Biodiversity Gatwick: A Summer Summary

Tuesday 26 August 2014

A Summer Summary

It's been a very busy summer so sticking with Rachel's trend of timely blogging, I decided to wait til the Himalayan Balsam had started to go over before kicking off the waders and getting back into the office to contribute to the blog. When you see the amount we've achieved in the last few months I think you'll agree that it was worth the wait!

We’ve been re-surfacing woodland paths, creating new habitats in the form of bug hotels and reptile hibernacula, not to mention keeping up with the Great Gatsbees – our thriving Honey Bee population. As always, however, one of the most important jobs has been trying to control the spread of Himalayan Balsam (Glandulifera impatiens) across Gatwick’s conservation zones and beyond.

This impressive plant can grow up to eight feet in a little over sixteen weeks, using an explosive mechanism in its seed heads to disperse seeds far and wide, before spreading quickly to dominate river banks, displacing native flora in the process. If you’d like to find out more, there’s a helpful article on the Sussex Wildlife Trust website here: http://www.sussexwildlifetrust.org.uk/blog/2014/07/greenspace-invader/


Himalayan Balsam in flower

Himalayan Balsam’s dependence on river systems for seed dispersal means that low-lying areas like Gatwick Airport, which is intersected by a number of water courses such as the River Mole, Gatwick Stream, Crawters Brook and Mans Brook, receives a constant influx of seeds throughout the summer. This makes the job of controlling its spread all the more important and begs the difficult question; where do we start?

After much deliberation (and some blindfolded pointing at a map), we decided to begin our battle at Povey Cross in the North West Zone with a team from Gatwick Airport’s Engineering and Asset Integration Department. On a scorching hot day at the end of June, this nine-strong group got stuck in, removing plants over an incredible 700 meter stretch of the banks of the Mole.

Engineering and Asset Integration with Balsam casualties at Povey cross

A little over a week later, volunteers from Southern Gas Networks took up the mantle in Horleyland Wood where Balsam had taken up residence in dense patches under the woodland canopy, encroaching from the adjoining Gatwick Stream and sewage treatment works. The following day reinforcements arrived in the form of GGP’s youth rangers. They set to work with boundless energy, pulling back more valuable habitat from the Balsam’s clutches.

Southern Gas came ready for action with matching overalls.

Youth Rangers at Horleyland wood, accompanied by one slightly less youthful ecologist.

By early July it was time to call in the elite squadron and GGPs weekly volunteer group got to grips with the Balsam in Riverside Garden Park, Horley, where the Gatwick stream joins the river Mole. Undeterred by the towering Balsam-covered banks, they put in a tremendous effort over two long and very hot days. Using ladders to scale the steep banks, they tirelessly removed plant after plant. This resulted in at least one volunteer taking a bath in the cool, calming waters of the Gatwick Stream. Despite these setbacks, their hard work paid off and we managed to clear the majority of the Balsam from the park, downstream from the underpass in the south-eastern corner.

GGP Volunteers tackle towering Balsam at Riverside

A final sweep of Riverside was carried out by a group of EDF office staff who came all the way from London to join the fight. The team were very thorough and spent the morning working away from the stream, removing any stragglers in the woodland edges where seed had been carried by winter flood waters. As the day wore on and we worked our way into open grassland, it became apparent that we were going to need a change of plan. Fueled by the scorching summer temperatures, much of the Balsam in these open areas was already setting seed and too much disruption at this stage would only facilitate its spread.

EDF's London team at Riverside

We proceeded carefully, using scissors and secateurs to carefully snip all of the seed pods into bin bags before ripping out the remainder of the plant. Six bin bags of seed were removed and prevented from entering the catchment that day.

As you can see from the map below we have made a big impact this year, and its all thanks to the fantastic work of our ever-growing volunteer network. All our volunteers have proved willing and able and always up for a challenge.

But as I said earlier, it hasn’t been all about Balsam this summer. I’d like to say a heartfelt thank you to everyone who has turned out to help with our many projects. And just to prove it, here are a few more pictures.