A review of fire effects across South American ecosystems: the role of climate and time since fire

Abstract

Background Fire is an important driver of ecosystem dynamics worldwide. However, knowledge on broad-scale patterns of ecosystem and organism responses to fires is still scarce. Through a systematic quantitative review of available studies across South America, we assessed fire effects on biodiversity and abundance of different organisms (i.e., plants, fungi, invertebrates, and vertebrates), plant fitness, and soil properties under four climate types, and time since the last fire (i.e., early and late post fire). We addressed: (1) What fire effects have been studied across South America? (2) What are the overall responses of biodiversity, abundance, fitness, and soil properties to fires? (3) How do climate and time since fire modulate those responses? Results We analyzed 160 articles reporting 1465 fire responses on paired burned and unburned conditions. We found no effect of fire on biodiversity or on invertebrate abundance, a negative effect on woody plant species and vertebrate abundance, and an increase in shrub fitness. Soil in burned areas had higher bulk density and pH, and lower organic matter and nitrogen. Fire effect was significantly more positive at early than at late post fire for plant fitness and for soil phosphorus and available nitrogen. Stronger negative effects in semiarid climate compared to humid warm climate suggest that higher temperatures and water availability allow a faster ecosystem recovery after fire. Conclusions Our review highlights the complexity of the climate–fire–vegetation feedback when assessing the response of soil properties and different organisms at various levels. The resilience observed in biodiversity may be expected considering the large number of fire-prone ecosystems in South America. The recovery of invertebrate abundance, the reduction of the vertebrate abundance, and the loss of nitrogen and organic matter coincide with the responses found in global reviews at early post-fire times. The strength of these responses was further influenced by climate type and post-fire time. Our synthesis provides the first broad-scale diagnosis of fire effects in South America, helping to visualize strengths, weaknesses, and gaps in fire research. It also brings much needed information for developing adequate land management in a continent where fire plays a prominent socio-ecological role.

Fire affects galling insect communities through vegetation changes in a subtropical seasonally semiarid forest

“…In addition, our results underline that unburned plots are exclusive habitats for a few galling insects and plants species, suggesting the importance of unburned sites for conservation purposes, particularly considering the scarce cover of unburned native forest in our study area (Argañaraz et al, 2020; Giorgis et al, 2017). In addition, given the high frequency of fire events in the study area (Argañaraz et al, 2020), it would be interesting to delve into the study of these non‐linear relationships between plant and galling insect communities, including additional fire scenarios, different times since the last fires and ideally different fire severities (Giorgis et al, 2021). Moreover, it would be interesting to extend the study of fire to the third trophic level and its interactions, to better understand the effects of fire on these forest ecosystems.…”

“…The total or partial removal of plant biomass by fire triggers successional changes in plant biodiversity and species composition, with consequent implications on the trophic web structure and species interactions (Bowman et al, 2016; He et al, 2019). Immediately after a fire, mobile organisms show different recovery rates, depending on their particular ecology and strategies to cope with fire, such as refuges and recolonisation (Giorgis et al, 2021; Pausas, 2019). Thus, studies about the effects of fire on insects have shown a broad range of responses related to different species traits, such as occupied trophic level, dispersal ability, functional group, and feeding strategy (Carbone et al, 2019; Kral et al, 2017; Moretti et al, 2006; Swengel, 2001).…”

Mapping South America’s Drylands through Remote Sensing—A Review of the Methodological Trends and Current Challenges

“…How may fire frequency be altering dryland's biodiversity at different scales? A very recent study indicated that available information on the fire regime remains limited for the continent [157]. Therefore, studies focused on fire perimeters, in addition to the severity mapping and landscape controls of fires, would help advance our knowledge about fire in drylands and be powerfully supported by LULC maps.…”

Survival and growth of cactus species after a wildfire in central Argentina: Differences among species and the effects of microenvironment characteristics

“…Most of the ecosystems where cacti occur are subject to different natural and anthropogenic disturbances (Goettsch et al 2015). Natural and human-induced fires are among the most important disturbances in the dry ecosystems of the Americas (Bond & Wilgen 1996;Kowaljow et al 2019;Giorgis et al 2021). Indeed, climatological models predict a worldwide increase in fire intensity and frequency because of global climate change (Pausas et al 2004;Wang et al 2015;Andela et al 2017).…”

“…2019; Giorgis et al . 2021). Indeed, climatological models predict a worldwide increase in fire intensity and frequency because of global climate change (Pausas et al .…”