Lizard Point 1.1

The Lizard peninsula, Cornwall, is the most southerly point of the United Kingdom and can be immediately recognised as different to the rest of the county. The Lizard is a designated SSSI (site of special scientific interest) by Natural England, it comes under SAC (special area of conservation) and it is also in an Area of Outstanding Natural Beauty (AONB). The Lizard also has the same legal status and protection as a National Park.

It is believed that over 500 million years ago, a section of the Earth’s mantle from beneath the oceanic crust which became attached during a collision of the ocean floor plates. The movement caused lava to spill out on the ocean floor which would solidify and therefore create igneous rock. This rocky layer began to rise to the surface bringing clays from the ocean floor which was rich in calcium carbonate because of the countless sea creatures. Around 350 million years ago, The underwater island collided with mainland Britain. It pushed into the surface of the most south westerly point of Cornwall and was then called Lizard Peninsula. The serpentine rocks of the Lizard peninsula are not found anywhere else in England which is what makes the Lizard so unique. The Serpentine of the Lizard is very rich in calcium as carbonates as lines of the material are visibly seen through the cliffs face which makes the Lizard more alkaline than other typical serpentine based soils. These carbonate lines most likely came up from the floor of the ocean during the rock formation (Westwood 2004). This is why the Lizard has such a high pH rating.

The soils of Cornwall are usually acidic which is because of the underlying granite rock. But the soils of the Lizard have no granite and are far more alkaline. The A horizon (humic layer) often sits directly above the bedrock which provide a very thin layer of soil which plants can take root.

There are many other natural restrictions to prevent many species of plants to inhabit at the Lizard such as the fierce winds. The Lizard is hit by more gales than any other part of mainland England as this is mainly because the mainland is sheltered by Ireland while the Lizard has nothing no break the strong winds, which is why the Lizard is hit by strength seven or more winds (Met Office, pers. comm 2008). Also the climate is much milder than the rest of Britain and is rarely affected by frost. It may have even escaped the glaciations during the last ice age. The refuge provided by this area has resulted in unusual ecological situations with many that still exist today which is reflected by the high level of rare and unusual species which are found there today (Howard, Roberts & McCartney 1997).

With the combination of these natural restrictions such as strong winds, alkaline soil, high salt tolerance, the Lizard is left with a unique and rare plant community which may be seen from Bass Point to Old Lizard Head. There are many diverse and rich plant communities at Lizard Point, with 30 or more flowering species which could occur in a single square metre (Frost 1987). There are many types of plant communities such as maritime crevice, therophyte and grassland which inhabit the coast of Lizard Point of which some are extremely rare and nationally scarce. These species of plants include Herniaria ciliolata, Lotus subbiflorus, L. incarnatum ssp, Clovers both common and rare such as Trifolium, incarnatum ssp, T. strictum, T. bocconei and many more species which thrive among this unique environment and plant communities which cannot be seen anywhere else in the UK (Frost 1987; French et al. 1999).  With 20 species in the Red Data Book and 53 species classed as Nationally Scarce (French, Murphy & Atkinson 1999).

Due to its unique and diverse geology, habitats, flora and habitats, much of the Lizard has many conservation designations such as Biogenic Reserve; Special Area of Conservation (SAC); Regionally Important Geological Site (RIGS); and National Nature Reserve (NNR) making it one of the largest in the UK (Howard et al., 1997).

The Flora at the Lizard has a slow cation exchange rate. This is means that the nutrients that are transported to and from the species are done at a slow rate. This is why the pH of the soil has continued to be alkaline. Soils with a high nutrient status such as woodlands has nutrients constantly being used and therefore they have a high cation exchange capacity which achieves a natural balance within the forest plant community. Although thin, low nutrient status soils like on The Lizard has a low cation exchange capacity and therefore can acidify very quickly if unbalanced (Frost 1987).

Plants on the Lizard can survive on the poor quality soil by slowly releasing a hydrogen nutrient (known as a proton/H+ ion), the plant can exchange this for a nutrient ion adhered to clay particles in soil.  The plant community on the Lizard can do this compared to other species of plants because the plants have adapted and evolved over millions of years and are used to low nutrient uptake to survive.  Small plants here that have evolved in low nutrient status soils have a low nutrient need and so they do not need to release so many protons and do not remove nutrients quickly. This is because of these tailored abilities that the species has. A fine balance is achieved by the replacement of alkaline minerals from the basic rock as this helps prevent the soil from turning acidic. Although this is a slow process and easily upset by alien influences like C. edulis that has not evolved here. (Osman 2009)