Artificial Vegetation Restoration Research Articles

Correlation between flood couplet-based sediment yield and rainfall patterns in a small watershed on the Chinese Loess Plateau

Understanding how rainfall patterns impact sediment yields during rainfall events is important to explore soil erosion changes and to prevent watershed flood disasters. However, few studies identified sediment yields variation affected by rainfall patterns at continuous deposited flood couplet scale. This study analyzed sediment yields under different rainfall patterns and correlated particle depositional features on the condition that the erosive environment was obviously changed by anthropogenic activities in a check dam-controlled small watershed on the Chinese Loess Plateau. Results showed that erosive rainfall events, having formed 40 flood couplets behind the check dam between 1978 and 2010, can be grouped into three rainfall patterns (i.e., rainfall patterns I, II, and III) according to changes in rainfall amount, erosivity, and duration. Rainfall pattern III, characterized by high rainfall amount and erosivity within a short duration (i.e., rainstorm) accounted for only 15.0 % of erosive rainfall events while yielding 44.7 % of the total sediment. Conversely, rainfall pattern I (the most common, 55.0 %), characterized by its long duration and relatively low rainfall amount and erosivity, only contributed 25.3 % of the total sediment. Both sediment yields and thickness proportions of coarse particle layer in flood couplets exhibited a decreasing trend under all three rainfall patterns. Meanwhile, the main factor that impacted sediment yields changed from rainfall in the 1980s and 1990s to the “Grain for Green” program dominated anthropogenic activities since 1999. For a small watershed with a few terraces and only one check dam at the outlet, artificial vegetation restoration significantly reduced coarse soil particle loss and sediment yield. Findings showed that sediment yield and deposition feature variations in flood couplets under different rainfall patterns are helpful in improving watershed soil and water conservation measures against flood disasters, particularly under rainstorms.

Effects of different artificial vegetation restoration modes on soil microbial community structuree in the soil erosion area of southern China

Investigating the effects of diverse artificial vegetation restoration methods on soil microbial communities is important for understanding soil health and achieving sustainable utilization of vegetation resources. In this study, the surface soil samples (0–10 cm) of three artificial vegetation restoration modes were selected as the research object which included the fenced forest, the arbor-shrub-grassland, and the chestnut forest in the soil and water loss area of South China. Three artificial vegetation restoration modes have significantly increased both the abundance and diversity of bacteria and fungi in areas affected by soil erosion, thus contributing to the stabilization of the ecosystem. Specifically, the arbor-shrub-grassland mode demonstrated the most significant improvements. Soil alkali nitrogen (71.10%, P = 0.000) and organic matter content (63.30%, P = 0.001) emerged as the primary factors driving this increase in bacterial and fungal diversity. After restoration, the composition of soil bacterial and fungal communities in soil erosion areas has undergone significant changes. However, it was observed that only the arbor-shrub-grassland mode could induce a shift in dominant bacterial species from Chloroflexi to Acidobacteria. Variations in soil bacterial and fungal community compositions across different modes were attributed to differences in soluble organic carbon (65.80%, P = 0.002) and soil bulk density (49.00%, P = 0.010). In conclusion, the increased fungal abundance and the bacterial shift observed in the arbor-shrub-grassland mode underscore its superior effectiveness in rehabilitating degraded soils, compared to both the fenced forest and the chestnut forest modes.

Vegetation restoration restrains rill erosion on slag heaps in high-altitude goldfields

Soil erosion leads to soil degradation and depletion of land resources, posing a significant threat to industrial production and ecological sustainability. In high-altitude regions, rill erosion is the main form of soil erosion in mining areas, however, our understanding of morphology and developmental characteristics of rills and the mechanisms influencing them remains limited. In this study, data were collected from 96 rill plots across two gold mines in the eastern Tibetan Plateau according to vegetation restoration modes (natural restoration (CK) and planted with Elymus dahuricus (ED), Medicago sativa (MS), and multi-plant mixed (Avena fatua L. + Elymus dahuricus + Medicago sativa + Oxytropis coerulea, MM)) and restoration periods (1 year, 3 years, 4 years, and 6 years). We investigated the variations of 7 indicators that can reveal rill morphological and developmental characteristics across different restoration modes and restoration periods, and utilized a partial least squares structural equation model (PLS-SEM) to analyze the effects of 15 indicators from topography, soil, and vegetation on rill erosion modulus (REM). The results indicated that artificial vegetation restoration effectively restrained rill development, notably by decreasing the frequency of wider (>15 cm) and deeper (>10 cm) rills when compared to CK plots. Planting MM and ED exhibited greater efficacy in controlling rill erosion than planting MS. However, the effectiveness of planting ED in controlling rill erosion gradually weakened with time, while MM consistently maintained a strong inhibitory effect. Topographic features, soil texture, and vegetation significantly influenced the REM through direct or indirect effects. Plant root functional traits were the main driving factors in reducing REM, affecting not only REM directly but also influencing vegetation-induced soil properties to indirectly effect REM.

