scholarly journals Warming Effects on Topsoil Organic Carbon and C:N:P Stoichiometry in a Subtropical Forested Landscape

Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 66
Author(s):  
Yuqiao Su ◽  
Zhuoling Wu ◽  
Peiyun Xie ◽  
Lu Zhang ◽  
Hui Chen
Keyword(s):  
Organic Carbon ◽  
Short Range ◽  
Incident Radiation ◽  
Important Variable ◽  
Lapse Rate ◽  
Total N ◽  
C:N:P Stoichiometry ◽  
Spatiotemporal Scales ◽  
Stoichiometric Ratios ◽  
Landscape Scales

Warming effects on agricultural and forest ecosystems have been well documented at broad spatiotemporal scales but less so at stand and landscape scales. To detect the changes in soil organic carbon (SOC) and carbon:nitogen:phosphorus (C:N:P) stoichiometry in response to a short-range warming gradient, we defined an inverse elevation-dependent warming gradient and developed a novel index of warming based on a common environmental lapse rate. We associated the warming gradient and warming index with the changes in SOC and C:N:P stoichiometry and tested the independence of warming effects using partial correlation analysis. SOC content and C:N:P stoichiometric ratios significantly decreased with warming, and the effect of warming on C:N:P stoichiometric ratios were stronger than on SOC content. The relationships of SOC content and C:N:P stoichiometric ratios with warming did not change after controlling for two other energy-related variables, i.e., transmitted total radiation and potential direct incident radiation. However, the strength in the relationships of C:N:P stoichiometric ratios with vegetation-related variables significantly decreased after the warming index was controlled for. As indicated by the random forest regression model, the warming index was the most important variable for predicting SOC variability and the second most important for predicting total N variability, while vegetation-related variables were the most important for predicting C:N:P stoichiometric ratios. Our results showed that warming was responsible for the decrease in SOC content and C:N:P stoichiometric ratios and the warming index was the most important variable for predicting SOC variability. Although the most important variables for C:N:P stoichiometric ratios were related to vegetation, the relationships between C:N:P stoichiometric ratios and vegetation-related variables were significantly affected by warming. These findings demonstrate that warming is the major driver of SOC variability and the decrease in SOC content, as well as of C:N:P stoichiometry, even along a short-range warming gradient.

C:N:P stoichiometry regulates soil organic carbon mineralization and concomitant shift of microbial community in paddy soil

2020 ◽  
Author(s):  
Zhenke Zhu ◽  
Xiaomeng Wei ◽  
Tida Ge ◽  
Jinshui wu ◽  
Andreas Richter
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Keystone Species ◽  
C Mineralization ◽  
Microbial Activities ◽  
P Fertilization ◽  
C:N:P Stoichiometry ◽  
Stoichiometric Ratios ◽  
Soc Mineralization

<p>Soil carbon (C), nitrogen (N), and phosphorus (P) contents and their stoichiometric ratios play modifying the microbial metabolism of C. Microbial populations vary in their strategies for C and nutrient acquisition to maintain the microbial biomass C:N:P balance. However, the regulation of soil C mineralization and microbial activities by stoichiometric ratios in input substrates becomes unpredictable in flooded soils because of the frequent redox fluctuations and general oxygen limitation. Stoichiometric control on input substrate (glucose) and soil organic carbon (SOC) mineralization were assessed by a manipulation experiment based on N or P fertilization in paddy soil. Glucose mineralization increased by nutrient addition up to 11.6% with combined N and P applications compared with addition without nutrients. During 100-days incubation, about 4.5% of SOC was mineralized in all five treatments, being increased by glucose and reduced by P fertilization. Glucose and SOC mineralization increased exponentially with the dissolved organic carbon (DOC):NH<sub>4</sub><sup>+</sup>-N, DOC:Olsen P, and microbial biomass (MB)C:MBN ratios. The glucose mineralization was negatively associated with the MBC:MBP ratio, suggesting that P addition relieved P limitation for microorganisms and increased microbial activities of labile C mineralization. The shift of bacterial community structure was significantly affected by the soil available and microbial biomass C:N:P stoichiometric ratios. The decrease of negative associations between bacterial taxa in the P-added soil indicated that microbial competition for nutrients was alleviated. 16S rRNA amplicon sequencing showed that combined C and nutrients application stimulated the Clostridia and β-Proteobacteria (r strategists) and increased the enzyme activities of β-glucosidase and β-acetyl-glucosaminidase. In contrast, after 100-day incubation, when the available substrate was exhausted, Syntrophus (K strategist) was found as the keystone species. Hence, soil microbial communities shifted their keystone species to acquire necessary elements to maintain the microbial biomass C:N:P stoichiometric balance in response to the change of resource C:N:P stoichiometry.</p>

