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)



Smartphone hemispherical photography

Hello all,

Hemispherical photography (HP) is a wide-spread method for assessing the canopy characteristics and light regime in a forest. In the following paper that we just published on Ecology and Evolution, we evaluated if such method can be carried out with smartphones equipped with (small and cheap) fish-eye lens. The answer: yes!

Please have a look here:

Rapid assessment of forest canopy and light regime using smartphone hemispherical photography


A picture creating by merging two quasi-hemispherical pictures collected with a smartphone camera.

Crowd-sourced data collection of forest regeneration growth

I am proud to announce the launch of a crowd-sourcing data collection campaign! The wide spread diffusion of smartphone and tablets, and the cheap fish-eye lenses available for such devices, can be a powerful complement to traditional research techniques. My aim is to involve foresters practitioners or simple forest visitors from all over the UK in a data collection related to the growth of conifer tree regeneration as function of the canopy cover. Please join the project and I will send you a free fish-eye lens for smartphone! Check more project details at



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!!