The following is a short summary of the habitat type and how to create/enhance it to a "good" condition. For an informed position, please refer to official up-to-date UKHAB documentation or the UK Government's Condition Assessment Sheet.

This habitat is associated with outcrops of serpentine and river gravels that are rich in heavy metals, as well as with artificial mine workings and spoil heaps (piles of refuse material from mining/excavation). Seral succession is slowed or arrested by the toxicity of the substrate.

The habitat contains open-structured ruderal or metallophyte species of lichens, bryophytes and vascular plants, such as Spring Sandwort (Sabulina verna), Alpine Pennycress (Thlaspi arvense) and genetically adapted races of species such as Thrift (Armeria maritima) and Bladder Campion (Silene vulgaris). Notable species include Forked Spleenwort (Asplenium septentrionale), (Ditrichum cornubicum), (Marsupella profunda), (Cephaloziella nicholsonii) and (Ditrichum plumbicola).

In northern parts of the UK, there are local populations of boreal species that characterise these habitat conditions in Scandinavia, such as Scottish Sandwort (Arenaria norvegica) and the endemic Shetland Mouse-ear (Cerastium nigrescens)

How to Create / Enhance to a "Good" condition

There are a set of criteria that are used to judge the condition of this habitat. These are listed below.

Condition Assessment Criteria	Criterion passed (Yes or No)
A	The parcel represents a good example of its habitat type, with a consistently high proportion of characteristic indicator species present relevant to the specific habitat type (and relative to Footnote 3 suboptimal species which may be listed in the UKHab description).1 Note - this criterion is essential for achieving Moderate or Good condition for non-acid grassland types only.
B	Sward height is varied (at least 20% of the sward is less than 7 cm and at least 20% is more than 7 cm) creating microclimates which provide opportunities for insects, birds and small mammals to live and breed.
C	Cover of bare ground is between 1% and 5%, including localised areas, for example, rabbit warrens2.
D	Cover of bracken Pteridium aquilinum is less than 20% and cover of scrub (including bramble Rubus fruticosus agg.) is less than 5%.
E	Combined cover of species indicative of suboptimal condition3 and physical damage (such as excessive poaching, damage from machinery use or storage, damaging levels of access, or any other damaging management activities) accounts for less than 5% of total area. If any invasive non-native plant species4 (as listed on Schedule 9 of WCA5) are present, this criterion is automatically failed.
Additional Criterion - must be assessed for all non-acid grassland types
F	There are 10 or more vascular plant species per m2 present, including forbs that are characteristic of the habitat type (species referenced in Footnote 3 and 5 cannot contribute towards this count). Note - this criterion is essential for achieving Good condition for non-acid grassland types only.

Condition Assessment Result	Condition Assessment Score
Acid grassland types (Result out of 5 criteria)
Passes 5 criteria	Good (3)
Passes 3 or 4 criteria	Moderate (2)
Passes 2 or fewer criteria	Poor (1)
Non-acid grassland types (Result out of 6 criteria)
Passes 5 or 6 criteria, including essential criterion A and additional criterion F.	Good (3)
Passes 3 - 5 criteria, including essential criterion A.	Moderate (2)
Passes 2 or fewer criteria; OR Passes 3 or 4 criteria excluding criterion A and F.	Poor (1)

Notes

Footnote 1 - Professional judgement should be used alongside the UKHab description.

Footnote 2 – For example, this could include small, scattered areas of bare ground allowing for plant colonisation, or localised patches not exceeding 5% cover.

Footnote 3 - Species indicative of suboptimal condition for this habitat type include:creeping thistle Cirsium arvense, spear thistle Cirsium vulgare, curled dock Rumex crispus, broad-leaved dock Rumex obtusifolius, common nettle Urtica dioica, creeping buttercup Ranunculus repens, greater plantain Plantago major, white clover Trifolium repens and cow parsley Anthriscus sylvestris. There may be additional relevant species local to the region and or site.

Footnote 4 – Assess this for each distinct habitat parcel. If the distribution of invasive non-native species varies across the habitat, split into parcels accordingly, applying a buffer zone around the invasive non-native species with a size relative to its risk of spread into adjacent habitat, by applying professional judgement.

Footnote 5 – Wildlife and Countryside Act 1981 (as amended).