Storage and Climatic Controlling Factors of Litter Standing Crop Carbon in the Shrublands of the Tibetan Plateau

Litter is an important component of terrestrial ecosystems and plays a significant role in carbon cycles. Quantifying regional-scale patterns of litter standing crop distribution will improve our understanding of the mechanisms of the terrestrial carbon cycle, and thus enable accurate predictions of the responses of the terrestrial carbon cycle to future climate change. In this study, we aimed to estimate the storage and climatic controlling factors of litter standing crop carbon in the Tibetan Plateau shrublands. We investigated litter standing crop carbon storage and its controlling factors, using a litter survey at 65 shrublands sites across the Tibetan Plateau from 2011–2013. Ordinary least squares regression analyses were conducted to estimate the relationships between litter standing crop carbon, longitude, and latitude. Multiple linear regressions were used to evaluate relationships among litter standing crop carbon, mean annual temperature (MAT), mean annual precipitation (MAP), and aboveground biomass. The litter standing crop carbon storage was 10.93 Tg C, 7.40 Tg C, and 3.53 Tg C in desert shrublands and alpine shrublands, respectively. Litter standing crop carbon decreased with longitude, and was stable with increasing latitude. Most (80%) of the litter standing crop was stored in branches, with only 20% stored in foliage in the shrublands on the Tibetan Plateau. The conversion coefficient was 0.44 for litter standing crop to litter standing crop carbon, and 0.39 and 0.45 for foliage and branch litter standing crop to foliage and branch litter standing crop carbon, respectively. Aboveground biomass can accelerate more inputs of litter and has a positive effect on litter standing crop carbon. MAT had a positive effect on litter standing crop carbon due to stimulating more input of aboveground biomass. However, MAP had a negative relationship with litter standing crop carbon by enhancing litter decomposition.

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Potential Production of Carbon Gases and Their Responses to Paleoclimate Conditions: An Example From Xiaolongtan Basin, Southeast Tibetan Plateau

Frontiers in Earth Science ◽

10.3389/feart.2021.582062 ◽

2021 ◽

Vol 9 ◽

Author(s):

Gen Wang ◽

Yongli Wang ◽

Zhifu Wei ◽

Zepeng Sun ◽

Wei He ◽

...

Keyword(s):

Organic Matter ◽

Tibetan Plateau ◽

Low Temperature ◽

Organic Carbon ◽

Carbon Cycle ◽

Higher Plants ◽

The Tibetan Plateau ◽

Climate Conditions ◽

Burial Flux ◽

Carbon Gases

Uplift of the Tibetan Plateau plays a significant and lasting role in the variations of climate conditions and global carbon cycle. However, our knowledge is limited due to the lack of long-sequence records revealing rates of CO2 and CH4 production, hampering our understanding of the relationship between paleoclimatic conditions, carbon cycling and greenhouse gas flux. Here, we present a combination of paleoclimate records and low-temperature thermal simulation results from sediments of the Xiaolongtan Basin at the southeastern margin of the Qinghai-Tibetan Plateau, spanning the late Miocene (14.1 ∼ 11.6 Ma). The n-alkane-derived proxies suggested that the sources of organic matter were obviously different: a mixed source including lower organisms and terrestrial higher plants for the Dongshengqiao Formation from 14.1 to 12.6 Ma, and a predominant contribution from terrestrial higher plants for Xiaolongtan Formation between 12.6 and 11.6 Ma. The paleoclimate was generally warm and humid as reflected by the lipid biomarkers, consistent with previous studies. In addition, the carbon gases (including CO2 and hydrocarbon gases) generated by the low-temperature thermal simulation experiments indicated a production rate of CO2 and CH4 were as high as 88,000 ml/kg rock and 4,000 ml/kg rock, respectively, implying there were certain amounts of carbon gases generated and released into the atmosphere during their shallow burial stage. Besides, the calculated production rate of carbon gases and the estimated burial flux of organic carbon varied in response to the variations of paleoclimate conditions. Based on these observations, we propose that the climate conditions predominantly controlled the formation and accumulation of organic matter, which consequently affected the production of carbon gases and burial flux of organic carbon. The results presented here may provide a significant insight into the carbon cycle in the southeast of the Tibetan Plateau.

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Estimation of aboveground biomass using in situ hyperspectral measurements in five major grassland ecosystems on the Tibetan Plateau

Journal of Plant Ecology ◽

10.1093/jpe/rtn025 ◽

2008 ◽

Vol 1 (4) ◽

pp. 247-257 ◽

Cited By ~ 53

Author(s):

M. Shen ◽

Y. Tang ◽

J. Klein ◽

P. Zhang ◽

S. Gu ◽

...

