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  • Writer's pictureSim Elliott

Flowering plants, Butterflies & Birds; Drought & Reduced Abundance. Iping & Stedham Commons.16.06.23

Iping and Stedham Commons are lowland heaths. Iping and Stedham Common Nature Reserve is situated just west of Midhurst and is one of the best examples of lowland heathland in Sussex. ... It is a great place to see some of the amazing wildlife that can only be found on this declining habitat. Over 80% of lowland heath has been lost from the UK in the last couple of centuries. On top of this the UK has 20% of the world’s lowland heath making the total area rarer than tropical rainforests. Iping and Stedham Commons | Sussex Wildlife Trust


Lowland Heaths have a range of plants and animals that are found only or mostly on acid heathlands, like Silver-Studded Blue Butterflies and Dartford Warblers; both of which I saw on this trip.


To get to Iping and Stedham Commons by public transport it is easiest to travel by bus or foot from Midhurst. You can get the bus 92 Bus Route & Timetable: Petersfield - Midhurst | Stagecoach (stagecoachbus.com); but this is a very irregular bus service that only runs 6 times day. It takes 4 minutes on the bus. If you use the bus get off at Stedham, Iping Lane and walk down Elsted Road (a turning south off the A272), after about 50m you'll reach the Iping and Stedham Commons car park: on your right (west) is an entrance to Iping Common, and to your left (east) is an entrance to Stedham.


However, you can walk to Stedham (the closest of the two adjoining commons) on pavement and footpath in 45 minutes. I usually walk from Midhurst; walking along the pavement of the A272 to the east entrance to Stedham, or sometimes I walk through the footpath that goes through Midhurst Common and the Severals (pine woodland and heath).


Midhurst can be reached by bus from Chichester 60 Bus Route & Timetable: Chichester - Midhurst | Stagecoach (stagecoachbus.com) or Worthing 1 Bus Route & Timetable: Worthing - Midhurst | Stagecoach (stagecoachbus.com). From Brighton the quickest way of getting to Midhurst is to get the train to Chichester (ca 55mins, twice an hour)) and then the bus from Chichester to Midhurst (ca. 45 mins, twice an hour)


The photographs are presented chronologically, in the roder of my walk through the commons.


All sections of text in italics are quotations, sources sited.


I am only an amateur naturalist; thus all identifications are provisional; if you note a mistake in identification please feel free to tell me. If you want to contact me about any aspect of this blog, email me at simeon[underscore]elliott[at]gmail[dot]com.


Extracts from the Reserve Profile Reserve profile | Sussex Wildlife Trust


Iping and Stedham Common nature ... is one of the best examples of lowland heathland in Sussex. Its extensive 125ha is mostly owned by Sussex Wildlife Trust and includes parts of Trotton Common and Bridgelands Plantation. It is a great place to see some of the amazing wildlife that can only be found on this rare habitat. ..


There is something about an expanse of open heathland in the heat of summer that is quintessentially English. Haze shimmers in the distance to create little mirages of refracted sky at the horizon of purple heather. The brown pods of the gorse pop open in the heat, shedding a shower of seeds into the dry sand below.


At first this seems like a barren, unforgiv­ing landscape, but close examination reveals a wealth of life, specially adapted to the harsh conditions. The dry acidic soils encourage the growth of plants – heathers, gorse, Birch, Scots Pine, Purple Moor-grass, but within these blocks of vegetation there is a host of animal life that can only exist within this habitat. The key is the dry sandy soil itself – wherever it is exposed at the surface, numerous insects tunnel their way through the soft material to create thousands of tiny burrows....


There are spider-hunting wasps and many mining bees, each one with a complex and particular life-history in which the heathland plays a crucial part. Heath Tiger Beetles are returning here too, thanks to a recovery programme, and can be seen in the late summer on purpose-made scrapes.


In June and July the blue confetti of tiny Silver-studded Blue butterflies can be seen fluttering over the Bell Heather. Their lives are inextricably linked to some of the ant species found here. The ants are duped into taking the caterpillars down into their subterranean nests and tending them in return for being able to feed on a sugary excretion the caterpillars exude, until they emerge the following year as an adult butterfly.


