scholarly journals Effects of vegetation restoration on soil quality in fragile karst ecosystems of southwest China

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9456
Author(s):  
Huiling Guan ◽  
Jiangwen Fan
Keyword(s):  
Soil Quality ◽  
Juglans Regia ◽  
Soil Layer ◽  
Vegetation Restoration ◽  
Pennisetum Purpureum ◽  
Toona Sinensis ◽  
Prunus Salicina ◽  
Karst Areas ◽  
Restoration Time ◽  
Karst Ecosystems

Soil quality assessment is important for karst ecosystems where soil erosion is significant. A large amount of vegetation restoration has been implemented since the early 21st century in degraded karst areas across southwestern China. However, the impacts on soil quality of different restoration types rarely have been compared systematically. In the current study, we investigated the soil quality after a number of vegetation restoration projects as well as their adjacent cropland by analyzing soil samples. Six vegetation restoration types were evaluated, including one natural restoration (natural shrubland, protected for 13 years), three economic forests (4 years Eucalyptus robusta, 4 years Prunus salicina and 6 years Zenia insignis) and two mixed forests (1 year Juglans regia–crop and 13 years Toona sinensis-Pennisetum purpureum ). We evaluated the benefits of different restoration types more accurately by setting each adjacent cropland as the control and setting the variation between the corresponding restored and control site as the evaluation object so that the background differences of six sites could be eliminated. The results indicated that natural shrubland, Toona sinensis-Pennisetum purpureum and Zenia insignis were effective in improving soil quality index (SQI) in degraded karst cropland largely due to their higher SOC and TN content. The variation of SQI (VSQI) of natural shrubland was significantly higher than that in Eucalyptus robusta, Prunus salicina and Juglans regia-crop in total soil layer (0–30 cm) (P < 0.05), indicating natural shrubland had better capacity to improve soil quality. The boosting regression tree model revealed that vegetation restoration type explained 73.49% and restoration time explained 10.30% of the variation in VSQI, which confirmed that vegetation restoration type and restoration time are critical for achieving soil reserves. Therefore, it is vital to select appropriate vegetation type in restoration projects and recovery for a long time in order to achieve better soil quality. The current study provides a theoretical basis on which to assess the effects of different vegetation restoration types on the heterogeneous degraded karst areas.

Recovery approach affects soil quality in fragile karst ecosystems of southwest China: Implications for vegetation restoration

2018 ◽  
Vol 123 ◽  
pp. 151-160 ◽  
Author(s):  
Danbo Pang ◽  
Jianhua Cao ◽  
Xinqiu Dan ◽  
Yinghui Guan ◽  
Xiawei Peng ◽  
...  
Keyword(s):  
Soil Quality ◽  
Southwest China ◽  
Vegetation Restoration ◽  
Karst Ecosystems ◽  
Recovery Approach

scholarly journals Soil Cover Improves Soil Quality in a Young Walnut Forest in the Sichuan Basin, China

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 236
Author(s):  
Liehua Tie ◽  
Maosong Feng ◽  
Congde Huang ◽  
Josep Peñuelas ◽  
Jordi Sardans ◽  
...  
Keyword(s):  
Soil Quality ◽  
Sichuan Basin ◽  
Soil Cover ◽  
Microbial Biomass Carbon ◽  
Juglans Regia ◽  
Soil Layer ◽  
Biological Indicators ◽  
Positive Interactions ◽  
Available Phosphorus ◽  
The Sichuan Basin