scholarly journals Effect of carbon and nitrogen addition on nitrous oxide and carbon dioxide fluxes from thawing forest soils

2017 ◽  
Vol 31 (3) ◽  
pp. 339-349 ◽  
Author(s):  
Wu Haohao ◽  
Xu Xingkai ◽  
Duan Cuntao ◽  
Li TuanSheng ◽  
Cheng Weiguo
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Soil Moisture ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Forest Soils ◽  
Mixed Forest ◽  
Soil Core ◽  
Total N ◽  
Nitrogen Inputs

AbstractPacked soil-core incubation experiments were done to study the effects of carbon (glucose, 6.4 g C m−2) and nitrogen (NH4Cl and KNO3, 4.5 g N m−2) addition on nitrous oxide (N2O) and carbon dioxide (CO2) fluxes during thawing of frozen soils under two forest stands (broadleaf and Korean pine mixed forest and white birch forest) with two moisture levels (55 and 80% water-filled pore space). With increasing soil moisture, the magnitude and longevity of the flush N2O flux from forest soils was enhanced during the early period of thawing, which was accompanied by great NO3−-N consumption. Without N addition, the glucose-induced cumulative CO2fluxes ranged from 9.61 to 13.49 g CO2-C m−2, which was larger than the dose of carbon added as glucose. The single addition of glucose increased microbial biomass carbon but slightly affected soil dissolved organic carbon pool. Thus, the extra carbon released upon addition of glucose can result from the decomposition of soil native organic carbon. The glucose-induced N2O and CO2fluxes were both significantly correlated to the glucose-induced total N and dissolved organic carbon pools and influenced singly and interactively by soil moisture and KNO3addition. The interactive effects of glucose and nitrogen inputs on N2O and CO2fluxes from forest soils after frost depended on N sources, soil moisture, and vegetation types.

scholarly journals Soil greenhouse gas fluxes from different tree species on Taihang Mountain, North China

2014 ◽  
Vol 11 (6) ◽  
pp. 1649-1666 ◽  
Author(s):  
X. P. Liu ◽  
W. J. Zhang ◽  
C. S. Hu ◽  
X. G. Tang
Keyword(s):  
Soil Moisture ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Temperature ◽  
Soil Ph ◽  
Tree Species ◽  
Soil Bulk Density ◽  
Total N ◽  
Gas Fluxes ◽  
Greenhouse Gas Fluxes

