scholarly journals Diversity and Functions of Endophytic Fungi Associated with Roots and Leaves of Stipa purpurea in an Alpine Steppe at Qinghai-Tibet Plateau

2020 ◽  
Vol 30 (7) ◽  
pp. 1027-1036
Author(s):  
Xiaoyan Yang ◽  
Hui Jin ◽  
Lihong Xu ◽  
Haiyan Cui ◽  
Aiyi Xin ◽  
...  
Keyword(s):  
Endophytic Fungi ◽  
Tibet Plateau ◽  
Alpine Steppe ◽  
Stipa Purpurea ◽  
Qinghai Tibet Plateau

Variations in seed characteristics among and within Stipa purpurea populations on the Qinghai–Tibet Plateau

Botany ◽  
2015 ◽  
Vol 93 (10) ◽  
pp. 651-662 ◽  
Author(s):  
Xiong Li ◽  
Xin Yin ◽  
Shihai Yang ◽  
Yunqiang Yang ◽  
Min Qian ◽  
...  
Keyword(s):  
Seed Size ◽  
Environmental Conditions ◽  
Landscape Heterogeneity ◽  
Interspecific Variation ◽  
Vital Role ◽  
Tibet Plateau ◽  
Alpine Steppe ◽  
Stipa Purpurea ◽  
Qinghai Tibet Plateau ◽  
Seed Characteristics

Variation in seed size is common among plant species, populations, and individuals. On the Qinghai–Tibet Plateau, previous studies have mainly focused on interspecific variation in seed size, with little information available regarding intraspecific variation. The alpine steppe is among the most important vegetation types on the plateau, where it plays a vital role in preserving landscape heterogeneity and diversity. Stipa purpurea Griseb., endemic to the Qinghai–Tibet Plateau, is the predominant species of the alpine steppe. In the present study, we measured seed characteristics of nine S. purpurea populations and analyzed possible sources and consequences of variation in these characteristics. Seed characteristics varied greatly among and within populations. Our findings suggest that variation in seed size and awn length may affect germination and dispersal, respectively. Surprisingly, environmental factors, rather than genome size, were significantly correlated with seed size. For example, relative humidity and number of windy days were strongly correlated with seed size and awn length, respectively. We believe that variation in seed characteristics is a consequence of complex environmental conditions correlated with longitude and latitude. The results indicated that variation in seed characteristics of S. purpurea is an adaptation to environmental conditions.

scholarly journals Spatial and Temporal Differences in Alpine Meadow, Alpine Steppe and All Vegetation of the Qinghai-Tibetan Plateau and Their Responses to Climate Change

2021 ◽  
Vol 13 (4) ◽  
pp. 669
Author(s):  
Hanchen Duan ◽  
Xian Xue ◽  
Tao Wang ◽  
Wenping Kang ◽  
Jie Liao ◽  
...  
Keyword(s):  
Climate Change ◽  
Alpine Meadow ◽  
Global Climate ◽  
Growing Season ◽  
Tibet Plateau ◽  
Vegetation Types ◽  
Analysis Method ◽  
Alpine Steppe ◽  
Qinghai Tibet Plateau ◽  
Variation Trends

Alpine meadow and alpine steppe are the two most widely distributed nonzonal vegetation types in the Qinghai-Tibet Plateau. In the context of global climate change, the differences in spatial-temporal variation trends and their responses to climate change are discussed. It is of great significance to reveal the response of the Qinghai-Tibet Plateau to global climate change and the construction of ecological security barriers. This study takes alpine meadow, alpine steppe and the overall vegetation of the Qinghai-Tibet Plateau as the research objects. The normalized difference vegetation index (NDVI) data and meteorological data were used as the data sources between 2000 and 2018. By using the mean value method, threshold method, trend analysis method and correlation analysis method, the spatial and temporal variation trends in the alpine meadow, alpine steppe and the overall vegetation of the Qinghai-Tibet Plateau were compared and analyzed, and their differences in the responses to climate change were discussed. The results showed the following: (1) The growing season length of alpine meadow was 145~289 d, while that of alpine steppe and the overall vegetation of the Qinghai-Tibet Plateau was 161~273 d, and their growing season lengths were significantly shorter than that of alpine meadow. (2) The annual variation trends of the growing season NDVI for the alpine meadow, alpine steppe and the overall vegetation of the Qinghai-Tibet Plateau increased obviously, but their fluctuation range and change rate were significantly different. (3) The overall vegetation improvement in the Qinghai-Tibet Plateau was primarily dominated by alpine steppe and alpine meadow, while the degradation was primarily dominated by alpine meadow. (4) The responses between the growing season NDVI and climatic factors in the alpine meadow, alpine steppe and the overall vegetation of the Qinghai-Tibet Plateau had great spatial heterogeneity in the Qinghai-Tibet Plateau. These findings provide evidence towards understanding the characteristics of the different vegetation types in the Qinghai-Tibet Plateau and their spatial differences in response to climate change.

