Taxonomic and Functional Resilience of Grasshoppers (Orthoptera, Caelifera) to Fire in South Brazilian Grasslands

Abstract

Fire is a frequent disturbance in grassland ecosystems enabling variability in habitat characteristics and creating important environmental filters for community assembly. Changes in vegetation have a large influence on herbivore insect assemblages. Here, we explored the responses of grasshoppers to disturbance by fire in grasslands of southern Brazil through a small-scale experiment based in paired control and burned plots. The resilience of grasshoppers was assessed by monitoring changes to their abundance, taxonomic, and functional parameters along time. Burned patches have been already recolonized by grasshoppers 1 month after fire and did not differ in terms of abundance and richness from control areas in any evaluated time within 1 year. Simpson diversity decreased 1 month after fire due to the increased dominance of Dichroplus misionensis (Carbonell) and Orphulella punctata (De Geer). In this period, grasshoppers presented in average a smaller body and a larger relative head size; these are typically nymph characteristics, which are possibly indicating a preference of juveniles for the young high-quality vegetation, or a diminished vulnerability to predation in open areas. Further, at 6 months after fire grasshoppers with smaller relative hind femur and thus lower dispersal ability seemed to be benefitted in burned patches. Finally, 1 year after fire grasshoppers became more similar to each other in relation to their set of traits. This study demonstrates how taxonomic and functional aspects of grasshopper assemblages can be complementary tools to understand their responses to environmental change.

Short-term spider community monitoring after cattle removal in grazed grassland

“…It is very possible that spiders and other invertebrates, such as beetles (Grandchamp et al, 2005;Woodcok et al, 2005), ants (Red & Andersen, 2000;Calcaterra et al, 2010) and grasshoppers (Hao et al, 2015;Ferrando et al, 2016) living in the vegetation could respond quicker and intensively to grassland management. Moreover, correlating abundance of these arthropods, would allow a better overview of how the fauna change without grazing perturbation.…”

“…In general it is not exactly know how the Pampa was before more than some 300 years ago, when disturbance increases dramatically after the European colonization due cattle introduction, uncontrolled fi re management, farming and silvicultural activities (Suertegaray & Silva, 2009;Rodrigues et al, 2010;Podgaiski et al, 2014;Ferrando et al, 2016). Considering theses disturbances, many components of the biota, as also the invertebrate fauna, should be directly aff ected.…”

Functional and taxonomic alpha and beta diversity responses to burning grasslands in southern Brazil

“…Firebreaks were assembled in 3‐m belts around each plot to prevent fire from spreading. Previous results of this experiment have been published elsewhere (fire‐related diversity of grasshoppers: Ferrando et al, 2016; spider assembly patterns: Podgaiski et al, 2013; detritivory and litter decay: Podgaiski et al, 2014; diversity of trips: Podgaiski et al, 2018) and details on the experimental design are addressed there.…”

Prescribed patch burnings increase thrips species richness and body size in grassland communities

“…Nevertheless, we pooled thrips data sampled from both methods for the analysis. More details on the study site and experimental design can be found in Podgaiski et al (2013Podgaiski et al ( , 2014, and Ferrando et al (2016).…”