Asymmetric Impacts of Diurnal Warming on Vegetation Carbon Sequestration of Marshes in the Qinghai Tibet Plateau

Global Biogeochemical Cycles, Год журнала: 2022, Номер 36(7)

Опубликована: Июль 1, 2022

Abstract As the world's Third Pole, Qinghai‐Tibet Plateau has a large area of marshes, which plays an important role in global carbon cycle. The net primary productivity (NPP) vegetation is crucial index for measuring flux marsh ecosystems. Understanding change NPP and its response to climatic assessing sequestration Based on MODIS data climate from 2000 2020, this study analyzed spatiotemporal determined relationship with factors Plateau. results showed that average annual marshes increased significantly by 11.70 ± 1.07 g C·m −2 /10a during 2000–2020, value about 184.37 11.12 . Spatially, obviously increasing trend northeast but decreasing southwest regions. Daytime maximum nighttime minimum temperatures had asymmetric effects NPP, larger positive effect temperature. Warmed winter spring summer promoted growth marshes. Additionally, precipitation could increase NPP. Our highlight impacts daytime should be adequately considered predicting Plateau, especially context diurnal warming.

Язык: Английский

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Evaluation of consistency among three NDVI products applied to High Mountain Asia in 2000–2015

Remote Sensing of Environment, Год журнала: 2021, Номер 269, С. 112821 - 112821

Опубликована: Ноя. 29, 2021

Язык: Английский

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Variation of vegetation autumn phenology and its climatic drivers in temperate grasslands of China

International Journal of Applied Earth Observation and Geoinformation, Год журнала: 2022, Номер 114, С. 103064 - 103064

Опубликована: Окт. 18, 2022

Understanding the variation of autumn phenology and its climatic drivers is important for predicting terrestrial carbon cycles in temperate grasslands China. Using meteorological data GIMMS NDVI during 1982–2015, this study analyzed variations end date vegetation growing season (EOS) their relationships with climate The results showed that EOS was delayed by 1.62 days/decade across For different grassland types, 1.65, 1.66, 1.34 meadows, steppes, desert respectively. In terms change effects, increasing summer precipitation temperatures crucial delaying increase could delay EOS, especially whereas significantly meadows. addition, we found influences nighttime daytime warming on were asymmetric. Specifically, maximum temperature meadows minimum steppes had a weakly advancing effect Our highlights distinct monthly types indicates impacts should be included simulating ecosystems arid/semi-arid regions.

Язык: Английский

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Disentangling the response of vegetation dynamics to natural and anthropogenic drivers over the Qinghai-Tibet Plateau using dimensionality reduction and structural equation model

Forest Ecology and Management, Год журнала: 2024, Номер 554, С. 121677 - 121677

Опубликована: Янв. 9, 2024

Язык: Английский

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Effects of climate change and grazing on the soil organic carbon stock of alpine wetlands on the Tibetan Plateau from 2000 to 2018

CATENA, Год журнала: 2024, Номер 238, С. 107870 - 107870

Опубликована: Фев. 9, 2024

Язык: Английский

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Nonlinear time effects of vegetation response to climate change: Evidence from Qilian Mountain National Park in China

The Science of The Total Environment, Год журнала: 2024, Номер 933, С. 173149 - 173149

Опубликована: Май 11, 2024

Язык: Английский

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Remote Sensing of Riparian Ecosystems

Remote Sensing, Год журнала: 2022, Номер 14(11), С. 2645 - 2645

Опубликована: Май 31, 2022

Riparian zones are dynamic ecosystems that form at the interface between aquatic and terrestrial components of a landscape. They shaped by complex interactions biophysical river systems, including hydrology, geomorphology, vegetation. Remote sensing technology is powerful tool useful for understanding riparian form, function, change over time, as it allows continuous collection geospatial data large areas. This paper provides an overview studies published from 1991 to 2021 have used remote techniques map understand processes shape habitats their ecological functions. In total, 257 articles were reviewed organised into six main categories (physical channel properties; morphology vegetation or field survey; canopy detection; application water indices; vegetation; fauna habitat assessment). The majority aerial RGB imagery reaches up 100 km in length Landsat satellite 1000 length. During recent decade, UAVs (unmanned vehicles) been widely low-cost monitoring mapping riverine environments. However, transfer RS managers stakeholders systematic source decision making successful management remains one challenges.

