The critical factors that affected the distribution of aboveground biomass in the alpine steppe and meadow, Tibetan Plateau

Abstract. Tibetan Plateau – the third pole of the world, with its extremly harsh and fragile ecological environment, is so sensitive to global change that it attracts many scientists' attention. Alpine grassland here is an important component of the global carbon cycle. Many studies have examined links between environmental factors and distribution of biomass, but little showed the critical environmental factors affecting the distribution of biomass. To document the general relationships between the habitat factors and aboveground biomass (AGB) in Tibetan Plateau, and to identify the critical factors for the distribution of AGB in the alpine steppe and meadow, the data of AGB and habitat factors from 110 field sites across the widely distributed alpine steppe and meadow of the plateau were compiled and analyzed with the classification and regression tree (CART) model, and the generalized additive model (GAM). The results showed that (1) the spatial pattern of AGB in alpine steppe was determined by six major environmental factors: soil organic carbon density of soil 0–30 cm depth (SOC1), longitude, mean annual precipitation (MAP), latitude, clay and soil moisture. As to the alpine meadow, the major factors were altitude, soil moisture, nitrogen, MAP and mean annual temperature (MAT). (2) As to the alpine steppe, increased SOC1, MAP and latitude were associated with increased AGB abundance, but increased longitude resulted in lower abundance of AGB. As to the alpine meadow, the distribution of AGB had strong negative relationships with altitude and soil moisture, but a positive correlation with soil nitrogen content across sites. The results suggested that the combined effects of meteorological factors, topographic factors, and soil factors were more significant for the spatial pattern of AGB in Tibetan Plateau. In addition, our work highlights the importance of further studies to seek effects of slope and aspect in alpine grassland.

Download Full-text

Meta-analysis of relationships between environmental factors and aboveground biomass in the alpine grassland on the Tibetan Plateau

Biogeosciences ◽

10.5194/bg-10-1707-2013 ◽

2013 ◽

Vol 10 (3) ◽

pp. 1707-1715 ◽

Cited By ~ 72

Author(s):

J. Sun ◽

G. W. Cheng ◽

W. P. Li

Keyword(s):

Soil Moisture ◽

Tibetan Plateau ◽

Environmental Factors ◽

Aboveground Biomass ◽

Alpine Meadow ◽

Meta Analysis ◽

Alpine Grassland ◽

Mean Annual Precipitation ◽

The Tibetan Plateau ◽

Alpine Steppe

Abstract. The Tibetan Plateau, known as the "world's third pole" for its extremely harsh and fragile ecological environment, has attracted great attention because of its sensitivity to global changes. Alpine grassland on the Tibetan Plateau has an important function in the global carbon cycle. Many studies have examined the effects of various environmental factors on biomass distribution. In this study, the relationships between the habitat parameters and the aboveground biomass (AGB) abundance on the Tibetan Plateau were examined through a meta-analysis of 110 field sites across the widely distributed alpine steppe and meadow. The obtained data were then analysed using the classification and regression tree model and the generalized additive model. The results showed that the AGB abundance in alpine steppe was positively correlated with six environmental factors, namely, soil organic carbon density of the top soil layer from 0 cm to 30 cm (SOC30 cm), longitude, mean annual precipitation (MAP), latitude, clay, and soil moisture. For the alpine meadow, five main factors were detected, namely, altitude, soil moisture, nitrogen, MAP, and mean annual temperature. The increased AGB abundance in the alpine steppe was associated with the increased SOC30 cm, MAP, and latitude, and the increased longitude resulted in decreased AGB abundance. For the alpine meadow, altitude and soil moisture showed strongly negative effects on AGB abundance, and soil nitrogen content was positively related to the AGB distribution across all examined sites. Our results suggest the combined effects of meteorological, topographic, and soil factors on the spatial patterns of AGB on the Tibetan Plateau.

Download Full-text

Precipitation and aridity index regulating spatial patterns of vegetation production and species diversity based on alpine grassland transect, Tibetan Plateau

10.7287/peerj.preprints.2495 ◽

2016 ◽

Author(s):

Jian Sun

Keyword(s):

