scholarly journals Age-Dependent Changes in Soil Respiration and Associated Parameters in Siberian Permafrost Larch Stands Affected by Wildfire

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 107
Author(s):  
Oxana V. Masyagina ◽  
Svetlana Y. Evgrafova ◽  
Oleg V. Menyailo ◽  
Shigeta Mori ◽  
Takayoshi Koike ◽  
...  
Keyword(s):  
Climate Change ◽  
Soil Respiration ◽  
Spatial Variation ◽  
Mutual Influence ◽  
Environmental Parameters ◽  
Field Studies ◽  
C Cycle ◽  
Study Sites ◽  
Global Fluctuations ◽  
Siberian Permafrost

The observed high spatial variation in soil respiration (SR) and associated parameters emphasized the importance of SR heterogeneity at high latitudes and the involvement of many factors in its regulation, especially within fire-affected areas. The problem of estimating CO2 emissions during post-fire recovery in high-latitude ecosystems addresses the mutual influence of wildfires and climate change on the C cycle. Despite its importance, especially in permafrost regions because of their vulnerability, the mutual influence of these factors on CO2 dynamics has rarely been studied. Thus, we aimed to understand the dynamics of soil respiration (SR) in wildfire-affected larch recovery successions. We analyzed 16-year data (1995–2010) on SR and associated soil, biological, and environmental parameters obtained during several field studies in larch stands of different ages (0–276 years) in the Krasnoyarsk region (Russia). We observed a high variation in SR and related parameters among the study sites. SR varied from 1.77 ± 1.18 (mean ± SD) µmol CO2 m−2 s−1 in the 0–10-year-old group to 5.18 ± 2.70 µmol CO2 m−2 s−1 in the 150–276-year-old group. We found a significant increasing trend in SR in the 88–141-year old group during the study period, which was related to the significant decrease in soil water content due to the shortage of precipitation during the growing season. We observed a high spatial variation in SR, which was primarily regulated by biological and environmental factors. Different parameters were the main contributors to SR in each group, an SR was significantly affected by the inter-relationships between the studied parameters. The obtained results can be incorporated into the existing SR databases, which can allow their use in the construction and validation of C transport models as well as in monitoring global fluctuations in the C cycle in response to climate change.

scholarly journals Patterns and controls of soil respiration and its temperature sensitivity in grassland ecosystems across China

2018 ◽  
Author(s):  
Jiguang Feng ◽  
Jingsheng Wang ◽  
Yanjun Song ◽  
Biao Zhu
Keyword(s):  
Climate Change ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Spatial Variation ◽  
Temperature Sensitivity ◽  
Annual Precipitation ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
The Mean ◽  
Grassland Types

Abstract. Soil respiration (Rs), a key process in the terrestrial carbon cycle, is very sensitive to climate change. In this study, we synthesized 54 measurements of annual Rs and 171 estimates of Q10 value (the temperature sensitivity of soil respiration) in grasslands across China. We quantitatively analyzed their spatial patterns and controlling factors in five grassland types, including temperate typical steppe, temperate meadow steppe, temperate desert steppe, alpine grassland, and warm-tropical grassland. Results showed that the mean (± SE) annual Rs was 582.0 ± 57.9 g C m−2 yr−1 across Chinese grasslands. Annual Rs significantly differed among grassland types, and positively correlated with mean annual temperature, mean annual precipitation, soil organic carbon content and aboveground biomass, but negatively correlated with latitude and soil pH (P < 0.05). Among these factors, mean annual precipitation was the primary factor controlling the spatial variation of annual Rs in Chinese grasslands. The mean contributions of growing season Rs and heterotrophic respiration to annual Rs were 78.7 % and 72.8 %, respectively. Moreover, the mean (± SE) of Q10 across Chinese grasslands was 2.60 ± 0.08, ranging from 1.03 to 8.13, and varied largely within and among grassland types, and among soil temperature measurement depths. Generally, the seasonal variation of soil respiration in Chinese grasslands cannot be well explained by soil temperature using the van't Hoff equation. Longitude and altitude were the dominant driving factors and accounted for 26.0 % of the variation in Q10 derived by soil temperature at the depth of 5 cm. Overall, our findings advance our understanding of the spatial variation and environmental control of soil respiration and Q10 across Chinese grasslands, and also improve our ability to predict soil carbon efflux under climate change on the regional scale.

