Change in the elevational pattern of vegetation greenup date across the Tianshan Mountains in Central Asia during 2001–2020

Ecological Indicators, Journal Year: 2022, Volume and Issue: 136, P. 108684 - 108684

Published: Feb. 18, 2022

Variations in land surface phenology (LSP) along elevation gradients strongly impact human life and wildlife species distribution across the Tianshan Mountains (TM) arid semiarid Central Asia. However, changes elevational patterns of LSP recent decades have not been well understood for TM. Here, we characterized vegetation greenup date (GUD) its pattern TM five subregions during 2001–2020, with Moderate Resolution Imaging Spectroradiometer (MODIS) time series enhanced index (EVI). Impacts temperature (LST) precipitation on GUD were also examined. The results show that mostly nonsignificant (P > 0.05). Approximately 13.4% region experienced significant advance GUD. Furthermore, at low middle elevations (approximately 1000–2500 m) showed greater proportions significantly earlier trends. This dependence led to altered First, most isolines shifts toward higher elevations, day year (DOY) 110 120 located exhibited mean than those others subregions. Specifically, DOY moved from approximately 1325 m 2126 a subregion. Second, increased observed several spatial trends may be primarily caused by LST April, particularly nighttime LST. provide information rangeland management context degradation

Language: Английский

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An Innovative Method of Monitoring Cotton Aphid Infestation Based on Data Fusion and Multi-Source Remote Sensing Using Unmanned Aerial Vehicles

Drones, Journal Year: 2025, Volume and Issue: 9(4), P. 229 - 229

Published: March 21, 2025

Cotton aphids are the primary pests that adversely affect cotton growth, and they also transmit a variety of viral diseases, seriously threatening yield quality. Although traditional remote sensing method with single data source improves monitoring efficiency to certain extent, it has limitations regard reflecting complex distribution characteristics aphid accurate identification. Accordingly, there is pressing need for efficient high-precision UAV technology effective identification localization. To address above problems, this study began by presenting fusion two kinds images, namely panchromatic multispectral using Gram–Schmidt image technique extract multiple vegetation indices analyze their correlation damage indices. After fusing between infestation degree was significantly improved, which could more accurately reflect spatial infestation. Subsequently, these machine learning techniques were applied modeling evaluation performance fused data. The results validation revealed GBDT (Gradient-Boosting Decision Tree) model GLI, RVI, DVI, SAVI based on performed best, an estimation accuracy R2 0.88 RMSE 0.0918, obviously better than other five models, combining imagery noticeably higher those imaging. images combined outperformed in terms precision efficiency. In conclusion, demonstrated effectiveness pest monitoring.

Language: Английский

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Varying effects of tree cover on relationships between satellite-observed vegetation greenup date and spring temperature across Eurasian boreal forests

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 899, P. 165650 - 165650

Published: July 18, 2023

Language: Английский

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Unraveling Effect of Snow Cover on Spring Vegetation Phenology across Different Vegetation Types in Northeast China

Remote Sensing, Journal Year: 2023, Volume and Issue: 15(19), P. 4783 - 4783

Published: Sept. 30, 2023

Snow cover has significantly changed due to global warming in recent decades, causing large changes the vegetation ecosystem. However, impact of snow on spring phenology different types Northeast China remains unclear. In this study, we investigated response start growing season (SOS) indicators using partial correlation analysis and stepwise regression from 1982 2015 based multiple remote sensing datasets. Furthermore, revealed underlying mechanisms a structural equation model. The results show that decreased days (SCD) an advanced end date (SCED) led SOS forests. Conversely, increased SCD delayed SCED grasslands. trends did not exhibit significant rainfed cropland. maximum water equivalent (SWEmax) most areas. proportion between SWEmax was small. varied across types. mainly exhibited positive correlations with forests, including deciduous broadleaf forests coniferous negative 18.61% 2.58%, respectively. grasslands croplands, exhibiting 4.87% 13.06%, impacted through “temperature effect” while it affected “moisture These provide enhanced understanding differences affecting under climate change China.

Language: Английский

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Satellite-Observed Spatio-Temporal Variation in Spring Leaf Phenology of Subtropical Forests across the Nanling Mountains in Southern China over 1999–2019

Forests, Journal Year: 2022, Volume and Issue: 13(9), P. 1486 - 1486

Published: Sept. 14, 2022

Knowledge of spatio-temporal variation in vegetation phenology is essential for understanding environmental change mountainous regions. In recent decades, satellite remote sensing has contributed to the across globe. However, subtropical mountains remains poorly understood, despite their important ecosystem functions and services. Here, we aim characterize pattern start growing season (SOS), a typical spring leaf phenological metric, forests Nanling Mountains (108–116° E, 24–27° N) southern China. SOS was estimated from time series GEOV2 area index (LAI) data at 1 km spatial resolution during period 1999–2019. We observed slightly earlier regional mean region (24–25° than those central northern also spatially varying elevation gradients SOS. The showed slope −0.2 days/year (p = 0.21) scale over addition, approximately 22% analyzed forested pixels experienced significantly < 0.1). Partial correlation analysis revealed that preseason air temperature most responsible climate factor controlling interannual this region. Furthermore, impacts on vary with forest types, mixed showing stronger between weaker winter evergreen broadleaf open forests. This suggests complication role regulating

Language: Английский

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Spatiotemporal variation of spring phenology and the corresponding scale effects and uncertainties: A case study in southwestern China

International Journal of Applied Earth Observation and Geoinformation, Journal Year: 2024, Volume and Issue: 135, P. 104294 - 104294

Published: Dec. 1, 2024

Language: Английский

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Divergent contribution of environmental factors to soil organic and inorganic carbon in different land use types in a forest-grassland ecotone of Inner Mongolia, China

Journal of Environmental Management, Journal Year: 2024, Volume and Issue: 373, P. 123875 - 123875

Published: Dec. 31, 2024

Language: Английский

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