There are also birds that are specifically associated with this landscape. Woodlarks rely on the bare sandy patches among the vegetation for nesting, ... From the ribbons of gorse that line the paths can be heard the scratchy song of the Dartford Warbler, another bird almost lost in Britain as heathland has decreased.


... On warm, still summer evenings, Nightjars ring out their curious churring call; sitting on the dead bough of a tree silhouetted against the setting sun, they purr like giant cats, and then fly off with a display of wing clapping and aerobatic manoeuvres. People come just to hear them, and it’s worth the visit.


The three key heathland birds: Woodlark, Nightjar and Tree Pipit, all nest on the ground. This makes them vulnerable to disturbance by dogs running free. The birds see dogs as predators, whatever the size and harmless character of the dog, and can abandon their nests resulting in the loss of eggs and chicks. It is essential for visitors to stick to the paths and keep all dogs on a short lead from March 1st until the beginning of September.


Many of the plants can only exist in this habitat. In wet, peaty seepages where almost no other plants can survive the very acid conditions, insectivorous sundews unfurl the sticky red droplets on their leaves ready to entrap any insect lured by the promise of some free sugar. The leaves then slowly curl over as the insect struggles – an ant, a fly, even a damselfly – and gradually digests them, absorbing nutrients which they can’t find in the soil. There’s a wet track at the lowest point of Stedham Common, in the south-west corner, and another at the lowest part of the track across Trotton Common where they are usually numerous – July is a good time to see them. The rare Marsh Clubmoss, only seen in a few sites in Sussex, can be spotted by the eagle-eyed in one or two of these areas.


Stedham Common


Wavy hair-grass, Deschampsia flexuosa. A grass which prefers acid soils


Broom Fork-moss, Dicranum scoparium. A common moss on heaths. Broom Fork-Moss is usually green (like all mosses). It's colour here reflects the fact that proceeding it there was six weeks of no rain. Moss is relatively resilient to low rain; but prolonged drought is a serious threat to mosses as well as all plant and animal life, and "lower plants", that are often overlooked in media discourses on nature and climate change, are important to ecosystems. An epic global study of moss reveals it is far more vital to Earth’s ecosystems than we knew - resilience At the time of writing this blog post 28.06.23 the Met Office announced that the UK will have its hottest June on record - Met Office


Whilst lowland heaths look dry in periods of low rainfall; the degree of desiccation when I visited can be seen in this image (it also shows how resilient gotse is to low rain levels)


Heath Rush, Juncus squarrosus abundant on lowland heaths


Dessicated Toad Rush, Juncus bufonius


Desiccated Heath Star-Moss Campylopus introflexus. C.introflexus is not fussy about habitat, except that it always grows in places with a low pH, such as on heathland Campylopus introflexus - British Bryological Society


Reindeer Moss. Cladonia portentosa is by far the commonest of the Reindeermosses in Britain and Ireland and, in many marginal areas, the only species found. ... Habitat: On heathlands, moorlands and dunes, also not uncommon on old leaning and fallen trees in open woodland; abundant in acid soil areas, more scattered in productive lowlands. Cladonia portentosa | The British Lichen Society


Bell Heather Erica cinerea. This was one of the few clumps of Bell Heather on Stedham and Iping Commons that looked as if it were flourishing. Most of the Bell Heather I saw on Iping Common was very desiccated or dead. I spoke to a long-term Sussex Wildlife Trust volunteer at Iping Common, who informed me that a lot of heather did not survive the 2022 drought. The 2022 drought followed on from a series of droughts: The 2018–2020 Multi‐Year Drought Sets a New Benchmark in Europe - Rakovec - 2022 - Earth's Future - Wiley Online Library


