Using a model based fourth-corner analysis to explain vegetation change following an extraordinary fire disturbance

Abstract

In ecosystems where large-scale disturbances are infrequent, the mode of succession may be difficult to discern and floristic surveys alone cannot be used determine the underlying processes causing vegetation change. To determine the causes of vegetation change in response to a large-scale fire event, we combined traditional floristic survey data, plant functional traits and environmental variables in a model-based solution to the fourth-corner problem. This approach allowed us to describe the trait-environment relationship and provides an intuitive matrix of environment by trait interaction coefficients. We could then quantify the strength and direction of associations between plant traits, species life-forms and environmental factors in two alpine plant communities over nine years post-fire. Initially, the fire drastically reduced vegetation cover and species density to very low levels. The fourth-corner analysis interaction coefficients indicated that over the course of the nine-year study a high abundance of graminoids, a low abundance of shrubs, tall species and those with high leaf dry matter content had the strongest associations with the two plant communities. We also found evidence for functional homogenisation between these two communities using this novel technique. Analysing plant traits and species responses post-fire in this manner can be used to infer the ecological processes driving shifts in vegetation.

The potentiality of Sentinel-2 to assess the effect of fire events on Mediterranean mountain vegetation

“…However, extreme events, such as fires, can have very important effects on the structure and composition of grasslands (Venn et al 2016). In the study area, a collapse of the vegetation cover just after the event was observed, followed by a recovery that favored the abundance of graminoids species with a large seed bank, as reported by Buma (2012).…”

Dynamics in plant diversity and composition on Australian alpine summits over time

“…Of particular issue for Australian alpine regions, is increasing fire severity and frequency with climate change (Hennessy et al 2005;Zylstra 2018), as these regions have historically experienced few fires (Dodson et al 1994;Kirkpatrick and Bridle 2013;Williams et al 2008). While some alpine vegetation communities have recovered from fire in the past, specialist communities and cryophilic species had limited capacity to recover post fire (Kirkpatrick et al 2010;Venn et al 2016). In the past decades, fires in the Australian Alps are becoming hotter, more frequent and covering larger areas with fires burning into alpine areas previously thought to have low flammability.…”

Spatial analysis of the Morrone wildfires (Majella National park, Central Italy) by remote sensing images

“…Tuttavia eventi straordinari come l'incendio oggetto di studio, possono avere degli effetti molto importanti sulla struttura e la composizione specifica delle praterie. Alcuni studi hanno dimostrato un crollo della copertura della vegetazione appena dopo l'evento, seguito da un recupero che ha favorito l'abbondanza di graminacee (Venn et al 2016).…”