Linking Vegetation Diversity and Soils on Highway Slopes: A Case Study of the Zhengzhou–Xinxiang Section of the Beijing–Hong Kong–Macau Highway

The rapid development of highways has caused a series of ecological problems, the restoration of which is an important part of highway construction. However, most related studies have focused only on the early stages of slope restoration. The present study investigated the Zhengzhou–Xinxiang section of the Beijing–Hong Kong–Macau Highway, which has been restored over more than 20 years, examining nine representative vegetation communities within this section and investigating their species diversity and soil physicochemical properties. Redundancy analysis and the grey correlation degree model were used to determine the relationship and coupling mechanism between vegetation diversity and soil physiochemical properties. The results showed some differences in the diversity of different vegetation communities and soil physicochemical properties; vegetation diversity was mainly influenced by organic material, total and available nitrogen, total and available phosphorus, slope, available potassium, and soil bulk density. Overall, environmental factors had a strong correlation with the Simpson dominance index and a weak correlation with the species richness index. The degree of coordination between vegetation community diversity and the soil coupling of the road slope remained on low and medium levels. Artificial vegetation restoration can regulate water and fertilizer resources and promote the restoration of highway slope vegetation.

Responses of soil bacterial community structure to different artificially restored forests in open-pit coal mine dumps on the loess plateau, China.

Artificial vegetation restoration is an effective method for improving soil quality. In areas experiencing coal mine subsidence, the microbial community is essential for reconstructing the ecological balance of the soil. Studies are needed to examine how soil microbial community structure respond to different artificial forest restoration types and ages, especially over long-term periods. Therefore, in this study, 10, 20, and 30-year trials were chosen with two restoration types: Pinus tabuliformis (PT) and Ulmus pumila (UP). The objective was to determine how various types and ages of forest restoration affect the structure of soil bacterial communities, as well as the soil environmental factors driving these changes. The results showed that artificial 30-year restoration for both PT and UP can improve soil physical and chemical properties more than restoration after 10 and 20 years. The soil bacterial community structure remarkably differed among the different forest types and restoration ages. The bacterial diversity was higher in UP than in PT; the alpha diversity at longer restoration years (30 and 20) was significantly higher than at 10 years for both PT and UP. Moreover, soil nutrients and pH were the primary soil environmental factors driving bacterial community structure in the PT and UP. Finally, the integrated fertility index (IFI) at 30 years of restoration was considerably higher for PT and UP, and thus, is more beneficial to the restoration of soil after coal mining. Our findings are useful for studying improvement in soil quality and the restoration of the ecological environment in mining areas.

Effects of artificial vegetation restoration on the fractions and availability of soil phosphorus in the water-level-fluctuating zone of Three Gorges Reservoir, China

Effects of artificial vegetation restoration on the fractions and availability of soil phosphorus in the water-level-fluctuating zone of Three Gorges Reservoir, China

Effects of vegetation restoration on soil properties and vegetation attributes in the arid and semi-arid regions of China

Driven by the goal of reversing desertification and recovering degraded lands, a wide range of vegetation restoration practices (such as planting and fencing) have been implemented in China's drylands. It is essential to examine the effects of vegetation restoration and environmental factors on soil nutrients to optimize restoration approaches. However, quantitative evaluation on this topic is insufficient due to a lack of long-term field monitoring data. This study evaluated the effects of sandy steppe restoration and sand dune fixation in the semi-arid desert, and natural and artificial vegetation restoration in the arid desert. It considered soil and plant characteristics using long-term (2005–2015) data from the Naiman Research Station located in the semi-arid region and Shapotou Research Station in the arid region of China's drylands. Results showed the sandy steppe had higher soil nutrient contents, vegetation biomass and rate of accumulating soil organic matter (OM) than the fixed dunes and moving dunes. Soil nutrient contents and vegetation biomass of the natural vegetation of Artemisia ordosica were higher than those of the artificial restoration of Artemisia ordosica since 1956. Artificial restoration had a higher rate of accumulating soil OM, total nitrogen (TN) and grass litter biomass than natural restoration. Soil water indirectly affected soil OM by affecting vegetation. Grass diversity was the main influencing factor on soil OM variance in the semi-arid Naiman desert while shrub diversity was the main factor in the arid Shapotou desert. These findings indicate that sand fixation in the semi-arid desert and vegetation restoration in the arid desert bring benefits for soil nutrient accumulation and vegetation improvement, and that natural restoration is preferable to artificial restoration. Results can be used to formulate sustainable vegetation restoration strategies, such as encouraging natural restoration, considering local resource constraints, and giving priority to restoring shrubs in arid areas with limited water.

