Protecting small populations of rare species. Case study on Dactylorhiza viridis (Orchidaceae) in Fancott Woods and Meadows SSSI, Bedfordshire, UK

Abstract

Dactylorhiza viridis is a small orchid species, sensitive to competition with dense and tall herbaceous vegetation. Its populations in Europe and in the UK have been declining over the last century. Small, isolated populations have remained in Protected Areas. The population of the species in Fancott Woods and Meadows Site of Special Scientific Interest (SSSI) was studied in 2011–2019. The number of orchid plants varies substantially from year to year, but the areas occupied by the population remain the same. Fruit production is high. The population is under threat from herbivores and from competition with tall vegetation on the meadow. Expansion of the vigorous herb Filipendula ulmaria was recorded on the meadow in 2009 that negatively affected the rare plant community. Additional management of an early hay cut was implemented on the meadow as a trial. A botanical survey of managed and control plots showed a reduction in the vigorous herbs, an increase in species number in the cut plots and a resulting more open sward. The orchid population also benefits from a more open sward. The management of the site is the key to the survival of this small orchid population.

Keywords

• conservation
• competition
• fruit set
• hay cut
• herbivory
• orchid population
• site management