Arbuscular mycorrhizal and dark septate endophytic fungi at 5,500 m on a glacier forefront in the Qinghai-Tibet Plateau, China

Symbiosis ◽  
2013 ◽  
Vol 60 (2) ◽  
pp. 101-105 ◽  
Author(s):  
Jianbin Pan ◽  
Yongjun Liu ◽  
Xinhua He ◽  
Shichang Kang ◽  
Yuhong Hou ◽  
...  
Keyword(s):  
Endophytic Fungi ◽  
Arbuscular Mycorrhizal ◽  
Tibet Plateau ◽  
Glacier Forefront ◽  
Qinghai Tibet Plateau

Response of plant functional traits to grazing for three dominant species in alpine steppe habitat of the Qinghai–Tibet Plateau, China

2016 ◽  
Vol 31 (4) ◽  
pp. 515-524 ◽  
Author(s):  
Jianxun Wang ◽  
Mengying Zhong ◽  
Ruixin Wu ◽  
QuanMin Dong ◽  
Kun Wang ◽  
...  
Keyword(s):  
Functional Traits ◽  
Dominant Species ◽  
Plant Functional Traits ◽  
Tibet Plateau ◽  
Alpine Steppe ◽  
Qinghai Tibet Plateau

scholarly journals Quantitative Assessment of the Impact of Physical and Anthropogenic Factors on Vegetation Spatial-Temporal Variation in Northern Tibet

2019 ◽  
Vol 11 (10) ◽  
pp. 1183 ◽  
Author(s):  
Qinwei Ran ◽  
Yanbin Hao ◽  
Anquan Xia ◽  
Wenjun Liu ◽  
Ronghai Hu ◽  
...  
Keyword(s):  
Population Density ◽  
Alpine Meadow ◽  
Tibet Plateau ◽  
Anthropogenic Factors ◽  
Physical Factors ◽  
Northern Tibet ◽  
Alpine Steppe ◽  
Key Factor ◽  
Qinghai Tibet Plateau ◽  
Vegetation Variation

The alpine grassland on the Qinghai-Tibet Plateau covers an area of about 1/3 of China’s total grassland area and plays a crucial role in regulating grassland ecological functions. Both environmental changes and irrational use of the grassland can result in severe grassland degradation in some areas of the Qinghai-Tibet Plateau. However, the magnitude and patterns of the physical and anthropogenic factors in driving grassland variation over northern Tibet remain debatable, and the interactive influences among those factors are still unclear. In this study, we employed a geographical detector model to quantify the primary and interactive impacts of both the physical factors (precipitation, temperature, sunshine duration, soil type, elevation, slope, and aspect) and the anthropogenic factors (population density, road density, residential density, grazing density, per capita GDP, and land use type) on vegetation variation from 2000 to 2015 in northern Tibet. Our results show that the vegetation index in northern Tibet significantly decreased from 2000 to 2015. Overall, the stability of vegetation types was sorted as follows: the alpine scrub > the alpine steppe > the alpine meadow. The physical factors, rather than the anthropogenic factors, have been the primary driving factors for vegetation dynamics in northern Tibet. Specifically, meteorological factors best explained the alpine meadow and alpine steppe variation. Precipitation was the key factor that influenced the alpine meadow variation, whereas temperature was the key factor that contributed to the alpine steppe variation. The anthropogenic factors, such as population density, grazing density and per capita GDP, influenced the alpine scrub variation most. The influence of population density is highly similar to that of grazing density, which may provide convenient access to simplify the study of the anthropogenic activities in the Tibet plateau. The interactions between the driving factors had larger effects on vegetation than any single factor. In the alpine meadow, the interaction between precipitation and temperature can explain 44.6% of the vegetation variation. In the alpine scrub, the interaction between temperature and GDP was the highest, accounting for 27.5% of vegetation variation. For the alpine steppe, the interaction between soil type and population density can explain 29.4% of the vegetation variation. The highest value of vegetation degradation occurred in the range of 448–469 mm rainfall in the alpine meadow, 0.61–1.23 people/km2 in the alpine scrub and –0.83–0.15 °C in the alpine steppe, respectively. These findings could contribute to a better understanding of degradation prevention and sustainable development of the alpine grassland ecosystem in northern Tibet.

