In her article ‘Focus on forest plastics: Reducing single-use plastics in Forestry’ in SCOTTISH FORESTRY Volume 77 No 3 Autumn/Winter 2023, Virginia Harden Scott examines the alternatives to using single-use plastic tree shelter guards to protect young trees from deer browsing.
She quotes the UK Forestry Standard as saying that ‘the use of plastics, whether made from oil based or bio-based polymers, should be avoided or reduced as much as possible’, and redundant products ‘should be removed and recycled to avoid the impacts of bio-accumulation in the forest soil’.
However, the reality is that plastic tree shelters ‘rarely have a closed loop life cycle’, she says, adding ‘significant numbers are lost in severe weather, or neglected and left on site, the key challenge being collection cost (possibly up to a third of the establishment cost). When left, they break down into microplastics, entering the soil and the marine environment, potentially harming organisms and leading to a loss of ecosystem services.’
Efforts are underway to develop alternative tree shelters made from biodegradable or recyclable materials although many alternatives have higher carbon footprints than conventional plastics and can also break down into microplastics. Recycling and composting these materials often require specialised facilities and they are sometimes triple the cost of conventional plastics. Experiments are finding that, actually, the conventional plastic route is better provided they are collected and recycled before degradation.
Shelter Guard Alternatives
Alternatives mentioned in the article include:
- Planting broadleaves at higher stocking densities to reduce establishment failure
- Using thorny and less tasty species, e.g. hawthorn and blackthorn, as nurses and natural protection for more palatable and vulnerable species
- Herbivore impact assessments to support better deer management and tree protection
- Applying sheep’s wool to tree leaders to deter deer
Using Trico®
Trico® deer repellent is also highlighted as a promising alternative that is cost-effective and environmentally friendly. Harden Scott’s article refers to two trials:
- Bowlts Chartered Surveyors: Initial trials in 2019 on conifers in unfenced areas demonstrated effective winter protection, though some spring shoots were browsed. Adjustments, including pre-planting application, reduced costs and ensured even coverage. Additional sprays in autumn and spring maintained effectiveness.
- Scottish Woodlands: Trico was used on broadleaves planted at higher densities in low-deer-pressure areas without shelters. The trials found it cheaper and effective under certain conditions, particularly in areas of low deer populations
To read the full article, click here.
More Trico® Trials
The trials mentioned above certainly echo the experiences of our customers that are finding Trico® either an excellent alternative to other methods of repelling hungry deer or an additional deterrent to add into a mix of approaches.
We – and our customers – continue to run innovative trials with Trico®. It is not licensed for use on food products so cannot be used in, say, orchards and vineyards or on vegetables. Similarly, because of its white colour, it is not suitable for use on ornamentals. While we do have a colourless version, Trico® Garden, for garden plant spraying, it is more expensive for larger-scale usage by, for example, commercial nurseries.
We ran a trial with ‘Deer’, the British Deer Society magazine, earlier in the year whereby sheep’s wool was soaked in Trico® (Pro version) and then put in lures (see images). The trial was somewhat inconclusive. The lures were used in a garden that had suffered from muntjac browsing in the spring and in a nearby sapling plantation. No further significant browsing was observed but, then again, there was very little additional browsing in adjacent control areas. We continue to monitor how it performs. To read the article, click here.
We have heard of other trials whereby Trico® Pro is being used innovatively i.e. not applied directly to plants or trees. We will report more on these as we know more.
Trico® on coppiced trees
Other interesting trials include Wildlife Trust for Cambs, Beds and Northants’ experiment at High Wood reserve in the west of Northamptonshire where roe deer and muntjac eat a variety of plants in the woodland including flowering plants such as bluebells as well as young scrub and coppiced hazel. This leads to a lack of understorey which means less nesting places for birds, like blackcap and chiffchaffs, and generally less diversity of species. They can also strip the bark from more mature trees causing them to die. The reserve is looking for a less expensive alternative to fencing and to protect plants and trees where it may be impossible to erect fencing. Encouraged by positive results at trials in Cambridgeshire, they sprayed coppiced tree trunks earlier this year.
We await a report on results and will provide an update soon! Read more about the trial here.
