> Epiphytes grow harmlessly on other plants, typically trees: most people are familiar with them as orchids, bromeliads and ferns, which are charismatic elements in tropical and sub-tropical forests (Figure 1).
> Equally charismatic, but perhaps less well known, are lichens, mosses and liverworts, which become the dominant epiphytes in Europe's temperate and boreal forests (Figure 2).
> These 'cryptogamic' plants and fungi lend international significance to UK conservation, and contribute importantly to diverse and healthy ecosystems; among their ecosystem-service roles:
- They are indicators of environmental quality, e.g. as air pollution bioindicators;
- They contribute to forest water and nutrient cycling, with certain species fixing-nitrogen directly from the atmosphere;
- They provide a microhabitat for bark-dwelling invertebrates, with implications across the forest food-web.
> Despite their diversity and ecological importance, the conservation biology of cryptogamic epiphytes was until recently severely under-researched in Britain. In 2003 RBGE's senior lichenologist, Dr Brian Coppins, suggested with respect to lichens that:
'The efficacy of [landscape management] would be enhanced by a much better autecological understanding of the individual lichens in relation to the dynamics of their habitat. Sadly, such information is rarely known, and calculated guesswork is the best that can currently be achieved'. 
> Over the past decade, RBGE researchers have worked with colleagues to address this knowledge gap, aiming to provide a solid evidence-base for lichen conservation.
> As an output, and made possible by joint-funding from The Esmée Fairbairn Foundation, this web-site provides an Epiphyte Tool-kit comprising two products:
A Description of Epiphyte Communities and Indicator Species :
- This is the first systematic description of Scotland’s epiphyte communities and species, and their habitat requirements. It represents baseline information on the status of Scotland's epiphytes for the early 21st Century, and aims to provide an accessible account of epiphyte diversity for the non-specialist.
Lichen Epiphyte Scenarios :
- It is often the case that decisions made during the present-day have long-term consequences; this is especially the case in forest and woodland conservation where the life-span of a single generation of trees can far exceed that of human policies and strategies.
- Decisions taken today about tree planting strategies, or on-going woodland management regimes, are embedded across many decades, and thinking about and exploring a spectrum of possible future scenarios is a useful way to help achieve robustness of decision-making in the face of uncertainty.
- This tool-kit provides a way to compare present-day (baseline) and future projected environmental suitability (2050s and 2080s) across a range of 382 lichen species, allowing for: (i) the long-term reduction in SO2 pollution observed across the UK, (ii) taking into account the Met Office Hadley Centre's ensemble projections of future climate change, and (iii) allowing the user to adjust for changed stand-scale tree species composition.
> For further information on RBGE's epiphyte research, please contact Chris Ellis.
 Coppins, B.J. (2003) Lichen conservation in Scotland. Botanical Journal of Scotland, 55: 27-38.