Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016)

Ndiabou Faye; Ramata Talla; Aissatou Thiam Ndong; Moustapha Bassimbe Sagna; Diara Sylla; Aly Diallo; Oumar Sarr; Aliou Guisse; Jean-Luc Peiry

doi:doi:10.11648/j.ajrs.20251302.15

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Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016)

Ndiabou Faye^*

, Ramata Talla

, Aissatou Thiam Ndong

, Moustapha Bassimbe Sagna

, Diara Sylla

, Aly Diallo

, Oumar Sarr, Aliou Guisse

, Jean-Luc Peiry

Published in American Journal of Remote Sensing (Volume 13, Issue 2)

Received: 10 November 2025 Accepted: 25 November 2025 Published: 17 December 2025

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Abstract

This study was conducted over a 34 km² area in the Ferlo region (northern Senegal). It aims to analyze the spatio-temporal dynamics of tree vegetation and the distribution of temporary ponds. The ponds were identified using satellite images acquired in September 2015 (rainy season), while woody vegetation was mapped for two periods: April 1972 and May 2016 (dry season), enabling a diachronic analysis over 44 years. The data were extracted from very high spatial resolution satellite images (<3 m): SPOT 6-7 for 2015-2016 and CORONA for 1972. Image processing (ortho-rectification, enhancement, automatic detection, mapping) enabled the creation of accurate maps, which were then analyzed according to the principles of landscape ecology using the open-source software R, GRASS 7.6, and QGIS 3.4. A total of 244 ponds were automatically detected, representing 1.29% of the study area (43.4 ha), organized in a NE-SW alignment. Diachronic analysis shows a significant collapse in tree cover between 1972 (12.3%) and 2016 (2%). However, this decline is not observed in ponds, where woody cover has remained stable. Between 1972 and 2016, the Ferlo ponds showed a significant improvement in vegetation cover: while half of the ponds had less than 55% cover in 1972, this value exceeded 60% in 2016. These results shed new light on the distribution of vegetation in Ferlo and highlight the central ecological role of ponds in plant resilience in the Sahel.

Published in	American Journal of Remote Sensing (Volume 13, Issue 2)
DOI	10.11648/j.ajrs.20251302.15
Page(s)	110-120
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2025. Published by Science Publishing Group

Keywords

Remote Sensing, Mapping, Woody Dynamics, Landscape Ecology, Sahelian Wetlands

References

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APA Style

Faye, N., Talla, R., Ndong, A. T., Sagna, M. B., Sylla, D., et al. (2025). Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016). American Journal of Remote Sensing, 13(2), 110-120. https://doi.org/10.11648/j.ajrs.20251302.15

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ACS Style

Faye, N.; Talla, R.; Ndong, A. T.; Sagna, M. B.; Sylla, D., et al. Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016). Am. J. Remote Sens. 2025, 13(2), 110-120. doi: 10.11648/j.ajrs.20251302.15

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AMA Style

Faye N, Talla R, Ndong AT, Sagna MB, Sylla D, et al. Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016). Am J Remote Sens. 2025;13(2):110-120. doi: 10.11648/j.ajrs.20251302.15

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@article{10.11648/j.ajrs.20251302.15,
  author = {Ndiabou Faye and Ramata Talla and Aissatou Thiam Ndong and Moustapha Bassimbe Sagna and Diara Sylla and Aly Diallo and Oumar Sarr and Aliou Guisse and Jean-Luc Peiry},
  title = {Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016)},
  journal = {American Journal of Remote Sensing},
  volume = {13},
  number = {2},
  pages = {110-120},
  doi = {10.11648/j.ajrs.20251302.15},
  url = {https://doi.org/10.11648/j.ajrs.20251302.15},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajrs.20251302.15},
  abstract = {This study was conducted over a 34 km2 area in the Ferlo region (northern Senegal). It aims to analyze the spatio-temporal dynamics of tree vegetation and the distribution of temporary ponds. The ponds were identified using satellite images acquired in September 2015 (rainy season), while woody vegetation was mapped for two periods: April 1972 and May 2016 (dry season), enabling a diachronic analysis over 44 years. The data were extracted from very high spatial resolution satellite images (<3 m): SPOT 6-7 for 2015-2016 and CORONA for 1972. Image processing (ortho-rectification, enhancement, automatic detection, mapping) enabled the creation of accurate maps, which were then analyzed according to the principles of landscape ecology using the open-source software R, GRASS 7.6, and QGIS 3.4. A total of 244 ponds were automatically detected, representing 1.29% of the study area (43.4 ha), organized in a NE-SW alignment. Diachronic analysis shows a significant collapse in tree cover between 1972 (12.3%) and 2016 (2%). However, this decline is not observed in ponds, where woody cover has remained stable. Between 1972 and 2016, the Ferlo ponds showed a significant improvement in vegetation cover: while half of the ponds had less than 55% cover in 1972, this value exceeded 60% in 2016. These results shed new light on the distribution of vegetation in Ferlo and highlight the central ecological role of ponds in plant resilience in the Sahel.},
 year = {2025}
}

