Dealing with Ash Dieback at the University

Ash Dieback (Hymenoscyphus fraxineus) is a fungal disease first recorded by the Forestry Commision in 2006 becoming prominent in the South East of England in 2012.

We have confirmations on Ash (Fraxinus excelsior) specimens within our University since 2018, as has been the case for other well monitored sites in Devon and Cornwall.

The infection is permanent with no control and, although mostly terminal, there is a high degree of variability with respect to the seriousness and speed of the symptoms. We are gifted with a high number of people exploring, enjoying and being amongst our grounds and any sign of symptom is considered with great caution so physical management of these trees today and in the future is a certainty.

The dilemma amongst the Grounds team is that we know how valuable Ash is to biodiversity as a habitat. It hosts Woodpeckers (Dendrocopos major), Tawny Owls (Strix aluco), Redstarts (Phoenicurus phoenicurus) and the team favourite the Nuthatch (Sitta europaea), all for nesting. The lichens and moss which grow freely are a food source for caterpillars.

We are able to balance these interests and find opportunity where people are safe, and friends of other species can continue to share the space together.

The solution we have employed, which you can see in the photo below, is to carry out a veteranisation process on a tree. The major limbs are completely removed until the crown has gone and there is only a trunk left standing. The tree is then ringbarked which involves removing the living tissue from around the trunk. With the xylem and phloem severing the plants’ ability to transport water and nutrients, the tree will die and decay and this breaking down process will become host to insect species.

Importantly as the trunk is short and wide with developed buttress roots, there is no expectation that this tree will fall.

The top of the trunk can now be coronet pruned. This describes a technique that aims to replicate the natural fracturing effect seen after a limb failure, where insect species can easily reside within and rainfall can sit and gather amongst the dead wood.

Trunk segmentations have been cut out, hollowed and an entrance point made. These have been re-attached to the trunk around all four compass points as a future bird nesting habitat.

For anyone that would like to visit this work its location can be found here – http://ex.ac.uk/veteran-ash-specimen

For the future, the best course of action is regularly monitoring the species we care for. After all a minority will also be genetically tolerant and that stock of trees amongst our collection will be vital for the long-term future of the woodlands and specimens here when we begin to repopulate.

 

Diseased tree upcycled into wildlife habitat tree stump and bird boxes

Unfortunately a diseased Ash tree behind the IAIS Building on Streatham Campus has had to be removed, but our Arb Team were keen to use this as an opportunity to help wildlife and increase wildlife habitats on campus, in keeping with our biodiversity and sustainability work practices.

It is now a wildlife habitat high stump which will harbour and benefit insects and wildlife for years to come and the team have also carved bird boxes into the trunk.

Great job team!

More Wow Wildflowers!

The wildflower areas at St Luke’s Campus are looking fantastic.

Wow Wildflowers!

The wildflowers at the Reed Hall beds are in flower and looking glorious.

Last year we trialled having wildflowers instead of the customary formal planting in these beds and they proved so popular with everyone and the bees, butterflies and insects that we’ve done it again!

‘Exeplore’ Podcast – grounds, gardening and green fingers

The University of Exeter has launched a official podcast called Exeplore and each episode will explore a different topic with students, staff and alumni; aiming to celebrate the richness of life within their global community.

Iain Park, Assistant Director of Grounds, joins them on the most recent episode to discuss why and how the university grounds offer such a great space for students, staff, plants, trees animals, wildlife, birds, and insects to thrive in.

Also discussed is the impact the COVID-19 lockdown had on the grounds in spring 2020.

Listen to the podcast at:

Spotify http://ex.ac.uk/crq

Apple Podcasts http://ex.ac.uk/crr

More information on the Wellbeing Walks that Iain talks about can be found at http://ex.ac.uk/crh

If you’re interested in keeping up to date with what’s going on in the grounds, follow the Grounds Instagram @universityofexetergrounds https://www.instagram.com/universityofexetergrounds/

 

Update on biological control treatment of Mealybugs

An update and photos from Drew, one of our amazing Horticultural Apprentices, on the biological treatment being carried out on the Ficus trees in The Forum Street:

“So yesterday at work I got to apply biological controls to our very poorly Ficus trees. They are suffering from a serious bout of Mealybug which suck the sap and are vectors for diseases. To help combat this in an eco-friendly way, we have applied a healthy dose of Australian ladybirds (Cryptolaemus montrouzieri) which will spend the next few weeks munching on the Mealybugs and hopefully leaving the Ficus much happier”.