Keyword(s):

Tibetan Plateau ◽

Aboveground Biomass ◽

The Tibetan Plateau ◽

Grassland Ecosystems

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Pedogenesis, permafrost, and soil moisture as controlling factors for soil nitrogen and carbon contents across the Tibetan Plateau

Global Change Biology ◽

10.1111/j.1365-2486.2009.01953.x ◽

2009 ◽

Vol 15 (12) ◽

pp. 3001-3017 ◽

Cited By ~ 113

Author(s):

FRANK BAUMANN ◽

JIN-SHENG HE ◽

KARSTEN SCHMIDT ◽

PETER KÜHN ◽

THOMAS SCHOLTEN

Keyword(s):

Soil Moisture ◽

Tibetan Plateau ◽

Soil Nitrogen ◽

Controlling Factors ◽

The Tibetan Plateau

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Projected changes of alpine grassland carbon dynamics in response to climate change and elevated CO2concentrations under Representative Concentration Pathways (RCP) scenarios

10.1101/595926 ◽

2019 ◽

Author(s):

Pengfei Han ◽

Xiaohui Lin ◽

Wen Zhang ◽

Guocheng Wang

Keyword(s):

Climate Change ◽

Tibetan Plateau ◽

Carbon Cycle ◽

Carbon Budget ◽

Carbon Fluxes ◽

Carbon Dynamics ◽

Alpine Grassland ◽

The Tibetan Plateau ◽

Rcp Scenarios ◽

Representative Concentration Pathways

AbstractThe Tibetan Plateau is an important component of the global carbon cycle due to the large permafrost carbon pool and its vulnerability to climate warming. The Tibetan Plateau has experienced a noticeable warming over the past few decades and is projected to continue warming in the future. However, the direction and magnitude of carbon fluxes responses to climate change and elevated CO2concentration under Representative Concentration Pathways (RCP) scenarios in the Tibetan Plateau grassland are poorly known. Here, we used a calibrated and validated biogeochemistry model, CENTURY, to quantify the contributions of climate change and elevated CO2on the future carbon budget in the alpine grassland under three RCP scenarios. Though the Tibetan Plateau grassland was projected a net carbon sink of 16 ~ 25 Tg C yr-1in the 21st century, the capacity of carbon sequestration was predicted to decrease gradually because climate-driven increases in heterotrophic respiration (Rh) (with linear slopes 0.49 ~ 1.62 g C m-2yr-1) was greater than the net primary production (NPP) (0.35 ~ 1.52 g C m-2yr-1). However, the elevated CO2contributed more to plant growth (1.9% ~ 7.3%) than decomposition (1.7% ~ 6.1%), which could offset the warming-induced carbon loss. The interannual and decadal-scale dynamics of the carbon fluxes in the alpine grassland were primarily controlled by temperature, while the role of precipitation became increasingly important in modulating carbon cycle. The strengthened correlation between precipitation and carbon budget suggested that further research should consider the performance of precipitation in evaluating carbon dynamics in a warmer climate scenario.

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Estimation of aboveground biomass using in situ hyperspectral measurements in five major grassland ecosystems on the Tibetan Plateau

Journal of Plant Ecology ◽

10.1093/jpe/rtp002 ◽

2009 ◽

Vol 2 (1) ◽

pp. 43-43

Author(s):

M. Shen ◽

Y. Tang ◽

J. Klein ◽

P. Zhang ◽

S. Gu ◽

...

Keyword(s):

Tibetan Plateau ◽

Aboveground Biomass ◽

The Tibetan Plateau ◽

Grassland Ecosystems

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Historical change of winter Tibetan Plateau snow cover and its controlling factors

10.5194/egusphere-egu21-6877 ◽

2021 ◽

Author(s):

Shixue Li ◽

Tomonori Sato ◽

Tetsu Nakamura

Keyword(s):

