Arid zone; Copernicus Global Land Cover (CGLS-LC100); Dynamic World (DW); Global Forest Cover Change (GFCC); Global Forest Watch (GFW); Xerophytic shrubs; Ecology, Evolution, Behavior and Systematics; Ecology; Earth-Surface Processes
Abstract :
[en] Global vegetation maps are essential tools for ecosystem monitoring, yet they often fail to accurately represent vegetation in arid regions. This study evaluates the performance of four global products—GFCC, GFW, CGLS-LC100, and DW—in the xerophytic shrublands of southwestern Madagascar, a region undergoing rapid deforestation. Satellite-derived estimates were compared with field data collected in 2022 from 41plots (900 m2 each) using the point-intercept method. Results revealed substantial discrepancies among products, with a coefficient of variation reaching 78.94 % for tree cover, primarily due to differences in vegetation definitions and classification methods. Aggregating tree and shrub cover into a single woody cover layer significantly reduced this variability by 58.19 %. Among the products tested, DW provided the most accurate estimates of woody cover (R2 = 0.70), while CGLS-LC100 was the most responsive to floristic composition. Product biases varied by vegetation type: DW and CGLS-LC100 tended to overestimate tree cover in structurally developed plots, while GFCC and GFW underestimated it in multi-stemmed thickets. Shrub cover was consistently underestimated across all products. In this context of active forest loss, overestimations may reflect past landscape conditions, while underestimations expose structural limitations. These findings highlight the need for mapping strategies that better capture the complexity of dryland vegetation.
Disciplines :
Environmental sciences & ecology
Author, co-author :
Ramalason, Felana Nantenaina ; Université de Liège - ULiège > Département GxABT > Biodiversité, Ecosystème et Paysage (BEP) ; Université d'Antananarivo - Ecole Supérieure des Sciences Agronomiques (ESSA-forêts), Mention Foresterie et Environnement, Antananarivo, Madagascar
Rakotondrasoa, Olivia Lovanirina; Université d'Antananarivo - Ecole Supérieure des Sciences Agronomiques (ESSA-forêts), Mention Foresterie et Environnement, Antananarivo, Madagascar
Linden, Arthur Vander; University of Liège –TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech. Passage des Déportés 2, Gembloux, Belgium
Renard, Guillaume ; Université de Liège - ULiège > TERRA Research Centre > Echanges Eau - Sol - Plantes
Ratsimba, Harifidy Rakoto; Université d'Antananarivo - Ecole Supérieure des Sciences Agronomiques (ESSA-forêts), Mention Foresterie et Environnement, Antananarivo, Madagascar
Bogaert, Jan ; Université de Liège - ULiège > Département GxABT > Biodiversité, Ecosystème et Paysage (BEP)
Bastin, Jean-François ; Université de Liège - ULiège > TERRA Research Centre > Biodiversité, Ecosystème et Paysage (BEP)
Language :
English
Title :
Potential of global vegetation maps in capturing xerophytic vegetation cover: insights from Madagascar's arid ecosystems
ULiège - Université de Liège ARES - Academy for Research and Higher Education
Funding text :
This work was produced within the framework of the AGRIFO project (Appui à la Gestion Durable et à la RestauratIon des FOurrés xérophiles du sud-ouest de Madagascar), funded by Académie de Recherche et de l'Enseignement Supérieur (ARES-CCD, Belgium) through the mobility program associated with the University of Liège.
Abel, C., Abdi, A.M., Tagesson, T., Horion, S., Fensholt, R., Contrasting ecosystem vegetation response in global drylands under drying and wetting conditions. Glob. Change Biol. 29 (2023), 3954–3969, 10.1111/gcb.16745.
Adzhar, R., Kelley, D.I., Dong, N., George, C., Torello Raventos, M., Veenendaal, E., Feldpausch, T.R., Phillips, O.L., Lewis, S.L., Sonké, B., Taedoumg, H., Schwantes Marimon, B., Domingues, T., Arroyo, L., Djagbletey, G., Saiz, G., Gerard, F., MODIS Vegetation Continuous Fields tree cover needs calibrating in tropical savannas. Biogeosciences 19 (2022), 1377–1394, 10.5194/bg-19-1377-2022.
Adzhar, R., Kelley, D.I., Dong, N., Torello Raventos, M., Veenendaal, E., Feldpausch, T.R., Philips, O.L., Lewis, S., Sonké, B., Taedoumg, H., Schwantes Marimon, B., Domingues, T., Arroyo, L., Djagbletey, G., Saiz, G., Gerard, F., Assessing MODIS Vegetation Continuous Fields tree cover product(collection 6): performance and applicability in tropical forests and savannas. https://doi.org/10.5194/bg-2020-460, 2021.