During the period 2018–2020, Europe experienced a series of hot and dry weather conditions with significant socioeconomic and environmental consequences. Yet, the extremity of these multi-year dry conditions is not recognized. ... Furthermore, future events based on climate model simulations Coupled Model Intercomparison Project v5 suggest that Europe should be prepared for events of comparable intensity as the 2018–2020 event but with durations longer than any of those experienced in the last 250 years. Our study thus emphasizes the urgent need for adaption and mitigation strategies to cope with such multi-year drought events across Europe. The 2018–2020 Multi‐Year Drought Sets a New Benchmark in Europe - Rakovec - 2022 - Earth's Future - Wiley Online Library


The more flourishing Bell Heath above and this Lesser spearwort, Ranunculus flammula, were in one of the bog areas of Stedham and Iping commons; where there was more moisture. Lesser spearwort can be found along the edges of ponds, lakes and streams, and in marshes and wet meadows. As a buttercup, it displays familiar, butter-yellow flowers. Lesser spearwort | The Wildlife Trusts


Soft-rush, Juncus effusus


Compact Rush - Juncus conglomeratus, An erect plant with a dull green stem bearing 12 to 30 strong longitudinal ridges. Inflorescence always compact and dark red brown Compact Rush | NatureSpot


Wood Dock, Rumex sanguineus


Haircap moss, Polytrichum sp., probably Juniper Haircap, P. juniperinum


Yorkshire-fog, Holcus lanatus


Iping Common


Famous, along with Stedham Common for it's Silver-Studded Blues


Some cattle, conservation grazing at the entrance to Iping Common


Silver-Studded Blues


A Silver-Studded Blue, Plebejus argus


I saw two Silver-Spotted Blues on Stedham Common, and about twenty on Iping Common; when I visited Iping in June of 2022, I saw serval hundred Silver-Studded Blues on Iping Common alone. It seems highly likely that the drought of 2022 is the cause if this decline, as much heather has been lost, and heather is a key Silver-Studded Blue caterpillar food plantL A wide variety of ericaceous and leguminous plants are used: on heathland, the most common are Heather (Calluna vulgaris), Bell Heather (Erica cinerea), Cross-leaved Heath (E. tetralix), gorses (Ulex spp). Silver-studded Blue | Butterfly Conservation (butterfly-conservation.org)


This small butterfly is found mainly in heathland where the silvery-blue wings of the males provide a marvellous sight as they fly low over the heather. The females are brown and far less conspicuous but, like the male, have distinct metallic spots on the hindwing. In the late afternoon the adults often congregate to roost on sheltered bushes or grass tussocks.

The Silver-studded Blue has a restricted distribution but occurs in large numbers in suitable heathland and coastal habitats. It has undergone a major decline through most of its range. Silver-studded Blue | Butterfly Conservation (butterfly-conservation.org)


Butterflies have been affected by drought before, in 1976 and 1995, and some species are yet to recover to their pre-1976 numbers. But unlike the 1976 drought, butterflies today are already in decline. Butterfly Conservation’s recent State of the UK’s Butterflies 2022 showed 80% of butterfly species have declined in abundance, distribution, or both since the 1970s.

With droughts are expected to become more frequent and severe as climate change continues, some butterfly species may be pushed towards extinction.


“Overall, the data for 2022 tells us that it was an average year for butterflies,” says Dr Richard Fox, Butterfly Conservation’s Head of Science. “However, it was a year of two halves with butterflies seen early and in about average total numbers (compared to the last 10 years) from April – July but then in greatly reduced abundance after the summer heatwave and drought.”


In general, warm weather is good for butterflies as they can be active, finding food, mating and laying eggs, adds Fox, but drought causes plants to wither and die, meaning female butterflies may struggle to find anywhere to lay their eggs, or there is not enough food for the caterpillars when they hatch.