Carbon Sequestration Characteristics of Different Restored Vegetation Types in Loess Hilly Region

Since 1999, the "Grain for Green" Program has been extensively implemented in the Loess Plateau region. This measure has largely been of concern not only for its contribution to soil erosion reduction but also for its effects on carbon sequestration. The aim of this study was to assess the carbon sequestration characteristics of different restored vegetation types in areas with severe soil erosion on the Loess Plateau and to compare the effects of restoration age and slope direction on the vegetation carbon sequestration. To evaluate the carbon density and composition characteristics of different ecosystem types, six typical vegetation types (including farmland, grassland, Hippophae rhamnoides Linn., Caragana korshinskii Kom., Robinia pseudoacacia L., and Populus davidiana Dode.) were selected in the Loess Hilly Region, i.e., Wuqi County and Zhidan County in Northern Shaanxi province, which is a typical area for the implementation of artificial vegetation restoration. The results showed that:① vegetation restoration in the semi-arid loess region had a profound impact on carbon sequestration. The carbon density of different vegetations, as well as different vegetation components including above-ground vegetation, below-ground roots, and litter, shared the same pattern as tree>scrub>grassland>farmland. The 0-40 cm soil layer of the farmland showed the lowest soil organic carbon density (1355.5 g·m-2), compared to which those of grassland, H. rhamnoides Linn., C. korshinskii Kom., R. pseudoacacia L., and P. davidiana Dode. were higher by 91.4%, 125.2%, 144.0%, 124.5%, and 232.6%, respectively. ② It was common in grassland, H. rhamnoides Linn., C. korshinskii Kom., and P. davidiana Dode. for the carbon density of different vegetation components as well as soil organic carbon density of different soil layers (0-5, 5-20, and 20-40 cm) to generally show an increasing trend with increased restoration age. ③ Slope direction had a significant impact on the vegetation carbon density only for H. rhamnoides Linn., C. korshinskii Kom., R. pseudoacacia L., and P. davidiana Dode., while showing the contrary for farmland and grassland. Soil organic carbon densities for sunny slopes were significantly lower than those for shaded slopes by 22.9%, 34.3%, 75.8%, 49.1%, 22.4%, and 69.4%, respectively, for farmland, grassland, H. rhamnoides Linn., C. korshinskii Kom., R. pseudoacacia L., and P. davidiana Dode. ④ Ecosystem carbon density varied significantly for different ecosystem types, among which farmland showed the lowest (2022.1 g·m-2), and grassland, H. rhamnoides Linn., C. korshinskii Kom., R. pseudoacacia L., and P. davidiana Dode. showed values higher by 48.7%, 152.8%, 125.1%, 166.3%, and 530.7%, respectively. The carbon density of each ecosystem component showed a pattern as follows:soil layer>above-ground vegetation layer>root layer>litter layer. Soil organic carbon constituted the main part of the ecosystem carbon density and accounted for 67.0%, 86.3%, 59.7%, 72.7%, and 56.5%, respectively, for farmland, grassland, H. rhamnoides Linn., C. korshinskii Kom., and R. pseudoacacia L. These results can provide an essential basis for scientific management of ecosystem carbon pools and promote ecological environment management on the Loess Plateau.

Assessment on spatiotemporal variations for minimum water consumption of vegetation in China based on constraint line method

Driven by climate change and artificial vegetation restoration, the actual vegetation water consumption (evapotranspiration) changes dramatically, in some relatively arid areas, the contradiction between growing vegetation water demand and limited terrestrial water resources becomes more prominent in recent years. For this reason, in actual ecological restoration or adjustment projects, clarifying the maximum vegetation coverage aiming at water balance is critical to maintain normal vegetation growth and sustainable use of water resources, and quantifying the minimum water consumption of vegetation (WCVmin) is a vital path to calculate this index. Currently, how to quantify WCVmin and identify its spatiotemporal variations remains unclear. Here we put forward an approach of quantifying WCVmin by using constraint line method and water balance principle, and we calculated the WCVmin of forest, shrubland and grassland and its spatiotemporal changes across China in 1990 and 2018, respectively. The results indicate: (1) our proposed method was proved to have robust spatiotemporal applicability; (2) compared with 1990, the average WCVmin rose by 7.46% in 2018, and the area that WCVmin enhanced accounts for 59.25%, in temperate continental and alpine climate zone, this proportion reached 81.76%; (3) meanwhile, the maximum plantable area of vegetation identified based on water balance (precipitation equals to WCVmin) reduced by 3.77%, which means it is increasingly difficult to implement sustainable vegetation restoration projects in relatively arid regions across China. This study is not only conducive to identify the regions where sustainable revegetation can be implemented under the constraint of water balance, but it also contributes to illustrate the evolution of the trade-off between vegetation water consumption and terrestrial water availability under changing circumstances.

