Monitoring of aeolian desertification on the Qinghai-Tibet Plateau from the 1970s to 2015 using Landsat images

Zhang, Chunlai; Li, Qing; Shen, Yaping; Zhou, Na; Wang, Xuesong; Li, Jiao; Jia, Wenru

doi:10.1016/j.scitotenv.2017.10.137

Cited by 98 publications

(45 citation statements)

References 28 publications

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“…Desertification results from climate change and human activities and has become an important factor preventing sustainable development in the arid, semiarid, and semihumid zones of the world, which currently account for 41% of the global land area (D'Odorico, Bhattachan, Davis, Ravi, & Runyan, 2013;Li, Zhang, Shen, Jia, & Li, 2016;Hu, Yu, et al, 2017;Zhang et al, 2017). Grassland ecosystems are susceptible to desertification, and their ecological restoration is difficult and slow (Peters, Yao, Sala, & Anderson, 2012).…”

Section: Introductionmentioning

confidence: 99%

Variation in physicochemical and biochemical soil properties among different plant species treatments early in the restoration of a desertified alpine meadow

Liu

Zeng

et al. 2019

Land Degrad Dev

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Soil nutrients, enzyme activities, and microbial biomass have important significance for biogeochemical cycles and are affected by vegetation restoration in degradation ecosystems. To explore the effects of replanting different plant species on soil restoration in a desertified alpine meadow on the eastern Tibetan Plateau and to optimize the restoration process with locally appropriate plant species, the soil physicochemical and biochemical properties were measured beneath the plant species Rhodiola kirilowii, Salix cupularis, and Kengyilia rigidula over two periods of vegetative growth (2 years and 5 years). The results showed that all the soil properties significantly improved over the recovery periods (p < .001) and the plant species significantly affected the patterns of soil bulk density, available resources, and biochemical properties (p < .05). However, R. kirilowii improved soil properties most significantly among the three plant species as the recovery time elapsed, and these improvements were strongly related to the greatest fresh vegetation biomass and coverage. Furthermore, R. kirilowii enhanced microbial biomass phosphorus even more, which is an important available phosphorus stock in the soil, and more effectively promoted the development of soil fungi than the two other species. Therefore, we suggest that R. kirilowii is the preferred species of the three to expedite the recovery of desertified alpine soil, and that the appropriate addition of P fertilizer and propelling the development of specific fungi groups in the soil are key to soil restoration in the desertified alpine meadow.

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Section: Introductionmentioning

confidence: 99%

Variation in physicochemical and biochemical soil properties among different plant species treatments early in the restoration of a desertified alpine meadow

Liu

Zeng

et al. 2019

Land Degrad Dev

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“…This represents an exciting potential for making continental-scale assessments of inundation frequency and extent, nevertheless, thresholds used to generate the thematic map can be adapted by the user and adapted for specific regions if needed. Indeed, the nomenclature for the thematic map was designed for ecohydrological characterisation, but this can be adapted for other class types to target other applications such as mapping terrestrial vegetation loss, vegetation fragmentation [90], and desertification (e.g., [91][92][93]).…”

Section: Discussionmentioning

confidence: 99%

Tropical Wetland (TropWet) Mapping Tool: The Automatic Detection of Open and Vegetated Waterbodies in Google Earth Engine for Tropical Wetlands

2020

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Knowledge of the location and extent of surface water and inundated vegetation is vital for a range of applications including flood risk management, biodiversity monitoring, quantifying greenhouse gas emissions, and mapping water-borne disease risk. Here, we present a new tool, TropWet, which enables users of all abilities to map wetlands in herbaceous dominated regions based on simple unmixing of optical Landsat satellite imagery in the Google Earth Engine. The results demonstrate transferability throughout the African continent with a high degree of accuracy (mean 91% accuracy, st. dev 2.6%, n = 10,800). TropWet demonstrated considerable improvements over existing globally available surface water datasets for mapping the extent of important wetlands like the Okavango, Botswana. TropWet was able to provide frequency inundation maps as an indicator of malarial mosquito aquatic habitat extent and persistence in Barotseland, Zambia. TropWet was able to map flood extent comparable to operational flood risk mapping products in the Zambezi Region, Namibia. Finally, TropWet was able to quantify the effects of the El Niño/Southern Oscillation (ENSO) events on the extent of photosynthetic vegetation and wetland extent across Southern Africa. These examples demonstrate the potential for TropWet to provide policy makers with crucial information to help make national, regional, or continental scale decisions regarding wetland conservation, flood/disease hazard mapping, or mitigation against the impacts of ENSO.Landsat) with microwave systems (e.g., AMSR: Advanced Microwave Scanning Radiometer, SMAP: Soil Moisture Active Passive) [17,20]. Similarly, there is growing evidence that information from global navigation systems (GNSS-R: Global Navigation Satellite System Reflectometry) can provide timely and reliable classifications of wetlands by exploiting signals over both open water and vegetated water surfaces [21][22][23][24]. These approaches provide valuable tools for quantifying wetland dynamics at continental scales with important applications such as characterising greenhouse gas flux [17,18,24,25]. However, assessments of wetland extent and dynamics using these approaches tend to be generated at relatively coarse spatial resolutions (e.g., 25-36 km) and have limited applicability for informing decisions at a national or sub-national level, particularly related to more fine-scale environmental challenges such as those related to biodiversity, public health, and flood hazard.In terms of inundation mapping, perhaps the most mature area of research is the use of EO satellite imagery for mapping flood water hazards [2][3][4][5]7,[26][27][28][29][30][31][32]. Radar imagery provides one of the most reliable means of detecting flood water mainly due to the fact that this imagery is: (i) independent of cloud cover, (ii) relatively high resolution (e.g., Sentinel-1: 10 m), (iii) relatively high revisit times (e.g., Sentinel-1: 6-12 days), and (iv) there is a strong signal (low backscatter) over relatively smooth water surfaces. ...

