Change trend and attribution analysis of leaf area index in the East African Plateau from 1982 to 2020

doi:10.13287/j.1001-9332.202409.021

Abstract

Abstract: The ecosystems on the East African Plateau are crucial for maintaining the biodiversity, water resource balance, and ecological equilibrium of the African continent. However, the spatiotemporal variations of vegetation and the driving factors remain unclear. We analyzed leaf area index (LAI) change trends in the East African Plateau based on the GIMMS LAI4g dataset and further conducted attribution analysis combining temperature and precipitation data, as well as 10 Dynamic Global Vegetation Models (DGVMs) in TRNEDY v9. The results showed that LAI of the East African Plateau had a modest change trend from 1982 to 1999 (2.5×10^-3 m²·m^-2·a^-1), but significantly increased from 2000 to 2020 (5.2×10^-3 m²·m^-2·a^-1), which was 2.1 times faster than that during 1982-1999. Temperature and precipitation had weak correlations with LAI from 1982 to 1999, but showed significant correlations from 2000 to 2020. The DGVMs demonstrated consistent attribution results, with temperature and precipitation contributing significantly more to the LAI variations from 2000 to 2020 compared to the period from 1982 to 1999. The results highlighted the key role of climate change in driving vegetation greening on the East African Plateau during 2000-2020, which could provide important evidence for ecological conservation and sustainable development strategies in the region.

Key words: climate change, leaf area index, East African Plateau, vegetation change

MA Yan, CHEN Tiexi, CHEN Xin, XIAO Yinmiao, ZHOU Shengjie, WANG Shengzhen. Change trend and attribution analysis of leaf area index in the East African Plateau from 1982 to 2020[J]. Chinese Journal of Applied Ecology, 2024, 35(9): 2561-2570.

