern and driving factors of forest carbon density in mountainous terrain is of great importance for monitoring forest carbon in support of sustainable forest management for mitigating climate change.Methods:We collected the forest inventory data in 2015 in Shanxi Province,eastern loess plateau of China,to explore the spatial pattern and driving factors of biomass carbon density(BCD)for natural and planted coniferous forests using Anselin Local Moran’s I,Local Getis-Ord G*and semivariogram analyses,and multi-group structural equation modeling,respectively.Results:The result of spatial pattern of BCDs for natural forests showed that the BCD was generally higher in the north but lower in the south of Shanxi.The spatial pattern for planted forests was substantially different from that for natural forests.The results of multi-group SEM suggested that elevation(or temperature as the alternative factor of elevation)and stand age were important driving factors of BCD for these two forest types.Compared with other factors,the effects of latitude and elevation on BCD showed much greater difference between these two forest types.The difference in indirect effect of latitude(mainly through affecting elevation and stand age)between natural and planted forests was to some extent a reflection of the difference between the spatial patterns of BCDs for natural and planted forests in Shanxi.Conclusions:The natural coniferous forests had a higher biomass carbon density,a stronger spatial dependency of biomass carbon density relative to planted coniferous forests in Shanxi.Elevation was the most important driving factor,and the effect on biomass carbon density was stronger for natural than planted coniferous forests.Besides,latitude presented only indirect effect on it for the two forest types.

关键词： Spatial pattern Spatial heterogeneity Multi-group structural equation modeling Stand age Elevation Mountainous terrain

Effects of nitrogen addition on the soil detachment in the typical grasslands of the loess plateau

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Journal of Mountain Science 2022年第12期19卷 3503-3516页

作者： LI Pan-pan WANG Bing YANG Yan-fen LIU Guo-bin State Key Laboratory of Soil Erosion and Dryland Farming on the loess plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYangling 712100China State Key Laboratory of Soil Erosion and Dryland Farming on the loess plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China

Nitrogen deposition will alleviate the nitrogen limitation in terrestrial ecosystems and greatly affect vegetation growth,thereby soil erosion.It is important to clarify the effects of nitrogen addition to the plant roots and soil properties on the soil erosion process.A nitrogen addition experiment was conducted in the grassland dominated by Bothriochloa ischaemum(Linn.)Keng(BI),which has received 0,2.5,5,and 10 g N m^(-2) yr^(-1)(N_(0),N_(2.5),N_(5)and N_(10),respectively)for three consecutive years.Then,a total of 150 undisturbed soil samples were collected(including bare soil control)and subjected to flowing water to test their soil detachment capacities under six shear stress levels(10.2 Pa to 29.9 Pa).Three-year nitrogen addition increased the soil bulk density,soil cohesion and nitrate nitrogen while decreasing the saturated hydraulic conductivity,soil water-stable aggregates,soil organic carbon,total nitrogen and ammonium nitrogen.The root mass density and root diameter decreased with nitrogen addition.And the root length,surface area and volume density of the N_(0) and N_(5) treatments were larger than those of the other treatments,while the plant roots were significantly inhibited by N_(10).Additionally,the soil detachment capacity(D_(c))and rill erodibility(K_(r))of the N_(0) and N_(5) treatments were significantly less than those of the N_(2.5) and N_(10)treatments,of which the Dc(0.020 kg m^(-2) s^(-1))of the N_(0) treatment was 69.0%,24.3%and 66.8%less than that of the N_(2.5),N_(5) and N_(10) treatments,respectively.The Kr of the N_(0) treatment was 0.0012 s m^(-1),which was 72.1%,25.0%and 70.0%less than that of the others.This study implies that an increase in nitrogen addition likely exacerbates soil erosion in the early(approximately 2.5 g N m^(-2) yr^(-1))and late phases(more than 10 g N m^(-2) yr^(-1)).However,when the nitrogen addition rate is approximately 5 g m^(-2) yr^(-1),soil erosion may be inhibited because of the responses of the plant roots and soil to nitrogen addition.

关键词： Nitrogen deposition Root traits Soil properties Soil detachment Grassland loess plateau

Effects of vegetation near-soil-surface factors on runoff and sediment reduction in typical grasslands on the loess plateau,China

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Journal of Arid Land 2022年第3期14卷 325-340页

作者： LI Panpan WANG Bing YANG Yanfen LIU Guobin State Key Laboratory of Soil Erosion and Dryland Farming on the loess plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYangling 712100China State Key Laboratory of Soil Erosion and Dryland Farming on the loess plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China

