Response of surface soil respiration to storm and Ips typographus (L.) disturbance in boreal Norway spruce stands. Response of surface soil respiration to storm and Ips typographus(L.) disturbance in boreal Norway spruce stands. Forests. Characteristics of stoichiometric soil C, N and P ratios as influenced by geological background in a karst graben area, southwest China. Forests.
Response of Soil Surface Respiration to Storm and Ips typographus (L.) Disturbance in Boreal Norway
- Introduction
- Materials and Methods 1. Research Area
- Results 1. Tree Mortality
- Discussion
- Conclusions
After carefully placing the chamber on top of the collar, the CO2 increases. Of the affected plots (SF and ID), the highest proportion of dead trees was in the Viitalampi SF plot, established in 2015, and the lowest in the Viitalampi ID plot, established in 2015 (69%). At Viitalampi, mean soil temperatures were significantly higher in the ID treatment.
Southwest China
Materials and Methods 1. Study Site
The vegetation at this studied site consisted of an evergreen broad-leaved forest, dominated by Castanopsis fargesii, Schima superba, Itea chinensis and a small amount of Miscanthus spp.; the soil type was red soil of the Ferralosol order in the GSCC [ 16 ], with a depth of >1 m [ 9 ]. The water volume concentration, conductivity and temperature of the surface calcareous soil and red soil were measured monthly for one year (Table 1; Figure 2). A rubber tube was embedded in the soil in the cylinder and exposed to the atmosphere; a waterstop clamp was used to seal the end of the pipe exposed to the atmosphere.
Results
Soil CO2 concentration in the calcareous soil and red soil profiles varied with depth, where it was usually higher at 50–60 cm and lower in the upper and deeper layers; this pattern was more apparent in the red soils (Figure 5). The average CO2 concentrations in the three calcareous soils were 11% higher than in the red soils (Table S2). Soil organic matter (SOM) on the surface of calcareous soil was clearly higher than that of red soil (Table 1), but deeper in the profile showed the opposite trend.
Soil moisture in the calcareous soil profile was horizontally and vertically higher than in the red soil profile (Table 1, Figure 2), which can. This process may also have caused a slow decline in CO2 concentration in the lower calcareous soil profile, resulting in a less pronounced two-way gradient than in the red soil profile. It is clear, therefore, that although reclamation is an active weathering process, the decomposition of soil organic matter and the associated inhalation CO2 emissions dominate the transport and cycling of carbon in the soil system.
Nevertheless, the rate of dissolution of carbonate tablets in air could indicate a rate of dissolution of carbonate rocks in bare karst areas, which is only 0.35 times that of calcareous soils. Bidirectional differences in carbonate rock dissolution rates were also evident in the two contrasting soils. Although salinization is an active weathering process, the decomposition of soil organic matter and the associated CO2 emissions in inhalation dominate the transport and cycling of carbon in the system.
The regularity of CO2 emissions from the soil of the epikarst ecosystem in Jinfu Mountain, Chongqing.Acta Geosci.
The Characteristics of Soil C, N, and P Stoichiometric Ratios as Affected by Geological Background in a
Material and Methods 1. Study Area
Different rocky desertification grades including LRD, MRD and SRD were selected in the same landform. Identical letters indicate no significant differences in the mean values between soils under different landforms at the 0.05 level. The red short line indicates the mean value of different rocky desertification degrees at the same geomorphological location.
The same letters indicate no significant differences in mean values between soils under different rocky desertification in the same landform at the 0.05 level. C:N ratios did not have a consistent regularity with worsening stony desertification among the three landforms, and there were no significant differences between stony desertification in the same landform. However, in this study, the N:P and C:P ratios increased with the worsening of stony desertification, more prominently in the area of rocks with severe stony desertification with strong disturbances.
In the intensive rocky desert environment, this aggregation effect becomes more apparent, combined with. In this work, we analyzed the C, N and P stoichiometry under different rocky desertification degrees from a basin, a slope and a plateau in the karst graben basin. Changes in soil quality in the process of karst rock desertification and evaluation of the impact on the ecological environment. Acta Ecol.
Low nitrate retention capacity of calcareous soils under a forest in the karst region of southwest China. Soil Biol.
Differential Responses and Controls of Soil CO 2 and N 2 O Fluxes to Experimental Warming and Nitrogen
Materials and Methods 1. Experimental Site
Repeated measure-ANOVA was used to analyze the effects of warming and N fertilization on soil CO2 and N2O fluxes. Relationships between soil CO2 fluxes and soil temperature (a), MBC (c), DOC (e), NH4+(f) and utilization of soil microbial substrates (g), and between soil N2O fluxes and soil temperature (b), NH4+(d) and carbon utilization of microbial communities (h). Few studies have investigated the direct relationship of soil microbial community to soil CO2 flux.