The soil quality index (SQI) is based on several key indicators and is used to assess soil quality. More than 250,000 ha of walnut saplings (Juglans regia L.) were planted in previous cropland areas in the Sichuan Basin, China, using a range of soil cover types that may affect soil quality with effects that are unclear. We investigated the effects of white film (WF), black film (BF), shade netting (SN), and maize straw (MS) soil cover types and an uncovered control type (CK) on soil chemical and biological indicators and the SQI in the 0–15 cm soil layer in a young walnut forest in the Sichuan Basin over a 27-month study period. The results showed that all soil cover types increased the soil organic matter (SOM), total potassium (TK), and available potassium (AK) concentrations (p < 0.05), whereas the total nitrogen (TN) and available nitrogen (AN) concentrations were greater only in soils covered by MS than in CK (p < 0.05). The available phosphorus concentrations were 64.1 and 193.2% greater in soils covered by BF and MS treatments, respectively, than in the CK (p < 0.05). The numbers of soil faunal groups (N) were 45.7, 36.4, 37.2, and 101.5% higher in WF, BF, SN, and MS, respectively, than in CK (p < 0.05); the individual numbers (S) were 92.3, 36.2, 100.8, and 154.5% greater in WF, BF, SN, and MS, respectively, than in CK (p < 0.05). The microbial biomass carbon (MBC) was 15.5, 32.3, 45.0, and 77.1% greater in WF, BF, SN, and MS than in CK, respectively (p < 0.05). Redundancy discriminant analysis revealed strong positive interactions between biological indicators (MBC, N, and S) and SOM, AN, and AK concentrations. SOM, TN, AK, S, and MBC were the minimum required variables for the effective assessment of the SQI. All four soil cover types led to an improved SQI (p < 0.05), and MS had the greatest effect on SOM, TN, AN, AP, N, S, MBC, and SQI (p < 0.05). In conclusion, all four soil cover types increased the SOM levels, TK, AK, and MBC concentrations, soil faunal diversity, and SQI. The MS treatment was the most cost-effective and efficient measure to improve soil fertility, ecological function, and overall soil quality in the studied walnut forest.

scholarly journals Assessment of Seasonal Variability in Soil Nutrients and Its Impact on Soil Quality under Different Land Use Systems of Lower Shiwalik Foothills of Himalaya, India

2021 ◽  
Vol 13 (3) ◽  
pp. 1398
Author(s):  
Tavjot Kaur ◽  
Simerpreet Kaur Sehgal ◽  
Satnam Singh ◽  
Sandeep Sharma ◽  
Salwinder Singh Dhaliwal ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Quality ◽  
Surface Soil ◽  
Sandy Loam ◽  
Monsoon Season ◽  
Soil Layer ◽  
Seasonal Effects ◽  
Land Use Systems ◽  
Post Monsoon ◽  
Significant Difference

The present study was conducted to investigate the seasonal effects of five land use systems (LUSs), i.e., wheat–rice (Triticum aestivum—Oryza sativa) system, sugarcane (Saccharum officinarum), orange (Citrus sinensis) orchard, safeda (Eucalyptus globules) forest, and grassland, on soil quality and nutrient status in the lower Satluj basin of the Shiwalik foothills Himalaya, India. Samples were analyzed for assessment of physico-chemical properties at four soil depths, viz., 0–15, 15–30, 30–45, and 45–60 cm. A total of 120 soil samples were collected in both the seasons. Soil texture was found to be sandy loam and slightly alkaline in nature. The relative trend of soil organic carbon (SOC), macro- and micro-nutrient content for the five LUSs was forest > orchard > grassland > wheat–rice > sugarcane, in the pre- and post-monsoon seasons. SOC was highly correlated with macronutrients and micronutrients, whereas SOC was negatively correlated with soil pH (r = −0.818). The surface soil layer (0–15 cm) had a significantly higher content of SOC, and macro- and micro-nutrients compared to the sub-surface soil layers, due to the presence of more organic content in the soil surface layer. Tukey’s multiple comparison test was applied to assess significant difference (p < 0.05) among the five LUSs at four soil depths in both the seasons. Principle component analysis (PCA) identified that SOC and electrical conductivity (EC) were the most contributing soil indicators among the different land use systems, and that the post-monsoon season had better soil quality compared to the pre-monsoon season. These indicators helped in the assessment of soil health and fertility, and to monitor degraded agroecosystems for future soil conservation.

