Different types of plants make up the British flora – land plants such as ferns, mosses, flowering plants and more. Some are green and contain chlorophyll. This enables plants to capture light energy which they use to produce food – sugar, starch and other carbohydrates. Without sources of food, most life on earth would not exist. There could still be mushrooms and algae but there would be no grains, vegetables, fruits or animals which also have to rely on plants.
Plants lie at the root of life on earth. They help to maintain a range of cycles basic to life so that they:
- Provide food for many different species including human beings
- Provide homes for many species
- Provide materials for people to use worldwide to include bamboo for scaffolding; reeds for making boats and thatching houses; yew for making bows; bog myrtle for repelling flies
- Provide a source of medicinal compounds – foxglove provides digitalis for stimulating the heart; the Rosy periwinkle is the source of treatment for leukaemia, and St John’s Wort can be used in treating depression
- Provide a sense of place contributing to the landscape and making places different from each other
- Provide a source of pleasure
- Keep botanists in work
Plants: Past and Present
Ten thousand years ago the ice Age led to Britain being largely scraped clear of its vegetation. As the ice retreated plant species began to return. At that time Britain was not an island but was linked to the continent by a land bridge and plants made their comeback from there. Pollen analysis has enabled us to gain a picture of what grew where.
Seven thousand years ago the English Channel formed and closed off the European route. By that time, some 1500 plant species had taken root and these formed the basis of Britain’s native flora. The areas in the south of England benefitted most from this European influx and many of the rare plants are still concentrated there today.
The English landscape was mostly covered with a dense form of woodland after the Ice Age. This is referred to as the wildwood. Today, such remaining areas of woodlands are rare and are referred to a s primary or ancient woodland. where trees have been felled and a site has been recolonised, this is referred to as secondary woodland.
Changes in plants
However, the list of plants found in the United Kingdom has not stood still since then. Many plants have been deliberately or accidentally introduced. The Romans brought Alexanders (Smyrnium olusatrum) with them for food and the Sweet Chestnut (Castanea sativa) which was later used for fencing. Some introductions have not benefitted the native wildlife found in the United Kingdom as many associated birds, animals and insects developed along with the plants growing here.
Changes in agriculture brought changes in human communities so that nomads became hunters and gatherers before settling down in one place. This was facilitated by the use of tools which enabled clearings to be made in the woodland. In turn, this led to changes in the plants being grown and harvested.
Changes in the sustainable uses of woods including developing the techniques of pollarding – cutting back trees to head height to prevent browsing by deer and horses – and coppicing – cutting back trees to some eighteeen inches high for use in making clogs, hurdle fences or handles for tools. Neither of these methods killed the tree. They continued to grow up from where they had left off.
As areas of the woodland could be cleared then the increasing light reaching the woodland floor enabled an early spring growth of flowers to develop. Plants such as Wood sorrel (Anemone nemorosa), Primose (Primula vulgaris), Bluebell (Hyacinthoides non-scripta) and Early purple orchid (Orchis mascula) developed to take advantage of lighter conditions before the leaves grew on the trees and blocked off the light.
The planting of a wood at Windsor in 1580 is taken as an indication of when larger scale manipulation of the natural vegetation began. Areas which were wooded then and remain so are referred to as ancient woodland. Ancient woodland is land which has had a continuous woodland cover since at least 1600 AD. A number of species are regarded as indicators of a long-established woodland.
These include Lime (Tilia cordata); Oxlip (Primula elatior); and shrubs such as Midland hawthorn (Crataegus laevigata) and Wild Service tree (Sorbus torminalis); and the Hay-scented buckler fern (Dryopteris aemula).
The increasing development of modes of transport and discovery of new lands led to plants being introduced for food and to gardens – the potato from South America and the Rhododendron from the Himalayas. Spices became a favoured method of brightening up the rather dull medieval European diet as well as providing medicinal cures and tonics.
The first plant records for Britain include Dittander (Lepidium latifolium) and Wild cabbage (Brassica oleracea) in the records of William Turner in 1548. In Cornwall it is the Barren Strawberry (Fragaria sterilis) recorded by Matthias de Lobel in 1567.
Large scale changes
In the twentieth century the development of large scale machinery – diggers and chainsaws – has meant that quick and instant changes could be brought about within the British landscape. Examples include the removal of hedges for road widening schemes; the draining of the wet woodland or marsh in the valley bottom; or the ploughing up of heathland and grasslands. The increasing pressures which accompany an increasing number of people on small islands has led to the removal of these plant communities to accommodate housing, workplaces or infrastructure such as transport routes.
We may well see a full-scale change in the types of vegetation which can grow in the twenty first century as a result of climate change. In the last decade of the twentieth-century Hearts tongue orchid (Serapia lingua) was first recorded in England. This is a plant which occurs in southern Europe. it is quite likely that the plant arrived on a bird’s foot. It is also likely that it continued to survive because the conditions are changing.
Policies, Conventions and Legislation
Laws and policies to safeguard endangered or threatened species of wild plants have been enacted relatively recently within the last twenty years in the United Kingdom. Much of the legislation post dates the United Nations Environment Conference held in 1972 in Stockholm.
Europe contains some 13,000 species of plant compared to some 500 bird species. The types vary from those of the desert-like conditions of the Mediterranean Basin to those of the arctic tundra.
The United Kingdom government has signed up to a number of international conventions and a European directive important for plant species. The most important ones are: