scholarly journals Observed Methane Uptake and Emissions at the Ecosystem Scale and Environmental Controls in a Subtropical Forest

Land ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 975
Author(s):  
Hui Wang ◽  
Hong Li ◽  
Zhihao Liu ◽  
Jianhua Lv ◽  
Xinzhang Song ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Global Climate ◽  
Negative Relationship ◽  
Subtropical Forest ◽  
Zhejiang Province ◽  
Flux Dynamics ◽  
Ch4 Flux ◽  
Control Factors ◽  
Environmental Controls ◽  
Forest Region

Methane (CH4) is one of the three most important greenhouse gases. To date, observations of ecosystem-scale methane (CH4) fluxes in forests are currently lacking in the global CH4 budget. The environmental factors controlling CH4 flux dynamics remain poorly understood at the ecosystem scale. In this study, we used a state-of-the-art eddy covariance technique to continuously measure the CH4 flux from 2016 to 2018 in a subtropical forest of Zhejiang Province in China, quantify the annual CH4 budget and investigate its control factors. We found that the total annual CH4 budget was 1.15 ± 0.28~4.79 ± 0.49 g CH4 m−2 year−1 for 2017–2018. The daily CH4 flux reached an emission peak of 0.145 g m−2 d−1 during winter and an uptake peak of −0.142 g m−2 d−1 in summer. During the whole study period, the studied forest region acted as a CH4 source (78.65%) during winter and a sink (21.35%) in summer. Soil temperature had a negative relationship (p < 0.01; R2 = 0.344) with CH4 flux but had a positive relationship with soil moisture (p < 0.01; R2 = 0.348). Our results showed that soil temperature and moisture were the most important factors controlling the ecosystem-scale CH4 flux dynamics of subtropical forests in the Tianmu Mountain Nature Reserve in Zhejiang Province, China. Subtropical forest ecosystems in China acted as a net source of methane emissions from 2016 to 2018, providing positive feedback to global climate warming.

scholarly journals Shifting environmental controls on CH<sub>4</sub> fluxes in a sub-boreal peatland

2013 ◽  
Vol 10 (12) ◽  
pp. 7971-7981 ◽  
Author(s):  
T. G. Pypker ◽  
P. A. Moore ◽  
J. M. Waddington ◽  
J. A. Hribljan ◽  
R. C. Chimner
Keyword(s):  
Soil Temperature ◽  
Net Ecosystem Exchange ◽  
P Value ◽  
Co2 Uptake ◽  
Ch4 Flux ◽  
Environmental Controls ◽  
Poor Fen ◽  
Abiotic And Biotic Factors ◽  
The Relationship ◽  
Northern Michigan

Abstract. We monitored CO2 and CH4 fluxes using eddy covariance from 19 May to 27 September 2011 in a poor fen located in northern Michigan. The objectives of this paper are to: (1) quantify the flux of CH4 from a sub-boreal peatland, and (2) determine which abiotic and biotic factors were the most correlated to the flux of CH4 over the measurement period. Net daily CH4 fluxes increased from 70 mg CH4 m−2 d−1 to 220 mg CH4 m−2 d−1 from mid May to mid July. After July, CH4 losses steadily declined to approximately 50 mg CH4 m−2 d−1 in late September. During the study period, the peatland lost 17.4 g CH4 m−2. Both abiotic and biotic variables were correlated with CH4 fluxes. When the different variables were analyzed together, the preferred model included mean daily soil temperature at 20 cm, daily net ecosystem exchange (NEE) and the interaction between mean daily soil temperature at 20 cm and NEE (R2 = 0.47, p value < 0.001). The interaction was important because the relationship between daily NEE and mean daily soil temperature with CH4 flux changed when NEE was negative (CO2 uptake from the atmosphere) or positive (CO2 losses to the atmosphere). On days when daily NEE was negative, 25% of the CH4 flux could be explained by correlations with NEE, however on days when daily NEE was positive, there was no correlation between daily NEE and the CH4 flux. In contrast, daily mean soil temperature at 20 cm was poorly correlated to changes in CH4 when NEE was negative (17%), but the correlation increased to 34% when NEE was positive. The interaction between daily NEE and mean daily soil temperature at 20 cm indicates shifting environmental controls on the CH4 flux throughout the growing season.

