scholarly journals Effects of rodent-induced land degradation on ecosystem carbon fluxes in an alpine meadow in the Qinghai–Tibet Plateau, China

Solid Earth ◽  
2015 ◽  
Vol 6 (1) ◽  
pp. 303-310 ◽  
Author(s):  
F. Peng ◽  
Y. Quangang ◽  
X. Xue ◽  
J. Guo ◽  
T. Wang
Keyword(s):  
Soil Respiration ◽  
Land Degradation ◽  
Alpine Meadow ◽  
Tibet Plateau ◽  
Co2 Fluxes ◽  
Ecosystem Carbon ◽  
Group I ◽  
Significant Difference ◽  
Group Ii ◽  
Qinghai Tibet Plateau

Abstract. The widespread land degradation in an alpine meadow ecosystem would affect ecosystem carbon (C) balance. Biomass, soil chemical properties and carbon dioxide (CO2) of six levels of degraded lands (D1–D6, according to the number of rodent holes and coverage) were investigated to examine the effects of rodent-induced land degradation on an alpine meadow ecosystem. Soil organic carbon (SOC), labile soil carbon (LC), total nitrogen (TN) and inorganic nitrogen (N) were obtained by chemical analysis. Soil respiration (Rs), net ecosystem exchange (NEE) and ecosystem respiration (ER) were measured by a Li-Cor 6400XT. Gross ecosystem production (GEP) was the sum of NEE and ER. Aboveground biomass (AGB) was based on a linear regression with coverage and plant height as independent variables. Root biomass (RB) was obtained by using a core method. Soil respiration, ER, GEP and AGB were significantly higher in slightly degraded (D3 and D6, group I) than in severely degraded land (D1, D2, D4 and D5, group II). Positive values of NEE average indicate that the alpine meadow ecosystem is a weak C sink during the growing season. The only significant difference was in ER among different degradation levels. Rs, ER and GEP were 38.2, 44.3 and 46.5% higher in group I than in group II, respectively. Similar difference of ER and GEP between the two groups resulted in an insignificant difference of NEE. Positive correlations of AGB with ER, NEE and GEP, and relatively small AGB and lower CO2 fluxes in group II, suggest the control of AGB on ecosystem CO2 fluxes. Correlations of RB with SOC, LC, TN and inorganic N indicate the regulation of RB on soil C and N with increasing number of rodent holes in an alpine meadow ecosystem in the permafrost region of the Qinghai–Tibet Plateau (QTP).

scholarly journals Effects of rodent-induced land degradation on ecosytem carbon fluxes in alpine meadow in the Qinghai–Tibet Plateau, China

2014 ◽  
Vol 6 (2) ◽  
pp. 3003-3023 ◽  
Author(s):  
F. Peng ◽  
Y. Quangang ◽  
X. Xue ◽  
J. Guo ◽  
T. Wang
Keyword(s):  
Soil Respiration ◽  
Land Degradation ◽  
Alpine Meadow ◽  
Net Ecosystem Exchange ◽  
Growing Season ◽  
Tibet Plateau ◽  
Organic C ◽  
Soil C ◽  
Significant Difference ◽  
Qinghai Tibet Plateau

Abstract. Land degradation induced by rodent activities is extensively occurred in alpine meadow ecosystem in the Qinghai–Tibet Plateau that would affect the ecosystem carbon (C) balance. We conducted a field experiment with six levels of land degradation (D1–D6, degradation aggravates from D1 to D6) to investigate the effects of land degradation on ecosystem C fluxes. Soil respiration (Rs), net ecosystem exchange (NEE), ecosystem respiration (ER) and gross ecosystem production (GEP) were measured from June to September 2012. Soil respiration, ER, GEP and above-ground biomass (AGB) was significantly higher in slightly degraded (D3 and D6) than in severely degraded land (D1, D2, D4 and D5). Positive averages of NEE in the growing season indicate that alpine meadow ecosystem is a weak C sink during the growing season. Net ecosystem exchange had no significant difference among different degraded levels, but the average NEE in slightly degraded group was 33.6% higher than in severely degraded group. Soil respiration, ER and NEE were positively correlated with AGB whereas soil organic C, labile soil C, total nitrogen (N) and inorganic nitrogen were associated with root biomass (RB). Our results highlight the decline of vegetation C storage of alpine meadow ecosystem with increasing number of rodent holes and suggest the control of AGB on ecosystem C fluxes, and the control of RB on soil C and N with development of land degradation.