Tibetan Plateau ◽

Primary Production ◽

Alpine Meadow ◽

Net Primary Production ◽

Aridity Index ◽

Alpine Grassland ◽

The Tibetan Plateau ◽

Aboveground Net Primary Production ◽

Alpine Steppe ◽

Unimodal Pattern

Although the relationship between the aboveground net primary production (ANPP) and speciesdiversity (SR) have been widely reported, there is considerable disagreement about the fitting patterns of SR–ANPP, which has been variously described as ‘positive’, ‘negative’, ‘unimodal’, ‘U-shaped’ and so on. Not surprisingly, the effect-factors including precipitation, aridity index and geographic conditions (e.g.,altitude, longitude and latitude) on ANPP and SR continue to interest researchers, especially the effects at high altitude regions. We investigated ANPP and SR from 113 sampled sites (399 plots) across alpine meadow and steppe in the Tibetan Plateau, which included Tibet, Qinghai and Sichuan province. The effects of various environmental factors (precipitation, temperature, aridity index, altitude, longitude,latitude and vegetation type on SR and ANPP) were explored. The results indicate that a unimodal pattern was confirmed between ANPP and SR in alpine steppe (R 2 =0.45, P <0.0001), alpine meadow ( R 2 =0.4, P <0.0001), and all samples across alpine grassland ( R 2 =0.52, P <0.0001). For the aboveground net primary production, the appropriate precipitation and aridity is 600mm and 42, respectively. Under thesame moisture conditions, the maximum value of diversity is 0.75. Longitude ( R 2 =0.69, P <0.0001) and altitude ( R 2 =0.48, P <0.0001) have positive and negative effects on aboveground net primary production, and a similar relationship exists with diversity ( R 2 =0.44, P <0.0001 and R 2 =0.3, P <0.0001).The same patterns of diversity and production responding to precipitation and the aridity index were evident in alpine steppe and meadow, and a unimodal pattern was confirmed between ANPP and SR in both locations.

Download Full-text

Effects of Patchiness on Surface Soil Moisture of Alpine Meadow on the Northeastern Qinghai-Tibetan Plateau: Implications for Grassland Restoration

Remote Sensing ◽

10.3390/rs12244121 ◽

2020 ◽

Vol 12 (24) ◽

pp. 4121

Author(s):

Wei Zhang ◽

Shuhua Yi ◽

Yu Qin ◽

Yi Sun ◽

Donghui Shangguan ◽

...

Keyword(s):

Soil Moisture ◽

Tibetan Plateau ◽

Surface Soil ◽

Alpine Meadow ◽

Alpine Grassland ◽

Grassland Restoration ◽

Landscape Indices ◽

Surface Soil Moisture ◽

Bare Patch

Surface soil moisture (SSM) is a key limiting factor for vegetation growth in alpine meadow on the Qinghai-Tibetan Plateau (QTP). Patches with various sizes and types may cause the redistribution of SSM by changing soil hydrological processes, and then trigger or accelerate alpine grassland degradation. Therefore, it is vital to understand the effects of patchiness on SSM at multi-scales to provide a reference for alpine grassland restoration. However, there is a lack of direct observational evidence concerning the role of the size and type of patches on SSM, and little is known about the effects of patches pattern on SSM at plot scale. Here, we first measured SSM of typical patches with different sizes and types at patch scale and investigated their patterns and SSM spatial distribution through unmanned aerial vehicle (UAV)-mounted multi-type cameras at plot scale. We then analyzed the role of the size and type of patchiness on SSM at both patch and plot scales. Results showed that: (1) in situ measured SSM of typical patches was significantly different (P < 0.01), original vegetation patch (OV) had the highest SSM, followed by isolate vegetation patch (IV), small bare patch (SP), medium bare patch (MP) and large bare patch (LP); (2) the proposed method based on UAV images was able to estimate SSM (0–40 cm) with a satisfactory accuracy (R2 = 0.89, P < 0.001); (3) all landscape indices of OV, with the exception of patch density, were positively correlated with SSM at plot scale, while most of the landscape indices of LP and IV showed negative correlations (P < 0.05). Our results indicated that patchiness intensified the spatial heterogeneity of SSM and potentially accelerated the alpine meadow degradation. Preventing the development of OV into IV and the expansion of LP is a critical task for alpine meadow management and restoration.

Download Full-text

Precipitation and aridity index regulating spatial patterns of vegetation production and species diversity based on alpine grassland transect, Tibetan Plateau

10.7287/peerj.preprints.2495v1 ◽

2016 ◽

Author(s):

Jian Sun

Keyword(s):

Tibetan Plateau ◽

Primary Production ◽

Alpine Meadow ◽

Net Primary Production ◽

Aridity Index ◽

Alpine Grassland ◽

The Tibetan Plateau ◽

Aboveground Net Primary Production ◽

Alpine Steppe ◽

Unimodal Pattern

Download Full-text

Plant diversity is closely related to the density of zokor mounds in three alpine rangelands on the Tibetan Plateau

PeerJ ◽

10.7717/peerj.6921 ◽

2019 ◽

Vol 7 ◽

pp. e6921 ◽

Cited By ~ 2

Author(s):

Yujie Niu ◽

Jianwei Zhou ◽

Siwei Yang ◽

Bin Chu ◽

Huimin Zhu ◽

...

