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

Irina Tatarenko,Open University ,Hilary Wallace,Graham Bellamy,Mike Dodd,Ecological Survey (Bangor) ,Wildlife Trust For Bedfordshire, Cambridgeshire And Northamptonshire ,Dryad Wildlife ,Andy Fleckney

doi:10.24189/ncr.2020.028

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.

Highlights

The loss of semi-natural grasslands became extensive in Europe including the UK due to intensified agriculture in the XX century (Jefferson & Pinches, 2009)
In 2017, an individual was noted near quadrats 18–20 of the hay-cut trial; another individual was recorded in quadrat 22 (Fig. 1) in the 2018 survey
Four plants were recorded in the site with high accuracy differential GPS in 2013 (Fig 1.); none of them were found in the 2019 revisit of their exact positions

Summary

Introduction

The loss of semi-natural grasslands became extensive in Europe including the UK due to intensified agriculture in the XX century (Jefferson & Pinches, 2009). Small fragments of species-rich meadows which survived under traditional management are protected in nature reserves and sites of special scientific interest (SSSI) (Rothero et al, 2016). Populations of orchids are vulnerable, requiring specific links with pollinators and mycorrhizal fungi to complete their life cycle (Honnay & Jacquemyn, 2007). Mycorrhizal specificity is low in Dactylorhiza, and the fungi have a broad geographic distribution, their actual occurrence is controlled by specific habitat conditions (Jacquemyn et al, 2016). On sites with relatively bulky and tall vegetation, orchid populations are often very small and even more vulnerable Conservation management of sites hosting small and isolated orchid populations should be very consistent and focusing on the protected species (Swarts & Dixon, 2009)

Methods

Results

Discussion

Conclusion