Язык: Английский

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Critical role of water conditions in the responses of autumn phenology of marsh wetlands to climate change on the Tibetan Plateau

Global Change Biology, Год журнала: 2023, Номер 30(1)

Опубликована: Дек. 12, 2023

Abstract The Tibetan Plateau, housing 20% of China's wetlands, plays a vital role in the regional carbon cycle. Examining phenological dynamics wetland vegetation response to climate change is crucial for understanding its impact on ecosystem. Despite this importance, specific effects phenology region remain uncertain. In study, we investigated influence end growing season (EOS) marsh across utilizing satellite‐derived Normalized Difference Vegetation Index (NDVI) data and observational data. We observed that regionally averaged EOS Plateau was significantly ( p < .05) delayed by 4.10 days/decade from 2001 2020. Warming preseason temperatures were found be primary driver behind delay vegetation, whereas cumulative precipitation showed no significant impact. Interestingly, responses varied spatially plateau, indicating regulatory hydrological conditions phenology. humid cold central regions, daytime warming EOS. However, areas with lower soil moisture exhibited weaker or reversed effect, suggesting complex interplays between temperature, moisture, Notably, arid southwestern regions increased rainfall directly EOS, while higher advanced it. Our results emphasize critical conditions, specifically shaping different regions. findings underscore need incorporate factors into terrestrial ecosystem models, particularly dry accurate predictions change. This informed conservation management strategies face current future challenges.

Язык: Английский

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Spatiotemporal fusion of multi-source remote sensing data for estimating aboveground biomass of grassland

Ecological Indicators, Год журнала: 2023, Номер 146, С. 109892 - 109892

Опубликована: Янв. 13, 2023

Accurate estimation of aboveground biomass grasslands is key to sustainable grassland utilization. However, most satellites cannot provide high temporal and spatial resolution data. Patterns dynamics associated with variability in climate conditions across spatiotemporal scales are yet be adequately quantified. A fusion model offers the opportunity combine advantages different remote sensing data achieve a frequency precision monitoring vegetation. We test flexible (FSDAF) methodology generate synthetic normalized difference vegetation index (NDVI) from Moderate-Resolution Imaging Spectroradiometer (MODIS) Landsat sets. The tested for semi-arid Xilin River Basin, China. Based on NDVI field measured an established watershed. Exploring changes its relationship environmental factors. results show that: (1) FSDAF performs well (R2 = 0.75) has clear textural features. (2) Support Vector Machine Aboveground Biomass not only ensured accuracy 0.78, RMSE 15.43 g/m2), but also generated maps higher (30 m) (8 days). (3) this area decreases southeast northwest, reaches peak at end July. average order meadow > typical desert grassland. (4) increased linearly increasing water content, organic carbon total nitrogen, was sensitive soil content. During early growing rapid period, mainly affected by both air temperature precipitation, while effects human activities gradually dominate middle late periods. This study helps improve dynamic biomass, provides scientific basis protection management arid regions.

Язык: Английский

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A 250 m annual alpine grassland AGB dataset over the Qinghai–Tibet Plateau (2000–2019) in China based on in situ measurements, UAV photos, and MODIS data

Earth system science data, Год журнала: 2023, Номер 15(2), С. 821 - 846

Опубликована: Фев. 14, 2023

Abstract. The alpine grassland ecosystem accounts for 53 % of the Qinghai–Tibet Plateau (QTP) area and is an important ecological protection barrier, but it fragile vulnerable to climate change. Therefore, continuous monitoring aboveground biomass (AGB) necessary. Although many studies have mapped spatial distribution AGB QTP, results vary widely due limited ground samples mismatches with satellite pixel scales. This paper proposed a new algorithm using unmanned aerial vehicles (UAVs) as bridge estimate on QTP from 2000 2019. innovations were follows: (1) in terms data acquisition, spatial-scale matching among traditional samples, UAV photos, MODIS pixels was considered. A total 906 pairs between field-harvested sub-photos 2602 sets pixel-scale (over 37 000 photos) collected during 2015–2019. validation sufficient scale-matched. (2) In model construction, quadrat scale (0.25 m2) successfully upscaled (62 500 based random forest stepwise upscaling methods. Compared previous studies, independent dependent variables achieved, effectively reducing impact mismatch. showed that correlation values estimated by vegetation indices higher than field-measured at scale. multi-year constructed estimation had good robustness, average R2 0.83 RMSE 34.13 g m−2. Our dataset provides input parameter comprehensive understanding role under global available National Tibetan Plateau/Third Pole Environment Data Center (https://doi.org/10.11888/Terre.tpdc.272587; H. Zhang et al., 2022).

Язык: Английский

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