Overview
The Sussex Wildlife Trust has some 32 nature reserves, home to a large number of interesting, unusual species, and comprised of rich, diverse habitats. This talk will not only look at these interesting components but will also examine the ecological relations underpinning these places, including their geology, hydrology and climate. We will start large scale, looking at our place on the globe and indeed in our solar system and then focus down to some familiar, and perhaps not so familiar places in Sussex.
Lynn’s Review
This month, Science at Fishbourne, welcomed Dr Tony Whitbred, former Chief Executive of the Sussex Wildlife Trust. We always look forward to his talks, learning something new each year. You can find my review of his talk last year: “There is No Wealth but Life,” here.
Dr Whitbred, began with some facts about The Sun; the star at the centre of our solar system; our source of heat and light, radiating energy equivalent to 2 billion atom bombs per second, or a boiling kettle every 2 sq m. That energy has been intercepted by plants over the past 3 ½ billion years. It then flows from plants to herbivores and on to carnivores. The energy, decreases as it goes through each layer of life’s pyramid, dissipating through the environment, so that only about 10% is carried forward into each layer.
Plants are more abundant where warmth is consistent and sunlight and water are present, and so climate affects which plants and animals will be found around the globe.
Ocean currents, play their part in our climate, making it warmer than it should be, considering our latitude. The Gulf Stream brings warm water from near the equator to our region. Overturning circulation is a system of ocean currents which form a vertical loop across the Atlantic Ocean, where warm surface water is carried from the Equator to the poles. Here, the water cools, sinks and returns at depth, towards the equator.
In Sussex our climate is influenced by remnant areas of the Atlantic micro climate, and by the Continental Climate (having more extremes than a temperate climate). The geography of the Downs, once a huge chalk dome which extended across Sussex, Surrey and North Kent, now eroded by weathering and time, has a complex geology of greensand, clay and chalk.
Sussex habitats are naturally affected by geography and climate, and Tony gave us a glimpse of the different species to be found in some of the 32 Sussex Nature Reserves:
Eridge Rocks, a majestic outcrop of sandstone amidst woodland, in the High Weald (between Crowborough and Tunbridge Wells) is not typical of Sussex. Influenced by the Atlantic micro climate, it provides a habitat for plants such as: Tunbridge Filmy Fern and Greater Whipwort; these plants like a moist, stable environment, and are more commonly found in the Lake District and Wales.
Ashdown Forest, Steadham and Iping Commons, share the geology of the Ashdown Beds (sandstone and siltstone layers). The Green Sand Ridge provides Heathland habitats of acidic, well-drained soil for Ling, Bell and Cross-leaved heather, and Bilberries. The low calcium, low nutrient soils allow species such as Sundew to evolve and catch flies. Insect species, such as the Golden Winged dragonfly and the Silver Studded blue butterfly (which has a symbiotic relationship with ants); the Heath crab spider; the Woodlark, Dartford Warbler and Stonechat.
Graffam Common (On the Greensand Ridge) was purchased, as a conifer plantation, by Sussex Wildlife Trust around 15 years ago. By discussion with local people heathland was re-established and Woodlark and Nightjar were provided with a habitat.
Weald woodlands in the west are: “Ebernoe,” a managed woodland where rides have been grazed and cut and nightingales sing; and “The Mens,” bought in 1974 then left as a non-intervention site. Here, rare, Bechstein’s and Barbastelle bats are found. Bats use the entire landscape and can travel 30kms a night. More trees and hedges have been planted to link up these woodlands, so providing Bat Corridors for their movement, and the bat population has doubled.
More traditional woodlands, examples of countryside as it was in the past, are at Woods Mill, the headquarters of The Sussex Wildlife Trust.
Wood anemones, like waterlogged, clay soils; they are slow to colonise, and so if found on verges, they may indicate ancient woodland habitats. Bluebells attract many visitors to our woodlands. They need open sites to establish and so respond well to coppicing. They are weaker indicators of ancient woodland.
Chalk Grasslands found at Levin Down, Ditchling Beacon and Malling Down, are highly species rich sites, where no one species dominates. Here, plants thrive in nutrient poor soils which offer a habitat built on calcium carbonate. 40 species may be found in 1 sq m. Here you will find Pyramid Orchids, Bee Orchids and, “The Pride of Sussex – Round-Headed Rampion,” as well as the Adonis Blue butterfly.
Sussex also has some of the richest wetlands in Europe, such as Amberley Wild brooks, where Bewick Swans, Lapwings, Egrets and Sea Eagles may be seen together with the Emperor Dragonfly and the Lesser Whirlpool, Ramshorn Snail. In the reedbeds there are Water Rail and Bearded Tits.
Pevensey Marshes, though not open to the public, is a site of specific scientific interest; managed with the help of grazing livestock.
Rye Harbour Nature Reserve and Discovery Centre is described as one of the largest and most important wildlife sites in England. This is an accreting coastline, and the town of Rye, once a seaside fishing community, is now 2 miles from the coast. Shingle has built up and provides a low nutrient location for certain specific plants such as the Yellow Long-Horned Poppy. Some endangered birds, such as the Little Tern and Wheatear, also depend on this habitat.
Does Nature Need Managing?
This is a complex issue. Humans, have, through agriculture, deforestation, and pollution, disrupted natural processes and ecosystems, and there are missing links in the chain of biodiversity. In the past, land mammals, grazed in woodlands and grasslands, so managing plant growth and adding to the nutrients in soils. There were also predators higher in the food chain, helping to keep the balance. There is therefore, a need for some management and restoration to help nature to recover.
Forms of management include: coppicing and clearing of trees to allow light into woodland, - even cutting into trees to create bat habitats-; reintroducing grazing on land; maintaining wild flower meadows and hedgerows; maintaining water levels in wetlands and overall, managing conditions for biodiversity.
Currently, local authorities, farmers, land users and community groups are working together to create networks and corridors through which nature can connect from one area to another. Locally, on the Manhood Peninsula, groups such as RSPB and the Manhood Wildlife and Heritage Group have been planting hundreds of trees and hedgerows, with the help of volunteers. There are funds available for this from local authorities, companies and Private Trusts.
BETTER, BIGGER, MORE, and JOINED were Dr Whitbred’s final words for future action.
Currently various policies on nature are under review and need public action. I add some links here should you be interested:
Stop Bottom Trawling in Marine Protected Areas
https://action.wildlifetrusts.org/page/171084/action/1
Planning and Infrastructure Bill Threatens Nature:
https://sussexwildlifetrust.org.uk/news/planning-and-infrastructure-bill-threatens-nature
Sussex is a wonderful county because of its micro climates and diverse geology. For more detailed information, the varied habitats covered by the Sussex Wildlife Trust, can all be found on their excellent Website:
https://sussexwildlifetrust.org.uk
Here, also, is a link to the wonderful group on the Manhood Peninsula: