scholarly journals Sedimentary archaeal amoA gene abundance reflects historic nutrient level and salinity fluctuations in Qinghai Lake, Tibetan Plateau

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Jian Yang ◽  
Hongchen Jiang ◽  
Hailiang Dong ◽  
Weiguo Hou ◽  
Gaoyuan Li ◽  
...  
2020 ◽  
Vol 12 (3) ◽  
pp. 528 ◽  
Author(s):  
Jingye Li ◽  
Jian Gong ◽  
Jean-Michel Guldmann ◽  
Shicheng Li ◽  
Jie Zhu

Land use/cover change (LUCC) has an important impact on the terrestrial carbon cycle. The spatial distribution of regional carbon reserves can provide the scientific basis for the management of ecosystem carbon storage and the formulation of ecological and environmental policies. This paper proposes a method combining the CA-based FLUS model and the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model to assess the temporal and spatial changes in ecosystem carbon storage due to land-use changes over 1990–2015 in the Qinghai Lake Basin (QLB). Furthermore, future ecosystem carbon storage is simulated and evaluated over 2020–2030 under three scenarios of natural growth (NG), cropland protection (CP), and ecological protection (EP). The long-term spatial variations in carbon storage in the QLB are discussed. The results show that: (1) Carbon storage in the QLB decreased at first (1990–2000) and increased later (2000–2010), with total carbon storage increasing by 1.60 Tg C (Teragram: a unit of mass equal to 1012 g). From 2010 to 2015, carbon storage displayed a downward trend, with a sharp decrease in wetlands and croplands as the main cause; (2) Under the NG scenario, carbon reserves decrease by 0.69 Tg C over 2020–2030. These reserves increase significantly by 6.77 Tg C and 7.54 Tg C under the CP and EP scenarios, respectively, thus promoting the benign development of the regional ecological environment. This study improves our understanding on the impact of land-use change on carbon storage for the QLB in the northeastern Qinghai–Tibetan Plateau (QTP).


2021 ◽  
Vol 188 ◽  
pp. 104451
Author(s):  
Guangyin Hu ◽  
Zhibao Dong ◽  
Zhengcai Zhang ◽  
Linhai Yang ◽  
Lewei Hao ◽  
...  

2013 ◽  
Vol 59 (7) ◽  
pp. 456-464 ◽  
Author(s):  
Jie Hou ◽  
Xiuyun Cao ◽  
Chunlei Song ◽  
Yiyong Zhou

The coupled nitrification–denitrification process plays a pivotal role in cycling and removal of nitrogen in aquatic ecosystems. In the present study, the communities of ammonia oxidizers and denitrifiers in the sediments of 2 basins (Guozhenghu Basin and Tuanhu Basin) of a large urban eutrophic lake (Lake Donghu) were determined using the ammonia monooxygenase subunit A (amoA) gene and the nitrite reductase gene. At all sites of this study, the archaeal amoA gene predominated over the bacterial amoA gene, whereas the functional gene for denitrification nirK gene far outnumbered the nirS gene. Spatially, compared with the Tuanhu Basin, the Guozhenghu Basin showed a significantly greater abundance of the archaeal amoA gene but less abundance of the nirK and nirS genes, while there was no significant difference of bacterial amoA gene copy numbers between the 2 basins. Unlike the archaeal amoA gene, the nirK gene showed a significant difference in community structure between the 2 basins. Archaeal amoA diversity was limited to the water–sediment cluster of Crenarchaeota, in sharp contrast with nirK for which 22 distinct operational taxonomic units were found. Accumulation of organic substances were found to be positively related to nirK and nirS gene copy numbers but negatively related to archaeal amoA gene copy numbers, whereas the abundance of the bacterial amoA gene was related to ammonia concentration.


2019 ◽  
Vol 44 (1) ◽  
pp. 70-93 ◽  
Author(s):  
Hai-cheng Wei ◽  
Guang-liang Hou ◽  
Qi-shun Fan ◽  
David B Madsen ◽  
Zhan-jie Qin ◽  
...  