Integrating Remote Sensing and Spatiotemporal Analysis to Characterize Artificial Vegetation Restoration Suitability in Desert Areas: A Case Study of Mu Us Sandy Land

One of the major barriers to hindering the sustainable development of the terrestrial environment is the desertification process, and revegetation is one of the most significant duties in anti-desertification. Desertification deteriorates land ecosystems through species decline, and remote sensing is becoming the most effective way to monitor desertification. Mu Us Sandy Land is the fifth largest desert and the representative area under manmade vegetation restorations in China. Therefore, it is essential to understand the spatiotemporal characteristics of artificial desert transformation for seeking the optimal revegetation location for future restoration planning. However, there are no previous studies focusing on exploring regular patterns between the spatial distribution of vegetation restoration and human-related geographical features. In this study, we use Landsat satellite data from 1986 to 2020 to achieve annual monitoring of vegetation change by a threshold segmentation method, and then use spatiotemporal analysis with Open Street Map (OSM) data to explore the spatiotemporal distribution pattern between vegetation occurrence and human-related features. We construct an artificial vegetation restoration suitability index (AVRSI) by considering human-related features and topographical factors, and we assess artificial suitability for vegetation restoration by mapping methods based on that index and the vegetation distribution pattern. The AVRSI can be commonly used for evaluating restoration suitability in Sandy areas and it is tested acceptable in Mu Us Sandy Land. Our results show during this period, the segmentation threshold and vegetation area of Mu Us Sandy Land increased at rates of 0.005/year and 264.11 km2/year, respectively. Typically, we found the artificial restoration vegetation suitability in Mu Us area spatially declines from southeast to northwest, but eventually increases in the most northwest region. This study reveals the revegetation process in Mu Us Sandy Land by figuring out its spatiotemporal vegetation change with human-related features and maps the artificial revegetation suitability.

Changes in soil C–N–P stoichiometry after 20 years of typical artificial vegetation restoration in semiarid continental climate zones

Vegetation restoration is one of the principal strategies for ecosystem recovery in degraded land of fragile regions, which is an important driving factor for soil fertility and elemental circulation. While the relationship between revegetation and soil C–N–P stoichiometry remains unclear. To evaluate the relationships between vegetation restoration and soil C–N–P stoichiometry, the distribution of soil C, N, and P within 0–30 cm soil depth under five typical artificial restored vegetation types on the Loess Plateau was analyzed and the influencing factors were evaluated. The results showed that soil C, N, and P contents were relatively lower at the study site than the mean values for topsoil in China. Compared with other vegetation types (Populus simonii Carr., Pinus tabuliformis Carr., and Caragana korshinskii Kom.), Medicago Sativa L. and Stipa bungeana Trin. helped improve soil fertility better; the soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) contents within the 0–30 cm soil layer respectively maximized under Stipa bungeana Trin. (3.30 g kg−1), Medicago Sativa L. (0.34 g kg−1), and Medicago Sativa L. (0.41 g kg−1). The values of soil C/N, C/P, and N/P for the five vegetation types were 9.50–11.85, 15.36–21.47, and 1.29–1.90, respectively. The contents of SOC and TN under the five vegetation types were significantly (P < 0.001) affected by soil depth and vegetation type (P < 0.001) and decreased with increasing soil depth. However, the TP content was significantly (P < 0.001) affected by vegetation type and not by soil depth. Considering the better adaptability of native species, native herb vegetation types should be considered first for ecological restoration in semiarid continental climate zones.