Differentiation and Interrelations of Two Representatives of Laudakia stellio Complex (Reptilia: Agamidae) in Israel

2011 ◽  
Vol 4 (2) ◽  
pp. 102-114 ◽  
Author(s):  
Evgenyi N. Panov ◽  
Larissa Yu. Zykova
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Habitat Preference ◽  
Additional Data ◽  
Near East ◽  
Field Studies ◽  
Subspecies Level ◽  
Limited Gene Flow ◽  
Study Sites ◽  
And Behavior

Field studies were conducted in Central Negev within the breeding range of Laudakia stellio brachydactyla and in NE Israel (Qyriat Shemona) in the range of an unnamed form (tentatively “Near-East Rock Agama”), during March – May 1996. Additional data have been collected in Jerusalem at a distance of ca. 110 km from the first and about 170 km from the second study sites. A total of 63 individuals were caught and examined. The animals were marked and their subsequent movements were followed. Social and signal behavior of both forms were described and compared. Lizards from Negev and Qyriat Shemona differ from each other sharply in external morphology, habitat preference, population structure, and behavior. The differences obviously exceed the subspecies level. At the same time, the lizards from Jerusalem tend to be intermediate morphologically between those from both above-named localities, which permits admitting the existence of a limited gene flow between lizard populations of Negev and northern Israel. The lizards from NE Israel apparently do not belong to the nominate subspecies of L. stellio and should be regarded as one more subspecies within the species.

scholarly journals Dynamics of the soil respiration response to soil reclamation in a coastal wetland

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiliang Song ◽  
Yihao Zhu ◽  
Weifeng Chen
Keyword(s):  
Soil Respiration ◽  
Soil Temperature ◽  
Soil Carbon ◽  
Water Content ◽  
Coastal Wetlands ◽  
Positive Relationship ◽  
Soil Reclamation ◽  
Diurnal Changes ◽  
Seasonal Scale ◽  
Study Sites

AbstractThe soil carbon (C) pools in coastal wetlands are known as “blue C” and have been damaged extensively owing to climate change and land reclamation. Because soil respiration (RS) is the primary mechanism through which soil carbon is released into the atmosphere at a global scale, investigating the dynamic characteristics of the soil respiration rate in reclaimed coastal wetlands is necessary to understand its important role in maintaining the global C cycle. In the present study, seasonal and diurnal changes in soil respiration were monitored in one bare wetland (CK) and two reclaimed wetlands (CT, a cotton monoculture pattern, and WM, a wheat–maize continuous cropping pattern) in the Yellow River Delta. At the diurnal scale, the RS at the three study sites displayed single-peak curves, with the lowest values occurring at midnight (00:00 a.m.) and the highest values occurring at midday (12:00 a.m.). At the seasonal scale, the mean diurnal RS of the CK, CT and WM in April was 0.24, 0.26 and 0.79 μmol CO2 m−2 s−1, and it increased to a peak in August for these areas. Bare wetland conversion to croplands significantly elevated the soil organic carbon (SOC) pool. The magnitude of the RS was significantly different at the three sites, and the yearly total amounts of CO2 efflux were 375, 513 and 944 g CO2·m−2 for the CK, CT and WM, respectively. At the three study sites, the surface soil temperature had a significant and positive relationship to the RS at both the diurnal and seasonal scales, and it accounted for 20–52% of the seasonal variation in the daytime RS. The soil water content showed a significant but negative relationship to the RS on diurnal scale only at the CK site, while it significantly increased with the RS on seasonal scale at all study sites. Although the RS showed a noticeable relationship to the combination of soil temperature and water content, the synergic effects of these two environment factors were not much higher than the individual effects. In addition, the correlation analysis showed that the RS was also influenced by the soil physico-chemical properties and that the soil total nitrogen had a closer positive relationship to the RS than the other nutrients, indicating that the soil nitrogen content plays a more important role in promoting carbon loss.

