Rodent assemblage composition as indicator of fire severity in a protected area of south‐central Chile

Abstract

Fires have a considerable impact on biological communities and ecosystems, within which the assessment of burned habitats requires consideration of indicator species or assemblages useful for monitoring. The short‐term effects of fires can be easily deduced from analysing assemblages of animals with short generation times and high fertility rates, such as rodents. Here, we evaluated the effect of fire severity in a protected area of southern Chile on abundance, composition and diversity of rodent assemblages. We sampled rodents and vegetation variables during summer and fall over two years (2017 and 2018) in forest stands with different levels of fire severity (high, low and unburned stands). Changes in diversity and abundance were found between unburned and burned stands, with these differences being more noticeable during the fall of the first year. Abundances of rodent species exhibited marked fluctuations over the study period, but two species consistently decreased their abundances as fire severity increased, and with the absence of one species in burned stands. The adverse fire effects were less evident during the second year due to the overall low capture rates (1.3–1.9%). Rodent species were differently affected by fire, with Irenomys tarsalis (arboreal rat) being the species most sensitive to fires. The effect of fire severity on abundance of rodent species was associated with changes in the vegetation variables, where dead wood, canopy and herb cover showed a low correlation (R = 0.147). Our results suggest that fires of high severity cause important disturbances on habitat and food resources that result in short‐term effects on the rodent assemblage. Fires apparently act as an ecological filter for the more specialised species while offering an opportunity for the settlement of generalist species. Hence, the monitoring of rodent species differing in their ecological traits, such as food habits and space use, offers an opportunity for assessing the short‐term recovery patterns of wildlife after fire disturbances.

Fire regimes shape biodiversity: responses of avian guilds to burned forests in Andean temperate ecosystems of southern Chile

“…The three sites suffered high-severity fires, i.e., crown fires with > 90% of trees and understory vegetation charred, in the surveyed areas. Furthermore, there was a dense layer of ash in the soil (up to 30 cm in depth) and large holes in the ground caused by tree stumps that were completely carbonized through below-ground combustion with evidence of tree carbonization, root damage, and significant loss of shrub vegetation (CONAF 2017, Zúñiga et al 2021.…”

Effects of habitat management on rodent diversity, abundance, and virus infection dynamics

“…The high proportion of generalist and forest-specialist species in control sites is indicative of the consequences of habitat degradation in the absence of prairie management, particularly from woody encroachment and loss of non-woody diversity (Miller et al, 2000; Brunsell et al, 2017). Although some studies have shown that burning increases the relative abundance of habitat generalists (e.g., Manyonyi et al, 2020; Zúñiga et al, 2020), such outcomes generally represent the immediate effects of fire, as opposed to prolonged effects from a decade or more of management. Indeed, rodent diversity at several of our burned sites varied considerably from a previous assessment shortly after active management began (Nelson, 2005), most notably by an increase in our study of prairie voles and fulvous harvest mice, two grassland specialist species (Table 2).…”

“…Rodents are the most diverse mammalian taxon, comprising approximately 40% of mammal species worldwide (Burgin et al, 2018), and play crucial roles in ecosystems, including both bottom-up (e.g., seed dispersal; Sunyer et al, 2013) and top-down (i.e., common prey; Geng et al, 2009) processes. Because many rodent species have a fast pace of life strategy (i.e., r-selected), their communities also quickly respond to changes in the environment (Zúñiga et al, 2020). For example, female hispid cotton rats ( Sigmodon hispidus ), a common grassland rodent in the USA, can produce up to 12 pups/litter every four weeks throughout the breeding season (Espinoza and Rowe, 1979).…”

Altered fire regimes modify lizard communities in globally endangered Araucaria forests of the southern Andes

“…A dense ash layer of ~ 30 cm deep covered the soil, and large holes in the ground caused by carbonized tree stumps occurred frequently. Moreover, root damage and total shrub vegetation loss occurred during the fires 67 , 68 .

Figure 4 Forest conditions of the four “treatments”: ( a ) unburned control [old growth forest with 5,000 year old araucarias]; ( b ) “long-term recovery” (16 years) [abundant CWD, evident understory and canopy regrowth]; ( c ) “short-term recovery” (3 years) [abundant CWD, understory and canopy regrowth is still scarce]; ( d ) “burned twice” (3 years of recovery) [scarce CWD, understory regrowth is scarce and canopy almost nonexistent].

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