Evaluation of coupling coordination relationship between different habitat materials and vegetation system in the engineering disturbed area

In order to explore the coupling coordination relationship between habitat materials and vegetation system in the engineering disturbed area, six different vegetation restoration patterns in Xiangjiaba engineering disturbed region were utilized as research objects. An evaluation system of 14 habitat materials indicators and 10 vegetation indicators was established. The weight of each indicator was determined by Principal Component Analysis (PCA), and the interrelationship between habitat material and vegetation system was investigated using the Partial Least Square Path model (PLS-PM). Finally, a model for the degree of coupling coordination between habitat materials and vegetation system under different vegetation restoration modes was constructed. The results showed that: 1) habitat materials and vegetation system are closely related, and the habitat materials have a stronger impact on ecosystem restoration. Artificial vegetation restoration technologies can effectively improve soil conditions in engineering disturbed areas, allowing for vegetation restoration in a healthy environment. 2) Under different vegetation restoration patterns, the habitat materials and vegetation coupling coordination index of natural forest plots, frame beam filling soil plots, thick layer base material spraying plots, guest external soil spray seeding plots, vegetation concrete plots, and abandon slag slope plots was 0.767, 0.673, 0.669, 0.625, 0.557, and 0.400, respectively. The development of habitat materials and vegetation in guest external soil spray seeding plots was of a synchronous type. The vegetation development lagged behind habitat materials in thick layer base material spraying plots, vegetation concrete plots, and abandon slag slope plots, while habitat materials lagged behind vegetation development in natural forest plots, frame beam filling soil plots. The model for the degree of coupling coordination between habitat materials and vegetation constructed in this study can serve as a scientific reference for evaluating the impact of ecological restoration engineering in other similar projects.

Spatial variability of surface soil water content and its influencing factors on shady and sunny slopes of an alpine meadow on the Qinghai–Tibetan Plateau

Soil moisture is a vital factor that influences soil characteristics and vegetation distributions in alpine meadow regions. Previous studies have mainly focused on the effects of alpine gradient change, climate change, and human activities on soil hydrological characteristics and vegetation distributions worldwide. However, the spatial variability of the surface soil water content and its influencing factors between shady and sunny slopes in alpine regions are seldom conducted, especially on the alpine meadow regions of the Qinghai–Tibetan Plateau. Based on soil sample collection, combined with statistical, geostatistical, stepwise regression, and geographical detector analysis, this study explores the spatial variability of the surface soil water content and its influencing factors on the shady and sunny slopes of the Mila Mountain pass area on the Qinghai–Tibetan Plateau. Results show that the average soil water content of various depths ranges from 23.14% to 35.52%. The soil moisture content of different soil layers on the shady and sunny slopes shows moderate variability. On the sunny slope, the spatial distribution of the soil water content in different soil layers is mostly patched and banded, while the soil water content on the shady slope shows patchy distribution. The correlation analysis shows that the soil water content of each soil layer has a very significant correlation (P < 0.01). Stepwise regression analysis shows that the main influencing factors of water content of different soil layers on the shady and sunny slopes are soil physical property indexes. Meanwhile, the vegetation coverage factor has a higher explanatory power except the physical indexes on the shady and sunny slopes. The index interaction detection shows interaction among all the evaluation indexes. On the shady slope, all the interactive combinations of the evaluation indexes in each soil layer shows a double-factor enhanced relationship. On the sunny slope, 60% of the interactive combinations of the evaluation indexes show a double-factor enhancement relationship, but 40% of the interactive combinations show a nonlinear enhancement relationship. This study contributes to knowledge on the variability of surface soil water content and its influencing factors on the shady and sunny slopes in the alpine meadow of the Tibetan Plateau, and provides guidance on artificial vegetation restoration and soil structure analysis in the alpine regions.

Effects of different vegetation restoration on soil nutrients, enzyme activities, and microbial communities in degraded karst landscapes in southwest China

The karst area in southwestern China is one of the largest and continuous karst landforms in the world, and its ecosystem is highly sensitive and fragile. Appropriate vegetation restoration modes are of great significance for sustaining and improving the stability of the karst ecosystem, the dominant landform type in southwest China. Bacteria, linking soil and plants, play an important role in regulating the succession and restoration of karst vegetation. However, it remains unclear how soil bacterial communities and soil biochemical properties respond to vegetation restoration practices in karst areas. In this study, a 13-year long-term trial was performed using three planting restoration modes of deciduous broad-leaved, mixed evergreen and deciduous broad-leaved forest, and evergreen broad-leaved forests, with controls of natural enclosure. We aimed to investigate the impact of different vegetation restoration modes on the structure of soil microbial communities and their driving mechanisms using 16S rDNA Illumina sequencing, combined with the determination of 11 soil indicators and statistical models. The results showed that artificial restoration can improve soil nutrient contents, enzyme activities and microbial biomass more effectively than natural closure, which is beneficial to the rapid restoration of vegetation after abandoning of farmland. Among them, the effect of deciduous broad-leaved treatment on artificial restoration mode was better than that of mixed evergreen and deciduous broad-leaved forest and evergreen broad-leaved forest. In sequencing results, artificial restoration increased the relative abundance of Proteobacteria, but decreased that of Acidobacteria. In addition, pH, soil microbial biomass carbon, and urease activity significantly increased bacterial diversity. Different vegetation restoration measures significantly changed the soil bacterial community structure. The bacterial community of deciduous broad-leaved forest was the most beneficial to the benign development of soil. Mantel test showed that pH and soil microbial biomass carbon and nitrogen were the key driving factors of the soil bacterial community. FAPROTAX analysis showed a significant positive correlation between sucrase activity and phototrophy functional bacteria. The results demonstrated that compared with natural enclosure, artificial vegetation restoration promoted rapid community succession, and construction of deciduous broad-leaved forest was the most effective way to manage karst areas, improve soil nutrients, alter its key microbial populations, promote ecosystem services, and eventually benefit the restoration of vegetation in karst areas.