Distribution and Seasonality of Macroalgae on Oyster Communities of Central Chesapeake Bay

1980 ◽  
Vol 23 (11) ◽  
Author(s):  
Judith L. Connor
Keyword(s):  
Life History ◽  
Sexual Reproduction ◽  
Chesapeake Bay ◽  
Physical Environment ◽  
Algal Species ◽  
Light Availability ◽  
Field Studies ◽  
Spatial And Temporal Distributions ◽  
Red Algal ◽  
Study Sites

AbstractField studies of the benthic macroalgae of fifteen selected Chesapeake Bay oyster communities were conducted over a period of a year (March 1977 to February 1978). Algal distribu tion and seasonal occurrence were studied in relation to changes in the physical environment. Salinity, temperature, and light availability were important factors in the spatial and temporal distributions of algae in these subtidal habitats.Seventeen species of Chlorophyta, Phaeophyta, and Rhodophyta were recorded from the fifteen study sites distributed over 130 kilometers within the Maryland portion of Chesapeake Bay. Species of Chlorophyta were associated with oyster communities throughout the year of study with maximum numbers of species and maximum biomass occurring in spring. Only once was a member of the Phaeophyta encountered; a single filamentous species, Ectocarpus, was collected during winter. Species of Rhodophyta were present throughout the year at the study sites.Most of the algae collected reproduced asexually by spores and/or vegetative fragments. Sexual reproduction occurred in some of the red algal species. The presence of tetrasporic and cystocarpic plants of Dasya baillouviana and Polysiphonia harveyi var. olneyi may indicate that the usual triphasic Florideophycean life history occurs in this estuary.

scholarly journals Historical climate controls soil respiration responses to current soil moisture

2017 ◽  
Vol 114 (24) ◽  
pp. 6322-6327 ◽  
Author(s):  
Christine V. Hawkes ◽  
Bonnie G. Waring ◽  
Jennifer D. Rocca ◽  
Stephanie N. Kivlin
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Soil Respiration ◽  
Carbon Cycling ◽  
Large Scale ◽  
Microbial Respiration ◽  
Rainfall Gradient ◽  
Soil Microbial ◽  
Historical Climate ◽  
Moisture Dependence

Ecosystem carbon losses from soil microbial respiration are a key component of global carbon cycling, resulting in the transfer of 40–70 Pg carbon from soil to the atmosphere each year. Because these microbial processes can feed back to climate change, understanding respiration responses to environmental factors is necessary for improved projections. We focus on respiration responses to soil moisture, which remain unresolved in ecosystem models. A common assumption of large-scale models is that soil microorganisms respond to moisture in the same way, regardless of location or climate. Here, we show that soil respiration is constrained by historical climate. We find that historical rainfall controls both the moisture dependence and sensitivity of respiration. Moisture sensitivity, defined as the slope of respiration vs. moisture, increased fourfold across a 480-mm rainfall gradient, resulting in twofold greater carbon loss on average in historically wetter soils compared with historically drier soils. The respiration–moisture relationship was resistant to environmental change in field common gardens and field rainfall manipulations, supporting a persistent effect of historical climate on microbial respiration. Based on these results, predicting future carbon cycling with climate change will require an understanding of the spatial variation and temporal lags in microbial responses created by historical rainfall.

scholarly journals Temporal-Spatial Variation and Controls of Soil Respiration in Different Primary Succession Stages on Glacier Forehead in Gongga Mountain, China

PLoS ONE ◽  
2012 ◽  
Vol 7 (8) ◽  
pp. e42354 ◽  
Author(s):  
Ji Luo ◽  
Youchao Chen ◽  
Yanhong Wu ◽  
Peili Shi ◽  
Jia She ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Spatial Variation ◽  
Primary Succession ◽  
Gongga Mountain

scholarly journals Distinct patterns in the diurnal and seasonal variability in four components of soil respiration in a temperate forest under free-air CO<sub>2</sub> enrichment