Vegetation near-soil-surface factors can protect topsoil from erosion,however,their contributions to the reduction of soil erosion,especially under natural rainfall events,have not been systematically recognized.This study was performed to quantify the effects of near-soil-surface factors on runoff and sediment under natural rainfall events on grasslands dominated by Bothriochloa ischaemum(Linn.)Keng(BI grassland)and Artemisia gmelinii Thunb.(AG grassland)in two typical watersheds on the loess plateau,China in 2018.By successive removal of the plant canopy,litter,biological soil crusts(BSCs)and plant roots,we established five treatments including plant roots,plant roots+BSCs,plant roots+BSCs+litter,intact grassland and bare land in each grassland type.In total,twenty runoff plots(5 m×3 m)with similar slopes and aspects were constructed in the two types of grasslands.Results showed that plant canopy,litter and roots reduced runoff,while BSCs,which swelled in the presence of water,increased runoff.In contrast,all of these factors reduced sediment yield.In addition,the reductions in runoff and sediment yield increased with I30(maximum 30-min rainfall intensity)for each vegetation near-soil-surface factor except for BSCs.Among these factors,plant canopy had the largest contribution to runoff reduction,accounting for 48.8% and 39.9% in the BI and AG grasslands,respectively.The contributions of these vegetation near-soil-surface factors to sediment yield reduction were similar(21.3%-29.9%)in the two types of grasslands except for BSCs in the AG grassland(10.3%).The total reduction in runoff in the BI grassland(70.8%)was greater than that in the AG grassland(53.1%),while the reduction in sediment yield was almost the same in both grasslands(97.4%and 96.7%).In conclusion,according to the effects of different vegetation near-soil-surface factors on runoff and sediment production,our results may provide more complete insight and scientific basis into the effects of various vegetation related factors in controlling soil ero

关键词： vegetation near-soil-surface factor grassland arid and semi-arid soil erosion loess plateau

Improving water-use efficiency by decreasing stomatal conductance and transpiration rate to maintain higher ear photosynthetic rate in drought-resistant wheat

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The Crop Journal 2017年第3期5卷 231-239页

作者： Yuping Li Hongbing Li Yuanyuan Li Suiqi Zhang State Key Laboratory of Soil Erosion and Dryland Farming on the loess plateau Northwest A&F University State Key Laboratory of Soil Erosion and Dryland Farming on the loess plateau Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources

In wheat, the ear is one of the main photosynthetic contributors to grain filling under drought stress conditions. In order to determine the relationship between stomatal characteristics and plant drought resistance, photosynthetic and stomatal characteristics and water use efficiency(WUE) were studied in two wheat cultivars: the drought-resistant cultivar ‘Changhan 58' and the drought-sensitive cultivar ‘Xinong 9871'. Plants of both cultivars were grown in pot conditions under well-watered(WW) and water-stressed(WS) conditions. In both water regimes,‘Changhan 58' showed a significantly higher ear photosynthetic rate with a lower rate of variation and a significantly higher percentage variation of transpiration compared to control plants at the heading stage under WS conditions than did ‘Xinong 9871' plants. Moreover,‘Changhan 58' showed lower stomatal density(SD) and higher stomatal area per unit organ area(A) under both water conditions. Water stress decreased SD, A, and stomatal width(SW), and increased stomatal length in flag leaves(upper and lower surfaces) and ear organs(awn, glume,lemma, and palea), with the changes more pronounced in ear organs than in flag leaves.Instantaneous WUE increased slightly, while integral WUE improved significantly in both cultivars. Integral WUE was higher in ‘Changhan 58', and increased by a greater amount, than in‘Xinong 9871'. These results suggest that drought resistance in ‘Changhan 58' is regulated by stomatal characteristics through a decrease in transpiration rate in order to improve integral WUE and photosynthetic performance, and through sustaining a higher ear photosynthetic rate, therefore enhancing overall drought-resistance.

关键词： Wheat Stomatal structure Ear photosynthesis Drought resistance Water use efficiency

Land use and land cover change processes in China's eastern loess plateau

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Research in Cold and Arid Regions 2015年第6期7卷 722-729页

作者： JinChang Li HaiXia Liu Yong Liu ZhiZhu Su ZiQiang Du Institute of Loess Plateau Shanxi University Historical Culture School Shanxi University

Using Landsat remote sensing images, we analyzed changes in each land use type and transitions among different land use types during land use and land cover change （LUCC） in Ningwu County, located in the eastern loess plateau of China, from 1990 to 2010. We found that grassland, woodland, and farmland were the main land use types in the study area, and the area of each type changed slightly from 1990 to 2010, whereas the area of water, construction land, and unused land increased greatly. For the whole area, the net change and total change were insignificant due to weak human activity intensity in most of the study area, and the LUCC was dominated by quasi-balanced two-way transitions from 1990 to 2010. The insignificant overall amount of LUCC appears to have resulted from offsetting of rapid increases in population, economic growth, and the im- plementation of a program to return farmland to woodland and grassland in 2000. This program converted more farmland into woodland and grassland from 2000 to 2010 than from 1990 to 2000, but reclamation of woodland and grassland for use as farmland continued from 2000 to 2010, and is a cause for concern to the local government.

关键词： land use and land cover change remote sensing forest restoration Ningwu County loess plateau

Various phyllospheric bacterial communities of four natural grasses and the impact factors in a copper tailings dam

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Various phyllospheric bacterial communities of four natural ...