The history of permanent human settlement in the high-altitude regions (>3000 m above sea level [masl]) of the Qinghai-Tibetan Plateau (QTP) is important in understanding human adaptation to this cold “Third Pole” region. The Qinghai Lake Basin was an important corridor used by prehistoric humans migrating to the inner QTP. Pastoralism is currently the most important means of sustaining permanent human settlement in the high-altitude regions of the QTP. However, the lack of reliable proxy measures reflecting prehistoric pastoral activities impedes our understanding of how pastoralism developed. The identification of coprophilous fungi in prehistoric cultural deposits may help refine the history of pastoralism. We collected 21 modern domesticated herbivore dung samples and 66 surface soil samples from the Qinghai Lake Basin for fungal spore analyses. We then evaluated how useful such analyses are for identifying grazing activities. Fifty-three samples were also collected from the JXG2 stratigraphic profile (∼10.0–0 ka; 3312 masl) for fungal spore analysis. Results indicate that low and stable values of the total concentration of coprophilous fungi were present from ∼10.0 to ∼5.5 ka. Concentrations gradually increased from ∼5.5 to ∼4.2 ka, significantly increased from ∼4.2 to ∼2.6 ka, and then increased dramatically after ∼2.6 ka. By combining these results with charcoal concentrations (>50 µm), lithic artifacts, bones and potsherds recovered from the JXG2 site, we infer that early pastoralism in Qinghai Lake Basin appeared between ∼6.0 to ∼5.5 ka and gradually intensified throughout the remainder of the Holocene as herding and farming gradually replaced hunting–gathering as the primary subsistence strategies. These results are supported by pollen records, archeological remains and historical records in the northeastern QTP.


Oryx ◽  
2012 ◽  
Vol 46 (1) ◽  
pp. 145-153 ◽  
Author(s):  
Chunlin Li ◽  
Zhigang Jiang ◽  
Xiaoge Ping ◽  
Jing Cai ◽  
Zhangqiang You ◽  
...  

AbstractIn 2008 Przewalski's gazelle Procapra przewalskii, endemic to the Qinghai–Tibetan Plateau, China, was recategorized from Critically Endangered to Endangered on the IUCN Red List. The species is still, however, threatened, and the human population and accompanying domestic livestock are increasing around Qinghai Lake. Here we provide up-to-date information on the distribution and population size of the species, evaluate its current conservation status and discuss the difficulties of protecting this gazelle species. We used both distance sampling and total counts to survey 16 sites where the species has been reported and found it at 13 of these, occupying a total area of c. 250 km2. Population size estimated from distance sampling (1,635) and total counts (1,544) was similar. About 20% of the gazelles located were in newly discovered areas for the species. The results indicate an overall growth in the population of Przewalski's gazelle since 2003, although some subpopulations have declined or been extirpated. In spite of conservation efforts Przewalski's gazelle is still threatened by habitat degradation and loss, habitat fragmentation, fencing, intensified competition with domestic livestock and predation. Further growth of this gazelle population is constrained by limited habitat availability and human–gazelle conflict. We recommend that management and conservation strategies need to incorporate comprehensive knowledge of the gazelle, long-term monitoring, and captive breeding of injured and orphaned gazelles to form a potential pool of individuals for future reintroductions to the historical range of the species outside the Qinghai Lake basin.


The Holocene ◽  
2018 ◽  
Vol 28 (11) ◽  
pp. 1712-1719 ◽  
Author(s):  
E ChongYi ◽  
YongJuan Sun ◽  
XiangJun Liu ◽  
Guangliang Hou ◽  
ShunChang Lv ◽  
...  

Qinghai Lake is the largest lake on the Tibetan Plateau (TP) and in China and has been a focus of paleoenvironmental and climatic research for decades. However, limited understanding of lake 14C reservoir effects (LRE) has led to inconsistent interpretations among proxies of different sediment cores. As such, the onset of LRE variability during the Holocene is still unclear. 14C dating of archeological samples from four locations (Gangcha, Shaliuheqiaoxi, and Shinaihai sites, and Niaodao section) including naked carp ( Gymnocypris przewalskii, Kessler) fish bones, animal bones and teeth, and charcoal was employed to estimate variations in LRE over the last few thousand years. LRE offsets calculated as the difference between LRE of animal bones and fish bones are more reliable than that of charcoal and fish bones due to the ‘old wood’ effect in charcoal. LRE offsets recorded in fish bones were ~0.5, ~0.6, and ~0.7 ka during the periods of 3.0–3.4 cal ka BP, 0.58–0.60 cal ka BP, and modern lake times, respectively, which may indicate a temporal minimum LRE offset. Unlike the wide spatial variations of LRE ages obtained from surface total organic carbon (TOC) samples of the modern Qinghai Lake, LRE offsets from the three contemporaneous locations in Qinghai Lake were all ~0.5 ka, suggesting efficient carbon mixing occurred in naked carp. However, the late-Holocene (~3.1 ka BP) LRE increased slightly with increasing salinity and decreasing lake level.


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