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TY  - JOUR
T1  - Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016)
AU  - Ndiabou Faye
AU  - Ramata Talla
AU  - Aissatou Thiam Ndong
AU  - Moustapha Bassimbe Sagna
AU  - Diara Sylla
AU  - Aly Diallo
AU  - Oumar Sarr
AU  - Aliou Guisse
AU  - Jean-Luc Peiry
Y1  - 2025/12/17
PY  - 2025
N1  - https://doi.org/10.11648/j.ajrs.20251302.15
DO  - 10.11648/j.ajrs.20251302.15
T2  - American Journal of Remote Sensing
JF  - American Journal of Remote Sensing
JO  - American Journal of Remote Sensing
SP  - 110
EP  - 120
PB  - Science Publishing Group
SN  - 2328-580X
UR  - https://doi.org/10.11648/j.ajrs.20251302.15
AB  - This study was conducted over a 34 km2 area in the Ferlo region (northern Senegal). It aims to analyze the spatio-temporal dynamics of tree vegetation and the distribution of temporary ponds. The ponds were identified using satellite images acquired in September 2015 (rainy season), while woody vegetation was mapped for two periods: April 1972 and May 2016 (dry season), enabling a diachronic analysis over 44 years. The data were extracted from very high spatial resolution satellite images (<3 m): SPOT 6-7 for 2015-2016 and CORONA for 1972. Image processing (ortho-rectification, enhancement, automatic detection, mapping) enabled the creation of accurate maps, which were then analyzed according to the principles of landscape ecology using the open-source software R, GRASS 7.6, and QGIS 3.4. A total of 244 ponds were automatically detected, representing 1.29% of the study area (43.4 ha), organized in a NE-SW alignment. Diachronic analysis shows a significant collapse in tree cover between 1972 (12.3%) and 2016 (2%). However, this decline is not observed in ponds, where woody cover has remained stable. Between 1972 and 2016, the Ferlo ponds showed a significant improvement in vegetation cover: while half of the ponds had less than 55% cover in 1972, this value exceeded 60% in 2016. These results shed new light on the distribution of vegetation in Ferlo and highlight the central ecological role of ponds in plant resilience in the Sahel.
VL  - 13
IS  - 2
ER  -

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Author Information

Ndiabou Faye

Department of Plant Biology, Cheikh Anta Diop University, Dakar, Senegal;Tessekere Human-Environment Observatory, CNRS/Cheikh Anta Diop University, Dakar, Senegal

Contact Email

http://orcid.org/0000-0002-2317-2062
Ramata Talla

Department of Plant Biology, Cheikh Anta Diop University, Dakar, Senegal;Tessekere Human-Environment Observatory, CNRS/Cheikh Anta Diop University, Dakar, Senegal

Contact Email

http://orcid.org/0009-0004-2774-965X
Aissatou Thiam Ndong

Department of Plant Biology, Cheikh Anta Diop University, Dakar, Senegal;Tessekere Human-Environment Observatory, CNRS/Cheikh Anta Diop University, Dakar, Senegal

Contact Email

http://orcid.org/0009-0007-7763-5521
Moustapha Bassimbe Sagna

Department of Plant Biology, Cheikh Anta Diop University, Dakar, Senegal;Tessekere Human-Environment Observatory, CNRS/Cheikh Anta Diop University, Dakar, Senegal

Contact Email

http://orcid.org/0009-0001-6871-9375
Diara Sylla

Department of Plant Biology, Cheikh Anta Diop University, Dakar, Senegal;Tessekere Human-Environment Observatory, CNRS/Cheikh Anta Diop University, Dakar, Senegal

Contact Email

http://orcid.org/0009-0002-4967-4420
Aly Diallo

Tessekere Human-Environment Observatory, CNRS/Cheikh Anta Diop University, Dakar, Senegal;Department of Agroforestry, Assane Seck University, Ziguinchor, Senegal

Contact Email

http://orcid.org/0000-0001-7567-3187
Oumar Sarr

Department of Plant Biology, Cheikh Anta Diop University, Dakar, Senegal;Tessekere Human-Environment Observatory, CNRS/Cheikh Anta Diop University, Dakar, Senegal

Contact Email
Aliou Guisse

Department of Plant Biology, Cheikh Anta Diop University, Dakar, Senegal;Tessekere Human-Environment Observatory, CNRS/Cheikh Anta Diop University, Dakar, Senegal

Contact Email

http://orcid.org/0000-0001-6883-7745
Jean-Luc Peiry

University of Clermont Ferrand-Geolab-UMR 6042, Clermont-Ferrand, France

Contact Email

http://orcid.org/0000-0001-7675-2741

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APA Style

Faye, N., Talla, R., Ndong, A. T., Sagna, M. B., Sylla, D., et al. (2025). Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016). American Journal of Remote Sensing, 13(2), 110-120. https://doi.org/10.11648/j.ajrs.20251302.15

