Observed changes in shallow soil temperatures in Northeast China, 1960-2007

2016 ◽  
Vol 67 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Y Liu ◽  
L Wang ◽  
B Liu ◽  
M Henderson
Keyword(s):  
Northeast China ◽  
Shallow Soil ◽  
Soil Temperatures

scholarly journals Seasonal variations in temperature sensitivity of soil respiration in a larch forest in the Northern Daxing’an Mountains in Northeast China

2021 ◽  
Author(s):  
Lin Yang ◽  
Qiuliang Zhang ◽  
Zhongtao Ma ◽  
Huijun Jin ◽  
Xiaoli Chang ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Soil Carbon ◽  
Respiration Rate ◽  
Temperature Sensitivity ◽  
Northeast China ◽  
Surface Soil ◽  
Soil Surface ◽  
Growing Season ◽  
Soil Temperatures ◽  
Daxing’An Mountains

AbstractTemperature sensitivity of respiration of forest soils is important for its responses to climate warming and for the accurate assessment of soil carbon budget. The sensitivity of temperature (Ti) to soil respiration rate (Rs), and Q10 defined by e10(lnRs−lna)/Ti has been used extensively for indicating the sensitivity of soil respiration. The soil respiration under a larch (Larix gmelinii) forest in the northern Daxing’an Mountains, Northeast China was observed in situ from April to September, 2019 using the dynamic chamber method. Air temperatures (Tair), soil surface temperatures (T0cm), soil temperatures at depths of 5 and 10 cm (T5cm and T10cm, respectively), and soil-surface water vapor concentrations were monitored at the same time. The results show a significant monthly variability in soil respiration rate in the growing season (April–September). The Q10 at the surface and at depths of 5 and 10 cm was estimated at 5.6, 6.3, and 7.2, respectively. The Q10@10 cm over the period of surface soil thawing (Q10@10 cm, thaw = 36.89) were significantly higher than that of the growing season (Q10@10 cm, growth = 3.82). Furthermore, the Rs in the early stage of near-surface soil thawing and in the middle of the growing season is more sensitive to changes in soil temperatures. Soil temperature is thus the dominant factor for season variations in soil respiration, but rainfall is the main controller for short-term fluctuations in respiration. Thus, the higher sensitivity of soil respiration to temperature (Q10) is found in the middle part of the growing season. The monthly and seasonal Q10 values better reflect the responsiveness of soil respiration to changes in hydrometeorology and ground freeze-thaw processes. This study may help assess the stability of the soil carbon pool and strength of carbon fluxes in the larch forested permafrost regions in the northern Daxing’an Mountains.

Assessment of viral assemblages in different types of wetland water in northeast China using RAPD-PCR

2020 ◽  
Vol 85 ◽  
pp. 183-196
Author(s):  
Y Sun ◽  
J Liu ◽  
Q Yao ◽  
J Jin ◽  
X Liu ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Water Samples ◽  
Northeast China ◽  
Bacterial Community Composition ◽  
Freshwater Wetlands ◽  
Viral Community ◽  
Rapd Pcr ◽  
Wetland Water ◽  
Different Types ◽  
Viral Communities

Viruses are the most abundant and ubiquitous biological entities in various ecosystems, yet few investigations of viral communities in wetlands have been performed. To address this data gap, water samples from 6 wetlands were randomly collected across northeast China; viruses in the water were concentrated by sequential tangential flow filtration, and viral communities were assessed through randomly amplified polymorphic DNA-PCR (RAPD-PCR) with 4 decamer oligonucleotide primers. Principal coordinate analysis and hierarchical clustering analysis of the DNA fingerprints showed that viral community compositions differed among the water samples: communities in the 2 coastal wetlands were more similar to each other than to those in the 4 freshwater wetlands. The Shannon-Weaver index (H) and evenness index (E) of the RAPD-PCR fingerprint also differed among the 6 wetlands. Mantel test revealed that the changes in viral communities in wetland water were most closely related to the water NH4+-N and inorganic C content, followed by total K, P, C and NO3--N. DNA sequence analysis of the excised bands revealed that viruses accounted for ~40% of all sequences. Among the hit viral homologs, the majority belonged to the Microviridae. Moreover, variance partitioning analysis showed that the viral community contributed 24.58% while environmental factors explained 30.56% of the bacterial community variation, indicating that the bacterial community composition was strongly affected by both viral community and water variables. This work provides an initial outline of the viral communities from different types of wetlands in northeast China and improves our understanding of the viral diversity in these ecosystems.

Multi-index drought characteristics in Songhua River basin, Northeast China

2019 ◽  
Vol 78 (1) ◽  
pp. 1-19 ◽  
Author(s):  
MA Faiz ◽  
D Liu ◽  
Q Fu ◽  
F Baig ◽  
AA Tahir ◽  
...  
Keyword(s):  
River Basin ◽  
Northeast China ◽  
Songhua River ◽  
Multi Index ◽  
Songhua River Basin ◽  
Drought Characteristics
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