References

[1] Zhu ZC, Piao SL, Myneni RB, et al. Greening of the earth and its drivers. Nature Climate Change, 2016, 6: 791-795
[2] Chen C, Park T, Wang XH, et al. China and India lead in greening of the world through land-use management. Nature Sustainability, 2019, 2: 122-129
[3] Piao SL, Yin GD, Tan JG, et al. Detection and attribution of vegetation greening trend in China over the last 30 years. Global Change Biology, 2015, 21: 1601-1609
[4] Pan NQ, Feng XM, Fu BJ, et al. Increasing global ve-getation browning hidden in overall vegetation greening: Insights from time-varying trends. Remote Sensing of Environment, 2018, 214: 59-72
[5] Yuan WP, Zheng Y, Piao SL, et al. Increased atmospheric vapor pressure deficit reduces global vegetation growth. Science Advances, 2019, 5: eaax1396
[6] Myers-Smith IH, Kerby JT, Phoenix GK, et al. Complexity revealed in the greening of the Arctic. Nature Climate Change, 2020, 10: 106-117
[7] Bi J, Myneni R, Lyapustin A, et al. Amazon forests' response to droughts: A perspective from the MAIAC product. Remote Sensing, 2016, 8: 356
[8] Wagner FH, Hérault B, Rossi V, et al. Climate drivers of the Amazon forest greening. PLoS One, 2017, 12(7): e0180932
[9] Chen X, Chen TX, He B, et al. The global greening continues despite increased drought stress since 2000. Global Ecology and Conservation, 2024, 49: e02791
[10] Li W, Du JK, Li SF, et al. The variation of vegetation productivity and its relationship to temperature and precipitation based on the GLASS-LAI of different African ecosystems from 1982 to 2013. International Journal of Biometeorology, 2019, 63: 847-860
[11] Chen TX, Zhou SJ, Liang CZ, et al. The greening and wetting of the Sahel have leveled off since about 1999 in relation to SST. Remote Sensing, 2020, 12: 2723
[12] Zeng N, Neelin JD, Lau KM, et al. Enhancement of interdecadal climate variability in the Sahel by vegetation interaction. Science, 1999, 286: 1537-1540
[13] Brandt M, Mbow C, Diouf AA, et al. Ground- and satellite-based evidence of the biophysical mechanisms behind the greening Sahel. Global Change Biology, 2015, 21: 1610-1620
[14] Zhou LM, Tian YH, Myneni RB, et al. Widespread decline of Congo rainforest greenness in the past decade. Nature, 2014, 509: 86-90
[15] Bunting EL, Southworth J, Herrero H, et al. Understanding long-term Savanna vegetation persistence across three drainage basins in Southern Africa. Remote Sen-sing, 2018, 10: 1013
[16] Pricope NG, Husak G, Lopez-Carr D, et al. The climate-population nexus in the East African Horn: Emerging degradation trends in rangeland and pastoral livelihood zones. Global Environmental Change, 2013, 23: 1525-1541
[17] Wei FL, Wang S, Fu BJ, et al. Vegetation dynamic trends and the main drivers detected using the ensemble empirical mode decomposition method in East Africa. Land Degradation & Development, 2018, 29: 2542-2553
[18] Williams CA, Hanan NP, Neff JC, et al. Africa and the global carbon cycle. Carbon Balance and Management, 2007, 2: 3
[19] Bullock EL, Healey SP, Yang Z, et al. Three decades of land cover change in East Africa. Land, 2021, 10: 150
[20] Zou LD, Stan K, Cao S, et al. Dynamic global vegetation models may not capture the dynamics of the leaf area index in the tropical rainforests: A data-model intercomparison. Agricultural and Forest Meteorology, 2023, 339: 109562
[21] Lindeskog M, Arneth A, Bondeau A, et al. Implications of accounting for land use in simulations of ecosystem carbon cycling in Africa. Earth System Dynamics, 2013, 4: 385-407
[22] Cao S, Li MY, Zhu ZC, et al. Spatiotemporally consistent global dataset of the GIMMS leaf area index (GIMMS LAI4g) from 1982 to 2020. Earth System Science Data, 2023, 15: 4877-4899
[23] Harris I, Osborn TJ, Jones P, et al. Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset. Scientific Data, 2020, 7: 109
[24] Haile GG, Tang QH, Hosseini-Moghari SM, et al. Projected impacts of climate change on drought patterns over East Africa. Earth's Future, 2020, 8: e2020EF001502
[25] Juma B, Olang LO, Hassan M, et al. Analysis of rainfall extremes in the Ngong River Basin of Kenya: Towards integrated urban flood risk management. Physics and Chemistry of the Earth, 2021, 124: 102929
[26] Evans J, Geerken R. Discrimination between climate and human induced dryland degradation. Journal of Arid Environments, 2004, 57: 535-554
[27] Wessels KJ, Prince SD, Malherbe J, et al. Can human-induced land degradation be distinguished from the effects of rainfall variability? A case study in South Africa. Journal of Arid Environments, 2007, 68: 271-297
[28] Fernández-Martínez M, Sardans J, Chevallier F, et al. Global trends in carbon sinks and their relationships with CO₂ and temperature. Nature Climate Change, 2019, 9: 73-79
[29] Ju JC, Masek JG. The vegetation greenness trend in Canada and US Alaska from 1984-2012 Landsat data. Remote Sensing of Environment, 2016, 176: 1-16
[30] Liu YC, Li Z, Chen Y. Continuous warming shift greening towards browning in the Southeast and Northwest High Mountain Asia. Scientific Reports, 2021, 11: 17920
[31] Zhang Y, Gentine P, Luo XZ, et al. Increasing sensiti-vity of dryland vegetation greenness to precipitation due to rising atmospheric CO₂. Nature Communications, 2022, 13: 4875
[32] Gao QZ, Schwartz MW, Zhu WQ, et al. Changes in global grassland productivity during 1982 to 2011 attributa-ble to climatic factors. Remote Sensing, 2016, 8: 384
[33] Hinzmann A, Mölg T, Braun M, et al. Tropical glacier loss in East Africa: Recent areal extents on Kilimanjaro, Mount Kenya, and in the Rwenzori Range from high-resolution remote sensing data. Environmental Research: Climate, 2024, 3: 011003
[34] United Nations Department of Economic and Social Affairs. World Population Prospects 2017-Volume I: Comprehensive Tables. Washington DC: United Nations, 2021
[35] Asilbekova K, Yarullina Z, Plocen M, et al. National State of the Environment Report: Uzbekistan. Bangkok: International Institute of Sustainable Development, 2023
[36] Wanyama D, Moore NJ, Dahlin KM. Persistent vegetation greening and browning trends related to natural and human activities in the Mount Elgon Ecosystem. Remote Sensing, 2020, 12: 2113
[37] Mutavi IN, Long'ora AE. Assessment of the effect of antropogenic activities on terrestrial biodiversity conservation in Matayos Division of Busia County, Kenya. EAS Journal of Humanities and Cultural Studies, 2019, 1, DOI: 10.36349/easjhcs.2019.v01i03.001
[38] Blake WH, Rabinovich A, Wynants M, et al. Soil erosion in East Africa: An interdisciplinary approach to realising pastoral land management change. Environmental Research Letters, 2018, 13: 124014
[39] Angassa A. Effects of grazing intensity and bush encroachment on herbaceous species and rangeland condition in southern Ethiopia. Land Degradation & Development, 2014, 25: 438-451
[40] Ruijsch J, Teuling AJ, Verbesselt J, et al. Landscape restoration and greening in Africa. Environmental Research Letters, 2023, 18: 064020
[41] Buxton J, Powell T, Ambler J, et al. Community-driven tree planting greens the neighbouring landscape. Scientific Reports, 2021, 11: 18239
[42] Murray-Tortarolo G, Anav A, Friedlingstein P, et al. Evaluation of land surface models in reproducing satellite-derived LAI over the high-latitude northern hemisphere. Part I: Uncoupled DGVMs. Remote Sensing, 2013, 5: 4819-4838
[43] Smith B, Prentice IC, Sykes MT. Representation of vegetation dynamics in the modelling of terrestrial ecosystems: Comparing two contrasting approaches within European climate space. Global Ecology and Biogeography, 2001, 10: 621-637
[44] Krinner G, Viovy N, de Noblet-Ducoudré N, et al. A dynamic global vegetation model for studies of the coupled atmosphere-biosphere system. Global Biogeochemical Cycles, 2005, 19, DOI: 10.1029/2003GB002199
[45] Zaehle S, Friend AD. Carbon and nitrogen cycle dynamics in the O-CN land surface model: 1. Model description, site-scale evaluation, and sensitivity to parameter estimates. Global Biogeochemical Cycles, 2010, 24, DOI: 10.1029/2009GB003522
[46] 车明亮, 陈报章, 王瑛, 等. 全球植被动力学模型研究综述. 应用生态学报, 2014, 25(1): 263-271
[47] Sun Y, Goll DS, Chang JF, et al. Global evaluation of the nutrient-enabled version of the land surface model ORCHIDEE-CNP v1.2 (r5986). Geoscientific Model Development, 2021, 14: 1987-2010
[48] Delon C, Galy-Lacaux C, Adon M, et al. Nitrogen compounds emission and deposition in West African ecosystems: Comparison between wet and dry savanna. Biogeosciences, 2012, 9: 385-402