scholarly journals Shifting environmental controls on CH<sub>4</sub> fluxes in a sub-boreal peatland

2013 ◽  
Vol 10 (7) ◽  
pp. 11757-11784 ◽  
Author(s):  
T. G. Pypker ◽  
P. A. Moore ◽  
J. M. Waddington ◽  
J. A. Hribljan ◽  
R. C. Chimner
Keyword(s):  
Soil Temperature ◽  
Net Ecosystem Exchange ◽  
P Value ◽  
Ch4 Flux ◽  
Environmental Controls ◽  
Poor Fen ◽  
Abiotic And Biotic Factors ◽  
The Relationship ◽  
Northern Michigan ◽  
Measurement Period

Abstract. We monitored CO2 and CH4 fluxes using eddy covariance from 19 May to 27 September 2011 in a poor fen located in northern Michigan. The objectives of this paper are to: (1) quantify the flux of CH4 from a sub-boreal peatland, and (2) determine which abiotic and biotic factors were the most correlated to the flux of CH4 over the measurement period. Net daily CH4 fluxes increased from 70 mg m−2 d−1 to 220 mg m−2 d−1 from mid May to mid July. After July, CH4 losses steadily declined to approximately 50 mg m−2 d−1 in late September. During the study period, the peatland lost 17.4 g CH4 m−2. Both abiotic and biotic variables were correlated with changes in CH4 flux. When the different variables were analyzed together, the preferred model included mean daily soil temperature at 20 cm, daily net ecosystem exchange (NEE) and the interaction between mean daily soil temperature at 20 cm and NEE (R2 = 0.47, p value < 0.001). The interaction was important because the relationship between daily NEE and mean daily soil temperature with CH4 flux changed in conjunction with changes in daily NEE. On days when daily NEE was negative, 25% of the CH4 flux could be explained by changes in NEE, however on days when daily NEE was positive, there was no correlation between daily NEE and the CH4 flux. In contrast, daily mean soil temperature at 20 cm was poorly correlated to changes in CH4 when NEE was negative (17%), but the correlation increased to 34% when NEE was positive. The interaction between daily NEE and mean daily soil temperature at 20 cm indicates shifting environmental controls on the CH4 flux throughout the growing season.

scholarly journals Forest Soil Respirations are More Sensitive to Nighttime Temperature Change in Eastern China

2018 ◽  
Vol 47 (1) ◽  
pp. 249-254
Author(s):  
Zhaoyong SHI ◽  
Ke LI ◽  
Yongming WANG ◽  
Bede S. MICKAN ◽  
Weikang YUAN ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Soil Temperature ◽  
Temperature Change ◽  
Global Climate ◽  
Eastern China ◽  
Growing Season ◽  
Mean Value ◽  
Apparent Temperature ◽  
Effect Of Temperature ◽  
The Difference

Soil respiration is one of the main fluxes in the global carbon cycle. The effect of temperature on soil respiration is well understood. The response of soil respiration to temperature warming is called apparent temperature sensitivity (Q10) of soil respiration, which is an important parameter in modeling soil CO2 effluxes under global climate warming. The difference of Q10 between daytime and nighttime was hardly reported although attentions are attracted by the differences of temperature change and its effects on vegetation productivity. In this study, we investigated the Q10 of soil respiration in daytime and nighttime by modeling empirical functions based on the in situ measurement of soil respiration and temperature in temperate and subtropical forests of eastern China. Our results showed that the Q10 of soil respiration is higher in nighttime with the mean value of 2.74 and 2.35 than daytime with the average of 2.49 and 2.18 in all measured months and growing season, respectively. Moreover, the explanatory rate of soil temperature to soil respiration in nighttime is also higher than in daytime in each site in both all measured and growing seasons. The Q10 and explanatory rate of soil temperature to soil respiration in nighttime is 1.08 and 1.15 times in daytime in growing season. These findings indicate that soil respiration has a bigger sensitivity to temperature in nighttime than daytime. The change of soil temperature explains more variation of soil respiration in nighttime than daytime.