Keyword(s):

Species Richness ◽

Soil Moisture ◽

Tibetan Plateau ◽

Plant Diversity ◽

Alpine Meadow ◽

Living Environment ◽

The Tibetan Plateau ◽

Alpine Steppe ◽

Alpine Shrub ◽

Plateau Zokor

Background Plateau zokor (Myospalax baileyi) is a subterranean rodent endemic to the Tibetan Plateau. This species has been generally viewed as a pest in China due to the competition for food with livestock and also causing soil erosion. As a result, plateau zokor has been the target of widespread poisoning or trapping campaigns designed to control or eliminate it since 1970s. But there is little research on the effect of plateau zokor on plant diversity in alpine rangelands. Therefore, objectively evaluating the positive effects of the plateau zokors disturbance on their living environment and plant communities is of great significance to understand the function of plateau zokor in alpine ecosystem. Methods Here, we selected three rangelands (alpine meadow, alpine steppe and alpine shrub meadow) in which plateau zokors are typically distributed on the Tibetan Plateau, and five zokor mound density gradients were selected in each rangeland type to study the effects of the mounds on soil moisture and temperature related to plant species diversity. Results The results showed that, with the mound density increasing, the soil temperature decreased significantly in all three rangeland types, and the soil moisture significantly increased in all three rangeland types. In the alpine meadow, both the plant diversity and cumulative species richness increased significantly with increasing mound density. The increase in broad-leaved forbs is the main reason for the increase of plant diversity in the alpine meadow disturbed by zokor mounds. In the alpine steppe, the plant diversity decreased significantly with increasing mound density, while the cumulative species richness initially decreased and then increased. In the alpine shrub meadow, the plant diversity first increased and then decreased with increasing mound density as did the cumulative species richness. In conclusion, plateau zokor mounds dominated the distribution of soil moisture and temperature and significantly affected plant diversity in these three rangelands on Tibetan Plateau; the results further deepen our understanding toward a co-evolved process.

Download Full-text

Dynamic of aboveground biomass and soil moisture as affected by short-term grazing exclusion on eastern alpine meadow of Qinghai-Tibet plateau, China

Chilean journal of agricultural research ◽

10.4067/s0718-58392016000300009 ◽

2016 ◽

Vol 76 (3) ◽

pp. 321-329 ◽

Cited By ~ 1

Author(s):

Haibo Liu ◽

Jianping Wu ◽

Xinhui Tian ◽

Wenhua Du

Keyword(s):

Soil Moisture ◽

Aboveground Biomass ◽

Alpine Meadow ◽

Tibet Plateau ◽

Short Term ◽

Grazing Exclusion ◽

Qinghai Tibet Plateau

Download Full-text

Aboveground community composition and soil moisture play determining roles in restoring ecosystem multifunctionality of alpine steppe on Qinghai-Tibetan Plateau

Agriculture Ecosystems & Environment ◽

10.1016/j.agee.2020.107163 ◽

2021 ◽

Vol 305 ◽

pp. 107163

Author(s):

Yudan Xu ◽

Shikui Dong ◽

Xiaoxia Gao ◽

Mingyue Yang ◽

Shuai Li ◽

...

Keyword(s):

Soil Moisture ◽

Tibetan Plateau ◽

Community Composition ◽

Alpine Steppe ◽

Ecosystem Multifunctionality

Download Full-text

Nitrogen fertilizer regulates soil respiration by altering the organic carbon storage in root and topsoil in alpine meadow of the north-eastern Qinghai-Tibet Plateau

Scientific Reports ◽

10.1038/s41598-019-50142-y ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Wen Li ◽

Jinlan Wang ◽

Xiaolong Li ◽

Shilin Wang ◽

Wenhui Liu ◽

...

Keyword(s):

Soil Moisture ◽

Tibetan Plateau ◽

Soil Respiration ◽

Alpine Meadow ◽

Growing Season ◽

N Storage ◽

The North ◽

C Storage ◽

North Eastern ◽

C And N

Abstract Soil respiration (Rs) plays a critical role in the global carbon (C) balance, especially in the context of globally increasing nitrogen (N) deposition. However, how N-addition influences C cycle remains unclear. Here, we applied seven levels of N application (0 (N0), 54 (N1), 90 (N2), 126 (N3), 144 (N4), 180 (N5) and 216 kg N ha−1 yr−1 (N6)) to quantify their impacts on Rs and its components (autotrophic respiration (Ra) and heterotrophic respiration (Rh)) and C and N storage in vegetation and soil in alpine meadow on the northeast margin of the Qinghai-Tibetan Plateau. We used a structural equation model (SEM) to explore the relative contributions of C and N storage, soil temperature and soil moisture and their direct and indirect pathways in regulating soil respiration. Our results revealed that the Rs, Ra and Rh, C and N storage in plant, root and soil (0–10 cm and 10–20 cm) all showed initial increases and then tended to decrease at the threshold level of 180 kg N ha−1 yr−1. The SEM results indicated that soil temperature had a greater impact on Rs than did volumetric soil moisture. Moreover, SEM also showed that C storage (in root, 0–10 and 10–20 cm soil layers) was the most important factor driving Rs. Furthermore, multiple linear regression model showed that the combined root C storage, 0–10 cm and 10–20 cm soil layer C storage explained 97.4–97.6% variations in Rs; explained 94.5–96% variations in Ra; and explained 96.3–98.1% in Rh. Therefore, the growing season soil respiration and its components can be well predicted by the organic C storage in root and topsoil in alpine meadow of the north-eastern Qinghai-Tibetan Plateau. Our study reveals the importance of topsoil and root C storage in driving growing season Rs in alpine meadow on the northeast margin of Qinghai-Tibetan Plateau.

Download Full-text