Bachantourian, M., Chaleplis, K., Gemitzi, A., Kalabokidis, K., Palaiologou, P., Vasilakos, C., Evaluation of MODIS, climate change initiative, and CORINE land cover products based on a ground truth dataset in a mediterranean landscape. Land, 11, 2022, 1453, 10.3390/land11091453.
Bastin, J.-F., Berrahmouni, N., Grainger, A., Maniatis, D., Mollicone, D., Moore, R., Patriarca, C., Picard, N., Sparrow, B., Abraham, E.M., The extent of forest in dryland biomes. Science 356 (2017), 635–638.
Bey, A., Sánchez-Paus Díaz, A., Maniatis, D., Marchi, G., Mollicone, D., Ricci, S., Bastin, J.-F., Moore, R., Federici, S., Rezende, M., Patriarca, C., Turia, R., Gamoga, G., Abe, H., Kaidong, E., Miceli, G., Collect Earth: land use and land cover assessment through augmented visual interpretation. Remote Sens., 8, 2016, 10.3390/rs8100807.
Brandt, M., Tucker, C.J., Kariryaa, A., Rasmussen, K., Abel, C., Small, J., Chave, J., Rasmussen, L.V., Hiernaux, P., Diouf, A.A., Kergoat, L., Mertz, O., Igel, C., Gieseke, F., Schöning, J., Li, S., Melocik, K., Meyer, J., Sinno, S., Romero, E., Glennie, E., Montagu, A., Dendoncker, M., Fensholt, R., An unexpectedly large count of trees in the West African Sahara and Sahel. Nature 587 (2020), 78–82, 10.1038/s41586-020-2824-5.
Breiman, L., Random forests. Mach. Learn. 45 (2001), 5–32, 10.1023/A:1010933404324.
Brinkmann, K., Noromiarilanto, F., Ratovonamana, R.Y., Buerkert, A., Deforestation processes in south-western Madagascar over the past 40 years: what can we learn from settlement characteristics?. Agric. Ecosyst. Environ., 195, 2014, 10.1016/j.agee.2014.06.008.
Brown, C.F., Brumby, S.P., Guzder-Williams, B., Birch, T., Hyde, S.B., Mazzariello, J., Czerwinski, W., Pasquarella, V.J., Haertel, R., Ilyushchenko, S., Schwehr, K., Weisse, M., Stolle, F., Hanson, C., Guinan, O., Moore, R., Tait, A.M., Dynamic World, Near real-time global 10 m land use land cover mapping. Sci. Data, 9, 2022, 251, 10.1038/s41597-022-01307-4.
Buchhorn, M., Lesiv, M., Tsendbazar, N.-E., Herold, M., Bertels, L., Smets, B., Copernicus global land cover layers—collection 2. Remote Sens., 12, 2020, 1044, 10.3390/rs12061044.
Chanteau, S., (eds.) Les pluies et la végétation, in: Atlas de la peste à Madagascar, 2006, IRD Éditions, 19–22, 10.4000/books.irdeditions.6600.
Cherif, E.K., Lucas, R., Ait Tchakoucht, T., Gama, I., Ribeiro, I., Domingos, T., Proença, V., Predicting fractional shrub cover in heterogeneous mediterranean landscapes using machine learning and sentinel-2 imagery. Forests, 15, 2024, 1739, 10.3390/f15101739.
De Marzo, T., Pflugmacher, D., Baumann, M., Lambin, E.F., Gasparri, I., Kuemmerle, T., Characterizing forest disturbances across the Argentine Dry Chaco based on Landsat time series. Int. J. Appl. Earth Obs. Geoinf., 98, 2021, 10.1016/j.jag.2021.102310.
Diédhiou, I., Mering, C., Sy, O., Sané, T., Cartographier par télédétection l'occupation du sol et ses changements: Application à l'analyse de la dynamique des paysages forestiers sénégambiens entre 1972 et 2016. echogeo 54. https://doi.org/10.4000/echogeo.20510, 2020.
Ermakov, M.S., Chi-squared test for hypothesis testing of homogeneity. J. Math. Sci. 273 (2023), 763–777, 10.1007/s10958-023-06539-2.
Fagan, M.E., A lesson unlearned? Underestimating tree cover in drylands biases global restoration maps. Glob. Change Biol. 26 (2020), 4679–4690, 10.1111/gcb.15187.
Gaspard, D.T., Venegas-Gonzalez, A., Beeckman, H., Randriamalala, R.J., Tomazello-Filho, M., De Ridder, M., Ramananantoandro, T., Tree Ring Responses to Climate Variability of Xerophytic Thickets from South Soalara, Madagascar - ScienceDirect. 2018.
