The Holy Loch nature reserve - Biodiversity research

Just how many species use Holy Loch Nature Reserve is still unclear in the fourth year of recording; we have now recorded 3331 species.
74% are invertebrates, 70% are insects and 35% are species of fly. 30% are species unknown to science and can only be identified via their unique DNA barcode. New insects are being trapped every month, even in the fourth year. The majority of species are very rare in the data set. Hundreds of species have not been recorded in the UK before, even more are unrecorded in Scotland.
Once soil DNA analysis starts in June 2026, those numbers will jump dramatically with soil dwelling worms and fungi. Complex predictive statistics suggest the species list could peak at around 7000. That's the #HLNR target!
The database is huge and growing, Holy Loch Nature Reserve has the highest known biodiversity of any small nature reserve in Scotland. FULL STOP.

Why are we using eDNA in the Soil?

We’re about to begin soil eDNA sampling at the Reserve because most of the fungi driving the reserve ecosystem are invisible. Fungi break down dead material, release nutrients, build soil structure, and form the underground networks that keep plants alive — but you can’t see any of that by eye. They are also food for hundreds of the reserve's invertebrates.
eDNA will let us detect the hidden fungi and map whole soil communities across every habitat — from the perched carr to the alder swamp, the aquifer‑fed flush, the vegetated shingle, and the full saltmarsh gradient.

All barcoding is carried out by UK Bioscan at the Sanger Institute and is funded by Wellcome.
Research funded by the Blodwen Lloyd Binns bequest administered by Glasgow Natural History Society and carried out by our partner The eDNA Consultancy.

the reserve biodiversity

May 2026 news - Reserve woodland categorised as rainforest

In just 75 years, the woodland has self-regenerated from scratch into a celtic rainforest with many species of plant you'd expect in an ancient woodland, most likely due to the inclusion of seeds and bulbs in soil dumped there by council workers over decades. See the news article in The Herald here.
There is a more detailed paper from the reserve ecologist, Dr Neil Hammatt, here .

January & February 2026 news round-up

January saw Andreas Wolff from BBC Alba make a news article about the return of our wonderful Holy Loch seagrass, with another article published in Scottish Field.
And, with a fantastic thank you, a group of volunteers carried out a huge plastics clean-up across the saltmarsh. In February, the reserve was awarded £1,000 from Glasgow Natural History Society to further research soil fungi across the reserve.

September news, National Biodiversity Network Award Finalists

The Reserve is very pleased to have been recognised for its biological recording with an award nomination from the National Biodiversity Network (NBN).
Full details here: Shortlist announced – NBN Awards for Wildlife Recording 2025
Biological recording lies at the heart of everything we do: every sighting, from the common to the rare, adds to a bigger picture of how wildlife is changing and helps shape decisions that protect nature for the future. Being recognised by the NBN is a testament to the dedication of everyone involved in recording at Holy Loch Nature Reserve, and highlights how local observations can contribute to national and global understanding of biodiversity.

August news, HEALTH REPORT

Using our vast and growing, database of invertebrates on the reserve, after four years I have finally been able to apply some basic ecological tests to get a health report for the woodland.
The AI-generated report is next.
Shannon Diversity Index (H'): 4.10 This exceptionally high value points to a rich community with a large number of species and a complex ecosystem structure. A high diversity index suggests that the ecosystem is resilient and can withstand environmental changes, as a loss of one species is less likely to have a catastrophic effect on the entire system.
Pielou's Evenness Index (J'): 0.88 This value, which is very close to its maximum of 1, indicates that the population is well-distributed among species. No single species dominates the ecosystem, which is a hallmark of a stable and balanced community.
Gini-Simpson Index (1-D): 0.96 This index is a measure of resilience. Its remarkably high value signifies a very low probability that two randomly selected individuals will belong to the same species. This is a strong indicator of a resilient and stable community, capable of adapting to environmental pressures.
Rich Species Inventory
The detailed species inventory, organized by family, reveals a vast array of life forms, including insects from many different orders such as Diptera (flies), Hymenoptera (wasps and bees), Lepidoptera (moths), and Coleoptera (beetles). The presence of diverse families like Cecidomyiidae (gall midges) and Chironomidae (non-biting midges), which include numerous BOLD bins, further highlights the complexity and richness of the woodland's invertebrate community.
Overall, the data paints a picture of a flourishing ecosystem with a high number of different species, none of which are overly dominant. This balance and variety are fundamental to the long-term health and stability of the woodland.

The reserve, the Holy Loch and surrounding area

The Reserve - Imagine a Scotland far removed from today's familiar man-made landscapes.

As the last ice retreated, around 10,000 years ago, the first humans arrived, likely by boat, to a land fringed by the Atlantic. This wasn't the Scotland of bare moorland, farms, roads and monotonous conifer plantations we see today. Instead, its shores were cloaked in green, temperate rainforest, bordered by rich coastal ecosystems.
Their arrival would have been a sensory sensation. The scent of damp earth and the cacophony of unfamiliar birds and insects would have filled the air. Towering trees met the shoreline, their branches heavy with moisture, lichens, ferns and mosses. Along the coast, extensive reed beds swayed, and expansive, flat saltmarshes stretched out, merging with the land.
For these early inhabitants, the rainforest offered edible plants and animals, while reed beds and saltmarshes provided shelter, food, and other resources. Their lives became intimately connected to this dynamic landscape, shaping their culture and understanding of the world.
Today, only fragments of this ancient rainforest and these coastal wetlands remain, whispering tales of a time when humanity first encountered a land of wild beauty and abundant natural resources.
Visitors can still experience these incredible habitats at Holy Loch Nature Reserve, offering a glimpse into Scotland's primeval past.

The formal reserve area comprises around 24 acres of ungrazed coastal marsh, vegetated gravel, temperate rainforest and (damp) "carr" woodland, most of which has naturally regenerated on top of a now disused council's roads waste midden.
However, the area of interest extends across the wider saltmarsh and out into the Holy Loch itself.
The saltmarsh is intersected by several burns which flow from the hills into the Holy Loch. Over 20 small pools on the marsh support an array of water plants and animals. Some of the pools are permanent while others are ephemeral. At the highest spring tides, most of the marsh is inundated by the sea.
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