Conifer seedlings on the make

A typical array of introduced conifers on woodland edge - Douglas Fir, European Larch and Lawson's Cypress.

Today I went out to get some photos of a few conifer species for the flora ID guide, hoping to plug some gaps by re-finding certain plants I had photographed some years ago on the Felbrigg Estate. I was in for a bit of a shock as, in my six-year absence from the area, there had been a lot of work done and many of the trees I was after were gone. This is not as drastic as it might sound, since the trees I was after are non-native species, which have been removed to allow a return of some of the area to natural heathland.

We have a long history in the UK of introducing trees from other parts of the world, some as ornamentals and others for forestry purposes. At Felbrigg, a number of trial plots were planted of a variety of conifer species, mostly from North America. But trees will do what trees will do and what is interesting is the regeneration of seedlings that has been taking place since the land was cleared and this was of interest to me for two reasons. The first reason is from a recording aspect. When recording for national or regional plant surveys, we try to avoid recording plants that are not an established part of the landscape, so there is often much discussion (heated sometimes!) as to what should be recorded and what should be ignored. Is a tree recordable once it is established? And if so, at what point does it pass from planted to recordable?! The debate will rage on, no doubt; however, if a plant self-regenerates by producing seedlings, then those seedlings were not planted by anyone and are certainly recordable, so scratching around for proof of seedlings is a common pass time for plant recorders!

My second point of interest in these seedlings comes in the ecology aspect of the plants and the significance for habitat management. Great swathes of conifer seedlings were covering the cleared areas at Felbrigg and this made me ponder on this aspect of a tree species life cycle. Conifers produce huge volumes of seed, but most of these seeds will fall beneath the established trees and will never germinate since conditions in the deep shade beneath the parent trees will not be suitable for them to grow well - which seems remarkably wasteful. However, after clear-felling takes place, the seedlings are exposed to light and air and spring up in huge abundance. I imagine that human clear-felling produces the same (or similar) conditions as a forest fire or a major wind-throw and clears the way for the next generation of trees to get started. So, ideally, trees need only drop seed the year before a forest fire but, since they have no way of being alerted to when such an event takes place, their only solution is to produce copious amounts of seed every year, just in case.

Western Hemlock-spruce (Tsuga heterophylla) seedlings were present in great abundance at Felbrigg today.

For habitat managers, the abundance of such seedlings can be very frustrating as the dense cover they produce will easily swamp out smaller or slower-growing species such as heathers. Tackling such problems is a constant battle for conservation organisations.

The sun shone nicely today and gave me plenty of opportunity to get the photos that I needed. Though some of my target species were gone, there was plenty enough to keep me busy!

A carpet of Lawson's Cypress (Chamaecyparis lawsoniana) seedlings blend in pretty well when covered in this morning's frost!

Being deciduous and thus leafless right now, the young plants of European Larch (Larix decidua) stood out readily among the other conifer seedlings.

Bright, glossy foliage and a fruity smell help to identify young Western Red-cedars (Thuja plicata).

There's an easy but painful way of confirming the identity of Sitka Spruce (Picea sitchensis) seedlings - just stick your hand into the needle-sharp foliage!

My prize for today - a seedling Noble Fir (Abies procera)

Among the sea of assorted conifer seedlings today, I was pleased to find a single seedling of Noble Fir. This species does not feature in the floras for Norfolk or Suffolk, so finding confirmed regeneration certainly puts Felbrigg on the map!