Lower Test Valley

Site of Special Scientific Interest · 50.9284, -1.4823

Also within

Hampshire County

Condition (Natural England)

Unfavourable Recovering (2) Favourable (7)
UnitFeatureConditionArea (ha)Assessed
SU360147 Unfavourable Recovering 17.05 2020-07-24
SU363150 Unfavourable Recovering 32.45 2020-07-24
SU364146 Favourable 12.36 2020-07-24
SU365138 Favourable 37.76 2020-07-24
SU365143 Favourable 27.13 2020-07-24
SU366147 Favourable 12.36 2020-07-24
SU368141 Favourable 7.72 2020-07-24
SU368147 Favourable 7.19 2020-07-24
SU369139 Favourable 0.39 2020-07-24

Climate exposure

This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.

Coastal

Coastal habitats are exposed to sea-level rise and storm erosion. Where hard sea defences sit behind them, there's nowhere landward to retreat to — a squeeze that keeps compressing the habitat no matter how well it's managed.

Geology & landscape

Landscape processes: Coastal

Birds & fish recorded

Birds

SpeciesSeason
reed warbler Breeding
reed warbler Roosting
sedge warbler Breeding
sedge warbler Roosting
swallow Breeding
swallow Roosting

Description

Area, 138.7 hectares 342.7 ac Description The site comprises the upper estuary of the River Test and exhibits from salt through brackish to freshwater conditions. It consists of one extensive reed Phragmites beds on the south coast with flanking meadowland intersected by numerous tidal creeks and flooded on spring tides a gradation of the most unimproved high water. The brackish grassland in the south of the site supports a varied flora with several species characteristic of saltmarsh habitat, for example, sea arrowgrass Triglochin maritimum, sea aster Aster tripolium and sea milkwort Glaux maritima. The rare bulbous foxtail Alopecurus bulbosus, a species whose distribution is rapidly contracting, occurs here, together with other uncommon species such as brook weed Samolus valerandi, spike rush Eleocharis uniglumis and the hybrid saltmarsh grass Puccinellia xkrusmaniana. Above the termination of tidal influence are extensive unimproved neutral meadows containing a colourful and species rich flora dominated by grasses such as Yorkshire fog Holcus lanatus, sweet vernal grass Anthoxanthum odoratum, ryegrass Lolium perenne and meadow fescue Schedonorus pratensis, with abundant sedges Carex species and rushes Juncus species. Several plants now rather uncommonly found owing to modern intensive agricultural methods are common here, including ragged-robin Silene flos-cuculi, water avens Geum rivale, lesser valerian Valeriana dioica, green winged orchid Anacamptis morio, flowering rush Butomus umbellatus, water whorl grass Catabrose aquatica and large bitter cress Cardamine amara. Groups of willows Salix species are widespread along drains and creeks and support notable populations of the nationally rare green flowered helleborine Epipactis phyllanthes var Vectensis in an atypical habitat, together with numbers of common helleborine Epipactis helleborine. Over 450 species of flowering plants have been recorded for the site as a whole. The site is also important for wetland breeding birds and as a wader and duck feeding and roosting ground. The reed beds support large breeding populations of reed warbler Acrocephalus scirpaceus and sedge warbler A. schoenobaenus. They also function as an autumn roost site for swallow and martin and a premigratory feeding site for various passerine birds, notably reed and sedge warbler. Status, Site of Special Scientific Interest SSSI notified under Section 28 of the Wildlife and Countryside Act, 1981

Species mentioned

English name
search for this in other sites
Latin name
search with Google
IUCN / Red List Type Family
swallow Hirundo rustica LC (Breeding) bird-swallow hirundinidae
sedge warbler Acrocephalus schoenobaenus LC (Breeding) bird-warbler acrocephalidae
reed warbler Acrocephalus scirpaceus LC (Breeding) bird-warbler acrocephalidae
bulbous foxtail Alopecurus bulbosus VU grass poaceae
sweet vernal grass Anthoxanthum odoratum LC grass poaceae
Yorkshire fog Holcus lanatus LC grass poaceae
perennial rye-grass Lolium perenne LC grass poaceae
meaow fescue Schedonorus pratensis VU grass poaceae
green-winged orchid Anacamptis morio NT herb orchidaceae
sea aster Aster tripolium Not listed in GB list herb asteraceae
flowering rush Butomus umbellatus LC herb butomaceae
large bittercress Cardamine amara LC herb brassicaceae
broad-leaved helleborine Epipactis helleborine DD herb orchidaceae
green flowered helleborine Epipactis phyllanthes LC herb orchidaceae
water avens Geum rivale LC herb rosaceae
sea milkwort Glaux maritima Not listed in GB list herb primulaceae
brookweed Samolus valerandi LC herb primulaceae
ragged-robin Silene flos-cuculi LC herb carophyllaceae
sea arrrowgrass Triglochin maritimum Not listed in GB list herb juncaginaceae
marsh valerian Valeriana dioica VU herb caprifoliaceae
slender spike rush Eleocharis uniglumis LC rush juncaceae

Insects to look out for

These moths, butterflies and beetles are known to feed on plants recorded at this site, and carry a notable UK conservation status — but a host-plant being present doesn't mean the insect has actually been recorded here. Treat this as "worth watching for," not a confirmed sighting.

SpeciesStatusVia host-plant

Chaetocnema sahlbergii
Vulnerable Glaux maritima
Marsh fritillary
Euphydryas aurinia
Vulnerable Valeriana dioica
Wall
Lasiommata megera
Near Threatened Holcus lanatus

Host-plant data: Cook et al. (2025), Traits data for the butterflies and macro-moths of Great Britain and Ireland, 2024, UK Centre for Ecology & Hydrology / Butterfly Conservation; and Padovani et al. (2020), Database of Insects and their Food Plants (DBIF), UK Centre for Ecology & Hydrology (both Open Government Licence). Contains data supplied by UK Centre for Ecology & Hydrology.

Plant communities

SM18 — Salt marsh

Juncus maritimus salt-marsh community

Matches 5 species from the description above: Glaux maritima, Holcus lanatus, Samolus valerandi, Silene flos-cuculi, Triglochin maritimum

Carex distans, Carex extensa, Carex otrubae, Juncus gerardii, Juncus maritimus, Amblystegium serpens, Kindbergia praelonga, Oenanthe lachenalii, Cirsium arvense, Scorzoneroides autumnalis, Sonchus arvensis, Cochlearia officinalis, Silene flos-cuculi, Atriplex hastata, Lotus corniculatus, Trifolium repens, Vicia cracca, Triglochin maritimum, Plantago maritima, Armeria maritima, Rumex crispus, Glaux maritima, Samolus valerandi, Ranunculus acris, Potentilla anserina, Galium palustre, Agrostis stolonifera, Elytrigia repens, Festuca rubra, Holcus lanatus, Poa pratensis, Schedonorus arundinaceus

SM28 — Salt marsh

Elymus repens salt-marsh community

Matches 5 species from the description above: Eleocharis uniglumis, Glaux maritima, Holcus lanatus, Lolium perenne, Triglochin maritimum

Bolboschoenus maritimus, Carex otrubae, Eleocharis uniglumis, Juncus gerardii, Kindbergia praelonga, Odontites verna, Anthriscus sylvestris, Apium graveolens, Heracleum sphondylium, Oenanthe crocata, Oenanthe lachenalii, Torilis japonica, Centaurea nigra, Cirsium arvense, Cirsium vulgare, Scorzoneroides autumnalis, Sonchus arvensis, Tripleurospermum maritimum, Cochlearia anglica, Cochlearia officinalis, Silene uniflora, Stellaria media agg., Atriplex hastata, Atriplex littoralis, Calystegia sepium, Lotus corniculatus, Medicago lupulina, Melilotus altissima, Trifolium repens, Vicia cracca, Triglochin maritimum, Plantago lanceolata, Plantago maritima, Rumex conglomeratus, Rumex crispus, Glaux maritima, Potentilla anserina, Galium aparine, Urtica dioica, Agrostis stolonifera, Alopecurus geniculatus, Arrhenatherum elatius, Dactylis glomerata, Deschampsia cespitosa, Elytrigia repens, Festuca rubra, Holcus lanatus, Lolium perenne, Poa pratensis, Puccinellia maritima, Schedonorus arundinaceus

SM16 — Salt marsh

Festuca rubra salt-marsh community

Matches 4 species from the description above: Anthoxanthum odoratum, Glaux maritima, Holcus lanatus, Triglochin maritimum

Atriplex portulacoides, Carex distans, Carex flacca, Juncus gerardii, Hypnum cupressiforme, Kindbergia praelonga, Rhytidiadelphus squarrosus, Scorzoneroides autumnalis, Cochlearia anglica, Cerastium fontanum, Sagina procumbens, Spergularia media, Atriplex hastata, Salicornia europaea, Lotus corniculatus, Trifolium repens, Triglochin maritimum, Plantago lanceolata, Plantago maritima, Armeria maritima, Limonium vulgare, Glaux maritima, Ranunculus acris, Potentilla anserina, Agrostis stolonifera, Anthoxanthum odoratum, Cynosurus cristatus, Festuca rubra, Holcus lanatus, Puccinellia maritima

SM20 — Saline lagoon, Salt marsh

Eleocharis uniglumis salt-marsh community

Matches 4 species from the description above: Eleocharis uniglumis, Glaux maritima, Samolus valerandi, Triglochin maritimum

Bolboschoenus maritimus, Carex distans, Carex extensa, Carex nigra, Eleocharis quinqueflora, Eleocharis uniglumis, Juncus articulatus, Juncus gerardii, Leptodictyum riparium, Oenanthe lachenalii, Hydrocotyle vulgaris, Scorzoneroides autumnalis, Atriplex hastata, Trifolium repens, Triglochin maritimum, Triglochin palustre, Plantago maritima, Armeria maritima, Glaux maritima, Samolus valerandi, Potentilla anserina, Galium palustre, Agrostis stolonifera, Alopecurus geniculatus, Festuca rubra

SM13 — Salt marsh

Puccinellia maritima salt-marsh community

Matches 3 species from the description above: Aster tripolium, Glaux maritima, Triglochin maritimum

Atriplex portulacoides, Juncus gerardii, Suaeda maritima, Aster tripolium, Cochlearia anglica, Cochlearia officinalis, Spergularia media, Atriplex hastata, Salicornia europaea, Salicornia perennis, Triglochin maritimum, Plantago maritima, Armeria maritima, Limonium humile, Limonium vulgare, Glaux maritima, Agrostis stolonifera, Festuca rubra, Puccinellia maritima, Spartina anglica, Spartina maritima, Bostrychia scorpioides, Fucus cottonii

SM19 — Saline lagoon, Salt marsh

Blysmus rufus salt-marsh community

Matches 3 species from the description above: Eleocharis uniglumis, Glaux maritima, Triglochin maritimum

Blysmus rufus, Carex extensa, Carex lepidocarpa, Carex nigra, Eleocharis quinqueflora, Eleocharis uniglumis, Juncus articulatus, Juncus gerardii, Amblystegium serpens, Calliergonell cuspidatum, Drepanocladus polygamus, Leptodictyum riparium, Oenanthe lachenalii, Scorzoneroides autumnalis, Cochlearia anglica, Trifolium repens, Triglochin maritimum, Triglochin palustre, Plantago maritima, Armeria maritima, Glaux maritima, Potentilla anserina, Agrostis stolonifera, Alopecurus geniculatus, Festuca rubra, Puccinellia maritima

SM10 — Salt marsh

Transitional low-marsh vegetation with Puccinellia maritima annual Salicornia species and Suaeda maritima

Matches 2 species from the description above: Aster tripolium, Triglochin maritimum

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Spergularia media, Salicornia europaea, Triglochin maritimum, Armeria maritima, Limonium vulgare, Puccinellia maritima, Spartina anglica

SM12 — Salt marsh

Rayed Aster Tripolium on slat marshes

Matches 2 species from the description above: Aster tripolium, Triglochin maritimum

Schoenoplectus lacustris, Juncus bufonius, Suaeda maritima, Aster tripolium, Spergularia marina, Spergularia media, Atriplex hastata, Salicornia europaea, Triglochin maritimum, Plantago maritima, Puccinellia distans, Puccinellia maritima, Spartina anglica

SM14 — Salt marsh

Halimione portulacoides salt-marsh community

Matches 2 species from the description above: Aster tripolium, Triglochin maritimum

Atriplex portulacoides, Juncus maritimus, Suaeda maritima, Artemisia maritima, Aster tripolium, Inula crithmoides, Spergularia media, Salicornia europaea, Salicornia perennis, Triglochin maritimum, Plantago maritima, Armeria maritima, Limonium vulgare, Elytrigia atherica, Puccinellia maritima, Spartina anglica

SM15 — Salt marsh

Juncus maritimus-Triglochin maritima salt-marsh community

Matches 2 species from the description above: Glaux maritima, Triglochin maritimum

Atriplex portulacoides, Carex extensa, Juncus gerardii, Juncus maritimus, Suaeda maritima, Oenanthe lachenalii, Artemisia maritima, Cochlearia anglica, Cochlearia officinalis, Spergularia media, Atriplex hastata, Salicornia europaea, Triglochin maritimum, Plantago maritima, Armeria maritima, Limonium humile, Limonium vulgare, Glaux maritima, Agrostis stolonifera, Festuca rubra, Phragmites australis, Puccinellia maritima, Spartina anglica, Fucus cottonii

SM17 — Salt marsh

Artemisia maritima salt-marsh community

Matches 2 species from the description above: Glaux maritima, Triglochin maritimum

Atriplex portulacoides, Juncus gerardii, Juncus maritimus, Suaeda maritima, Suaeda vera, Artemisia maritima, Cochlearia anglica, Cochlearia officinalis, Spergularia media, Atriplex hastata, Salicornia europaea, Triglochin maritimum, Plantago coronopus, Plantago maritima, Armeria maritima, Limonium vulgare, Glaux maritima, Agrostis stolonifera, Elytrigia atherica, Elytrigia repens, Festuca rubra, Hordeum marinum, Parapholis strigosa, Puccinellia maritima

SM23 — Salt marsh

Spergularia marina-Puccinellia distans salt-marsh community

Matches 2 species from the description above: Glaux maritima, Triglochin maritimum

Atriplex portulacoides, Juncus bufonius, Suaeda maritima, Spergularia marina, Spergularia media, Atriplex hastata, Salicornia europaea, Triglochin maritimum, Plantago maritima, Polygonum aviculare, Glaux maritima, Agrostis stolonifera, Alopecurus geniculatus, Elytrigia atherica, Festuca rubra, Parapholis strigosa, Puccinellia distans, Puccinellia maritima

SM24 — Salt marsh

Elymus pycnanthus salt-marsh community

Matches 2 species from the description above: Aster tripolium, Glaux maritima

Atriplex portulacoides, Juncus gerardii, Juncus maritimus, Hypnum cupressiforme, Suaeda vera, Artemisia maritima, Aster tripolium, Sonchus arvensis, Atriplex hastata, Atriplex littoralis, Beta vulgaris sp maritima, Plantago maritima, Armeria maritima, Limonium vulgare, Glaux maritima, Potentilla anserina, Galium aparine, Agrostis stolonifera, Ammophila arenaria, Elytrigia atherica, Festuca rubra, Parapholis strigosa, Phragmites australis, Puccinellia maritima

SM25 — Salt marsh

Suaeda vera drift-line community

Matches 2 species from the description above: Glaux maritima, Triglochin maritimum

Atriplex portulacoides, Suaeda maritima, Suaeda vera, Artemisia maritima, Cochlearia anglica, Cochlearia danica, Cochlearia officinalis, Spergularia media, Atriplex littoralis, Salicornia europaea, Salicornia perennis, Triglochin maritimum, Plantago maritima, Limonium vulgare, Glaux maritima, Elytrigia atherica, Festuca rubra, Puccinellia maritima, Bostrychia scorpioides, Pelvetia canaliculata

SM11 — Salt marsh

Aster tripolium var. discoideus salt-marsh community

Matches 1 species from the description above: Aster tripolium

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Spergularia media, Salicornia europaea, Salicornia perennis, Plantago maritima, Puccinellia maritima, Spartina anglica, Bostrychia scorpioides, Fucus vesiculosus, Pelvetia canaliculata

SM21 — Salt marsh

Suaeda vera-Limonium binervosum salt-marsh community

Matches 1 species from the description above: Glaux maritima

Atriplex portulacoides, Frankenia laevis, Suaeda maritima, Suaeda vera, Artemisia maritima, Cochlearia anglica, Cochlearia danica, Cochlearia officinalis, Sagina maritima, Spergularia marina, Spergularia media, Salicornia europaea, Plantago maritima, Armeria maritima, Limonium bellidifolium, Limonium binervosum, Limonium vulgare, Glaux maritima, Elytrigia atherica, Festuca rubra, Puccinellia maritima

SM6 — Salt marsh

Spartina anglica salt-marsh community

Matches 1 species from the description above: Aster tripolium

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Cochlearia anglica, Spergularia media, Atriplex hastata, Salicornia europaea, Plantago maritima, Limonium vulgare, Puccinellia maritima, Spartina anglica, Catenella caespitosa, Fucus vesiculosus, Fucus vesiculosus ecad volubilis

SM7 — Salt marsh

Arthrocnemum perenne stands

Matches 1 species from the description above: Aster tripolium

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Spergularia media, Salicornia europaea, Salicornia perennis, Limonium vulgare, Puccinellia maritima, Bostrychia scorpioides

SM8 — Salt marsh

Annual Salicornia salt-marsh community

Matches 1 species from the description above: Aster tripolium

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Salicornia europaea, Puccinellia maritima, Spartina anglica

SM9 — Salt marsh

Suaeda maritima salt-marsh community

Matches 1 species from the description above: Aster tripolium

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Salicornia europaea, Puccinellia maritima, Spartina anglica

A14 — Fast flowing river and stream

Myriophyllum alterniflorum community

Isolepis fluitans, Juncus bulbosus, Fontinalis antipyretica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Lemna minor, Callitriche stagnalis, Littorella uniflora, Potamogeton filiformis, Potamogeton gramineus, Potamogeton natans, Ranunculus peltatus, Chara spp., Nitella hyalina

A17 — Chalk river and stream, Fast flowing river and stream

Ranunculus penicillatus ssp. pseudofluitans community

Berula erecta, Nasturtium officinale, Elodea canadensis, Lemna minor, Callitriche stagnalis, Veronica beccabunga, Polygonum amphibium, Polygonum hydropiper, Potamogeton crispus, Potamogeton pectinatus, Ranunculus penicillatus ssp. pseudofluitans

A18 — Fast flowing river and stream

Ranunculus fluitans community

Fontinalis antipyretica, Fontinalis squamosa var. curnowii, Myriophyllum alterniflorum, Myriophyllum spicatum, Elodea canadensis, Mentha aquatica, Lemna gibba, Lemna minor, Potamogeton perfoliatus, Ranunculus fluitans, Glyceria fluitans, Phalaris arundinacea

A9 — Fast flowing river and stream, Marginal and inundation, Pond ditch and canal, Sluggish river and stream

Potamogeton natans community

Schoenoplectus lacustris, Juncus bulbosus, Sparganium angustifolium, Sparganium erectum, Sparganium minimum, Alisma plantago-aquatica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Elodea canadensis, Lemna minor, Lemna trisulca, Nymphaea alba, Callitriche platycarpa, Callitriche stagnalis, Littorella uniflora, Potamogeton natans, Ranunculus trichophyllus, Glyceria fluitans, Chara subspinosa

SM1 — Salt marsh

Zostera communities

Zostera angustifolia, Zostera marina, Zostera noltei, Spartina anglica, Porphyra umbilicalis, Chondria dasyphylla, Polysiphonia nigra, Chara aspera, Chaetomorpha linum, Chaetomorpha tortuosa, Cladophora battersii, Cladophora retroflexa, Ulva intestinalis, Ulva lactuca, Fucus spiralis

SM2 — Salt marsh

Ruppia maritima salt-marsh community

Ruppia maritima

SM22 — Salt marsh

Halimione portulacoides-Frankenia laevis salt-marsh community

Atriplex portulacoides, Frankenia laevis, Suaeda maritima, Spergularia media, Salicornia europaea, Salicornia perennis, Plantago coronopus, Plantago maritima, Armeria maritima, Limonium vulgare, Elytrigia juncea, Festuca rubra, Parapholis strigosa, Puccinellia maritima

SM26 — Salt marsh

Inula crithmoides stands

Atriplex portulacoides, Suaeda maritima, Inula crithmoides, Spergularia media, Salicornia europaea, Salicornia perennis, Plantago maritima, Armeria maritima, Limonium vulgare, Elytrigia atherica, Festuca rubra, Puccinellia maritima, Spartina anglica, Bostrychia scorpioides

SM3 — Salt marsh

Eleocharis parvula salt-marsh community

Eleocharis parvula

SM4 — Salt marsh

Spartina maritima salt-marsh community

Suaeda maritima, Salicornia europaea, Salicornia perennis, Puccinellia maritima, Spartina anglica, Spartina maritima

SM5 — Salt marsh

Spartina alterniflora salt-marsh community

Puccinellia maritima, Spartina alterniflora, Spartina anglica