In this study, we found that patterns of microbial substrate use had a direct negative effect on soil CO2 flux (Figures 4a and 5a). In addition, soil carbon quality and quantity, as well as soil microbes and nitrogen, significantly influenced soil CO2 flux. In this study, there was a relative lack of soil C and no effect on the microbial community caused by N fertilization.
A surprising finding was that soil NH4+-N had a negative effect on soil CO2 flux in this study (Figure 4a). The positive effect of soil NH4+ on soil CO2 flux was reported in temperate and subtropical forests [12,50]. Since soil N2O emission was positively related to soil CO2 flux, soil NH4+ had a negative effect on soil N2O emission.
This study revealed different feedback patterns and controls of soil CO2 and N2O fluxes in subalpine plantation forest under climate warming and N deposition, and further highlighted the important contributions of soil microbes to GHG fluxes.
Nitrogen Addition Affects Soil Respiration Primarily through Changes in Microbial Community Structure
No significant differences in SOC, TN, ammonium N (NH4+-N) or nitrate N (NO3--N) were detected after three years of N deposition (Table 1). Relative carbon (C) distribution (%) in different chemical shift regions in 13C cross-polarization magic angle spinning of soils under different nitrogen addition treatments, Table S2. The exponential relationship between soil CO2 emission rate and soil temperature in each subplot under different nitrogen addition treatments, Table S3 Effects of N addition on phospholipid fatty acid biomarker concentration (nmol g−1soil).
Differential responses of soil respiration and its components to nitrogen addition among biomes: a meta-analysis. Globe. Non-linear response of microbial activity across a nitrogen addition gradient in a soil from the Gurbantunggut Desert, northwest China. Soil Biol. Microbial community structure and function: Effect of silvicultural burning and topographic variability in northern Alberta.Soil Biol.
Fungal growth and effects of different wood-decomposing fungi on the native bacterial community of contaminated and uncontaminated soils. Biol. Experimental evaluation of methods for quantitative determination of dissolved organic nitrogen (DON) and dissolved organic carbon (DOC) in soil. Soil Biol. Soil respiration and its autotrophic and heterotrophic components in response to nitrogen addition among different degraded temperate grasslands. Soil Biol.
The reduction of soil microbial diversity is associated with the reduction of microbial biomass under nitrogen addition.Soil Biol.
The Influence of Land Use Patterns on Soil Bacterial Community Structure in the Karst Graben Basin
Materials and Methods 1. Study Sites
It can be seen that the physico-chemical properties of the soil were different in forests, shrubs and grasslands (Table 1). TN and SOC in forest land were higher than those in shrubland and grassland. The dominant phyla were different in the three land use types, as well as in layers A and B, as seen in Figure 1.
In layer B, the alpha diversity indices of the three land use patterns were not significantly different, except for the Simpson index. Heat map illustrating the mean relative frequency of the 45 most abundant OTUs with >0.5% abundance in stratum B with different land uses (b). Heatmap representing the relationship between soil physicochemical parameters and the most abundant OTUs with >0.5% abundance in the surface layer (c) and deep layer (d).
Spearman's correlations showing the relationship between the soil physico-chemical parameters and dominant phyla in the three land use types. The diversity indices of soil bacterial communities in the three land use types decreased with increasing soil depth, which was consistent with the changes in soil physicochemical properties. In the B layer, Acidobacteria had a significantly negative correlation with TP (Figure 5), although the proportion of Acidobacteria in the three land use patterns did not differ significantly.
TN and SOC in the woodland were higher than those in the shrubland and grassland.
Effects of Plum Plantation Ages on Soil Organic Carbon Mineralization in the Karst Rocky
Desertification Ecosystem of Southwest China
Materials and Methods 1. Study Area
Camus and Digitaria sanguinalis (Linn.) Scop. The dominant plants on the abandoned land were herbs, dominated by Miscanthus with a small amount of Conyza canadensis (Linn.) Cronq. There were no significant differences in SOC mineralization rate among the three planting ages, but it was significantly lower than CK. At the last stage (62–90 days), the mineralization rate of SOC CK started to be lower than that of the soil under plum plantations with different ages, and the difference was significant.
Cumulative soil organic carbon mineralization under plum plantations of different ages Carbon mineralization showed a curvilinear relationship with time during the incubation period (ranging from day 0 to day 90) (Figure 3). Throughout the incubation, the cumulative release of CO2 was higher in CK than that in plum plantations of different ages. The first-order kinetic equation was used to fit the cumulative mineralization of SOC in plum plantations with different ages, and the fitting results were good (R2>0.90).
Therefore, the difference of SOC mineralization in plum plantations with different ages was mainly due to the difference in SOC content. Plum planting significantly reduced SOC content by about 50% compared to abandoned land, which can be attributed to the changes in agricultural management (e.g. forest clearing, cultivation and mineral N fertilisers). The C/N value in the studied soils was relatively stable, and no significant difference was found between plum plantations with different ages.
The cumulative rate of SOC mineralization and mineralization in plum plantations of different ages is decreased compared to the abandoned land.