Effects of land-use/land-cover changes on land crab,Cardisoma guanhumi, abundance in Puerto Rico

2008 ◽  
Vol 24 (4) ◽  
pp. 417-423 ◽  
Author(s):  
Yogani Govender ◽  
Alberto M. Sabat ◽  
Elvira Cuevas
Keyword(s):  
Land Use ◽  
Puerto Rico ◽  
Land Cover ◽  
Soil Temperature ◽  
Surface Soil ◽  
Negative Relationship ◽  
Land Use Land Cover ◽  
Land Crab ◽  
Cardisoma Guanhumi ◽  
Crab Abundance

AbstractThe land crabCardisoma guanhumipopulations have been on the decline in Puerto Rico for the last three decades. While some studies suggest overexploitation and pesticides as causing the observed population declines, the effect of land-use/land-cover (LULC) changes have not been investigated. In this study we compared the abundance and size ofCardisoma guanhumiin five different LULC types (mangroves, grasslands, forest, urban and industrial), and investigated the relationship between differences in physical microhabitat conditions among the LULC types with crab abundance and size. Although no significant differences in size were found among the different LULC types, crabs were significantly less abundant in grassland sites. Surface soil temperature, depth to groundwater and air temperature were found to vary significantly among the LULC types. Of these, only surface soil temperatures had a significant negative relationship with crab abundance. It appears that high variation in soil temperature and a high groundwater table observed in the grasslands is most detrimental to crabs. Interestingly, during the time when land crab populations declined there was corresponding change of LULC from agriculture to grasslands.Cardisoma guanhumiis resilient to changes in LULC, however, changes that alter their access to groundwater and escape from high soil temperature reduce their habitat.

scholarly journals Effects of Grazing Pattern on Ecosystem Respiration and Methane Flux in a Sown Pasture in Inner Mongolia, China

Atmosphere ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 5
Author(s):  
Baoling Mei ◽  
Hongyu Yue ◽  
Xunhua Zheng ◽  
William McDowell ◽  
Qingshan Zhao ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Soil Temperature ◽  
Inner Mongolia ◽  
Nitrate Nitrogen ◽  
Ecosystem Respiration ◽  
Ammonium Nitrogen ◽  
Agricultural Practice ◽  
Ch4 Flux

The establishment of sown pasture is an important agricultural practice in many landscapes. Although both native grassland and sown pasture play a key role in the global carbon cycle, due to lack of data and field experiments, our understanding of grassland CH4 fluxes and CO2 emissions remains limited, especially when it comes to sown pasture. We measured ecosystem respiration and CH4 fluxes in response to a variety of potential drivers (soil temperature, soil moisture, ammonium nitrogen, nitrate nitrogen and dissolved organic carbon) in CG (continuous grazing), RG (rotational grazing) and UG (ungrazed) plots in sown grassland for one year in Inner Mongolia. Fluxes of CH4 and ecosystem respiration were measured using static opaque chambers and gas chromatography. Grazing significantly reduced ecosystem respiration (p < 0.01), and grazing pattern significantly influenced respiration in CG and RG plots (p < 0.01). We find that the sown grassland is a net sink for atmospheric CH4. No influence of grazing pattern was observed on CH4 flux in CG, RG and UG (p > 0.05). Soil temperature is the most important factor influencing ecosystem respiration and CH4 flux in the sown grassland, with soil moisture playing a secondary role to soil temperature. Variation in levels of ammonium nitrogen, nitrate nitrogen and dissolved organic carbon had little influence on ecosystem respiration or CH4 flux (except in UG plots). The values obtained for ecosystem respiration of grasslands have a large uncertainty range, which may be due to spatial variability as well as differences in research methods. Mean CH4 fluxes measured only during the growing season were much higher than the annual mean CH4 fluxes.