Abstract. The objectives of this study were to investigate seasonal variation of greenhouse gas fluxes from soils on sites dominated by plantation (Robinia pseudoacacia, Punica granatum, and Ziziphus jujube) and natural regenerated forests (Vitex negundo var. heterophylla, Leptodermis oblonga, and Bothriochloa ischcemum), and to identify how tree species, litter exclusion, and soil properties (soil temperature, soil moisture, soil organic carbon, total N, soil bulk density, and soil pH) explained the temporal and spatial variation in soil greenhouse gas fluxes. Fluxes of greenhouse gases were measured using static chamber and gas chromatography techniques. Six static chambers were randomly installed in each tree species. Three chambers were randomly designated to measure the impacts of surface litter exclusion, and the remaining three were used as a control. Field measurements were conducted biweekly from May 2010 to April 2012. Soil CO2 emissions from all tree species were significantly affected by soil temperature, soil moisture, and their interaction. Driven by the seasonality of temperature and precipitation, soil CO2 emissions demonstrated a clear seasonal pattern, with fluxes significantly higher during the rainy season than during the dry season. Soil CH4 and N2O fluxes were not significantly correlated with soil temperature, soil moisture, or their interaction, and no significant seasonal differences were detected. Soil organic carbon and total N were significantly positively correlated with CO2 and N2O fluxes. Soil bulk density was significantly negatively correlated with CO2 and N2O fluxes. Soil pH was not correlated with CO2 and N2O emissions. Soil CH4 fluxes did not display pronounced dependency on soil organic carbon, total N, soil bulk density, and soil pH. Removal of surface litter significantly decreased in CO2 emissions and CH4 uptakes. Soils in six tree species acted as sinks for atmospheric CH4. With the exception of Ziziphus jujube, soils in all tree species acted as sinks for atmospheric N2O. Tree species had a significant effect on CO2 and N2O releases but not on CH4 uptake. The lower net global warming potential in natural regenerated vegetation suggested that natural regenerated vegetation were more desirable plant species in reducing global warming.

scholarly journals Effect of Nitrogen and Molybdenum on Post Harvest Soil Characteristics and Economic Yield of Bush Bean (Phaseolus vulgaris L.).

2010 ◽  
pp. 9-14
Author(s):  
MK Hossain ◽  
MS Islam
Keyword(s):  
Phaseolus Vulgaris ◽  
Organic Carbon ◽  
Soil Characteristics ◽  
Ammonium Molybdate ◽  
Research Field ◽  
Treatment Combination ◽  
Net Benefit ◽  
Total N ◽  
Post Harvest ◽  
Bush Bean

A field experiment was carried out at the research field of Sher-e-Bangla Agricultural University, Dhaka during December 2006 to February 2007 to study the effect of nitrogen and molybdenum on post harvest soil characteristics and economic yield of bush bean (Phaseolus vulgaris L.). The treatments consisted of 5 levels of N (0, 40, 80, 120 and 160 kg ha-1) designated and 3 levels of Mo (0, 0.5 and 1.0 kg ha-1). Urea and ammonium molybdate were used as the sources of nitrogen and molybdenum, respectively. The characteristics of the post harvest soils showed a marked variation in relation to soil pH, soil organic carbon, N, P, K and S content in the post harvest soil due to application of N and Mo. The highest organic carbon (0.60%) and total N (0.072%) was obtained from N120. The highest organic carbon (0.60%) and total N (0.068%) was obtained from Mo0.5. The maximum organic carbon was obtained (0.63%) from N120Mo0.5 treatment combination. The maximum total N was obtained (0.075%) from N160Mo0.5 treatment combination. The results of economic analysis showed that the highest net benefit of Tk.1,68,722.00 ha-1 was obtained in N120Mo0.5 treatment and the lowest net benefit of Tk.16,559.00 ha-1 was found in control.

scholarly journals Soil greenhouse gas fluxes from different tree species on Taihang Mountain, North China

2013 ◽  
Vol 10 (7) ◽  
pp. 11037-11076 ◽  
Author(s):  
X. P. Liu ◽  
W. J. Zhang ◽  
C. S. Hu ◽  
X. G. Tang
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Temperature ◽  
Tree Species ◽  
Soil Bulk Density ◽  
Soil Co2 ◽  
Total N ◽  
Gas Fluxes ◽  
Greenhouse Gas Fluxes ◽  
N2o Fluxes