Gorelick, N., Hancher, M., Dixon, M., Ilyushchenko, S., Thau, D., Moore, R., Google Earth engine: planetary-scale geospatial analysis for everyone. Rem. Sens. Environ., 202, 2017, 10.1016/j.rse.2017.06.031.
Hänke, H., Barkmann, J., Coral, C., Enfors Kaustky, E., Marggraf, R., Social-ecological traps hinder rural development in southwestern Madagascar. E&S, 22, 2017, art42, 10.5751/ES-09130-220142.
Hansen, M.C., Potapov, P.V., Moore, R., Hancher, M., Turubanova, S.A., Tyukavina, A., Thau, D., Stehman, S.V., Goetz, S.J., Loveland, T.R., Kommareddy, A., Egorov, A., Chini, L., Justice, C.O., Townshend, J.R.G., High-resolution global maps of 21st-century forest cover change. Science 342 (2013), 850–853, 10.1126/science.1244693.
IPCC. Climate change 2023: synthesis report. Lee, H., Romero, J., (eds.) Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, 2023, IPCC. Intergovernmental Panel on Climate Change (IPCC), Geneva, Switzerland, 10.59327/IPCC/AR6-9789291691647.
Karl, J.W., McCord, S.E., Hadley, B.C., A comparison of cover calculation techniques for relating point-intercept vegetation sampling to remote sensing imagery. Ecol. Indic. 73 (2017), 156–165, 10.1016/j.ecolind.2016.09.034.
Lebzak, E.V., Modern problems and directions of development of forest cartography. Interexpo GEO-Siber. 1 (2022), 198–205, 10.33764/2618-981X-2022-1-198-205.
Leprun, J.-C., Grouzis, M., Randriambanona, H., Post-Cropping Change and Dynamics in Soil and Vegetation Properties after Forest Clearing: Example of the Semi-arid Mikea Region (Southwestern Madagascar) - Science Direct. 2009.
Lewin, A., Murali, G., Rachmilevitch, S., Roll, U., Global evaluation of current and future threats to drylands and their vertebrate biodiversity. Nat. Ecol. Evol. 8 (2024), 1448–1458, 10.1038/s41559-024-02450-4.
Los, S.O., Rosette, J.A.B., Kljun, N., North, P.R.J., Chasmer, L., Suárez, J.C., Hopkinson, C., Hill, R.A., Van Gorsel, E., Mahoney, C., Berni, J.A.J., Vegetation height and cover fraction between 60° S and 60° N from ICESat GLAS data. Geosci. Model Dev. (GMD) 5 (2012), 413–432, 10.5194/gmd-5-413-2012.
Ma, X., Ding, J., Wang, T., Lu, L., Sun, H., Zhang, F., Cheng, X., Nurmemet, I., A pixel dichotomy coupled linear kernel-driven model for estimating fractional vegetation cover in arid areas from high-spatial-resolution images. IEEE Trans. Geosci. Rem. Sens. 61 (2023), 1–15, 10.1109/TGRS.2023.3289093.
Nuzzo, R.L., Histograms: a useful data analysis visualization. PM&R 11 (2019), 309–312, 10.1002/pmrj.12145.
Nzabarinda, V., Bao, A., Xu, W., Uwamahoro, S., Xiaoran, H., Habiyakare, T., Sindikubwabo, C., Habumugisha, J.M., Itangishaka, A.C., A simple model to predict the spatiotemporally vegetation dynamics in terms of precipitation and temperature. Environ. Dev., 44, 2022, 100769, 10.1016/j.envdev.2022.100769.
Pelletier, C., Webb, G.I., Petitjean, F., Temporal convolutional neural network for the classification of satellite image time series. Remote Sens., 11, 2019, 523, 10.3390/rs11050523.
Piñeiro, G., Perelman, S., Guerschman, J.P., Paruelo, J.M., How to evaluate models: observed vs. predicted or predicted vs. observed?. Ecol. Model. 216 (2008), 316–322, 10.1016/j.ecolmodel.2008.05.006.
Prăvălie, R., Bandoc, G., Patriche, C., Sternberg, T., Recent changes in global drylands: evidences from two major aridity databases. Catena (Cremling.) 178 (2019), 209–231, 10.1016/j.catena.2019.03.016.
Ramond, J.-B., Jordaan, K., Díez, B., Heinzelmann, S.M., Cowan, D.A., Microbial biogeochemical cycling of nitrogen in arid ecosystems. Microbiol. Mol. Biol. Rev., 86, 2022, 10.1128/mmbr.00109-21.