湘西石漠化区3种造林模式土壤真菌群落结构差异

PDF HTML阅读 XML下载 导出引用 引用提醒 湘西石漠化区3种造林模式土壤真菌群落结构差异 DOI: 10.5846/stxb202008072061 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 中央级科研院所基本科研业务费重点项目（CAFYBB2019SZ003）；中南林业科技大学研究生科技创新基金（CX20192026） Differences of soil fungal community structure under three afforestation modes in rocky desertification region of Western Hunan Province Author: Affiliation: Fund Project: “Degradation mechanism and restoration technology of typical forests in South China 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:湘西石漠化地区是我国生态系统脆弱而又敏感的区域，土壤微生物在维持石漠化区森林生态系统结构和功能稳定中发挥重要作用。选取石漠化地区立地条件相同的32年生的马尾松纯林、光皮桦纯林及马尾松-光皮桦混交林为研究对象，以立地条件相似的未造林荒地演变成的灌草群落作为对照，比较分析石漠化地区不同造林模式对土壤真菌群落结构和多样性的影响及其主要驱动因素。采用Illumina HiSeq第二代高通量测序技术，分析了3种森林土壤真菌群落组成及多样性。结果表明，不同造林模式下土壤真菌优势类群不同，光皮桦、马尾松-光皮桦混交林以及石漠化灌草地土壤真菌优势门均为子囊菌门（Ascomycota），且在石漠化灌草地相对丰度最大，为64.0%；马尾松则以担子菌门（Basidiomycota）为优势类群，其相对丰度占57.9%。混交林土壤真菌物种总数和Shannon指数显著高于马尾松和光皮桦林地，整体上真菌群落多样性表现为：未造林灌草地 > 混交林 > 马尾松林 > 光皮桦林。与未造林灌草地相比，马尾松-光皮桦混交林和光皮桦纯林显著提升了土壤有机碳（SOC）和全氮（TN）含量。Mantel test检验结果显示，真菌群落结构与全磷（TP）、有机碳（SOC）、铵态氮（NH4+-N）、硝态氮（NO3--N）、全氮（TN）、pH和含水量（SWC）具有显著相关性（P<0.05），其中土壤SOC、TN、pH值对真菌群落结构影响最大。冗余分析（RDA）结果发现，子囊菌（Ascomycota）与pH、TP、SOC、TN、AP、NO3--N含量均呈正相关；担子菌门（Basidiomycota）和被孢霉门（Mortierellomycota）主要与NH4+-N成正相关，与pH、TP、SOC、TN、AP、NO3--N呈负相，而罗氏菌门（Rozellomycota）与SWC呈正相关（P<0.05）。综上，相比针叶纯林，石漠化地区针阔混交林能通过增加土壤SOC、TN而显著提高真菌群落多样性，促进土壤肥力状况的提升。此研究结果可以为石漠化区人工植被恢复以及土壤肥力管理提供依据。 Abstract:Rocky desertification area in Western Hunan province is a fragile and sensitive area of ecosystem in China. Soil microorganisms play an important role in maintaining the stability of forest ecosystem structure and function in rocky desertification area. Thirty two year-old pure Pinus massoniana forest, pure Betula luminifera forest and mixed Pinus massoniana and Betula luminifera forest in rocky desertification area with the same site conditions were selected as the research objects. The non-forested shrub grassland with the similar site conditions was taken as the control to compare and analyze the influence of different afforestation modes on soil fungal community structure and diversity and their main driving factors. The composition and diversity of soil fungal communities in three forests were analyzed by Illumina HiSeq second-generation high-throughput sequencing technology. The results showed that the dominant groups of soil fungi were different under different afforestation modes. The dominant phylum of soil fungi in Betula luminifera, mixed forest and non-forested shrub grassland were Ascomycota, and the relative abundance was the largest in non-forested shrub grassland, which was 64.0%. Basidiomycota was the dominant group in Pinus massoniana, its relative abundance accounted for 57.9%. The total number of soil fungal species and Shannon index of mixed forest were significantly higher than those of Pinus massoniana and Betula luminifera forest. On the whole, the diversity of fungal community was as follows:non-forested shrub grassland > mixed forest > Pinus massoniana forest > Betula luminifera forest. The contents of soil organic carbon (SOC) and total nitrogen (TN) in the mixed forest and Betula luminifera pure forest were significantly higher than those in non-forested shrub grassland. Mantel test showed that fungal community structure was significantly correlated with total phosphorus (TP), SOC, ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3--N), TN, pH and water content (SWC) (P<0.05). Soil SOC, TN and pH had the greatest impact on fungal community structure. Redundancy analysis (RDA) showed Ascomycetes were positively correlated with pH, TP, SOC, TN, AP and NO3--N content; Basidiomycetes and Mortierella were mainly positively correlated with NH4+-N, and negatively correlated with pH, TP, SOC, TN, AP and NO3--N. There was a positive correlation between Rozellomycota and SWC. In conclusion, compared with pure coniferous forest, coniferous and broad-leaved mixed forest in rocky desertification area can significantly improve the diversity of fungal community by increasing soil SOC and TN, and promote the improvement of soil fertility. The results can provide basis for artificial vegetation restoration and soil fertility management in rocky desertification area. 参考文献 相似文献 引证文献

