Fire and plant diversity at the global scale

Abstract

Aim Understanding the drivers of global diversity has challenged ecologists for decades. Drivers related to the environment, productivity and heterogeneity are considered primary factors, whereas disturbance has received less attention. Given that fire is a global factor that has been affecting many regions around the world over geological time scales, we hypothesize that the fire regime should explain a significant proportion of global coarse‐scale plant diversity. Location All terrestrial ecosystems, excluding Antarctica. Time period Data collected throughout the late 20th and early 21st century. Taxa Seed plants (= spermatophytes = phanerogamae). Methods We used available global plant diversity information at the ecoregion scale and compiled productivity, heterogeneity and fire information for each ecoregion using 15 years of remotely sensed data. We regressed plant diversity against environmental variables; thereafter, we tested whether fire activity still explained a significant proportion of the variance. Results Ecoregional plant diversity was positively related to both productivity (R2 = .30) and fire activity (R2 = .38). Once productivity and other environmental variables were in the model (R2 = .50), fire regime still explained a significant proportion of the variability in plant diversity (overall model, R2 = .71). The results suggest that fire drives temporal and spatial variability in many ecosystems, providing opportunities for a diversity of plants. Main conclusions Fire regime is a primary factor explaining plant diversity around the globe, even after accounting for productivity. Fires delay competitive exclusion, increase landscape heterogeneity and generate new niches; thus, they provide opportunities for a large variety of species. Consequently, fire regime should be considered in order to understand global ecosystem distribution and diversity.

The sedimentary and remote‐sensing reflection of biomass burning in Europe

“…That the best regression model is related to fire number for both tMIC and tMAC is surprising given that the majority of recent studies suggest significant relationships between charcoal and burned area or fire intensity (Colombaroli & Gavin, ; Duffin et al, ; Higuera et al, ; Leys et al, , Appendix S13). Early calibration studies, where regional scales and/or long historical fire records were considered (MacDonald et al, ; Tinner et al, ) also identified fire number as a significant factor explaining charcoal abundance at regional scales, in accordance with more recent observations (Pausas & Ribeiro, ). Furthermore, this parameter is very sensitive to uncertainties in the amount of time contained within a sediment sample, possibly explaining why it was not significant in studies where only charcoal concentrations (and not influx) were calculated (Duffin et al, ; Whitlock & Millspaugh, ).…”

“…intensity) and area burned. Fire frequency has been found to be indicative of a region's fire-related land-use practices and population densities (Catry et al, 2010) but is also linked to regional fire-proneness and flammability (Pausas & Ribeiro, 2017). While fire intensity refers to the energy release of a fire, the area burned is related to fuel connectivity and is useful for calculating fire rotation periods (Bond & Keeley, 2005), as well as fire-related carbon emissions (van der Werf, Peters, van Leeuwen, & Giglio, 2012).…”

A global synthesis of fire effects on pollinators

“…Fires not only modify plant and animal community compositions, but also the biotic interactions (García, Castellanos, & Pausas, ; Pausas & Parr, ), with consequences for ecosystem functioning and the services they provide. While the effect of wildfires on plant communities is well studied across many ecosystems around the world (Bradstock, Williams, & Gill, ; Keeley, Bond, Bradstock, Pausas, & Rundel, ; Pausas & Ribeiro, ), their effect on biotic interactions is still poorly known. An especially relevant interaction is pollination, as most flowering plants (85%), including most crops (75%), rely on animal pollinators for sexual reproduction (Klein et al, ; Ollerton, Winfree, & Tarrant, ).…”

Cambios florísticos inducidos por la frecuencia de fuego en el Chaco Serrano.

“…A escala global la diversidad vegetal responde positivamente con la actividad del fuego, debido a que este retrasa la exclusión competitiva, y genera heterogeneidad de ambientes y nuevos nichos (Pausas & Ribeiro, 2017). Sin embargo, la respuesta al fuego a escala local puede variar entre biomas y ecosistemas (Pausas & Ribeiro, 2017).…”

“…Sin embargo, la respuesta al fuego a escala local puede variar entre biomas y ecosistemas (Pausas & Ribeiro, 2017). Nuestro trabajo muestra que en base a 23 años de registro de la frecuencia de fuego, la riqueza vegetal no responde de acuerdo con lo predicho por la hipótesis de disturbio intermedio (Connell, 1978;Huston, 1979), pues aquí observamos la menor riqueza de especies tanto en los sitios de baja como de alta frecuencia de fuego.…”