Table 1.
Description of spider and plant traits used in the study.
Table 2.
Vegetation variables in burned and unburned experimental plots at different sampling periods.
Table 3.
Summary of the results of spider functional resilience to fire.
Figure 1.
Relationships between spider traits and vegetation traits in burned and control plots.
Co-inertia analysis results: (A) ordination of control (light-green symbols) and burned plots (dark-orange symbols) based on spider (triangle) and plant traits (square); PCA of (B) spider and (C) plant traits. Short arrows indicate that the plant and animal traits occupy similar positions in the ordination space. Numbers (1 to 7) indicate the blocks. Highlighted traits (B, C) mean significant association with burned or control plots.
Figure 2.
Spider assembly patterns in ecological gradients.
Trait convergence assembly pattern (TCAP) under gradients of plant biomass (A) and plant FD (B). Trait divergence assembly pattern (TDAP) in gradient of plant FD (C). The TDAP plot is composed of an ordination diagram generated on Euclidian distances computed on the composition of spiders communities after fuzzy weighting by the traits which maximized the expression of TDAP (body, chel, eye, iw, ow) related to plant FD. Green symbols mean control plots and orange symbols mean burned plots.
Table 4.
Summary of the results of spider assembly patterns in ecological gradients.
Figure 3.
Conceptual map of the main findings of the study for an intermediated time after fire.
Unburned plots were most characterized by graminoid-form and taller plants leading to increased proportions of ground hunter spiders. Plant biomass gradient also acted as an important environmental filter for this kind of spiders probably by maintaining proper conditions of shelters and microclimate in soil surface. On the other hand, burned plots presented increased proportions of rosette-form plants with broader leaves which favored spiders building orb webs; this hunting strategy also converged positively in the plant FD gradient influenced by suitable vegetation structure to attach their webs. Additionally, spider individuals occurring in more functionally diverse plant communities were more functionally diverse concerning their traits (body, chelicerae and eye size, and web type building) because functionally diverse plant communities provide more ecological niches and increased possibility of resource exploitation, following the habitat heterogeneity hypothesis. Photo in the left: Araneidae web in Eryngium horridum (Apiaceae) by Denise Dell'Aglio; Photo in the right: Lycosa erythrognatha by Estevam Cruz.