Abstract. The objectives of this study were to investigate seasonal variation of greenhouse gas fluxes from soils on sites dominated by plantation (Robinia pseudoacacia, Punica granatum, and Ziziphus jujube) and natural regenerated forests (Vitex negundo var. heterophylla, Leptodermis oblonga, and Bothriochloa ischcemum), and to identify how tree species, litter exclusion, and soil properties (soil temperature, soil moisture, soil organic carbon, total N, soil bulk density, and soil pH) explained the temporal and spatial variance in soil greenhouse gas fluxes. Fluxes of greenhouse gases were measured using static chamber and gas chromatography techniques. Six static chambers were randomly installed in each tree species. Three chambers were randomly designated to measure the impacts of surface litter exclusion, and the remaining three were used as a control. Field measurements were conducted biweekly from May 2010 through April 2012. Soil CO2 emissions from all tree species were significantly affected by soil temperature, soil moisture, and their interaction. Driven by the seasonality of temperature and precipitation, soil CO2 emissions demonstrated a clear seasonal pattern, with fluxes significantly higher during the rainy season than during the dry season. Soil CH4 and N2O fluxes were not significantly correlated with soil temperature, soil moisture, or their interaction, and no significant seasonal differences were detected. Soil CO2 and N2O fluxes were significantly correlated with soil organic carbon, total N, and soil bulk density, while soil pH was not correlated with CO2 and N2O emissions. Soil CH4 fluxes did not display pronounced dependency on soil organic carbon, total N, soil bulk density, and soil pH. Removal of surface litter resulted in significant decreases in CO2 emissions and CH4 uptakes, but had no significant influence on N2O fluxes. Soils in six tree species acted as sinks for atmospheric CH4. With the exception of Ziziphus jujube, Soils in all sites acted as sinks for atmospheric N2O. Tree species had a significant effect on CO2 and N2O fluxes but not on CH4 uptake. The lower net global warming potential in natural regenerated vegetation suggested that natural regenerated vegetation were more desirable plant species in reducing global warming.

scholarly journals Arboreal spiders in coffee agroecosystems: Untangling the web of local and landscape influences driving diversity

2013 ◽  
Author(s):  
Zachary Hajian-Forooshani ◽  
David Gonthier ◽  
Linda Marín ◽  
Aaron L Iverson ◽  
Ivette Perfecto
Keyword(s):  
Agricultural Intensification ◽  
Global Climate ◽  
Biodiversity Loss ◽  
Important Variable ◽  
Point Of View ◽  
Suitable Habitat ◽  
Shade Trees ◽  
Coffee Plantations ◽  
Landscape Scales ◽  
Coffee Cultivation

Agricultural intensification is implicated as a major driver of global biodiversity loss. Local management and landscape scale factors both influence biodiversity in agricultural systems, but there are relatively few studies to date looking at how local and landscape scales influence biodiversity in tropical agroecosystems. Understanding what drives the diversity of groups of organisms such as spiders is important from a pragmatic point of view because of the important biocontrol services they offer to agriculture. Spiders in coffee are somewhat enigmatic because of their positive or lack of response to agricultural intensification. In this study, we provide the first analysis, to our knowledge, of the arboreal spiders in the shade trees of coffee plantations. In the Soconusco region of Chiapas, Mexico we sampled across 38 sites on 9 coffee plantations. Tree and canopy connectedness were found to positively influence overall arboreal spider richness and abundance. We found that different functional groups of spiders are responding to different local and landscape factors, but overall elevation was most important variable influencing arboreal spider diversity. Our study has practical management applications that suggest having shade grown coffee offers more suitable habitat for arboreal spiders due to a variety of the characteristics of the shade trees. Our results which show consistently more diverse arboreal spider communities in lower elevations are important in light of looming global climate change. As the range of suitable elevations for coffee cultivation shrinks promoting arboreal spider diversity will be important in sustaining the viability of coffee.

scholarly journals Organic carbon and total nitrogen stocks in soils of the Lena River Delta

2012 ◽  
Vol 9 (12) ◽  
pp. 17263-17311 ◽  
Author(s):  
S. Zubrzycki ◽  
L. Kutzbach ◽  
G. Grosse ◽  
A. Desyatkin ◽  
E.-M. Pfeiffer
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Active Layer ◽  
River Delta ◽  
River Terrace ◽  
Total N ◽  
Lena River ◽  
Carbon Mass ◽  
Organic Carbon Pool ◽  
Lena River Delta