scholarly journals Freeze-thaw processes of active layer regulate soil respiration of alpine meadow in the permafrost region of the Qinghai-Tibet Plateau

2019 ◽  
Author(s):  
Junfeng Wang ◽  
Qingbai Wu ◽  
Ziqiang Yuan ◽  
Hojeong Kang
Keyword(s):  
Soil Respiration ◽  
Active Layer ◽  
Alpine Meadow ◽  
Water Status ◽  
Tibet Plateau ◽  
Permafrost Region ◽  
Permafrost Degradation ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Qinghai Tibet Plateau

Abstract. Freezing and thawing action of the active layer plays a significant role in soil respiration (Rs) in permafrost regions. However, little is known about how the freeze-thaw process regulates the Rs dynamics in different stages for the alpine meadow underlain by permafrost on the Qinghai-Tibet Plateau (QTP). We conducted continuous in-situ measurements of Rs and freeze-thaw process of the active layer at an alpine meadow site in the Beiluhe permafrost region of QTP to determine the regulatory mechanisms of the different freeze-thaw stages of the active layer on the Rs. We found that the freezing and thawing process of active layer modified the Rs dynamics differently in different freeze-thaw stages. The mean Rs ranged from 0.56 to 1.75 μmol/m2s across the stages, with the lowest value in the SW stage and highest value in the ST stage; and Q10 among the different freeze-thaw stages changed greatly, with maximum (4.9) in the WC stage and minimum (1.7) in the SW stage. Patterns of Rs among the ST, AF, WC, and SW stages differed, and the corresponding contribution percentages of cumulative Rs to annual total Rs were 61.54, 8.89, 18.35, and 11.2 %, respectively. Soil temperature (Ts) was the most important driver of Rs regardless of soil water status in all stages. Our results suggest that as the climate warming and permafrost degradation continue, great changes in freeze-thaw process patterns may trigger more Rs emissions from this ecosystem because of prolonged ST stage.

scholarly journals Soil respiration of alpine meadow is controlled by freeze–thaw processes of active layer in the permafrost region of the Qinghai–Tibet Plateau

2020 ◽  
Vol 14 (9) ◽  
pp. 2835-2848
Author(s):  
Junfeng Wang ◽  
Qingbai Wu ◽  
Ziqiang Yuan ◽  
Hojeong Kang
Keyword(s):  
Soil Respiration ◽  
Active Layer ◽  
Alpine Meadow ◽  
Tibet Plateau ◽  
Permafrost Region ◽  
Permafrost Degradation ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Qinghai Tibet Plateau

Abstract. Freezing and thawing action of the active layer plays a significant role in soil respiration (Rs) in permafrost regions. However, little is known about how the freeze–thaw processes affect the Rs dynamics in different stages of the alpine meadow underlain by permafrost in the Qinghai–Tibet Plateau (QTP). We conducted continuous in situ measurements of Rs and freeze–thaw processes of the active layer at an alpine meadow site in the Beiluhe permafrost region of the QTP and divided the freeze–thaw processes into four different stages in a complete freeze–thaw cycle, comprising the summer thawing (ST) stage, autumn freezing (AF) stage, winter cooling (WC) stage, and spring warming (SW) stage. We found that the freeze–thaw processes have various effects on the Rs dynamics in different freeze–thaw stages. The mean Rs ranged from 0.12 to 3.18 µmol m−2 s−1 across the stages, with the lowest value in WC and highest value in ST. Q10 among the different freeze–thaw stages changed greatly, with the maximum (4.91±0.35) in WC and minimum (0.33±0.21) in AF. Patterns of Rs among the ST, AF, WC, and SW stages differed, and the corresponding contribution percentages of cumulative Rs to total Rs of a complete freeze–thaw cycle (1692.98±51.43 g CO2 m−2) were 61.32±0.32 %, 8.89±0.18 %, 18.43±0.11 %, and 11.29±0.11 %, respectively. Soil temperature (Ts) was the most important driver of Rs regardless of soil water status in all stages. Our results suggest that as climate change and permafrost degradation continue, great changes in freeze–thaw process patterns may trigger more Rs emissions from this ecosystem because of a prolonged ST stage.