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ACS Style

Faye, N.; Talla, R.; Ndong, A. T.; Sagna, M. B.; Sylla, D., et al. Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016). Am. J. Remote Sens. 2025, 13(2), 110-120. doi: 10.11648/j.ajrs.20251302.15

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AMA Style

Faye N, Talla R, Ndong AT, Sagna MB, Sylla D, et al. Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016). Am J Remote Sens. 2025;13(2):110-120. doi: 10.11648/j.ajrs.20251302.15

Copy | Download

@article{10.11648/j.ajrs.20251302.15,
  author = {Ndiabou Faye and Ramata Talla and Aissatou Thiam Ndong and Moustapha Bassimbe Sagna and Diara Sylla and Aly Diallo and Oumar Sarr and Aliou Guisse and Jean-Luc Peiry},
  title = {Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016)},
  journal = {American Journal of Remote Sensing},
  volume = {13},
  number = {2},
  pages = {110-120},
  doi = {10.11648/j.ajrs.20251302.15},
  url = {https://doi.org/10.11648/j.ajrs.20251302.15},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajrs.20251302.15},
  abstract = {This study was conducted over a 34 km2 area in the Ferlo region (northern Senegal). It aims to analyze the spatio-temporal dynamics of tree vegetation and the distribution of temporary ponds. The ponds were identified using satellite images acquired in September 2015 (rainy season), while woody vegetation was mapped for two periods: April 1972 and May 2016 (dry season), enabling a diachronic analysis over 44 years. The data were extracted from very high spatial resolution satellite images (<3 m): SPOT 6-7 for 2015-2016 and CORONA for 1972. Image processing (ortho-rectification, enhancement, automatic detection, mapping) enabled the creation of accurate maps, which were then analyzed according to the principles of landscape ecology using the open-source software R, GRASS 7.6, and QGIS 3.4. A total of 244 ponds were automatically detected, representing 1.29% of the study area (43.4 ha), organized in a NE-SW alignment. Diachronic analysis shows a significant collapse in tree cover between 1972 (12.3%) and 2016 (2%). However, this decline is not observed in ponds, where woody cover has remained stable. Between 1972 and 2016, the Ferlo ponds showed a significant improvement in vegetation cover: while half of the ponds had less than 55% cover in 1972, this value exceeded 60% in 2016. These results shed new light on the distribution of vegetation in Ferlo and highlight the central ecological role of ponds in plant resilience in the Sahel.},
 year = {2025}
}

Copy | Download

TY  - JOUR
T1  - Ponds as Ecological Refuges: Dynamics of Woody Vegetation in Ferlo (1972–2016)
AU  - Ndiabou Faye
AU  - Ramata Talla
AU  - Aissatou Thiam Ndong
AU  - Moustapha Bassimbe Sagna
AU  - Diara Sylla
AU  - Aly Diallo
AU  - Oumar Sarr
AU  - Aliou Guisse
AU  - Jean-Luc Peiry
Y1  - 2025/12/17
PY  - 2025
N1  - https://doi.org/10.11648/j.ajrs.20251302.15
DO  - 10.11648/j.ajrs.20251302.15
T2  - American Journal of Remote Sensing
JF  - American Journal of Remote Sensing
JO  - American Journal of Remote Sensing
SP  - 110
EP  - 120
PB  - Science Publishing Group
SN  - 2328-580X
UR  - https://doi.org/10.11648/j.ajrs.20251302.15
AB  - This study was conducted over a 34 km2 area in the Ferlo region (northern Senegal). It aims to analyze the spatio-temporal dynamics of tree vegetation and the distribution of temporary ponds. The ponds were identified using satellite images acquired in September 2015 (rainy season), while woody vegetation was mapped for two periods: April 1972 and May 2016 (dry season), enabling a diachronic analysis over 44 years. The data were extracted from very high spatial resolution satellite images (<3 m): SPOT 6-7 for 2015-2016 and CORONA for 1972. Image processing (ortho-rectification, enhancement, automatic detection, mapping) enabled the creation of accurate maps, which were then analyzed according to the principles of landscape ecology using the open-source software R, GRASS 7.6, and QGIS 3.4. A total of 244 ponds were automatically detected, representing 1.29% of the study area (43.4 ha), organized in a NE-SW alignment. Diachronic analysis shows a significant collapse in tree cover between 1972 (12.3%) and 2016 (2%). However, this decline is not observed in ponds, where woody cover has remained stable. Between 1972 and 2016, the Ferlo ponds showed a significant improvement in vegetation cover: while half of the ponds had less than 55% cover in 1972, this value exceeded 60% in 2016. These results shed new light on the distribution of vegetation in Ferlo and highlight the central ecological role of ponds in plant resilience in the Sahel.
VL  - 13
IS  - 2
ER  -

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