Biology subjects

Dreyer, E.

Publications and source records attributed to Dreyer, E..

2 recordsLinked to original sources

bioRxiv2025

Riparian Vegetation and Water Quality: A Case Study of Protected and Unprotected Rivers in the Atlantic Rainforest of Brazil

The Atlantic Rainforest, a biodiversity hotspot, has undergone significant fragmentation, with only 11% to 16% of its original cover remaining. Freshwater ecosystems within this rainforest are essential habitats, hosting high levels of biodiversity. This study assessed water quality and freshwater invertebrate diversity in rivers within and outside protected areas of the Non-Governmental Organisation Iracambi in Minas Gerais, Brazil, during the wet season from September to December 2022. We hypothesised that rivers with riparian vegetation would exhibit higher biotic indices and overall better water quality compared to unprotected rivers. Abiotic parameters air and water temperature, salinity, pH, conductivity, dissolved oxygen, flow rate, and nitrate concentration, were measured across 16 river sites, and freshwater invertebrates were surveyed to calculate Biotic Indices based on pollution tolerance. Results indicated that protected sites had a significantly higher mean biotic index compared to unprotected sites, suggesting better water quality in protected areas. Species richness was also higher in protected rivers, with 16 taxa identified compared to 11 in unprotected rivers. Pollution-tolerant species, such as Annelida and Argulidae, were more prevalent in unprotected rivers, while pollutant-intolerant species, such as Plecoptera and Spinadis, were more common in protected rivers. These findings highlight the importance of riparian vegetation in maintaining water quality and biodiversity, highlighting the need for ongoing monitoring and conservation initiatives in the Atlantic Rainforest especially in remote or isolated areas.

ecology↗

bioRxiv2018

Genomics of microgeographic adaptation in the hyperdominant Amazonian tree Eperua falcata Aubl. (Fabaceae).

Plant populations can undergo very localized adaptation, allowing widely distributed populations to adapt to divergent habitats in spite of recurrent gene flow. Neotropical trees - whose large and undisturbed populations often span a variety of environmental conditions and local habitats - are particularly good models to study this process. Here, we carried out a genome scan for selection through whole-genome sequencing of pools of populations, sampled according to a replicated sampling design, to evaluate microgeographic adaptation in the hyperdominant Amazonian tree Eperua falcata Aubl. (Fabaceae). A high-coverage genomic resource of [~]250 Mb was assembled de novo and annotated, leading to 32,789 predicted genes. 97,062 bi-allelic SNPs were detected over 25,803 contigs, and a custom Bayesian model was implemented to uncover candidate genomic targets of divergent selection. A set of 290 divergence outlier SNPs was detected at the regional scale (between study sites), while 185 SNPs located in the vicinity of 106 protein-coding genes were detected as replicated outliers between microhabitats within regions. Outlier genomic regions are involved in a variety of physiological processes, including plant responses to stress (e.g., oxidative stress, hypoxia and metal toxicity) and biotic interactions. Together with evidence suggesting microgeographic divergence in functional traits, the discovery of genomic targets of microgeographic adaptation in the Neotropics is consistent with the hypothesis that local adaptation is a key driver of ecological diversification, operating across multiple spatial scales, from large- (i.e. regional) to microgeographic- (i.e. landscape) scales.

evolutionary biology↗