The following article by Steve Ashby, outlines the reasons why restrictions on the movement of tree ferns have been necessary.
Tree Fern Imports
Steve Ashby, Plant Health Division, Defra
The issue of tree fern imports became prominent for the Plant Health Service in 2004 with several important findings of pests in consignments of tree ferns. There had been some findings of pests in previous years but in 2005 the problem got significantly worse. It is not known why 2005 was so bad – clearly there has been a big increase in the popularity of Tree ferns over the last decade. But also there have been changes in the approach of exporters – inspectors report that consignments are not being fumigated, while the increase in demand could have brought more exporters into the market.
Most tree fern imports come from Australia and New Zealand. Unlike some plants there are no specific requirements applying to tree ferns imported into the European Union. The UK’s import requirements are the same as all member states of the European Community. There has been debate in the past involving the EC’s Standing Committee on Plant Health, which implements and overseas all import requirements. The committee also decides which category plants fall into – are tree ferns; trees, shrubs, or herbaceous perennials? But it is clear that, as ‘plants for planting’ they are covered by the general requirements which apply to all plants for planting, principally that they must be grown in nurseries.
Again, there is a problem with definitions – what does ‘grown’ mean and what constitutes a nursery? The purpose of these requirements is to ensure that the plants have spent sufficient time under controlled conditions to allow pests to emerge and be treated. The exporting country must issue a Phytosanitary Certificate – this is a declaration that the plants are free from harmful organisms and that they meet the importing country’s stated requirements.
So what happens to the ferns when they arrive? All plants for planting must be inspected for pests and diseases and to ensure that they comply with import requirements. For cost and convenience reasons they are mostly inspected at the importer’s premises. The Plant Health and Seeds Inspector checks the plants to make sure they are free from pests. Given the conditions under which tree ferns are transported – packed tightly in shipping containers, it was more effective to check the plants once they had been on the importers’ premises for a period of time.
In one particular case the inspector had been called back by the importer – who responsibly had recognised there was a problem. Having acclimatised, yellow flatworms started emerging from the pots. Alerted by this the inspector collected a whole menagerie of non-native species, including beetles, caterpillars, centipedes, millipedes, cockroaches, yellow flatworms, landshrimps, nematodes, slugs, spiders and wasps. The range of invertebrates found was a challenge for the CSL diagnostic team responsible for identifying the species and giving a preliminary assessment of the risks associated. The yellow flatworms were discovered to be of the species Fletchamia sugdeni. A Melbourne trap-door spider was also found. This is from the same family as the notorious Sydney Funnel Web spider, but its venom is not harmful to humans. It could, however, give a nasty bite.
The finding of this menagerie of creatures in several different consignments suggested strongly that the import requirements were not met – all these creatures suggested that the plants were being taken straight from the forest. These findings also highlighted the fact that the inspectors only had limited powers to deal with the issue – where there were not plant pests present they needed to seek the co-operation of the importer to tackle the other pests. But there were clearly wider concerns about the possible threat to the environment if some of these pests were to establish, as well as threats to operators handling material in which there are Australian spiders.
So the action the Plant Health Service took was to write to the exporting countries to remind them of our import requirements and their wider responsibilities to restrict the spread of invasive species. We also outlined what we would understand by the term ‘nursery’, not just a patch of forest with a fence round it. Although it took a good while to get a response, we heard in January that Australia were suspending exports of tree ferns to the EU and were requiring exporters to ensure that the ferns were nursery-grown Soon after that we heard that New Zealand were taking similar action. In both cases we have now agreed some transitional measures to allow trade to continue and avoid major losses for people who have already agreed contracts.