Biodiversity Health Check

Theme:	ECOLOGY NETWORKS
Current Topic:	Nature Recovery Plan
Thread Title:	Biodiversity Health Check
Thread Number:	5 of 7
Learning Focus:	Dive into the biological data of Salcombe Hill. From rare Wood White butterflies to ancient fern populations, explore the species that define this unique Devon ecology network..

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To the casual observer, the rolling landscapes surrounding Salcombe might appear as little more than a pleasant, pastoral backdrop, a simple arrangement of grass and trees. It is easy to dismiss these green spaces as mere scenery, yet beneath this familiar surface lies a complex, invisible engine of life. The Salcombe ecological network is no monolithic parkland; it is a hidden powerhouse of biological diversity, functioning as a vital sanctuary for a vast array of specialised species that often go unnoticed.

This exploration reveals the most impactful findings from a recent biodiversity survey conducted across eleven distinct local sites. While these records are born from a series of "casual visits" rather than an exhaustive multi-year census, the evidence reveals a landscape at a crossroads. From the microscopic to the majestic, the network supports a significant degree of biodiversity across all four primary categories of life, asserting an ecological weight that far exceeds its geographic footprint.

Our mission is to look beyond the general greenery and understand the specific residents of this network. By moving past academic summaries, we can uncover which populations are flourishing, which are facing a perplexing silence, and how our local management choices can safeguard the long-term vitality of our environment.

The Fern Paradise: Why Salcombe is a "Pteridophyte" Haven

One of the most striking revelations from the survey is the extraordinary success of Pteridophytes, more commonly known as ferns. While the eleven sites of the Salcombe network represent only a fraction of the broader Sidmouth region, they hold a staggering 73.3% of all fern species recorded in the entire survey area. This concentration transforms the network into a genuine regional stronghold for this ancient and resilient lineage of plants.

These ferns are not scattered haphazardly; they have claimed the shaded sanctuaries of our woodland areas and the sheltered, humid corridors of Milltown Lane. This diversity is particularly poignant when compared to other spore-producing plants like mosses. For instance, while you will find "enormous quantities" of moss in Page Wood, the variety there is surprisingly thin, dominated almost exclusively by two species: Plait-leaved Cypress-moss (Hypnum cupressiforme) and Wood Star-moss (Mnium hornum). The ferns, by contrast, have found a way to diversify and thrive, proving that these specific microclimates are of irreplaceable value.

The Lepidoptera Stronghold: More Than Just Common Butterflies

In the arthropod world of Salcombe, the Lepidoptera, the vibrant order of butterflies and moths, reign supreme. The survey confirmed that 58.7% of the total species recorded in the region are actively utilising this network. During the heat of mid-summer, our hedgerows and grasslands are not just scenery; they are bustling highways of movement and reproduction.

The network supports a vital balance between well-known neighbours and elusive rarities. While a walk through the grass will easily kick up the Meadow Brown, the Gatekeeper, and various "whites," the area also provides a critical refuge for species that are increasingly hard to find elsewhere. These include the Dark-green Fritillary, the Wall, and the nationally scarce Wood White.

The survival of these winged icons is tied directly to the health of their habitat. The proposed management plans to enhance our grasslands and hedgerows are not just aesthetic improvements; they are essential life-support systems for these populations.

The Silent Skies: Unpacking the Decline of Local Birds

Perhaps the most sobering discovery is a perplexing silence where there should be song. Bird diversity within the network is surprisingly low, sitting at just 32.1%. For a network of eleven sites with such varied terrain, this figure is a loud alarm bell, reflecting both national pressures and local habitat challenges.

This decline is driven by two primary factors. Beyond the general national struggle of farmland birds, our local woodlands are currently paying the price for historical planting choices. Large stretches of these woods consist of conifer plantations, monocultures that lack the structural diversity and rich insect life found in native forests. Most woodland birds find these "evergreen deserts" inhospitable for nesting or foraging. The solution requires an urgent, long-term shift: by restoring open, broadleaf-based woodlands and fostering insect-rich grasslands, we can begin to invite the music back into our skies.

In Defence of "Hated" Weeds: The Diptera Connection

What many gardeners dismiss as "untidy" or "weedy" is actually a vital pollinator buffet. The "umbellifer" flowers, those with umbrella-like clusters such as Wild Carrot, Hogweed, Corky-fruited Water-dropwort, and Wild Angelica, serve as the infrastructure for the network’s Diptera (flies and hoverflies). Currently, these sites support 56.4% of regional Diptera species, which act as the ecosystem's essential clean-up crew and secondary pollinators.

Even the frequently "hated" Alexanders play a role of immense value. Often targeted for removal because of their vigorous growth, these plants provide a critical early-season food source for flies and hoverflies emerging when few other flowers are in bloom. By reframing our view of these overlooked plants, we protect the insect base that sustains the entire food chain.

The Missing Bees: A Call for More Clover

While butteflies and flies are holding their ground, the Hymenoptera, our bees, wasps, and ants, are significantly under-represented at only 39.3%. While the shadow of regional pesticide use looms large, the survey highlights a specific, localised hunger: a lack of the Leguminaea (the pea family).

Many of our most critical bee species are specialists that rely on Leguminaea plants, such as clover and vetch, for high-quality nectar and pollen. Currently, this family is missing from many areas within the network. To rectify this, we need a rallying cry for more clover. A simple, practical shift in how we seed and mow our grasslands could provide the forage necessary to bring our pollinators back from the brink.

Conclusion: A Network in Transition

The Salcombe network is a landscape of profound ecological weight, holding over half of the region's flora and two-thirds of its grass species across just eleven sites. However, it is clearly a network in transition. While it remains a stronghold for ferns and butterflies, the data reveals an environment under stress, particularly regarding our birds and bees.

Our management choices today will dictate the biodiversity of tomorrow. The evidence suggests that even focused, small-scale interventions, planting more broadleaf trees to replace conifers or encouraging the humble clover in our fields, can fundamentally reshape the survival of our local species. How we choose to manage these green spaces will determine whether the hidden world in our backyard continues to fade or begins a vibrant new chapter.

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