Kinver Edge Pig Project Day 11

A lack of technical know how means I’ve been unable to upload video clips of the pigs crunching their way through stems of Himalayan balsam.

Foreground: plot one was occupied for 7 days, leaving around 10-15% bracken cover and
removing all of the Himalayan balsam present. Midground: the second plot contains around
50/50 bracken / balsam. The background shows the woodland glade dominated by bracken.

It is now day 11 of the pig project at Kinver Edge: using Hampshire pigs in small plots to study their affect upon Himalayan balsam. They are a well documented tool against bracken, and also to recover commercial plantations for nature conservation; although their use against balsam appears to be little studied.

Bracken is endemic throughout the project area, to the detriment to the more favourable lowland acidic grassland species, particularly wavy hair-grass. Interspersed through the dense bracken stands, Himalayan balsam appears to be slowly spreading; and this mix makes it difficult to undertake typically labour intense balsam pulling management.

We have agreed with Natural England to undertake the pig project for a limited time. To allow the pigs into areas where balsam is seeding would be creating bigger problems for us, as the merest touch of the plant can send seeds 7 metres in any direction. Once flowering of balsam stands is well established, the work of the pigs will focus upon tackling bracken, although it would be possible to manually removed a few flowering stems from selected plots in order to maximise the presence of the pigs.

Performance so far?

The pigs have been in the second plot, which contains a large number of balsam stems, since July 8th. The majority of the balsam is now flattened against the ground after the pigs rooted at their bases; but knocking the stems down is insufficient as the plant can produce new roots. However, the pigs are eating the plants: both upright stems, and those prone and crushed underfoot; and they appear to be happy eating every part of the plant – flowers, stems, roots, and leaves.

There is a minor concern that they appear less interested in smaller balsam shoots, less than 15cm in height. Although smaller stems were eventually removed in the first plot towards the end of the first week.



Day 11 and the Hampshires are really tucking in to the Himalayan balsam: a sweet smelling, juicy, and crunchy plant.



Eventual result.

The first plot still contains around 10-15% bracken, with the remaining area now bare and devoid of bracken mulch. The action of the pigs should have brought a range of viable seed to the surface, which we will monitor in 2013. Although the next 12 months could see bracken intrusion which will need keeping in check, we can expect to see a return of wavy hair-grass, bent grasses, and possibly flowering plants such as heather and heath bedstraw.

Our aim is to create a diverse field layer of grasses and flowering plants, which includes bracken in the matrix.