New paper on light-growth dynamics of tree seedlings

Dear all,

I’m glad to announce we published a new paper titled “Light-growth responses of Sitka spruce, Douglas fir and western hemlock regeneration under continuous cover forestry” on Forest Ecology and Management. We developed predictive models for height and diameter growth that will allow accurate modelling of the study species in continuous cover forestry management.

The highlights of the study were:

  • Understanding the light response of natural regeneration is essential for continuous cover forestry.
  • Modelling light-growth requires species-specific non-linear functions.
  • Tree size and intra-regeneration competition can affect the growth rate and the asymptotic growth.
  • An increasing shade tolerance ranking was identified as Douglas fir ≤ Sitka spruce < western hemlock.
  • An apical dominance ratio of 1.5 is an indication of Sitka spruce seedlings with adequate growth.

Please follow this link to be able to download the study: (note the link will be valid until the 12th June 2018)



IUFRO 125th Anniversary Congress

Hello everyone,

I am really glad that I have been accepted to present a poster at the massive IUFRO 125th Anniversary Congress! Since the huge number of work submitted to the conference, the competition must have been hard. I will present early height and radial growth models for Sitka spruce, Douglas fir and western hemlock regenerating tree as function of light availability, tree size and intra-regeneration competition. Stay in touch for a preview of my poster here!

Before the conference, I will be attending the summer school of the European Dendroecological Fieldweek, hosted in the remote Chalet-Refuge Les Trois Fours, Vosges Mountains, France.


IUFRO Spruce 2015 Conference (2)

Hello everyone. Last August I attended the IUFRO conference on “Ecology, silviculture and management of spruce species in mixed forests” organized in Alberta. It was a very interesting event, with a high quality of participants: from silviculture to GIS and Remote sensing experts, from forest modelers to policy makers. I am proud to have made my contribution too, presenting the following poster:

poster_Bianchi A4

I am glad that my research is indeed progressing. The “take home” message from the poster is: Sitka spruce seedlings growth can be modelled as a function of light measured with hemispherical pictures. Data from very different forests (a larch forest with Sitka spruce regeneration and a pure spruce plantation) were consistent.

We considered the growth ratio (the ratio between the observed shoot leader growth and the potential growth of the same tree growing in full light) instead of the absolute leader growth: the results show that we can move forward with this approach!

Now it’s time to collect more data! I’ll keep you posted.

The tree dome

Hello everyone. After a nice Christmas break, I eventually started some action! Together with Gruffud, another forestry student from Bangor University, we are surveying some plots around Clocaenog forest, one of the few sites where CCF is being tested in the UK (read more on: The forest comprises many Sitka spruce stands where different intensity of thinning and various types of shelterwood are being implemented, all focused to obtain the best natural regeneration. The Natural Resources Wales staff managing the site is very keen to help research activities. Thanks!

Gruff is particularly interested in studying the relationship between light regime and regeneration undercover, so we are taking some hemispherical pictures in each plot. We will later investigate the correlations (if any!) between stand characteristics, canopy transmittance and regeneration characteristics.

© Gruffudd Rhys-Sambrook

© Gruffudd Rhys-Sambrook

We’ll keep you updated!!

Modelling forest growth in a changing environment

On Friday the 5th of December Simon Lloyd, Director of the Royal Forestry Society, gave a talk at the Bangor Forestry Students Association about resilience and new paradigms for British woodlands.

The key message was that accellerated tree diseases, unmanaged pests, climate change, and new economic scenarios are already affecting British forestry, forcing woodland managers to change their management decisions. A shift from traditional even-aged monospecific coniferous plantations was advocated, as well as the idea that natural local broadleaves are a simple panacea for all the problems.

Continuous Forest Cover approaches, use of alternative minor species, accepting to change landscapes were some of the suggestions Simon Lloyd provided. He admitted that there is not enough knowledge about new some of the new approaches and more data must be collected. As an example is where owners of novel tree species can share their experience.

As a forest modeller, the question I have to ask myself is: how versatile should be a forest model nowadays? Should I prepare one that is able to take into consideration possible climate change scenarios? Or with the option to incorporate easily more species and situations, and to change parameters for the ones already considered? Models based on analysis of the statistical relationships of data collected now might lose validity soon under the drivers of change described by Simon Lloyd.