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“…For example, land freezing and thawing is common in highland areas, and water frozen in soil is one of the main sources of water for highland plants [49]. The dry climate will cause the area of frozen soil to expand, the melting layer of the season will be thickened, and even the permafrost under the soil surface will disappear completely, which will directly lead to the reduction of soil moisture in the root layer of the plant, the drying of the topsoil and the reduction of vegetation coverage [50,51,52]. Previous studies have shown that with the increase of grassland degradation, soil fertility (organic matter, nitrogen, phosphorus) [53], water holding capacity, and total porosity continue to decrease, while the soil bulk density, freeze-thaw days [54], and freeze-thaw cycles continue to increase.…”

Section: Response Of L Rotata To Climate Changementioning

confidence: 99%

Response of Lamiophlomis rotata (Benth.) Kudo to degradation of alpine grasslands in the western Sichuan plateau, China

Niu

Sun

et al. 2020

Preprint

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Background: Lamiophlomis rotata (Benth.)Kudo, also known as Duyiwei in China, is considered to be one of the most common Tibetan medicine. It is famous for the significant effects on improving blood circulation and relieving pain. Due to the environmental deterioration and excessive consumption, the wild resources of L.rotata is decreasing year by year. However, its artificial cultivation has not been realized. This study aimed to initially explore the adaptation mechanism of L.rotata to degraded alpine grassland, and provide reference for its wild tending and artificial cultivation.Methods: In this study, we used a sample method to conduct a population ecological survey of plants and collect plant leaf samples from mildly, moderately, and extremely degraded grassland. The content of SOD, POD, CAT, PRO, MDA, SS, SP, carotene, chlorophyll A and chlorophyll B in different sample leaves was measured by colorimetry. Microscopic characteristics of the cross-section, epidermis and submicroscopic structure of the leaves were observed and compared.Results: The density of L. rotata in moderately degraded grassland was the highest，where L. rotata had the strongest resistance. And the analysis of seven physiological indicators combined with stress resistance showed that the average content of MDA, SOD, POD, CAT and SS is the highest in L. rotata of the moderately degraded grassland. The microscopic observation showed that, by increasing the thickness of the epidermis, the density of the glandular scales, the proportion of palisade tissue and the number of gland scales, L. rotata was able to adapt to the degraded grassland. Meanwhile, morphological studies have shown that L. rotata could enhance root growth in the degraded grassland. Furthermore, in response to the degradation of alpine grassland on the Qinghai-Tibet Plateau, L. rotata population and biomass distribution in the underground parts have increased. However, L. rotata does not have a competitive advantage in mildly degraded grassland. Compare with the mildly and moderately habitat, the population of L. rotata is small in the extremely degraded habitat.Conclusion: The results showed that among the 3 levels of degraded grassland, L. rotata in the moderately degraded grassland shows the strongest resistance. This study can provide a reference for breeding and ecological planting of L. rotata, suggests that in the nursery stage, the medium degraded grassland should be chosen for ecological breeding to enhance the survival rate of seedlings. While after large-scale planting, reasonable community interventions, like the P. fruticosa+F. rubra community, should be built to simulate the yield of medicinal materials.

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Monitoring of aeolian desertification on the Qinghai-Tibet Plateau from the 1970s to 2015 using Landsat images

Cited by 98 publications

References 28 publications

Variation in physicochemical and biochemical soil properties among different plant species treatments early in the restoration of a desertified alpine meadow

Variation in physicochemical and biochemical soil properties among different plant species treatments early in the restoration of a desertified alpine meadow

Tropical Wetland (TropWet) Mapping Tool: The Automatic Detection of Open and Vegetated Waterbodies in Google Earth Engine for Tropical Wetlands

Response of Lamiophlomis rotata (Benth.) Kudo to degradation of alpine grasslands in the western Sichuan plateau, China

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