Global Warming ◽

Tibetan Plateau ◽

Snow Cover ◽

Internal Variability ◽

Controlling Factors ◽

Historical Change ◽

The Tibetan Plateau ◽

Vapor Flux ◽

The Impact ◽

Tibetan Plateau Snow Cover

This study investigates the controlling factors of the interannual variability of Tibetan Plateau snow cover (TPSC) in winter. Since snow observation in Tibetan Plateau is limited in space and time, high-resolution multi-satellite data for TPSC were analyzed during 1982-2016. In addition, a large ensemble AGCM experiment from d4PDF (hereafter, HIST), driven by observed SST and anthropogenic forcings were analyzed during 1951-2010 to compare the contributions arising from internal variability and external forcings including the change in greenhouse gases (GHGs) concentration on TPSC variation. In this study TPSC fraction (hereafter, TPSCF) is defined as the percentage of the snow-covered area over the Tibetan Plateau. For both observation and HIST, high and low TPSCF years determined by the standardized January-March TPSCF were analyzed. The range of interannual TPSCF variation (i.e., TPSCF difference between high and low TPSCF years) is about 11% in both observation and the model, suggesting the AGCM well reproduced the TPSCF variability in the interannual timescale.&#160;We found that high TPSCF is linked to a positive-AO-like pattern. The interannual variation of the observed AO index and TPSCF are significantly correlated. In d4PDF high TPSCF more likely appears with a higher (positive) AO index and vice versa. In high TPSCF years, the subtropical jet is strengthened, which significantly enhances zonal water vapor flux reaching the plateau supporting more precipitation. Another interesting result is a disagreement for ENSO&#8217;s contribution to TPSC appears between observation and HIST. However, several members in HIST show a feature close to the observation, in which TPSCF anomalies are not sensitive to the El Ni&#241;o/La Ni&#241;a events. Thus, this weak linkage between ENSO and TPSCF is more likely due to the limited cases of observations rather than the model bias. Finally, by comparing HIST and non-warming experiments (NAT), we found historical global warming has decreased the snow-to-rain ratio over TP. Nonetheless, increased precipitation compensates for it. As a result, the impact of historical global warming on TPSCF could be considered negligibly weak.

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Features and controlling factors of drainage networks in the Tibetan Plateau

10.5194/egusphere-egu2020-4303 ◽

2020 ◽

Author(s):

Minhui Li ◽

Baosheng Wu ◽

Yi Chen

Keyword(s):

Tibetan Plateau ◽

Yangtze River ◽

Yellow River ◽

Controlling Factors ◽

River Networks ◽

The Tibetan Plateau ◽

Self Similarity ◽

Drainage Networks ◽

Yarlung Zangbo River ◽

Yalong River

Tibetan Plateau is the source of many major rivers in Asia. Drainage networks of these rivers vary in shapes and features due to complex climatic and geomorphic conditions. In this study, we extracted drainage networks in the source area of Yellow River, Yangtze River and Yarlung Zangbo River from 90-m-resolution SRTM DEM. We chose 62 sub-basins in the Yellow River, 96 sub-basins in the Yangtze River and 120 sub-basins in the Yarlung Zangbo River and tested self-similarity of drainage networks in two ways. First, we tested self-similarity for traditional Horton laws. Based on Horton-Strahler order, the results indicate that rivers with low levels generally obey Horton laws while rivers with high levels show deviation. Second, we tested statistical self-similarity in the topology of river networks. Random self-similar networks (RSN) model which combines self-similarity and randomness shows topological features of river networks statistically. Real networks were decomposed into generators that produce the network. The results demonstrate that the generators of RSN model obey a geometric distribution and the parameter p, which describes the distribution of generators, ranges from 0.401 to 0.587. Self-similarity holds in a statistical sense in the selected basins in the Tibetan Plateau. Motivated by the need to understand the controlling factors of drainage networks in Tibetan Plateau, these sub-basins were divided into groups according to possible controlling factors, such as climate, tectonic and geology. Analysis shows that Horton ratios and generators of low-level rivers are affected by precipitation, but the relationship between these parameters of high-level rivers and these factors is not obvious. In order to further explore the controlling factors, we analyzed three typical rivers (Tao River, Yalong River and Lasa River) in more details. For Yalong River, Tao River and Lasa River, bifurcation ratios are 4.46, 5.00 and 4.37 while the length ratios are 2.35, 2.71 and 2.30 respectively. The Normalized Concavity Index for Tao River, Lasa River and Yalong River are -0.129, -0.082 and 0.009 respectively, indicating that the profiles of the first two rivers are concave-up and that of Yalong River is convex-up. The influence of climate is well reflected in the structure and longitudinal profiles of the drainage network in the Tibetan Plateau. Strong tectonic activities in the eastern margin of the Tibetan Plateau destroy the network of Yalong River, resulting in river capture to maintain equilibrium.

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