Influence of soil temperature on growth traits of European beech seedlings

2015 ◽  
Vol 45 (3) ◽  
pp. 246-251 ◽  
Author(s):  
Ines Štraus ◽  
Tanja Mrak ◽  
Mitja Ferlan ◽  
Peter Železnik ◽  
Hojka Kraigher
Keyword(s):  
Soil Temperature ◽  
Leaf Area ◽  
Growth Traits ◽  
Global Climate ◽  
Specific Root Length ◽  
European Beech ◽  
Forest Tree ◽  
Root Tip ◽  
Soil Temperatures ◽  
One Year

European beech (Fagus sylvatica L.) is an economically and ecologically important forest tree species in Europe. Expected future temperature increases due to global climate change may significantly affect growth of beech trees and consequently influence carbon cycling in beech forests. We tested the hypothesis that soil temperature influences the growth of both belowground and aboveground parts of beech seedlings. One-year-old seedlings were transferred into rhizotrons and subjected to two different soil temperatures for 2 years while the soil moisture level was kept constant. The main effect of the soil temperature was a changed biomass of the woody part of the seedlings. Soil temperature significantly influenced the biomass of shoots and roots and diameter of the stem, which were the highest for the seedlings grown in conditions of soil temperatures maintained in the range of summer soil temperatures from the site of origin of the seedlings. Increased soil temperature also resulted in increased specific root length and specific root tip density. Root-to-shoot ratio and leaf parameters (leaf mass, number of leaves, and specific leaf area), except for leaf area ratio, were not influenced by soil temperature.

scholarly journals Fluxo de calor no solo modelado a partir de dados de temperatura em dois níveis de profundidade em uma floresta tropical na Amazônia Ocidental

2018 ◽  
Vol 40 ◽  
pp. 138
Author(s):  
Antônio Vinicius do Prado Rodrigues ◽  
Nelma Tavares Dias Soares ◽  
Renata Gonçalves Aguiar ◽  
Alberto Dresch Webler ◽  
Bruno Soares de Castro
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Soil Temperature ◽  
Tropical Forest ◽  
Large Scale ◽  
Energy Exchange ◽  
Global Climate ◽  
Soil Heat Flux ◽  
Measured Data ◽  
Biological Reserve

The global climate is dependent of ecological balance of forests, especially tropical. The heat flux in the soil is an important factor in studies of energy balance representing the main form of energy exchange between soil and atmosphere. The aim of the present work was to estimate soil heat flux using soil temperature measurements at two depth levels in a tropical forest in the Western Amazon, in order to obtain coherent data for both the use of the values and for the filling of failures in database. Had been used data on temperature and soil heat flux collected in a micrometeorological tower belonging to the towers network of the Large Scale Biosphere-Atmosphere Program in the Amazon, located in the Jaru Biological Reserve. The estimated data presented 94% agreement with the measured data, the two have similar behaviors that allow the use in filling of failures in a demonstrative way. However, there is a delay in the estimated values of the heat flux in the soil in relation to the measured one, which interferes in the result of the model, provoking more studies to improve it.

