Do soil properties with elevation affect alpine "grass-line"? Findings from Haibei, northern Tibetan Plateau

Author(s):  
Zuonan Cao ◽  
Zhenhuan Guan ◽  
Peter Kühn ◽  
Jinsheng He ◽  
Thomas Scholten

<p>Many species showed that their richness and distribution shifts climate-driven towards higher elevation in Tibetan Plateau. However, vegetation and soil data from alpine grassland elevational gradients are rare (Huang et al., 2018). It is mostly unknown how the "grass-line" will respond to global warming and whether soils play a significant role in the vegetation pattern in high-altitude regions. At a local scale, the growth and distribution of vegetation at its upper limit may depend on nutrient limitation, as shown for treelines from the Himalayas. For example, the limited nutrient supply of soil N, K, Mg, and P becomes more intense with elevation, which declines in nutrient supply spatially coincides with abrupt changes in vegetation composition and growth parameters (Schwab et al., 2016). And low soil nutrient availability could affect tree growth in the Rolwaling Himal, Nepal treeline ecotone (Drollinger et al., 2017). To better understand the interrelationship between soil properties and grass growth at this upper limit, we took random soil samples in 3 altitudes, 3 geomorphic positions with 3 depth increments from Haibei grassland, northern Tibetan Plateau. Soil properties, like texture, bulk density, total C, N, and P fractions, were analyzed and compared to vegetation data.<br>Further, soil and vegetation data from open-top chambers (OTC) experiments to simulate global warming were analyzed better to understand the role of temperature for grass line-shift. The first results show that species composition change with altitude towards grassland plant communities with lower demands for P, which can be compared with the nutrient addition experiment that P addition alone significantly affects species diversity and biomass in the same area (Ren et al., 2016). We suppose that specific combinations of soil properties could limit grass growth and be even more marked than the warming, which controls biodiversity and biomass production in high mountain grassland ecosystems. </p>

2020 ◽  
Author(s):  
Zuonan Cao ◽  
Peter Kühn ◽  
Thomas Scholten

<p>The Tibetan Plateau is the third-largest glaciated area of the world and is one of the most sensitive regions due to climate warming, such as fast-melting permafrost, dust blow and overgrazing in recent decades. In the past 50 years, the warming rate on the Tibetan Plateau is higher than the global average warming rate with 0.40 ± 0.05 °C per decade. The climate warming is most distinct in the northeastern Tibetan Plateau, implying increasing air and surface temperatures as well as duration and depth of thawing. The main ecological consequences are a disturbed vegetation cover of the surface and a depletion of nutrient-rich topsoils (Baumann et al., 2009, 2014) coupled with an increase of greenhouse gas emissions, mainly CO<sub>2</sub> (Bosch et al., 2017). Due to the extreme environmental conditions resulting from the intense and rapid tectonic uplift, highly adaptive and sensitive ecosystem have developed, and the Plateau is considered to be a key area for the environmental evolution of Earth on regional and global scales, which is particularly sensitive to global warming (Jin et al., 2007; Qiu, 2008). Climate warming and land-use change can reduce soil organic carbon (SOC) stocks as well as soil nitrogen (N) and phosphorus (P) contents and soil quality. Many species showed their distributions by climate-driven shifts towards higher elevation. In Tibetan Plateau, however, the elevational variations of the alpine grassland are rare (Huang et al., 2018) and it is largely unknown how the grass line will respond to global warming and whether soils play a major role. With this research, the hypothesis is tested that soil quality, given by SOC, N and P stocks and content, is a driving factor for the position and structure of the grass line and that soil quality is one of the major controls of biodiversity and biomass production in high-mountain grassland ecosystems.</p><p>A Fourier transformation near and mid-infrared spectroscopy (FT-NMIRS) should be used to measure soil P fractions rapid and for large numbers of soil samples, and analyze environmental factors, including temperature, precipitation, soil development, soil fertility, and the ability of plants to adapt to the environmental impact of climate using FT-NMIRS.</p><p>We explored first near-infrared spectroscopy (NIRS) in soils from grassland on the Tibetan Plateau, northwestern China and extracted P fractions of 196 samples from Haibei Alpine Meadow Ecosystem Research Station, Chinese Academy of Sciences, at four depths increments (0-10 cm 10-20 cm 20-40 cm and 40-70 cm) with different pre-nutrient additions of nitrogen (N) an P. The fractionation data were correlated with the corresponding NIRS soil spectra and showed significant differences for depth increments and fertilizer amendments. The R<sup>2</sup> of NIRS calibrations to predict P in traditional Hedley fractions ranged between 0.12 and 0.90. The model prediction quality was higher for organic than for inorganic P fractions and changed with depth and fertilizer amendment. The results indicate that using NIRS to predict the P fractions can be a promising approach compared with traditional Hedley fractionation for soils in alpine grasslands on the Tibetan Plateau.</p>


