Faculté des Sciences
Faculté des Sciences

The influence of soil treatments on post fire regeneration of native vegetation in a context of reforestation in an arid landscape in southern Portugal

Toisoul Laurent, Madeleine ULiège
Promotor(s) : ULM, Florian ; Bastin, Jean-François ULiège ; Romain, Anne-Claude ULiège
Date of defense : 8-Nov-2022 • Permalink :
Title : The influence of soil treatments on post fire regeneration of native vegetation in a context of reforestation in an arid landscape in southern Portugal
Translated title : [fr] L'influence des traitements du sol sur la régénération de la végétation native avec feux de forêt dans un contexte de reforestation dans un paysage aride du sud du Portugal
Author : Toisoul Laurent, Madeleine ULiège
Date of defense  : 8-Nov-2022
Advisor(s) : ULM, Florian 
Bastin, Jean-François ULiège
Romain, Anne-Claude ULiège
Committee's member(s) : Colinet, Gilles ULiège
Falzone, Claudia ULiège
Language : English
Number of pages : 56
Keywords : [en] Wildfire
[en] Portugal
[en] Native vegetation
[en] Reforestation
[en] Regeneration
[en] Cistus ladanifer
Discipline(s) : Life sciences > Environmental sciences & ecology
Research unit : cE3c–Center for Ecology, Evolution and Environmental Changes (Faculdade de Ciências da Universidade de Lisboa)
Name of the research project : R3forest - Using exotic biomass for post-fire recovery: Reuse, Regenerate and Reforest
Target public : Professionals of domain
Institution(s) : Université de Liège, Liège, Belgique
Degree: Master en sciences et gestion de l'environnement, à finalité spécialisée en surveillance de l'environnement
Faculty: Master thesis of the Faculté des Sciences


[en] Wildfires have increased in intensity and extent in Portugal over the past decade. Such events
significantly alter ecosystems and negatively affect soil properties and vegetation cover, leading
to erosion, nutrient loss, and vegetation depletion. Under such poor conditions, human
interventions to improve soil richness are often needed to accelerate forest recovery and native
vegetation regeneration. The objective of this study is to evaluate the effects of soil treatments
on native vegetation and their impact on the survival of seedlings planted for reforestation
purposes. As part of a broader research project, several soil treatments were applied on recently
burned soil: control zone; prior vegetation removal; creation of contour bunds; creation of
contour bunds and woodchips disposal; creation of contour bunds and green waste compost
disposal. This research will focus on addressing (1) the influence of each treatment on soil
properties of which soil organic matter (SOM) and soil moisture (SM); (2) the influence of soil
treatments on native vegetation biomass, cover, and moisture and their interactions with soil
properties; (3) the impact of the presence and development of native vegetation on the survival
rate of tree and shrub seedlings planted on site. Particular attention will be pay to the effects of
the treatments on one native species, Cistus ladanifer by examining its abundance and some of
its phenological parameters. Finally, (2bis) this work investigated the development of a simple
tool to assess biomass in the field using green vegetation cover as a proxy.
The results showed that soil organic matter is higher where there have been no treatments or
only vegetation removal. This is likely due to (i) field preparation, which may have removed
burned organic materials and turned over the soil layer, and (ii) higher vegetation cover in these
plots. Biomass and cover of native vegetation are also higher in these plots, likely due to (i)
vegetation removal by machinery and (ii) the layer of supplemental organic material
(woodchips or compost) preventing plant growth. Native vegetation is more humid where
contour bunds were created, likely due in part to (i) increased infiltration rates and rooting
depth, and (ii) less abundant vegetation and lignified species. Cistus ladanifer grows more
humid, taller, and with larger leaf areas in the same plots, indicating that this species may be a
good indicator of treatment effects. There is a negative correlation between the presence of
native vegetation (including Cistus ladanifer) and the survival rate of trees and shrubs,
indicating that native vegetation may compete with them. However, it is more likely that the
planted trees and shrubs survived better thanks to the positive effect of the organic amendments,
which simultaneously reduced vegetation cover. Finally, a linear regression between biomass
and GVC showed that GVC is a good proxy for biomass estimation.



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  • Toisoul Laurent, Madeleine ULiège Université de Liège > Master sc. & gest. env., à fin.


Committee's member(s)

  • Colinet, Gilles ULiège Université de Liège - ULiège > Département GxABT > Echanges Eau - Sol - Plantes
    ORBi View his publications on ORBi
  • Falzone, Claudia ULiège Université de Liège - ULiège > DER Sc. et gest. de l'environnement (Arlon Campus Environ.) > Surveillance de l'environnement
    ORBi View his publications on ORBi
  • Total number of views 32
  • Total number of downloads 57

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