Effects of Grass and Forests and the Infiltration Amount on Preferential Flow in Karst Regions of China

2020 ◽  
Author(s):  
Xiaoqing Kan ◽  
Jinhua Cheng
Keyword(s):  
Organic Matter ◽  
Preferential Flow ◽  
Water Movement ◽  
Vegetation Restoration ◽  
Water Infiltration ◽  
Rocky Desertification ◽  
Restoration Planning ◽  
Karst Areas ◽  
Matrix Flow ◽  
Natural Grassland

&lt;p&gt;&amp;#160; Preferential flow is an important water infiltration phenomenon in karst regions because it can quickly transport surface water to deep soil and increases available water for underground root growth. The response of preferential flow to vegetation restoration requires urgent investigation due to the special soil structure of karst regions. In order to study the effect of vegetation restoration on water movement in karst regions, four kinds of ponded water infiltration experiments were carried out in Pinus Yunnanensis plantation forestland, secondary forestland, and natural grassland. A brilliant blue dyeing experiment was conducted to visualize the distribution of water infiltration in soil (a total of 150 stained images from vertical soil slices). Results showed that the average depth of matrix flow in natural grassland was approximately six times those in plantation and secondary forestlands. An increase in matrix flow will have a negative effect on the development of preferential flow. Water transported in preferential flow paths affects the distribution of nutrients and organic matter in the soil. However, preferential flow in grassland can promote the accumulation of available nutrients, and preferential flow in plantations can inhibit the loss of organic matter. Preferential flow in grasslands and forest plantations is less than that in native forests soils. The results of SEM showed that preferential flow increases the percolation of water in soils. The effect is that preferential flow can obstructs water uptake by the roots under low rainfall conditions, and decreases surface runoff before soil saturation under high rainfall conditions. In the process of nutrient element migration, preferential flow has a good contribution, which is conducive to the migration and accumulation of elements required for surface vegetation growth. The contribution of preferential flow needs to be considered in studies on vegetation restoration planning and land degradation. Reasonable allocation of plantation forests has a certain mitigation effect on soil erosion in Karst areas, and preferential flow under this special geomorphological type is worth studying. Preferential flow can transport nutrients to deeper soil for roots according to the data of this study. Therefore, plantation is feasible under karst landform conditions, but it is better to combine herbaceous plants in a plantation. The results could provide suggestions for the restoration of rocky desertification and the advantages or disadvantages of vegetation restoration engineering in karst areas.&lt;/p&gt;

scholarly journals Calcium content and high calcium adaptation of plants in karst areas of southwestern Hunan, China

2018 ◽  
Vol 15 (9) ◽  
pp. 2991-3002 ◽  
Author(s):  
Xiaocong Wei ◽  
Xiangwen Deng ◽  
Wenhua Xiang ◽  
Pifeng Lei ◽  
Shuai Ouyang ◽  
...  
Keyword(s):  
Plant Species ◽  
Calcium Content ◽  
Vegetation Restoration ◽  
Plant Functional Groups ◽  
Ecological Problem ◽  
Rocky Desertification ◽  
Exchangeable Ca ◽  
High Calcium ◽  
Karst Areas ◽  
Ecosystem Reconstruction

Abstract. Rocky desertification is a major ecological problem of land degradation in karst areas. In these areas, the high soil calcium (Ca) content has become an important environmental factor that can affect the restoration of vegetation. Consequently, the screening of plant species that can adapt to high Ca soil environments is a critical step in vegetation restoration. In this study, three grades of rocky desertification sample areas were selected in karst areas of southwestern Hunan, China (LRD: light rocky desertification; MRD: moderate rocky desertification; and IRD: intense rocky desertification). Each grade of these sample areas had three sample plots in different slope positions, each of which had four small quadrats (one in rocky-side areas, three in non-rocky-side areas). We measured the Ca content of leaves, branches, and roots from 41 plant species, as well as soil total Ca (TCa) and exchangeable Ca (ECa) at depths of 0–15, 15–30, and 30–45 cm in each small quadrat. The results showed that the soil Ca2+ content in rocky-side areas was significantly higher than that in non-rocky-side areas (p<0.05). The mean soil TCa and ECa content increased gradually along with the grade of rocky desertification, in the order IRD > MRD > LRD. For all plant functional groups, the plant Ca content of aboveground parts was significantly higher than that of the belowground parts (p<0.05). The soil ECa content had significant effects on plant Ca content of the belowground parts but had no significant effects on plant Ca content of the aboveground parts. Of the 41 plant species that were sampled, 17 were found to be dominant (important value > 1). The differences in Ca2+ content between the aboveground and belowground parts of the 17 dominant species were calculated, and their correlations with soil ECa content were analyzed. The results showed that these 17 species can be divided into three categories: Ca-indifferent plants, high-Ca plants, and low-Ca plants. These findings provide a vital theoretical basis and practical guide for vegetation restoration and ecosystem reconstruction in rocky desertification areas.

