Search bioRxiv⌕ Search

Biology subjects

Hasui, E.

Publications and source records attributed to Hasui, E..

2 recordsLinked to original sources

Relative fire-proneness of land cover types in the Brazilian Atlantic Forest

Fires are increasingly affecting tropical biomes, where landscape-fire interactions remain understudied. We investigate the fire-proneness--the likelihood of a land use or land cover (LULC) type burning more or less than expected based on availability--in the Brazilian Atlantic Forest (AF). This biodiversity hotspot is increasingly affected by fires due to human activities and climate change. Using a selection ratio-based approach, we analyzed fire-LULC interactions in 40,128 fires over a 35-year period (1987-2022) across various ecoregions in the AF. Our findings revealed that secondary forests, forest areas that have regrown after major disturbances, burned 61% more than expected by chance, whereas old-growth forests, native forests that have developed over very long periods, burned 57% less than expected, highlighting a nearly inverse relationship in their fire-proneness. Interestingly, our data indicate that pastures in the AF are less prone to fire than expected, despite being considered among the land uses that burn the most in Brazil. Other LULCs showed variable fire-proneness, with some differences between ecoregions. Over time, the fire-proneness of secondary forests decreased, likely due to forest aging and changes in land management practices. We emphasize the necessity for tailored fire management strategies that address the unique vulnerabilities of secondary forests, particularly in the context of ongoing restoration efforts aimed at increasing native forests. Effective measures, including the implementation of fire-smart management practices and enhancing the perceived value of secondary forests among local communities, are crucial for mitigating fire risks. Integrating these strategies with incentive-based approaches can bolster fire prevention, ensuring the long-term success of restoration programs. Our study provides a framework for understanding fire-landscape dynamics in tropical forests and offers actionable insights for practitioners working to safeguard these biomes from the escalating threat of wildfires. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=182 HEIGHT=200 SRC="FIGDIR/small/604452v2_ufig1.gif" ALT="Figure 1"> View larger version (70K): org.highwire.dtl.DTLVardef@612bc4org.highwire.dtl.DTLVardef@1806cc0org.highwire.dtl.DTLVardef@63c47corg.highwire.dtl.DTLVardef@1f8b252_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIEvaluation of land cover fire-proneness in a tropical biome using a selection ratio. C_LIO_LISecondary forests burned 61% more; old-growth forests 57% less than expected by chance. C_LIO_LIPastures in the Atlantic Forest seem less fire-prone than expected, despite frequent burns. C_LIO_LIFire-proneness of secondary forests has generally been decreasing over time. C_LIO_LITailored fire management is essential to protect secondary forests in restoration efforts. C_LI

ecology↗

Different phylogenetic characteristics of Icterids: would they be evolutionary strategies to avoid parasitism by Molothrus spp.?

Some birds exhibit the behavior of nest parasitism, which involves laying their eggs in the nests of other species to be incubated and cared for by the adoptive parents. Among all the studies conducted on this subject, there is a gap regarding the nest type of nest parasites and their hosts. Therefore, using species from the Icteridae family, this study aimed to identify if there is a tendency for more closed nests to be less parasitized than open nests and if there is a phylogenetic relationship between them. In this context, we expected open nests to be an ancestral condition to closed nests, serving as an evolutionary feature to avoid nest parasitism. We also analyzed other characteristics such as the number of eggs, nest type and parental care. As a result, we observed that open nests were more common, while closed nests were predominant in a specific clade and some isolated species. The analyses indicated a phylogenetic signal clustered within the Icteridae family concerning nest types, which may imply a selective pressure. However, we cannot assert that it is a direct response to nest parasitism, as closed nests are also parasitized, specifically by M. oryzivorus. Parental care and diet type also showed phylogenetic signal, indicating that these changes were not random. However, we did not observe associations in host selection by the parasites based on these characteristics. Furthermore, we found a progression in the number of species parasitized by Molothrus spp. along the phylogenetic lineage. We also observed a similarity in host choice between M. ater and M. aeneus, indicating evolutionary convergence, as they are not sister groups.

ecology↗