Heath land is threatened due to the pressures of agriculture and especially urbanisation.
Species invasions from adjoining plant communities, have established and are completely changing the nature of heathlands. Woody weed invasion has become a major consideration of heathland management.
Low-growing shrubs usually under 0.5 m tall in individuals or clumps not touching to interlocking generally forming less than 25% cover. Trees and shrubs generally less than 25% cover.
Heath land supports a large number of rare and beautiful species of wildlife. Already over 1000 species have been recorded on Yateley Common, Hampshire, UK and many more remain to be discovered. Unfortunately, many of these species are threatened due to the loss of heath land throughout Britain.
The essential common features of heathland appear not to be climatic. Instead, heathland communities are characterised by nutrient-poor soils, (although this is contested as heathlands in the UK, dominated by calluna and erica species appear to have high concentrations of phosphorous and nitrogen), and a fire regime of relatively frequent, high intensity fires. These two features substantially determine all community processes, including maturation and regeneration, and also drive the whole of the dependent faunal community. High species richness and diversity is a feature of heathlands, dominated by small-leaved sclerophyllous shrubs, a paucity of grasses and ephemeral herbs with an abundance of sedges and similar sclerophyllous monocots. Most species have particular adaptations to recovery from fires, including, long-term soil seed store with fire-induced germination. Principal regeneration is usually immediately post-fire, so regeneration between fires is often negligible, leading to low growth rates and low primary productivity. Soils with low to very low concentrations of inorganic nutrients, have tight nutrient cycling; low foliage turnover, thus long-lived plant parts with low protein but high carbohydrate foliage and high root:shoot ratios. Heathland species exhibit intricate mechanisms for capturing and retaining these nutrients. As the heathland ages, species richness apparently decreases - rapidly by about five years post-fire and then gradually as the long- lived, large woody dominants re-establish more or less complete canopies, unless fire prevents this succession.
During the last 200 years over 90% of the heath land in north-east Hampshire has been lost.
Heath land is one of the rarest habitats in the world. It is even more threatened than the rain forest.