Area: 101.5 hectares
Mostly in Cornwall Area of Outstanding Natural Beauty.
Description and Reasons for Notification:
This estuarine site extends across Lambe Creek, Calenick Creek and the Truro River at the northwestern limits of the Fal Estuary complex. The major habitat feature of the site is tidal mudflats which are feeding grounds for wildfowl and wading birds, including nationally important numbers of a rare wader. The site also includes saltmarsh, adjoining ancient semi-natural woodland and a heronry.
The site is primarily important for wildfowl and wading birds. The Truro River section regularly supports nationally important numbers of black-tailed godwit Limosa limosa during autumn and winter. The site is also used for feeding by up to 500 dunlin Calidris alpina, 200 shelduck Tadorna tadorna, 300 teal Anas crecca, and smaller numbers of other waders including redshank Tringa totanus, greenshank T. nebularia, curlew Numenius arquata, whimbrel N. phaeopus and oystercatcher Haematopus ostralegus. The use which birds make of the different parts of the site and its relationship to feeding areas in other parts of the Fal complex of estuaries, varies with time of year, weather and tide.
Relatively undisturbed agriculturally improved pastureland to the south of Calenick Creek outside the site, is used by roosting waders during high spring tides.
Saltmarsh communities have developed in a number of localities within the site, most notably at Calenick Creek where species within the turf include reflexed saltmarsh-grass Puccinellia distans subsp. distans, sea couch Elytriga atherica, sea aster Aster tripolium, sea arrow-grass Triglochin maritima, sea club-rush Scirpus maritimus and sea rush Juncus maritimus.
At Calenick Creek the saltmarsh is immediately continuous with a semi-natural ancient wood, dominated by coppiced sessile oak Quercus petraea, showing a classic transition from estuarine to woodland communities. Within the wood is an understorey of holly Ilex aquifolia and Hazel Corylus avellana. The ground flora is typically dominated by bramble Rubus fruticosus agg., honeysuckle Lonicera periclymenum and, where slopes permit an increase in soil-depth and fertility, there are stands of bluebell Hyacinthoides non-scripta.
Three other small ancient semi-natural woodlands abut the estuary. These are similar in character to Calenick Wood but variations in exposure and past management result in wide variations in the abundance of shrub and herb species, notably holly and greater woodrush Luzula sylvatica. The latter dominates large areas of Penpol Wood.
A heronry at Kea Wood, one of the three largest heronries in Cornwall, contains about 13 nests, and herons Ardea cinerea regularly feed along the estuary.