字幕表 動画を再生する 英語字幕をプリント Our forests and woodlands are sanctuaries for many of our wildlife. In a world where there is increasing pressure on and loss of species of our plant and animal kingdom these places are becoming more and more important. To catch a glimpse of a red squirrel on a woodland walk is a precious moment because reds are shy and spend most of their time in the lofty canopy of trees. Unlike its much larger American cousin, the grey squirrel, which is much more obvious and not shy at all, reds prefer to live in conifer trees but can be equally at home in broadleaves like hazel woodlands or even parkland. In the Fota Wildlife Park they have become quite used to people and you'd have a much better chance of seeing one. They love the red squirrels in Fota and are very concerned about the findings of a recent survey. Well the survey has just been completed, it's been sponsored by COFORD. We found that the grey, since the last survey was done in about the mid 1990's, the grey has spread significantly in the country. It now occupies over half the land area and has, we reckon now, replaced the red in certainly Meath. The red has become very, very rare in counties like Westmeath, Kilkenny, Carlow, Louth and this pattern may well be repeated if nothing is done in the future to help protect the red. Kerry and Cork, the greys are on the frontier there, they're coming into Limerick, they're coming into North Cork. It's a very ancient hazel woodlands down there, red squirrels will be replaced very, very quickly. So the people in Fota are right to be concerned as their red squirrels may not be there for much longer. The American grey squirrel was introduced about 100 years ago. They have a broader appetite but they also carry a virus which is deadly to the reds. One of the benefits to the red squirels is the conifer plantations that are growing up around us because this is the type of habitat where the reds have a natural advantage over the greys. Scots pine is one of their favourites and if you actually look on the ground, if you're out on a walk on a Sunday, maybe you might find little pine cones that have been stripped like that. That's typical evidence that you have red squirrels. The greys prefer broadleaf woodlands where they've done tremendous damage already. They can cause widespread destruction in these young plantations and the Forest Service has put an awful lot of money into planting young broadleaves in Ireland and this stock does stand a high chance of just being written off by the grey squirrel. And the greys also threaten our few remaining native woodlands. The solution I suppose is habitat management for reds they protect our coniferous plantations. There would probably, inevitably, need to be some control done of grey squirrels in the country. We know from what happened in England where reds are now virtually extinct that if nothing is done to protect our red squirrels they're doomed and have little hope to survive. No action on our part will have grave consequences for these beautiful little creatures. Another endangered species who has taken to nesting in the young forestry plantations is the hen harrier. The hen harrier is a rare bird and we have only 140 pairs left in Ireland. The male is grey with black wingtips, quite distinctive to see from a distance, while the female is brown and larger than the male. They live in the uplands and have taken to hiding their nests into young forestry plantations. The food being passed on from the male to the female on the nest is sensational to watch. They use these young plantations until the canopy closes. So future forest management must ensure that there's always enough young plantations. If you were down in the woods today you might come across more than you bargained for. There are some truly exotic species out there. I'm actually in the forest today fogging the canopy above us with this machine. It spews out an insecticidal fog that rises through the canopy and knocks all the insects down onto my collectors. I collect them, bring them back to the lab and identify what's there. The forest canopy has been described as the last great wilderness. We know less about the forest canopy than the depths of the Earth's poles. Yet we think that close to half of all the terrestrial species live up there. For the first time in Ireland the canopy is being studied in a research project PLANFORBIO funded by COFORD. I'm looking at the canopy insects in a range of Irish forest types, Sitka spruce plantations, plantations with canopy mixes and also native woodlands, to see if there is any differences between the forest types in what lives in the canopy and also to see if we can maximise biodiversity in our plantation forests. What's special about up in the canopy? Well it's never really been studied in Ireland before. It's very anecdotal evidence we have, so just word of mouth, what's up there and we really need to know what's in Irish forests. They're a growing part of the landscape so we need to find out what's up there so we can plan to manage forests better in the future so more species can live there. In a canopy like this, in my sample area alone, which is about 24 metres squared, I'll get tens of thousands of insects from that canopy. The types of insects you do get will be aphids and mites because the aphids will tend to feed on the sap and the leaves themselves then the mites can be predatory or herbivorous and then you get other insects like spiders, beetles, flies and harvest men which are related to spiders and are also predatory. So there's a wide range and they all feed on each other and the plants and it's very interconnected. I have a parasitic wasp here and what they do is lay their eggs in caterpillars and the eggs develop in the living caterpillar and actually eat their way out. Here's a caterpillar, they are very important as herbivores and they can do a lot of damage to trees but they also break down leaf matter and stuff like that. Ladybird larvae: so ladybirds are very important in keeping down the aphid populations. The PLANFORBIO Research also investigates plant life in the canopy, birds living in the forest and, in particular, the hen harrier. They all occupy a niche in the forest ecosystem. Knowing what species live there and how they work together will help us to plan forests with biodiversity in mind. So many animals depend on our forests, colourful ones but also less eye-catching ones, they all need a place to call home. So we need to plan our forests in a way that will help them to thrive.