The predator insects, Cryptolaemus montrouzieri, being placed on the Ficus trees

The predator insects, Cryptolaemus montrouzieri, being placed on the Ficus trees

A Cryptolaemus montrouzieri on its way to eat a Mealybug

One of the Ficus trees wrapped in the fleece to prevent the insects from escaping

All the Ficus trees wrapped in the fleece to prevent the insects from escaping

Ghostly going ons?

Ghostly going ons in The Forum? Don’t worry our Ficus trees haven’t turned into huge ghosts!

The trees have a Mealybug infestation, so we are introducing predatory insects (Cryptolaemus montrouzieri) to deal with them.

Mealybug

Cryptolaemus are harmless to people, pets and wildlife and will not become a pest in their own right.

Cryptolaemus montrouzieri

By using predatory insects as an organic form of biological control, we are avoiding the use of harmful pesticides.

The fleece coverings have been placed over the trees to keep the process and insects contained.

These information sheets have been produced by our Horticultural Apprentices and will be on display next to the Ficus trees to explain the process to passerbys.

New Research – big bumblebees learn locations of best flowers

Big bumblebees take time to learn the locations of the best flowers, new research shows.

Meanwhile smaller bumblebees – which have a shorter flight range and less carrying capacity – don’t pay special attention to flowers with the richest nectar.

University of Exeter scientists examined the “learning flights” which most bees perform after leaving flowers.

Honeybees are known to perform such flights – and the study shows bumblebees do the same, repeatedly looking back to memorise a flower’s location.

“It might not be widely known that pollinating insects learn and develop individual flower preferences, but in fact bumblebees are selective,” said Natalie Hempel de Ibarra, Associate Professor at Exeter’s Centre for Research in Animal Behaviour.

“On leaving a flower, they can actively decide how much effort to put into remembering its location.

Bumblebee flower

Bumblebees carry out “learning flights” after leaving flowers (credit: Natalie Hempel de Ibarra)

Bumblebees carry out “learning flights” after leaving flowers (credit: Natalie Hempel de Ibarra)

“The surprising finding of our study is that a bee’s size determines this decision making and the learning behaviour.”

In the study, captive bees visited artificial flowers containing sucrose (sugar) solution of varying concentrations.

The larger the bee, the more its learning behaviour varied depending on the richness of the sucrose solution.

Smaller bees invested the same amount of effort in learning the locations of the artificial flowers, regardless of whether sucrose concentration was high or low.

“The differences we found reflect the different roles of bees in their colonies,” said Professor Hempel de Ibarra.

“Large bumblebees can carry larger loads and explore further from the nest than smaller ones.

“Small ones with a smaller flight range and carrying capacity cannot afford to be as selective, so they accept a wider range of flowers.

“These small bees tend to be involved more with tasks inside the nest – only going out to forage if food supplies in the colony are running low.”

The study was conducted in collaboration with scientists from the University of Sussex.

The bees were observed in greenhouses at the University of Exeter’s award-winning Streatham Campus, and Professor Hempel de Ibarra thanked the university’s Grounds and Gardens team for their continued support.

The study was funded by the Leverhulme Trust.

The paper, published in the journal Current Biology, is entitled: “Small and large bumblebees invest differently when learning about flowers.”

Feelgood Friday – Positive Pebbles on Streatham Campus

Some positive and heart warming news for a Feelgood Friday!

Pebbles with positive supportive messages have appeared along a pavement at the bottom of Stocker Road on Streatham Campus.

What a lovely initiative and we hope they bring smiles to faces and help people feel less alone.

#bekind #bepositive

Celebrating our fantastic Grounds Team staff!

Unfortunately, due to the current restrictions, the annual Grounds Staff Celebration Event could not take place this year.

However, we were determined to still go ahead with the staff awards and pictured are some of the very deserving winners.

The last photo is the creative drum roll done before every award was announced!

We would like to thank EVERYONE in the Grounds Team for all their hard work, dedication and motivation during this very difficult year. You are all absolute stars ⭐⭐