2011 ◽  
Vol 8 (10) ◽  
pp. 3077-3092 ◽  
Author(s):  
L. Taneva ◽  
M. A. Gonzalez-Meler
Keyword(s):  
Soil Respiration ◽  
Seasonal Variability ◽  
Ecosystem Respiration ◽  
Co2 Efflux ◽  
Diurnal Variability ◽  
Soil C ◽  
Free Air ◽  
C Cycle ◽  
Strong Control ◽  
Average Contribution

Abstract. Soil respiration (RS) is a major flux in the global carbon (C) cycle. Responses of RS to changing environmental conditions may exert a strong control on the residence time of C in terrestrial ecosystems and in turn influence the atmospheric concentration of greenhouse gases. Soil respiration consists of several components oxidizing soil C from different pools, age and chemistry. The mechanisms underlying the temporal variability of RS components are poorly understood. In this study, we used the long-term whole-ecosystem 13C tracer at the Duke Forest Free Air CO2 Enrichment site to separate forest RS into its autotrophic (RR) and heterotrophic components (RH). The contribution of RH to RS was further partitioned into litter decomposition (RL), and decomposition of soil organic matter (RSOM) of two age classes – up to 8 yr old and SOM older than 8 yr. Soil respiration was generally dominated by RSOM during the growing season (44% of daytime RS), especially at night. The contribution of heterotrophic respiration (RSOM and RL) to RS was not constant, indicating that the seasonal variability in RR alone cannot explain seasonal variation in RS. Although there was no diurnal variability in RS, there were significant compensatory differences in the contribution of individual RS components to daytime and nighttime rates. The average contribution of RSOM to RS was greater at night (54%) than during the day (44%). The average contribution of RR to total RS was ~30% during the day and ~34% during the night. In contrast, RL constituted 26% of RS during the day and only 12% at night. About 95% of the decomposition of soil C older than 8 yr (Rpre-tr) originated from RSOM and showed more pronounced and consistent diurnal variability than any other RS component; nighttime rates were on average 29% higher than daytime rates. In contrast, the decomposition of more recent, post-treatment C (Rpre-tr) did not vary diurnally. None of the diurnal variations in components of RH could be explained by only temperature and moisture variations. Our results indicate that the variation observed in the components of RS is the result of complex interaction between dominant biotic controls (e.g. plant activity, mineralization kinetics, competition for substrates) over abiotic controls (temperature, moisture). The interactions and controls among roots and other soil organisms that utilize C of different chemistry, accessibility and ages, results in the overall soil CO2 efflux. Therefore understanding the controls on the components of RS is necessary to elucidate the influence of ecosystem respiration on atmospheric C-pools at different time scales.

Consistent differences in macroparasite community composition among populations of three-spined sticklebacks,Gasterosteus aculeatusL.

Parasitology ◽  
2012 ◽  
Vol 139 (11) ◽  
pp. 1478-1491 ◽  
Author(s):  
JOB DE ROIJ ◽  
ANDREW D. C. MacCOLL
Keyword(s):  
Spatial Variation ◽  
Community Composition ◽  
Gasterosteus Aculeatus ◽  
Parasite Community ◽  
Field Studies ◽  
Habitat Characteristics ◽  
Parasite Communities ◽  
Geographical Distances ◽  
Host Parasite ◽  
Relative Differences

SUMMARYParasite ecologists are often interested in the repeatability of patterns in parasite communities in space and/or time, because of implications for the dynamics of host-parasite interactions. Field studies usually examine temporal and spatial variation in isolation or limit themselves to a small number of host populations. Here, we studied the macroparasite communities of 12 populations of three-spined stickleback,Gasterosteus aculeatusL., on North Uist, Scotland, separated by small geographical distances, during the breeding season in 2 consecutive years (2007 and 2008) to determine: (1) the extent of spatial variation in macroparasite communities, (2) whether this variation is consistent across years, and (3) whether habitat characteristics can explain differences in macroparasite community composition among populations. We found substantial variation in parasite communities among populations. Generally, measures of parasite community composition were higher in 2008 than in 2007, but this effect of year was consistent across populations, such that the relative differences in these measures among populations changed little between years. These data suggest that there is short-term stability in the spatial variation in macroparasite communities of North Uist sticklebacks. However, none of the 5 habitat characteristics measured explained spatial variation in any measure of parasite community composition.

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