Changes in vegetation composition and plant diversity with rangeland degradation in the alpine region of Qinghai-Tibet Plateau

2015 ◽  
Vol 37 (1) ◽  
pp. 107 ◽  
Author(s):  
Lin Tang ◽  
Shikui Dong ◽  
Ruth Sherman ◽  
Shiliang Liu ◽  
Quanru Liu ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Large Scale ◽  
Alpine Meadow ◽  
Vegetation Indices ◽  
Desert Ecosystem ◽  
Tibet Plateau ◽  
Vegetation Composition ◽  
Rangeland Degradation ◽  
Alpine Steppe ◽  
Qinghai Tibet Plateau

The changes in vegetation composition and plant diversity of three different alpine ecosystems: alpine meadow, alpine steppe and alpine desert, impacted by different levels of degradation (healthy, lightly degraded and moderately degraded) were examined across a large-scale transect on the Qinghai-Tibet Plateau. The alpine meadow was dominated by sedges, the alpine steppe was dominated by grasses and the alpine desert was dominated by shrubs. The alpine meadow had the highest species diversity, whereas the alpine steppe had the lowest and tended to be dominated by a few species. Forbs were the dominant and most diverse functional group in the alpine meadow and the alpine steppe, which was different from the alpine desert. The importance values of the dominant species and levels of diversity measured by various vegetation indices were only slightly different in the degraded sites as compared with the non-degraded alpine meadow and steppe, whereas the alpine desert showed large changes in the composition and diversity of the plant community in response to degradation. In conclusion, the plant composition of the alpine meadow and alpine steppe ecosystems was more stable and appeared more resistant to disturbance than that of the alpine desert ecosystem.

scholarly journals Vegetation Mapping in the Permafrost Region: A Case Study on the Central Qinghai-Tibet Plateau

2022 ◽  
Vol 14 (1) ◽  
pp. 232
Author(s):  
Defu Zou ◽  
Lin Zhao ◽  
Guangyue Liu ◽  
Erji Du ◽  
Guojie Hu ◽  
...  
Keyword(s):  
Thermal State ◽  
Vegetation Type ◽  
Confusion Matrix ◽  
Kappa Coefficient ◽  
Tibet Plateau ◽  
Landsat 8 ◽  
Permafrost Region ◽  
Vegetation Map ◽  
Alpine Steppe ◽  
Qinghai Tibet Plateau

An accurate and detailed vegetation map is of crucial significance for understanding the spatial heterogeneity of subsurfaces, which can help to characterize the thermal state of permafrost. The absence of an alpine swamp meadow (ASM) type, or an insufficient resolution (usually km-level) to capture the spatial distribution of the ASM, greatly limits the availability of existing vegetation maps in permafrost modeling of the Qinghai-Tibet Plateau (QTP). This study generated a map of the vegetation type at a spatial resolution of 30 m on the central QTP. The random forest (RF) classification approach was employed to map the vegetation based on 319 ground-truth samples, combined with a set of input variables derived from the visible, infrared, and thermal Landsat-8 images. Validation using a train-test split (i.e., 70% of the samples were randomly selected to train the RF model, while the remaining 30% were used for validation and a total of 1000 runs) showed that the average overall accuracy and Kappa coefficient of the RF approach were 0.78 (0.68–0.85) and 0.69 (0.64–0.74), respectively. The confusion matrix showed that the overall accuracy and Kappa coefficient of the predicted vegetation map reached 0.848 (0.844–0.852) and 0.790 (0.785–0.796), respectively. The user accuracies for the ASM, alpine meadow, alpine steppe, and alpine desert were 95.0%, 83.3%, 82.4%, and 86.7%, respectively. The most important variables for vegetation type prediction were two vegetation indices, i.e., NDVI and EVI. The surface reflectance of visible and shortwave infrared bands showed a secondary contribution, and the brightness temperature and the surface temperature of the thermal infrared bands showed little contribution. The dominant vegetation in the study area is alpine steppe and alpine desert. The results of this study can provide an accurate and detailed vegetation map, especially for the distribution of the ASM, which can help to improve further permafrost studies.

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