Author(s):  
Stephen Okhumata Dania ◽  
Adebimpe Omowumi Ayegbe ◽  
Bright Ehijiele Amenkhienan

Compost is an important source of organic fertilizer that can be used to amend degraded soil to improve soil nutrient and crops yield. This experiment was to evaluate the effect of sawdust – piggery compost on soil properties, growth and yield of maize and it was carried out at the Ambrose Alli University Teaching and Research Farm, Emaudo, Ekpoma, Edo State. The experiment was fitted in a Randomized Complete Block Design (RCBD) with seven treatments and three replicates. The treatments were; control (0), 2, 4, 6, 8, 10 and 12 tonnes of sawdust – piggery compost per hectares (ha-1). Data collected were analysed using ANOVA and LSD was used to separate means. Soil nutrients were below critical levels and the application of compost improved fertility status of the soil. Growth parameters, dry matter yield, cob weight, grain yield and nutrient uptake were determined. It was observed that application of Sawdust – piggery compost significantly (p 0.05) increased the growth of maize compared to control. The application of 8 to 12 tonnes of sawdust – piggery compost significantly (p 0.05) increased the plant height, leaf area and stem girth of maize compared to other treatments. The application of 8 to 12 tonnes per hectares (ha-1) of sawdust – piggery compost significantly (p 0.05) increased the cob weight, grain and dry matter yield of maize compared to other treatments, however, the application of 10 t ha-1 of compost to maize increased grain yield of maize than others rate of applications with the yield value of 4.60 t ha-1. The uptake of nitrogen, phosphorus and potassium were higher with application of 12 tonnes of compost. In conclusion, the application rates of 10 t ha-1 of sawdust – piggery compost per hectare on nutrient depleted soils will improve the growth and yield of maize.


2013 ◽  
Vol 26 (1) ◽  
pp. 85-109 ◽  
Author(s):  
Lan Cuo ◽  
Yongxin Zhang ◽  
Qingchun Wang ◽  
Leilei Zhang ◽  
Bingrong Zhou ◽  
...  

Abstract Gridded daily precipitation, temperature minima and maxima, and wind speed are generated for the northern Tibetan Plateau (NTP) for 1957–2009 using observations from 81 surface stations. Evaluation reveals reasonable quality and suitability of the gridded data for climate and hydrology analysis. The Mann–Kendall trends of various climate elements of the gridded data show that NTP has in general experienced annually increasing temperature and decreasing wind speed but spatially varied precipitation changes. The northwest (northeast) NTP became dryer (wetter), while there were insignificant changes in precipitation in the south. Snowfall has decreased along high mountain ranges during the wet and warm season. Averaged over the entire NTP, snowfall, temperature minima and maxima, and wind speed experienced statistically significant linear trends at rates of −0.52 mm yr−1 (water equivalent), +0.04°C yr−1, +0.03°C yr−1, and −0.01 m s−1 yr−1, respectively. Correlation between precipitation/wind speed and climate indices characterizing large-scale weather systems for four subregions in NTP reveals that changes in precipitation and wind speed in winter can be attributed to changes in the North Atlantic Oscillation (NAO), the Arctic Oscillation (AO), the East Asian westerly jet (WJ), and the El Niño–Southern Oscillation (ENSO) (wind speed only). In summer, the changes in precipitation and wind are only weakly related to these indices. It is speculated that in addition to the NAO, AO, ENSO, WJ, and the East and South Asian summer monsoons, local weather systems also play important roles.


2017 ◽  
Author(s):  
Zhu Zhang ◽  
Shugui Hou ◽  
Shuangwen Yi

Abstract. Dating of ice cores drilled in the high mountain glaciers is difficult because seasonal variations cannot be traced at depth due to rapid thinning of the ice layers. Here we provide the first luminescence dating of the basal sediment of the Chongce ice cap in the northwest Tibetan Plateau. Assuming the sediment is of similar (or older) age as the surrounding ice, the dating result of 42 ± 4 ka provides an upper limit for the age of the ice cap. This result is more than one magnitude younger than the previously suggested age of the basal ice of the nearby Guliya ice cap (~ 40 km in distance).


Geology ◽  
2000 ◽  
Vol 28 (8) ◽  
pp. 715-718 ◽  
Author(s):  
Hongbo Zheng ◽  
Christopher McAulay Powell ◽  
Zhisheng An ◽  
Jie Zhou ◽  
Guangrong Dong

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