Biology subjects

Garrett, N. R.

Publications and source records attributed to Garrett, N. R..

4 recordsLinked to original sources

bioRxiv2025

Sampling intensity and temporal persistence of airborne eDNA in partially enclosed spaces

Airborne environmental DNA (eDNA) has shown promise as a terrestrial biomonitoring tool and its ecological applications are expanding. Despite its growing use, airborne eDNA does not yet have the extensive body of supporting research like its aquatic counterpart, with considerable uncertainty remaining concerning how airborne eDNA behaves, with regards to signal duration, and how much sampling effort is needed to capture DNA in a given airspace. By using airborne eDNA in a semi-controlled environment which acted as an artificial roost where bat species and their abundances were known, we estimated the sampling intensity (both the number of samples and number of sampling events) required to capture bat diversity of a given airspace, as well as signal persistence of airborne eDNA. Together these data provide a temporal scale for airborne eDNA measurements. The majority of species richness was detected using as little as 4 samplers in this enclosed space and the greater the number of sampling events, the fewer samplers were needed. Both air movement and the type of environment (i.e., enclosed space, open area etc.) are likely to impact detection and need to be considered during study design. eDNA also appeared to settle out of the air quickly, suggesting that detections likely reflect recent activity, which also has important implication for rare species which may only have a narrow window for detection. Our results add to the growing body of literature that indicate airborne eDNA can be a useful biosurvey method, especially for rapid surveys in communities with high turnover rates.

ecology↗

bioRxiv2025

Contrasted effects of human pressure on biodiversity in the UK: a multi-taxonomic assessment using airborne environmental DNA

Human activities have significantly modified habitats, resulting in a global biodiversity crisis. Here, we leveraged the first national-scale biodiversity survey based on airborne environmental DNA, comparing the effects of three human pressure indices increasing in complexity and scope across diverse vertebrates, insects, plants and fungi. While most taxa exhibited higher diversity in urban areas compared to rural ones, we uncovered more complex patterns using the landscape-pollution and human footprint indices, including dual diversity peaks at both high and moderate levels of human pressure. We also show an effect of human pressure on community composition even when local species richness remained stable: regardless of the human pressure index, anthropogenic sites were mostly characterized by synanthropic and invasive species. Overall, our results underscore the complex interactions among anthropogenic pressures, taxon diversity and community composition, demonstrating the value of multi-taxon analyses and multiple indices to better understand biodiversity patterns at large scales.

ecology↗

bioRxiv2025

First national survey of terrestrial biodiversity using airborne eDNA

Near real-time data across taxa are necessary for quantifying biodiversity at regional to continental scales and evaluating conservation measures. Yet, standardized methods and globally distributed infrastructure are still lacking. In this study, we conducted the first national survey of terrestrial biodiversity using a metabarcoding approach on airborne environmental DNA collected by a national ambient air quality monitoring network. Our goal was to perform a multi-taxonomic biodiversity assessment at a national scale, compare detections with those of another large-scale monitoring approach (citizen sciences) and estimate a tentative minimum eDNA transportation distance. We identified over 1,100 taxa, including vertebrates, invertebrates, protists, fungi and plants covering a wide range of life history traits and ecological niches. Citizen science and eDNA detections were complementary, with eDNA better mapping less charismatic and difficult to spot taxa, demonstrating its potential to align with global conservation goals. Airborne eDNA signals were relatively local, likely due to the deposition of the larger particles from the air over shorter distances and limited wind transportation at near ground level. Overall, our results show that molecular protocols integrated into existing air quality monitoring networks can provide standardized, biodiversity monitoring at relatively low field cost, with potential for broad scalability.

ecology↗

bioRxiv2022

Out of thin air: surveying tropical bat roosts through air sampling of eDNA

Understanding roosting behaviour is essential to bat conservation and biomonitoring, often providing the most accurate methods of assessing population size and health. However, roosts can be challenging to survey. Roosts can be physically impossible to access or present risks for researchers and disturbance during monitoring can disrupt natural bat behaviour and present material risks to the population e.g. disrupting hibernation cycles. One solution to this is the use of non-invasive monitoring approaches. Environmental (e)DNA has proven especially effective at detecting rare and elusive species particularly in hard-to-reach locations. It has recently been demonstrated that eDNA is carried in air and, when collected in semi-confined spaces can provide remarkably accurate profiles of biodiversity, even in complex tropical communities. In this study we deploy novel airborne eDNA collection for air for the first time in a natural setting and use this approach to survey difficult to access potential roosts in the neotropics. Using airborne eDNA we confirmed the presence of bats in 9 out of 12 roosts. The identified species matched previous historical records of roost use obtained from photographic and live capture methods demonstrating the utility of this approach. We also detected the presence of the white-winged vampire bat (Diaemus youngi) which had never been confirmed in the area but was long suspected. In addition to the bats, we also detected several non-bat vertebrates, including the big-eared climbing rat (Ototylomys phyllotis), which has previously been observed in and around bat roosts. We also detected eDNA from other local species known to be in the vicinity. Using airborne eDNA to detect new roosts and monitor known populations, particularly when species turnover is rapid, could maximize efficiency for surveyors while minimizing disturbance to the animals. This study presents the first applied use of airborne eDNA collection for ecological analysis and demonstrates a clear utility for this technology in the wild.

ecology↗