Abstract. The Lena River Delta, which is the largest delta in the Arctic, extends over an area of 32 000 km2 and likely holds more than half of the entire soil organic carbon mass stored in the seven major deltas in the northern permafrost regions. The geomorphic units of the Lena River Delta which were formed by true deltaic sedimentation processes are a Holocene river terrace and the active floodplains. Their mean soil organic carbon stocks for the upper 1 m of soils were estimated at 29 kg m−2 ± 10 kg m−2 and at 14 kg m−2 ± 7 kg m−2, respectively. For the depth of 1 m, the total soil organic carbon pool of the Holocene river terrace was estimated at 121 Tg ± 43 Tg, and the soil organic carbon pool of the active floodplains was estimated at 120 Tg ± 66 Tg. The mass of soil organic carbon stored within the observed seasonally thawed active layer was estimated at about 127 Tg assuming an average maximum active layer depth of 50 cm. The soil organic carbon mass which is stored in the perennially frozen ground below 50 cm soil depth, which is excluded from intense biogeochemical exchange with the atmosphere, was estimated at 113 Tg. The mean nitrogen (N) stocks for the upper 1 m of soils were estimated at 1.2 kg m−2 ± 0.4 kg m−2 for the Holocene river terrace and at 0.9 kg m−2 ± 0.4 kg m−2 for the active floodplain levels, respectively. For the depth of 1 m, the total N pool of the river terrace was estimated at 4.8 Tg ± 1.5 Tg, and the total N pool of the floodplains was estimated at 7.7 Tg ± 3.6 Tg. Considering the projections for deepening of the seasonally thawed active layer up to 120 cm in the Lena River Delta region within the 21st century, these large carbon and nitrogen stocks could become increasingly available for decomposition and mineralization processes.

scholarly journals Organic carbon and total nitrogen stocks in soils of the Lena River Delta

2013 ◽  
Vol 10 (6) ◽  
pp. 3507-3524 ◽  
Author(s):  
S. Zubrzycki ◽  
L. Kutzbach ◽  
G. Grosse ◽  
A. Desyatkin ◽  
E.-M. Pfeiffer
Keyword(s):  
Organic Carbon ◽  
Active Layer ◽  
River Delta ◽  
The Arctic ◽  
River Terrace ◽  
Total N ◽  
Lena River ◽  
The Holocene ◽  
Lena River Delta ◽  
N Pool

Abstract. The Lena River Delta, which is the largest delta in the Arctic, extends over an area of 32 000 km2 and likely holds more than half of the entire soil organic carbon (SOC) mass stored in the seven major deltas in the northern permafrost regions. The geomorphic units of the Lena River Delta which were formed by true deltaic sedimentation processes are a Holocene river terrace and the active floodplains. Their mean SOC stocks for the upper 1 m of soils were estimated at 29 kg m−2 ± 10 kg m−2 and at 14 kg m−2 ± 7 kg m−2, respectively. For the depth of 1 m, the total SOC pool of the Holocene river terrace was estimated at 121 Tg ± 43 Tg, and the SOC pool of the active floodplains was estimated at 120 Tg ± 66 Tg. The mass of SOC stored within the observed seasonally thawed active layer was estimated at about 127 Tg assuming an average maximum active layer depth of 50 cm. The SOC mass which is stored in the perennially frozen ground at the increment 50–100 cm soil depth, which is currently excluded from intense biogeochemical exchange with the atmosphere, was estimated at 113 Tg. The mean nitrogen (N) stocks for the upper 1 m of soils were estimated at 1.2 kg m−2 ± 0.4 kg m−2 for the Holocene river terrace and at 0.9 kg m−2 ± 0.4 kg m−2 for the active floodplain levels, respectively. For the depth of 1 m, the total N pool of the river terrace was estimated at 4.8 Tg ± 1.5 Tg, and the total N pool of the floodplains was estimated at 7.7 Tg ± 3.6 Tg. Considering the projections for deepening of the seasonally thawed active layer up to 120 cm in the Lena River Delta region within the 21st century, these large carbon and nitrogen stocks could become increasingly available for decomposition and mineralization processes.

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