Water Use Characteristics of Two Dominant Species in the Mega-Dunes of the Badain Jaran Desert

The sparse natural vegetation develops special water use characteristics to adapt to inhospitable desert areas. The water use characteristics of such plants in desert areas are not yet completely understood. In this study, we compare the differences in water use characteristics between two dominant species of the Badain Jaran Desert mega-dunes—Zygophyllum xanthoxylum and Artemisia ordosica—by investigating δ2H and δ18O in plant xylem (the organization that transports water and inorganic salts in plant stems) and soil water, and δ13C in plant leaves. The results indicate that Z. xanthoxylum absorbed 86.5% of its water from soil layers below 90 cm during growing seasons, while A. ordosica derived 79.90% of its water from the 0–120 cm soil layers during growing seasons. Furthermore, the long-term leaf-level water use efficiency of A. ordosica (123.17 ± 2.13 μmol/mol) was higher than that of Z. xanthoxylum (97.36 ± 1.16 μmol/mol). The differences in water use between the two studied species were mainly found to relate to their root distribution characteristics. A better understanding of the water use characteristics of plants in desert habitats can provide a theoretical basis to assist in the selection of species for artificial vegetation restoration in arid areas.

Differences in soil water and nutrients under catchment afforestation and natural restoration shape herbaceous communities on the Chinese Loess Plateau

The Chinese Loess Plateau (CLP) is one of the areas with the most serious soil erosion worldwide. Vegetation restoration is the main way to control soil erosion and combat land degradation in this region. Using the methods of afforestation and natural restoration, there are large differences in the diversity pattern and community structure of the herbaceous plants, which affects the ecological security and restoration effectiveness. However, current studies are often less focused on this aspect, or only woody plants are considered. In this study, two adjacent catchments with similar geological backgrounds but different restoration methods on the CLP were selected; one catchment was subject to afforestation, and the other was subject to natural grassland revegetation. To clarify the environmental causes of the different performances of the herbaceous communities under these two restoration methods, the functional traits and species diversity patterns of the herbaceous plants, soil physicochemical properties and topographic factors in the two catchments were investigated. The results showed that there were significant differences in the functional traits of the herbaceous communities between these two different restoration methods. Natural restoration produced a significantly higher diversity of herbaceous plants than did afforestation. Differences in soil water, nitrate nitrogen and rapidly available phosphorus contents between the two catchments were the key reasons for the functional traits and diversity differences between the herbaceous communities. Moreover, we found that hillslopes and gullies showed different patterns in water-related functional traits, especially in the naturally restored catchment, which was probably caused by the soil water differences in these two landforms. The results of this study can help us better understand the diversity patterns of herbaceous communities under the measures of natural and artificial vegetation restoration on the CLP.

