UK Bloomers Valley: A Species-Based Approach to Mesotrophic Grassland Restoration
Research to support UK grassland restoration: comparing different methods of reintroducing wild flower species, using seed as the starter medium.
Adam Devenish monitors the performance of Centaurea nigra seedlings planted as seedling plugs, Bloomers Valley, Wakehurst Place, September 2011. Photo: Kate Hardwick.
Traditional UK farming practices favoured the development of semi-natural grassland communities; however, the intensification of agriculture has resulted in widespread habitat fragmentation and biodiversity reduction. Among the many challenges facing grassland restoration projects is the loss of traditional seed transfer methods, such as sheep herding, that have reduced seed dispersal between sites, thereby creating a landscape in which small pockets of grasslands have become effectively land-locked, either by woodland or species-poor agricultural land. In order to combat this problem many grassland restoration projects rely on supplementing their sites with seeds.
This project started in 2009 and continues to 2012 and compares different methods of reintroducing wild flower species into a depleted grassland habitat, using seed as the starter medium. Treatment methods include i) direct sowing seed vs planting seedling plugs; ii) seedlings germinated on agar plates in the lab vs seedlings germinated on compost pans in the nursery; iii) compost plugs vs site soil plugs. Plots are monitored to record seedling emergence (for the direct sown seed treatment), survival, vegetative growth and reproductive success.
Preliminary findings from the first year's results indicate plug planting to be a favourable way to introduce plants into a grassland habitat, with over 98% of plants surviving their first month. Direct seed sowing was less successful, with no species achieving more than 40% emergence in the field and none managing reproductive growth in their first year. However, this would be an appropriate option for some species, if seed were plentiful and resources for nursery propagation were limited. Laboratory-germinated seedlings propagated in compost plugs were generally the most successful treatment for growth and flowering success. However, not all species fitted this trend, which highlights the need for species-specific research to determine optimum reintroduction methods. The first year’s results have been written up in an MSc thesis for University College London by Adam Devenish and final results will be presented in peer-reviewed publications.
In another element of the project, demonstration plots have been set up in Bloomers Valley (Wakehurst Place) to show different grassland restoration techniques, including direct seeding, green hay strewing and the adapted ‘whole crop’ method of green hay application. During the summer, interpretation boards explain the different methods to visiting members of the public, and both the experimental and demonstration plots are used as a teaching resource by Kew staff.
Project partners and collaborators
University College London
Weald Meadows Initiative
John Ellerman Foundation
Length of project:
Five year strategic goals:
• Banking of seed collections: Fundamental science programme expanded on seed biology, and an increased proportion of research output directed towards new or improved restoration or sustainable utilisation methods in response to identified need
• Enabling the use of those collections in, (a) afforestation/habitat restoration, and, (b) food security/livelihoods: Data bases, image collections for plant use and protocols expanded for the collection, storage and propagation of species, and climate/soil requirements
• Restoration science and applied communications: A multidisciplinary species-level science programme established addressing gaps in restoration science, especially the biology of founder populations
• Delivery of restoration on the ground: At least one flagship demonstration project established on both the Kew and Wakehurst estates for public viewing and engagement
Conferences and workshops:
Poster presented at Society for Ecological Restoration International conference in Mexico, 21-25 August 2011.
Demonstration plots and experimental data used in Flora Locale Training course: Seed collecting & use for restoration and re-introduction (Ref SE2), 6 July, 2011.