Combined response and effect plant fire traits differ among regions with different fire histories

Pedro Jaureguiberry, Sandra Díaz

This is a plain language summary of a Functional Ecology Research article which can be found here.

Fire is a very important ecological factor in many regions of the world, influencing the characteristics of a region’s vegetation. Plants can respond to fire via resprouting (R) or seeding (S), which rely on the regeneration from vegetative tissues that survived fire or on the recruitment of new individuals from seeds. Plant flammability (F), on the other hand, refers to a plant’s effects on communities and ecosystems. These response and effect characteristics of plants in relation to fire have not been considered jointly before.

In this study, we proposed a three-dimensional model that combined R, S and F to explore recurrent combinations of these characteristics (hence “fire syndromes”). For each dimension, we assigned three possible categories, reflecting low, medium and high values of R, S and F, resulting in a total of 27 possible fire syndromes. Given that different fire histories (for example in relation to its frequency, intensity and seasonality) can shape the characteristics of plants, we argue that species from regions with different fire histories should have different fire syndromes.

Post-fire vegetation recovery in the Chaco seasonally dry woodlands of central Argentina. Post-fire dynamics depends not only on the response of plants to fire through resprouting and/or seeding, but also on how plants burn during fire, that is, on their flammability (credit: Pedro Jaureguiberry)

To illustrate our study, we used information on the fire syndromes of 24 species that are common in the Chaco seasonally-dry forest of central Argentina, where fire history is relatively moderate, and we compared them to 33 species from Mediterranean-type climate ecosystems (MTCEs), where fire history is long and intense. We found that MTCEs species had more variety of syndromes and higher values of R, S and F than Chaco species. We also collected information on 4,032 species from seven regions with contrasting fire histories, from long and intense (MTCEs) to very recent (New Zealand), and explored whether the values of R, S and F differed between them. We found significantly higher frequencies of high values of all three variables in MTCEs compared to the other regions, where intermediate and low values predominated, supporting our argument. Our model should contribute to the understanding of the role of fire in the evolution of plant characteristics across regions with contrasting fire regimes.

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