Spatial Heterogeneity and Driving Factors of Soil Moisture in Alpine Desert Using the Geographical Detector Method

Soil moisture is a vital factor affecting the hydrological cycle and the evolution of soil and geomorphology, determining the formation and development of the vegetation ecosystem. The previous studies mainly focused on the effects of different land use patterns and vegetation types on soil hydrological changes worldwide. However, the spatial heterogeneity and driving factors of soil gravimetric water content in alpine regions are seldom studied. On the basis of soil sample collection, combined with geostatistical analysis and the geographical detector method, this study examines the spatial heterogeneity and driving factors of soil gravimetric water content in the typical alpine valley desert of the Qinghai–Tibet Plateau. Results show that the average value of soil gravimetric water content at different depths ranges from 3.68% to 7.84%. The optimal theoretical models of soil gravimetric water content in 0–50 cm layers of the dune are different. The nugget coefficient shows that the soil gravimetric water content in the dune has a strong spatial correlation at different depths, and the range of the optimal theoretical model of semi-variance function is 31.23–63.38 m, which is much larger than the 15 m spacing used for sampling. The ranking of the influence of each evaluation factor on the alpine dune is elevation &gt; slope &gt; location &gt; vegetation &gt; aspect. The interaction detection of factors indicates that an interaction exists among evaluation factors, and no factors are independent of one another. In each soil layer of 0–50 cm, the interaction among evaluation factors has a two-factor enhancement and a nonlinear enhancement effect on soil gravimetric water content. This study contributes to the understanding of spatial heterogeneity and driving factors of soil moisture in alpine deserts, and guidance of artificial vegetation restoration and soil structure analysis of different desert types in alpine cold desert regions.

Effects of drought and rainfall events on soil autotrophic respiration and heterotrophic respiration

The changes of surface vegetation cover, caused by the return of farmland to forest and grassland, can not only effectively control soil erosion, but also significantly increase soil organic carbon reserves. However, few studies are currently available on the control mechanism of soil CO2 emission after artificial vegetation restoration, particularly on sloping land. This lack of knowledge increases the uncertainty of quantitative estimations of the effect of soil carbon cycle in conversions of cultivated land to forest. This study selected three different plantation types from re-forested hillslopes and monitored both soil respiration and its component changes. The goal was to describe the responses of soil heterotrophic respiration (Rh), soil autotrophic respiration (Ra), and total soil respiration (Rt) to drought and precipitation. Furthermore, the effects of climate warming and drought on soil respiration were evaluated in these reforested areas. A two-year experiment was conducted in the Haihe River Basin of China to study the effects of drought and precipitation on Rt and Rh. The results showed that: (1) soil drought significantly decreased soil respiration carbon emissions. In 2014, rainfall was 20.25 % lower than in 2013, and soil respiration carbon emissions were 5% lower (95 % confidence interval from 1% to 8.1 %). (2) Rainfall significantly increased carbon emissions from soil respiration by 33 % after rainfall (95 % confidence interval from 29.9%–36.5%). (3) Ra and Rh showed different responses to climate warming and drought, where Rh is more sensitive to drought than Ra, and the percentage of Rh in Rt (PRh) was positively correlated with soil moisture. These results show that the increase in soil respiration after vegetation restoration may not be as strong as predicted for semi-humid regions. Climate warming also results in lower soil moisture and less precipitation, which neutralizes part of the positive feedback from the soil-carbon climate.

Community diversity of ground-dwelling beetles in secondary oak Forest and its adjacent restored poplar Forest

In order to restore the vegetation of forests, China has implemented the project of restoring the farmland to the forest. With the advancement of this project, the artificial vegetation restoration area adjacent to the forest is expanding. In this study, a secondary oak forest, its adjacent restored poplar forest and the secondary oak forest-restored forest ecotone were selected as the study sample plots, and the ground-dwelling beetle community was investigated by pitfall trap method for exploring the diversity characteristics of the ground-dwelling beetle community in this complex ecosystem, in order to reveal the relationship between the ground-dwelling beetle and the environmental changes. In this study, 2458 ground-dwelling beetles belonging to 94 species of 24 families were collected from the secondary oak forest and its adjacent restored poplar forest from April to September 2017, of which Scarabaeidae, Carabidae and Silphidae were the dominant communities of ground-dwelling beetles in the sample plots. The order of the species number and individuals number of ground-dwelling beetles in the different types of vegetation was the secondary oak forest > ecotone > restored poplar forest in turn, with significant differences. The estimation of nonparametric species richness showed that the sampling intensity was not fully saturated, indicating that more surface beetle species could be collected. The Margalef richness index, Simpson diversity index (λ), Hill diversity index (N2), Pielou evenness index (E1), Hill evenness index (E2) and modified Hill evenness index (EHill) of surface beetles were significantly different in the different habitats, and higher diversity and evenness of the surface beetles were maintained in the restored poplar forest, indicating that the restoration and re-naturalization of forest vegetation could increase the insect species and community stability. The community similarity analysis indicated that the ground-dwelling beetle community among the secondary oak forest, the ecotone and the restored poplar forest was at the middle level of dissimilarity. The edge effect intensity analysis suggested that there was a negative edge effect in the ecotone between the secondary oak forest and the restored poplar forest.