How Do Plants Respond Biochemically to Fire? The Role of Photosynthetic Pigments and Secondary Metabolites in the Post-Fire Resprouting Response

Abstract

Resprouting is one of the main regeneration strategies in woody plants that allows post-fire vegetation recovery. However, the stress produced by fires promotes the biosynthesis of compounds which could affect the post-fire resprouting, and this approach has been poorly evaluated in fire ecology. In this study, we evaluate the changes in the concentration of chlorophylls, carotenoids, phenolic compounds, and tannins as a result of experimental burns (EB). We asked whether this biochemical response to fire could influence the resprouting responses. For that, we conducted three EB in three successive years in three different experimental units. Specifically, we selected six woody species from the Chaco region, and we analyzed their biochemical responses to EB. We used spectrophotometric methods to quantify the metabolites, and morphological variables to estimate the resprouting responses. Applying a multivariate analysis, we built an index to estimate the biochemical response to fire to EB per each species. Our results demonstrate that photosynthetic pigment concentration did not vary significantly in burnt plants that resprout in response to EB, whereas concentrations of secondary metabolites (phenolic compounds and tannins) increased up to two years after EB. Our main results showed that phenolic compounds could play a significant role in the resprouting responses, while photosynthetic pigments seem to have a minor but significant role. Such results were reaffirmed by the significant correlation between the biochemical response to fire and both resprouting capacity and resprouting growth. However, we observed that the biochemical response effect on resprouting was lower in tree species than in shrubby species. Our study contributes to the understanding of the biochemical responses that are involved in the post-fire vegetation recovery.

Unraveling the Adaptive Chemical Traits of Rhamnidium elaeocarpum in Response to Fire and Environmental Factors in Pantanal Wetlands

“…The absence of chemical defense variability in plants under stress caused by the environment or other organisms would imply a possible population reduction. Therefore, high chemical diversity allows plants to respond to various environmental conditions, as Santacruz-García et al (2021) reported in a recent study on six woody species from the Chaco, including a Rhamnaceae family species with wide variations in total phenolic and tannin concentrations. Our results presented a high standard deviation value, suggesting a high intrapopulation variability, which can be attributed to adaptation, according to Valares (2011).…”

Efecto de la quema prescrita en el valor nutricional de tallos aéreos de Schoenoplectus tatora (Kunth) Palla, Lago Titicaca, Perú

“…Contrariamente en el totoral sin quema las concentraciones fueron significativamente superiores en el rebrote (8,69 %) y significativamente menores hacia la madurez (5,96 %) (Figura 2d). Aunque no hubo un efecto claro por el uso del fuego, sí se evidencia un relativo incremento en el totoral con quema en la etapa de crecimiento, similar a lo hallado por Santacruz et al (2021) quienes explican que el incremento en los compuestos lipídicos por efecto de la quema, entre los que incluyen altos niveles de fenoles, promueven su regeneración y crecimiento, como una respuesta funcional al fuego.…”

Ecophysiological and Growth-Related Traits of Two Geophytes Three Years after the Fire Event in Grassland Steppe

“…The higher Chl throughout the whole season for I. pumila from the burned site can also be linked to the increased post-fire N content in the soil, as previously discussed. The study with six woody species found that chlorophyll content does not differ significantly between control and burned plants, implying that plant physiological stability can be restored even 6 months after burning [ 57 ]. In contrast to these findings, our study found significant variations in Chl content even 3 years after the fire, indicating that further research should reveal differences in this regard between woody and herbaceous species.…”