Biology subjects

Andrello, M.

Publications and source records attributed to Andrello, M..

4 recordsLinked to original sources

bioRxiv2023

Spatial conservation prioritisation for intraspecific genetic diversity of three forest tree species with a fragmented distribution in Italy

The Kunming-Montreal Global Biodiversity Framework recognised the urgency of taking action to conserve intraspecific genetic diversity (IGD) as an insurance against habitat degradation and environmental change. Recent work suggests that 90-99% of IGD should be conserved to safeguard viability of future generations. Here, we addressed such a conservation issue in three forest tree species in Italy: silver fir (Abies alba Mill.), Heldreichs pine (Pinus heldreichii H. Christ), and pedunculate oak (Quercus robur L.). We used microsatellite markers to measure IGD of 36 (A. alba), 15 (P. heldreichii) and 25 (Q. robur) natural sites, including several putative glacial refugia. We developed a spatial conservation planning (SCP) analysis to quantify the genetic irreplaceability of each site and identify the minimum set coverage ensuring IGD protection. Finally, we compared SCP results with the contributions to allelic diversity within and between sites, total allelic diversity and private allelic richness. We found that between 44% and 73% of sites were required to conserve 90-99% of the alleles, and that this conservation effort held even when targeting lower percentages of alleles to protect (50-75%). Glacial refugia were often included in the minimum set coverage, confirming theoretical and biogeographical expectations. Finally, sites with high genetic irreplaceability were found to have higher private allelic richness on average. These results are discussed in the light of the biogeographic history of the species studied and the current policies for the conservation of forest genetic resources.

evolutionary biology↗

bioRxiv2022

Global connectivity and networks of marine reserves

Cooperation between countries in managing and protecting shared marine resources is beneficial both ecologically and economically, but how best to establish the cooperation needed at a global scale is largely unknown. Here, we used hydrodynamic modelling to identify ecologically connected networks of marine reserves (MRs) and evaluated these networks with socio-economic indicators. Most of the networks are homogenous with similar levels of development, shared languages, and other cultural values. However, we found that 17% (11/66) of the largest networks (>20 MRs) span multiple countries. These heterogenous networks are composed of countries with different economic, political, and cultural views. Countries that control more, larger marine reserves also have a more even ratio of source reserves to sinks. We discuss that, while such economic and cultural homogeneity might lead to more efficient ecological management in the short term, heterogeneous networks may prove to be more resilient in the longer term, when climate change will modify marine connectivity.

systems biology↗

bioRxiv2021

How many replicates to accurately estimate fish biodiversity using environmental DNA on coral reefs?

Quantifying the diversity of species in rich tropical marine environments remains challenging. Environmental DNA (eDNA) metabarcoding is a promising tool to face this challenge through the filtering, amplification, and sequencing of DNA traces from water samples. However, the reliability of biodiversity detection from eDNA samples can be low in marine environments because eDNA density is low and certainly patchy in this vast, heterogenous and dynamic environment. So, the number of sampling replicates and filtered volume necessary to obtain accurate estimates of biodiversity in rich tropical marine environments using eDNA metabarcoding is still unknown. Here, we used a paired sampling design of 30L per replicate on 68 reef transects from 8 sites in three tropical regions and identified fish Molecular Taxonomic Units (MOTUs) using a 12S marker. We quantified local biodiversity variation as MOTU richness, compositional turnover and compositional nestedness between replicated pairs of seawater samples. We report strong turnover of MOTUs between replicated pairs of samples undertaken in the same location, time, and conditions. Paired samples contained non-overlapping assemblages rather than subsets of one-another. As a result, localised diversity accumulation curves showed that even 6 replicates (180L) in the same location underestimated local diversity (for an area <1km). However, sampling of regional diversity using [~]25 replicates in variable locations (often covering 10s of km) achieved saturation of biodiversity accumulation curves. Our results demonstrate high variability of diversity estimates perhaps arising from heterogeneous and local distribution of eDNA distribution in seawater or highly skewed frequencies of eDNA traces. This high compositional variability has consequences for using eDNA to monitor temporal and spatial biodiversity changes of local assemblages. Future biomonitoring efforts could be strongly undermined by a high level of false-negative detections under low replication protocols. We reveal the need to increase replicates or increase sampled water volume to better inform management of marine biodiversity using eDNA.

ecology↗

bioRxiv2021

A global map of human pressures on tropical coral reefs

As human activities on the worlds oceans intensify, mapping human pressures is essential to develop appropriate conservation strategies and prioritize investments with limited resources. Here, we map non-climatic pressures on coral reefs using the latest quantitative data layers on fishing, nitrogen and sediment pollution, coastal and industrial development, and tourism. Across 54,596 coral reef pixels worldwide, we identify the top-ranked local pressure and estimate a cumulative pressure index mapped at 0.05-degree ([~]5 km) resolution. Fishing was the most common top-ranked pressure followed by water pollution (nutrients and sediments), although there is substantial variation by regions. We also find that local pressures are similar inside and outside a proposed global portfolio of coral reef climate refugia. We provide the best available information to inform critical conservation strategies and ensure local pressures are effectively managed to increase the likelihood of the persistence of coral reefs to climate change.

ecology↗