Sam Witham – Conservation Research Student
Hello, I am Sam Witham, the new conservation intern student from the University of York. During my year with the National Park, I’ll be undertaking a research project as part of my degree looking at the restoration of plantations on ancient woodland sites (PAWS). Although I am still undecided on my actual hypothesis, currently I am thinking of comparing the biodiversity and success of planted deciduous forests to forests formed by natural regeneration.
I’ve been here since the beginning of September and I’ve been involved with a wide variety of work so far to get a feel for what people do in the Conservation Department.
Recently I’ve been involved in tree seed collecting for the UK National Tree Seed Project (UKNTSP) with a team from Kew. A genetically representative collection of all UK tree/shrub species is needed, and one of the important seed zones includes the North York Moors.
Within each UK seed zone, seeds from all locally native tree species need to be collected. Where possible, these seeds are collected from altitudes above and below 300m.
The seeds will be stored at the Millennium Seed Bank in West Sussex. Along with seed samples, herbarium samples (pressed plant samples) are taken to show how features such as leaf structure vary across the UK. DNA samples are also taken.
When out in the field, the GPS coordinates of each tree the seeds are taken from are recorded, and a tag added to the tree so it can be found again in the future. Seeds are only collected from branches, as seeds found on the floor will have a greatly reduced lifespan in storage due to damage by pests or pathogens. Seeds are taken from as many branches of the tree as possible as each flower on the tree is likely to have been pollinated by a different male tree.
Interestingly, acorns from oak trees are not collected as currently there is no way of storing them for long periods as they die when they dry out and are also easily infected by fungal diseases. Trials of storage using liquid nitrogen are ongoing but the majority of the acorns even with this method still become unviable and will not germinate.
So at the moment the only way to preserve our local gene pool of oaks is to help keep oaks growing here.
The National Park Authority attempts to collect 30,000 locally sourced acorns per year
from around the North York Moors – and around a third of these are expected to germinate. The acorns are grown on and planted out around the area and not only does this help preserve the local gene pool and maintain the area’s natural heritage but it also creates and reinvigorates valuable native woodland habitat for many species. Also, using locally sourced and grown trees helps reduce the risk of transmission of tree diseases around the country.