Effects of grazing exclusion on soil respiration components in an alpine meadow on the north-eastern Qinghai-Tibet Plateau

CATENA ◽  
2020 ◽  
Vol 194 ◽  
pp. 104750
Author(s):  
Jinlan Wang ◽  
Yuzhen Liu ◽  
Wenxia Cao ◽  
Wen Li ◽  
Xiaojun Wang ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Alpine Meadow ◽  
Tibet Plateau ◽  
Grazing Exclusion ◽  
The North ◽  
North Eastern ◽  
Qinghai Tibet Plateau

scholarly journals Impact of hemodialysis on the wellbeing of chronic kidney diseases patients: a pre-post analysis

2020 ◽  
Vol 27 (1) ◽  
Author(s):  
Um-e-Kalsoom ◽  
Sabiha Khan ◽  
Israr Ahmad
Keyword(s):  
Quality Of Life ◽  
Social Support ◽  
Perceived Social Support ◽  
Kidney Diseases ◽  
Chronic Kidney Diseases ◽  
Group I ◽  
Significant Difference ◽  
Group Ii ◽  
The Impact

Abstract Background Hemodialysis may have serious psychological impact upon patients suffering from chronic kidney diseases. The aim of the present study is to investigate the impact of hemodialysis on the wellbeing of individuals with chronic kidney diseases (CKD). Result A sample consists of (N = 100) CKD patients referred from neurology ward of Leady Reading Hospital Peshawar. Data was collected from both male (50%) and female (50%) in 2017. Participants were divided into two groups on the basis of pre-set criteria. In group I, individuals with 4–5 stage of CKD referred first time for dialysis treatment were recruited. Group II comprised of CKD patients with 1–3 stage. Demographic data sheet, Pakistan Anxiety and Depression, WHO Quality of Life scale, and Perceived Social support scale (PSS) were used to test the hypotheses. Paired sample t test was use to see the difference between pre- and post-analysis of depression, anxiety, QOL, and PSS in group I (experimental group). Results suggests significant difference on depression (p > .001), anxiety (p > .001), and QOL (p > .001), while no significant difference was reported on perceived social support (p <.673). Findings also indicate no significant difference between group I and group II on QOL depression, anxiety, and PSS. Conclusion The findings concluded that patients under hemodialysis treatment suffered from depression, anxiety, and poor quality of life.

Role of Cord Blood Carboxyhemoglobin in Detecting Significant Hyperbilirubinemia in Term Neonates with ABO Alloimmunization

2021 ◽  
Author(s):  
Mahir Tıraş ◽  
Emrah Can ◽  
Şahin Hamilçıkan
Keyword(s):  
Cord Blood ◽  
Total Serum ◽  
Healthy Controls ◽  
Term Neonates ◽  
Group Iii ◽  
Group I ◽  
Significant Difference ◽  
Group Ii ◽  
Positive Direct ◽  
Severe Hyperbilirubinemia

Objective This study aimed to assess whether cord blood carboxyhemoglobin (COHb) levels in jaundiced term neonates with and without a positive direct Coombs test (DCT) and in healthy controls could be used as a predictor of severe hyperbilirubinemia. The percentage of cord blood COHb should be higher among neonates with Coombs-positive ABO hemolytic disease than among those with Coombs-negative ABO incompatibility and higher than that of ABO-compatible control neonates. Study Design This cross-sectional descriptive study of 198 term neonates comprised three subgroups: group I featured 68 DCT-positive ABO-incompatible neonates (ABO + DCT), group II featured 60 DCT-negative ABO-incompatible neonates with hyperbilirubinemia (ABO–DCT), and group III featured 70 healthy controls. COHb was determined by an OSM3 hemoximeter. Results Group I differed from groups II and III for cord blood bilirubin, cord blood hemoglobin, and cord blood hematocrit. Groups I and II had higher mean total serum bilirubin (TSB) levels than group III, while there was no difference in the mean TSB levels between groups I and II. There was no significant difference between the COHb group means for groups I, II, and III (p = 0.98). The area under the receiver operating characteristic curve calculated for group I/group III and group II/group III were found to be 0.62 and 0.54, respectively. Conclusion COHb levels did not prove to be superior to the DCT for predicting the risk of developing severe hyperbilirubinemia in term neonates. Key Points

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