A botanical survey was undertaken at Heartwood in 2011 to record and monitor changes in plant species diversity and composition; particularly with regard to successional changes from arable to woodland habitats both within the natural regeneration area (referred to as ?The Thicket?) and within the sapling plantation plots. Botanical surveys were also undertaken within Pudler?s and Langley Wood to monitor any potential changes to the ground flora of existing ancient woodland (e.g. the original environmental impact assessment identified the potential for open access to lead to detrimental impacts on woodland ground flora).
The aims of the botanical survey were therefore to:
- compile a comprehensive botanical baseline data set for each study area; and
- undertake systematic sampling of each study area in order to record and monitor long-term temporal variations in plant species diversity.
Four specific areas were identified for further botanical study (see Map), these were:
- Pudler?s Wood
- The Thicket (an area of natural regeneration adjacent to the south-east edge of Pudler?s Wood)
- Langley Wood; and
- Sapling plantation area (adjacent to the northern edge of Langley Wood).
In order to form a baseline data set a botanical species list was compiled for each of the four study areas. The first visit was carried out in September 2011 by Laura Gravestock, Andrew Harris, Brenda Harrold, John Moss, Paula Shipway, Jean Williamson, assisted by Chris Shortall and Alison Moore. Further baseline surveys are planned for spring and summer 2012. The results are shown in the Heartwood Forest Botanical Species List.
In conjunction with the baseline surveys, systematic sampling techniques were employed within each study area, by Laura Gravstock, John Moss, Paula Shipway and Jean Williamson commencing in spring 2012. These comprised 2m x 2 m quadrats spaced at 10 m intervals along a 50 m transect (see map). Each study area contained two transects, separated by at least 20 m; making a total of 10 quadrats per area surveyed. The ends of each transect were
marked with wooden stakes to allow the same transect locations to be used in future years. These results are also shown in the table below.
Due to the persistent wet weather throughout April and the amount of standing water in parts of the study areas, the spring surveys could not be completed until the end of May 2012. Transect surveys were repeated in the autumn of 2012. The surveys were repeated in 2015 and 2017 using 10x10 m quadrats along the same transects. As expected the natural regeneration area plots, where the density of trees and shrubs is high, are becoming less diverse as canopy cover increases.
In 2016, a species list of plants occurring west from B651 was compiled by Agneta Burton, Ian Denholm, Claudia Harflett, Alla Mashanova, Linda McArdle, and Jenny Spurgeon visiting the site in June and August. Overall, 210 species were recorded. No distinction was made between the species occurring naturally and introduced in flower mixtures. It was noted that in addition to uncommon species some of the native species looked unusual (e.g. extremely tall) and most likely came from the mixtures. An account of species recorded in the old woods between 2016 and 2024 was published in The Hertfordshire Naturalist 2024. The table with the species from this publication can be found here.