Randriamalala, J.R., Hervé, D., Letourmy, P., Carrière, S.M., Effects of slash-and-burn practices on soil seed banks in secondary forest successions in Madagascar. Agric. Ecosyst. Environ. 199 (2015), 312–319, 10.1016/J.AGEE.2014.09.010.
Randriamalala, J.R., Radosy, H.O., Ramanakoto, M., Razafindrahanta, H., Ravoninjatovo, J.-M., Haingomanantsoa, R.S., Ramananantoandro, T., Allometric models to predict the individual aboveground biomass of shrubs of Malagasy xerophytic thickets. J. Arid Environ., 202, 2022, 104751, 10.1016/j.jaridenv.2022.104751.
Randrianasolo, Z.H., Razafimahatratra, A.R., Razafinarivo, R.N.G., Randrianary, T., Rakotovololonalimanana, H., Rajemison, A.H., Mamitiana, A., Andriamanalina, R.L., Rakotosoa, A., Ramananantoandro, T., Which allometric models are the most appropriate for estimating aboveground biomass in secondary forests of Madagascar with Ravenala madagascariensis?. Sci. Afr., 6, 2019, e00147, 10.1016/j.sciaf.2019.e00147.
Sexton, J.O., Noojipady, P., Song, X.P., Feng, M., Song, D.X., Kim, D.H., Anand, A., Huang, C., Channan, S., Pimm, S.L., Townshend, J.R., Conservation policy and the measurement of forests. Nat. Clim. Change 6 (2015), 192–196.
Sexton, J.O., Song, X.-P., Feng, M., Noojipady, P., Anand, A., Huang, C., Kim, D.-H., Collins, K.M., Channan, S., DiMiceli, C., Global, 30-m resolution continuous fields of tree cover: landsat-based rescaling of MODIS vegetation continuous fields with lidar-based estimates of error. Int. J. Digital Earth 6 (2013), 427–448.
Tian, F., Brandt, M., Liu, Y.Y., Rasmussen, K., Fensholt, R., Mapping gains and losses in woody vegetation across global tropical drylands. Glob. Change Biol. 23 (2017), 1748–1760.
Torbick, N., Qi, J., Ge, J., Olsen, J., Lusch, D., An assessment of africover and GLC2000 using general agreement and videography techniques. Proceedings. 2005 IEEE International Geoscience and Remote Sensing Symposium, 2005. IGARSS ’05. Presented at the 2005 IEEE International Geoscience and Remote Sensing Symposium, 2005, 2005, IGARSS ’05., IEEE, Seoul, Korea, 5005–5008, 10.1109/IGARSS.2005.1526801.
Vieilledent, G., Grinand, C., Rakotomalala, F.A., Ranaivosoa, R., Rakotoarijaona, J.-R., Allnutt, T.F., Achard, F., Combining global tree cover loss data with historical national forest cover maps to look at six decades of deforestation and forest fragmentation in Madagascar. Biol. Conserv. 222 (2018), 189–197, 10.1016/j.biocon.2018.04.008.
Wang, J., Yang, X., Wang, Z., Cheng, H., Kang, J., Tang, H., Li, Y., Bian, Z., Bai, Z., Consistency analysis and accuracy assessment of three global ten-meter land cover products in rocky desertification region—a case study of southwest China. IJGI, 11, 2022, 202, 10.3390/ijgi11030202.
White, A., Sparrow, B., Leitch, E., Foulkes, J., Flitton, R., Lowe, A.J., Caddy-Retalic, S., AusPlots Rangelands survey protocols manual, 2012, University of Adelaide Press https://www.tern.org.au/wp-content/uploads/TERN-Rangelands-Survey-Protocols-Manual_web.pdf.
Zhang, X., Pan, Q., Zhao, Y., Huang, Q., Research on spatial deviation analysis model of land-use change. Li, D., Ma, H., (eds.) Presented at the MIPPR 2005 Image Analysis Techniques, 2005, 60440C, 10.1117/12.652320 Wuhan, China.
Zhang-Zheng, H., Adu-Bredu, S., Duah-Gyamfi, A., Moore, S., Addo-Danso, S.D., Amissah, L., Valentini, R., Djagbletey, G., Anim-Adjei, K., Quansah, J., Sarpong, B., Owusu-Afriyie, K., Gvozdevaite, A., Tang, M., Ruiz-Jaen, M.C., Ibrahim, F., Girardin, C.A.J., Rifai, S., Dahlsjö, C.A.L., Riutta, T., Deng, X., Sun, Y., Prentice, I.C., Oliveras Menor, I., Malhi, Y., Contrasting carbon cycle along tropical forest aridity gradients in West Africa and Amazonia. Nat. Commun., 15, 2024, 3158, 10.1038/s41467-024-47202-x.
