Mighty oaks from little acorns grow

Sam Witham – Conservation Research Student

Sam Witham, Conservation Student Intern - copyright NYMNPAHello, 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.

UK National Tree Seed Project - collecting in the North York Moors - copyright NYMNPARecently 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.

Only trees from ancient semi-natural woodland are collected from, because planted trees might
not be of local origin and therefore will not UK National Tree Seed Project - collecting in the North York Moors - copyright NYMNPArepresent the local gene pool.

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.UK National Tree Seed Project - collecting in the North York Moors - copyright NYMNPA

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.

Acorns collected to be grown on - copyright NYMNPA

Sam and a couple of oak trees - copyright NYMNPAI will keep you posted on the interesting things I get up to during my time at the National Park!

2 thoughts on “Mighty oaks from little acorns grow

  1. I think it would be most useful to visit both Kew Gardens and the Millenium Seed Bank.

  2. Pingback: Saving up for the future | The official blog for the North York Moors National Park

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