Botany

The diverse habitats of the two moors give rise to an impressive species-rich flora, over 800 flowering plants and ferns having been recorded on or in the immediate vicinity of the moors. Additionally there are records of over 100 mosses and liverworts, 300 fungi and 100 lichens.

Sheep-Laurel Kalmia angustifolia

Human activity has had an impact on the flora of the moors, starting with Bronze Age farmers whose activities probably accelerated the loss of the primeval forests which grew before the formation of the raised mires. Extensive drainage by Vermuyden and others, followed by warping of parts of the peatlands will have had an effect too. A horticultural enterprise by William Casson in the 19th century has left a troublesome legacy of Rhododendron ponticum, and there also remains a small population of North American Sheep-Laurel Kalmia angustifolia together with another North American plant, Springbeauty Claytonia perfoliata. Limestone ballast was deposited to make a solid base for the tramways used to remove peat earlier in the 20th century, and these have been colonised by calcifers. The more aggressive drainage needed for peat milling placed severe stresses on the more ecologically demanding species.

80% of the area of both moors is peat, supporting a range of acidic, nutrient-poor, habitats. One of the first documented losses came from the deep peat pools - the famous Rannoch-Rush Scheuchzeria palustris - some time between 1870 and the 1940s. Both the Great Sundew Drosera Longiflora and Oblong-leaved Sundew D. intermedia have also disappeared, but the Round-leaved Sundew D. rotundifolia still thrives among the Spagnum. Flooded peat workings contain Bulbous Rush Juncus bulbosus and the carniverous bladderworts Utricolaria. Heather Calluna vulgaris prefers the drier peat banks but the Cross-leaved Heath Erica tetralix likes damp places, often among tussocks of Hare's-tail Cotton Grass Eriophorum vaginatum.

Himalayan Balsam
Impatiens glandulifera

The heaths are dominated by Heather, Bracken Pteridium aquilinum and Purple Moor-grass Molinia caerulea. A rich variety of lichens grow in these areas, including the rare Cladonia sulphurina, found on Hatfield Moors - normally it grows at high altitudes. The vascular flora of these heaths is usually very limited, except in the sandy grass-heath at Lindholme, where Red Fescue Festuca rubra, Heath Speedwell Veronica officinalis and Harebell Campanula rotundifolia are to be found.

The lagg zones around the mires have been severely reduced by drainage and encroachment by agriculture. What remains is dominated by Common Reed, although the reedbed and meadow at Inkle Moor contain Ragged Robin Lychnis flos-cuculi, Common Meadow-rue Thalictrum flavum and Marsh Pea Lathyrus palustris.

Trackways and paths reveal some unuaual species, such as Greater Yellow-rattle Rhinanthus augustifolius which grows on stretches of paths on Crowle Moor. Ominously Himalayan Balsam Impatiens glandulifera is spreading rapidly along the Lincolnshire side of the Thorne Warping drain. Lindholme supports Corn Spurrey Spergula arvensis and Common Stork's Bill Erodium cicutarium on sandy disturbed areas.

Fly Agaric Amanita muscaria

Birch scrub thrives on the drier areas and few plants can thrive among it, exceptions being Cross-leaved Heath, Cranberry and Common Cottongrass. Bog Rosemary Andromeda polifolia also still competes in Poor Piece on Hatfield Moors. Birch does have the advantage of being a host plant to a wide range of fungi, typical species are Fly Agaric Amanita muscaria and bracket fungi such as Piptoporus betulinus. Where the birch has matured to woodlands little survives on the woodland floor apart from grasses - Wavy Hair Grass Deschampsia flexuosa and Sweet Vernal Grass Anthoxanthum odoratum. The willow carr at Will Pits on Thorne Moors provides a good environment for several ferns. Broad Buckler-fern Dryopteris dilatata and Male-fern D. Filix-mas are common here.

Please click here for a checklist of Fern-allies and Ferns on Thorne Moors

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Thorne Moors Botanical Survey

2011 was the second season of this enormous undertaking initiated by Ian McDonald. Thorne Moors is around 1900 hectares, much of it like the Southern Canals and the Paraffin Ponds are potentially dangerous, so the project was an incredibly ambitious challenge. New data from Thorne have already superseded the recently published South Yorkshire Plant Atlas entries, most notably in the rediscovery of Lathyrus palustris. The colony is at serious risk, and like much of Thorne Moors, the compartment is assessed as unfavourable and declining.

2011 survey work, as a conservative estimate, has amounted to some 472 man hours and logged around 287 species from 14 of the 28 1km grid squares which make up Thorne Moors bringing the total species count to date of approximately 330 species. The total number of records for the last two seasons amounts to some 2620.

When the surveywas first mooted it was not initially envisaged that Crowle Moors would be included. However as the survey progressed it seemed desirable that if possible the land to the east of Swinefleet Warping Drain and out-with ‘The Yorkshire Triangle’ be surveyed, particularly the recent acquisitions by Natural England and North Lincolnshire Council as these sites were new and now accessible to naturalists. Crowle Moors (LWT Reserves) were already considered to be well documented. 2012 will be the third season covering Thorne Moors and will also see a single season of field work on Crowle Moors to at least provide a baseline for new areas acquired and entering conservation management.

2012 Dates

Thorne:
19 May,
2 June,
4 August,
18 August.

Crowle:
7 April,
12 May,
9 June,
7 July.

If any one is interested in participating and contributing, please see or for further details.