scholarly journals Analysis of biogeochemical processes in plastic-covered soil during establishment period in strawberry cultivation

2020 ◽  
Vol 2 (10) ◽  
Author(s):  
M. Meyer ◽  
D. Diehl ◽  
G. E. Schaumann ◽  
K. Muñoz
Keyword(s):  
Microbial Biomass ◽  
Soil Quality ◽  
Elevated Temperatures ◽  
Soil Layer ◽  
Aggregate Stability ◽  
Belowground Biomass ◽  
Agricultural Practice ◽  
Soil Processes ◽  
Plastic Mulching ◽  
The Impact

Abstract Plastic mulching (PM) has become a widely applied agricultural practice to optimize plant growth. However, it is still under debate how PM influences biogeochemical soil processes and thus important factors of soil quality, such as soil organic matter (SOM) composition, aggregate stability and microbial biomass. Our objective was to identify the impact of PM on biogeochemical soil processes. Therefore, we compared a plastic-covered strawberry cultivation system (PC) with an uncovered system (NC) in three soil layers (0–10, 10–30 and 30–60 cm) at three dates during a 4-month period of strawberry establishment from their transplanting in summer to the beginning of winter. The PC shifted the microclimate of the soil towards higher temperatures but lower moistures in the 0–35 cm soil layer compared to uncovered soil. Predominantly in the surface layer, the PC reduces leaching processes, which can improve nutrient (fertilizer) use efficiency. PC increased SOM and shifted SOM to a more stable SOM. The higher SOM under PC despite larger microbial biomass and elevated temperatures, indicate that belowground biomass inputs compensate the potential SOM losses by an enhanced SOM decomposition under PC. We demonstrated that PC influenced soil processes already within the 4-month period of strawberry establishment, partially down to the 30–60 soil layer. Further, long-term studies are required to estimate the influence of multi-annual PM application on biogeochemical soil processes and on soil quality.

Research on the Construction Technique of Super-Large Diameter Rock-Socketed Piles in Karst Areas

2012 ◽  
Vol 446-449 ◽  
pp. 1486-1490
Author(s):  
Hao Feng Xing ◽  
Ming Hui Meng ◽  
Wan Xue Long ◽  
Guan Bao Ye ◽  
Wen Yong He
Keyword(s):  
Relative Density ◽  
Clay Soil ◽  
Large Diameter ◽  
Soil Layer ◽  
Guizhou Province ◽  
Geological Condition ◽  
Construction Technique ◽  
Research Results ◽  
Geological Conditions ◽  
Karst Areas

It is difficult for the large diameter pile to bore the hole and ensure its quality under the complicated geological condition in karst areas. In order to get the feasible construction method, the construction technique of super-large diameter rock-socketed piles in karst areas was explored in this paper on the basis of Hezhang Super Maior Bridge project in Guizhou province. The adaptability of the construction plan at this site was expounded firstly; and then the technologies for dealing with the problems of buried hammer, inclined hole, slurry leakage, which often occur during the process of boring pile hole under complicated geological conditions, were deeply researched. The research results show that it is effective to use the slurry with the relative density of 1.30 to 1.35 to prevent the pebble soil layer from collapsing, to prevent the pile hole from inclining by backfilling rubble in tilted stratum, to treat the slurry leakage problem by backfilling rubble, clay soil and bagged cement; and to handle the hammer stuck through the skills of underwater blasting, salvaging with pothook and light pounding with small hammer. It is proved that the method of light pounding with small hammer is preferable to handle the stuck hammer occured in backfill hole. The study provides the theoretical guidance and reference for similar projects.

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