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Biosecurity advice for forest visitors

Tree health can have a dramatic impact on our landscapes. However, there are simple steps you can take to help limit the spread of plant diseases when you visit woodlands, parks and gardens.

Tree and plant diseases can live in mud and water.

After cycling through our green spaces, washing the mud from your bike between rides can help limit the spread of plant disease between places.

If you brush the mud and leaves from your boots between visits to different parks, gardens and woodlands you can limit the spread of plant diseases between different places.

By brushing the mud from your buggies and boots between woodland play sessions, you can limit the spread of tree disease.

Scientific research into the spread of plant pests and diseases

There have been scientific studies looking into how tree and plant pests and diseases are spread, and how we can help limit this spread.

In 2007, a Forest Research study analysed how frequently Phytophthoras could be found in mud and leaf material on the boots of walkers who had visited sites infected with Phytophthoras. Those in the survey sample had been known to have walked in sites infected with Phytophthoras.  The results of the study found that 30% of the samples from walker’s boots were contaminated with Phytophthoras.  The source of the contamination was fragments of infected leaves, which had broken down and incorporated into the litter layer of the soil. This is of greater concern when considered with the fact that Phytophthora kernoviae (the Phytophthora pathogen that affects larch trees found in the SW of the UK) can survive in both air-exposed and litter-embedded infected leaves for more than a year. 

In 2012, an Australian study looked into the effectiveness of vehicle washing and roadside sanitation treatment in limiting the spread of pests and diseases. The results strongly suggest that the possibility of Phytophthora. lateralis spread in soil or mud on footwear should not be disregarded. Boot cleaning, at the very least with water and a stiff-bristle brush, should be undertaken to help limit the spread of pests and diseases.

In 2005, a small study in New Zealand demonstrated the importance of cleaning boots after visiting a site known to have a Phytophthora infection.  The study found that the Phytophthora remained infectious even after one year after  being found in the soils.  The authors recommended that contaminated soil should be removed from boots following a visit, and that the cleaning should be done in a secure location, so as not to infect any water courses.  Such actions would, the authors noted, potentially prevent the spread of the Phytophthora to new locations.  Given the longevity of Phytophthoras it is important that any contaminated material is not moved into a new site or area. 

Last updated: 21st September 2017