“The knock-on effect is fewer butterflies in the following generation,” says Fox. “We have already seen an indication of this in the 2022 data for some of those species with a generation that flies in late summer and autumn, and sadly we can expect to see a decline in numbers of other species in 2023 too.Kerry Taylor-Smith 06/04/2023 UK butterflies hit hard by extreme weather, findings show (yourweather.co.uk)


Dead and non-blooming heathers; widespread across Iping Comon


Between March and now (end of June) I have walked two to three times a week in Sussex, mostly on the Downs, but also in High Weald ghyll-woods and on lowland heath. Of the butterfly species that I expect to see on the Downs in this time frame (Adonis Blues, Common Blues, Small Blues, Brimstones, Small and Large Whites, Meadow Browns, Small Heaths, Walls, Small Coppers) I have seen approximately only 25-50% of the numbers of these butterflies I saw in 2022. If this drought was a one-off event Butterflies could recover from this, but, June 2023 is likely to be the hottest June on record UK will have its hottest June on record - Met Office

Data gathered by the UKBMS [UK Butterfly MOnitoring Scheme] has shown serious negative impacts of droughts on butterflies in 1976 and 1995. Some species have never recovered their former abundance levels after the 1976 drought, although habitat destruction is likely to be a major factor in their failure to bounce back.


Butterfly Conservation’s Head of Science, Dr Richard Fox, said: “UK butterfly populations fluctuate naturally from year to year, largely due to the weather, but the long-term trends are mainly driven by deterioration of habitats due to inappropriate management and pollution, and climate change Hot and dry summer impacts UK butterfly populations | UK Centre for Ecology & Hydrology (ceh.ac.uk)


Widespread drought-sensitive butterfly population extinctions could occur in the UK as early as 2050 according to a new study published today in the scientific journal Nature Climate Change. “The results are worrying. Until I started this research, I hadn’t quite realised the magnitude and potential impacts from climate change. For drought-sensitive butterflies, and potentially other taxa, widespread population extinctions are expected by 2050. To limit these loses, both habitat restoration and reducing CO2 emissions have a role. In fact, a combination of both is necessary.Severe droughts could lead to widespread losses of butterflies by 2050 | UK Centre for Ecology & Hydrology (ceh.ac.uk)


Tree Pipit, Anthus trivialis, RSPB Red List. Widespread summer visitors to the UK, they occur in particularly high densities in Western uplands. Their population has undergone declines over the past 25 years, especially in central and southern England. Tree Pipit Bird Facts | Anthus Trivialis - The RSPB


Some more Silver Studded Blues


Dartford Warbler, Sylvia undata. This small, dark, long-tailed warbler is resident in the UK and has suffered in the past from severe winters. The Dartford warbler's population crashed to a few pairs in the 1960s, since when it has gradually recovered, increasing in both numbers and range. It is still regarded as an Amber List species. It will perch on top of a gorse stem to sing, but is often seen as a small flying shape bobbing between bushes. Dartford Warbler Bird Facts | Sylvia Undata - The RSPB


Reindeer Lichen, Cladonia portentosa and Cross-leaved heath heather Erica tetralix,. in very dry conditions Cross-leaved heath is a type of heather that likes bogs, heathland and moorland. It has distinctive pink, bell-shaped flowers that attract all kinds of nectar-loving insects.Cross-leaved heath | The Wildlife Trusts


More Heath Star Moss; a favourite moss of mine!


Cracked and parched ground



Goldren Ringed Dragonfly, Cordulegaster boltonii A Dragonfly that likes acid water on heaths. Breeds in acidic rivers and streams of all sizes. May be found away from its breeding habitat over heathland.

Threats


Mistle Thrush, Turdus viscivorus


The Mistle Thrush is the UK's largest thrush species.


The Mistle Thrush is a handsome bird with a brown back, greyish nape and crown and spotted breast and belly. Pairs may produce up to three clutches in a good year. The male has a wistful song which is often performed during or just after wet and windy weather, giving the species its folkname 'stormcock'.


The Mistle Thrush is found throughout Britain & Ireland expect for the Northern and Western Isles. Its population has undergone a decline in the UK since the late-1970s and the species has been on the UK Red List since 2015. The cause of this decline is not fully understood, but it might be linked to degradation of farmland habitat Mistle Thrush | BTO - British Trust for Ornithology

Tormentil, Potentilla erecta; another acid heath specialost


Tormentil can be found growing on acid grassland, heathland and moorland, but even pops up alongside roads. It bears yellow, buttercup-like flowers, but with only four petals (buttercups have five). Tormentil | The Wildlife Trusts






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