The 38 years of the microclimate change dynamics across a cropland-windbreak-desert transition zone in the Ulan Buh Desert, northern China

2021 ◽  
Author(s):  
Guan Wang ◽  
Fengmin Luo ◽  
Zhiming Xin ◽  
Junran Li ◽  
Huijie Xiao
Keyword(s):  
Climate Change ◽  
Soil Temperature ◽  
Transition Zone ◽  
Global Climate Change ◽  
Climatic Factors ◽  
Global Climate ◽  
Change Dynamics ◽  
The Past ◽  
Aeolian Erosion ◽  
Ulan Buh Desert

&lt;p&gt;The windbreak system is a major component of successful agricultural systems in arid deserts throughout the world. Ulan Buh Desert is one of the eight biggest deserts in China, and the oases there offer residence and cropland for over 90% of the local residents. However, due to climate change and human disturbances, the Ulan Buh Desert continues spreading to the south, bringing more pressure on the windbreak systems there. Meanwhile, the Chinese government put much effort into greening the desert, establishing artificial shrubs to prevent dune movement and soil loss. How microclimate in the cropland-windbreak-desert system responded to human activities and climate change has rarely been studied. In this study, we investigated the microclimate change dynamics across the cropland-windbreak-desert transition zone during the past 38 years. Two 50 m climatological towers, located in the same distance inner and outside a shelterbelt, have continuously monitored climatic factors, including air temperature, soil temperature, relative humidity, precipitation, evaporation, layered wind speeds, etc., and aeolian erosion related factors, such as layered dustfall. The long-time fluctuations of the inside and outside climatic factors have been analyzed, and the global climate change data, local land-use history, as well as the record of afforestation activities implemented by government and local people, were also collected. The results revealed that both the inside and outside windbreak air temperatures and soil temperatures increased during the past 38 years, which agrees with the global warming phenomenon. The inner windbreak air temperature is consistently lower than the outer windbreak areas, and the temperature difference is biggest in summer and smallest in winter. However, the soil temperature difference between the outside and inner windbreak is unstable. In 1995, 2002, and 2004, the dune areas even had lower soil temperature than the inner cropland. The precipitation is 0.5~100.7mm higher in cropland and the evaporation is lower in cropland when comparing to outside dune areas, but their annual variations changed greatly. The wind speed and erosion rate are significantly lower in cropland than desert dune areas, and the seasonal change exhibited a bimodal curve pattern. The results suggest that the cropland-windbreak-desert transition zone responded to global climate change simultaneously. Although the shelterbelt still creates a favorable regional climatic condition for the cropland, the differences between the inner and outer windbreak areas narrowed during the past 10 years. The aeolian erosion rate reduced significantly in outside windbreak dune areas, which may largely attribute to the artificial Haloxylon ammodendron communities planted at the southeastern margin of the desert.&lt;/p&gt;

scholarly journals Asymmetric Soil Warming under Global Climate Change

2019 ◽  
Vol 16 (9) ◽  
pp. 1504 ◽  
Author(s):  
Hui Zhang ◽  
Binhui Liu ◽  
Daowei Zhou ◽  
Zhengfang Wu ◽  
Ting Wang
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Surface Soil ◽  
Global Climate ◽  
Average Rate ◽  
Daily Maximum ◽  
Agricultural Practice ◽  
Soil Warming ◽  
Surface Soil Temperature ◽  
The Difference

Daily surface soil temperature data from 360 weather stations in China during 1962–2011 were retrieved and analyzed. The data revealed two aspects of asymmetric soil warming. Firstly, there was asymmetry between day and night in terms of increases in soil temperature. The daily maximum surface soil temperature ( S T max ) and daily minimum surface soil temperature ( S T min ) increased at rates of 0.031 and 0.055 °C/year over the 50-year interval, respectively. As a consequence of the more rapid increases in S T min , the soil diurnal temperature range (SDTR) decreased at most stations (average rate of –0.025 °C/year), with the most profound decrease in winter (–0.08 °C/year). The solar duration (SD) was positively related to SDTR and is regarded as the key underlying cause of the decreasing SDTR. Secondly, there was asymmetry between the soil and air in the temperature increase. The differences between soil and air temperature ( T D ) were highest in summer (2.76 °C) and smallest in winter (1.55 °C), which decreased by 0.3 °C over the study interval, this meant agricultural practice plans based on air temperature alone may be severely limited. The difference between soil temperature and air temperature reduces at night. This would facilitate the wintering of perennials in areas near the zero-contour line.

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