Tree Height to Crown Diameter Ratio

[peatff]

I could be tha Fibonacci sequence applies, the so called golden ratio that appears in nature regularly.

[10 Bears]

It's used a lot in continuous cover forestry in regards to stability etc- try looking for some FC information notes or the continuous cover forestry group for further information.

 

Thanks for the tip. I have already been through a lot of the available material but there is not a satisfactory ratio that I can find.

[10 Bears]

Ah, I see, that does make sense (I think). Could you not take some site/species specific ratios as a benchmark to estimate the remainder?

 

Well, what I am working with at the moment is based on the combination of a couple of metrics. There are ratios for tree height to dbh, and then for dbh to crown radius. I have combined these in to a 'working' model but there is little information on the most suitable ratio to use aside from specific species - again coming back to the concerns that Kevin had for inter-species differences.

 

This combined approach appears OK - but I have found some errors in the model following more extensive testing.

[10 Bears]

How about you take all your survey data ever in spreadsheet form, and calculate the average ratio from that? Oddly I would have no bother doing this as I have never cleared out survey data from my handheld, it would take me about 5 minutes to come up with a figure in Excel. Or use your own data more selectively, from surveys that you know were mainly maiden open grown mature trees?

 

It's gopt to be impossible to generalise. The ratio for any tree is partly a manifestation of apical dominance, but there will be factors of maturity, species, variety, competition, exposure.

 

For example during the week I took down a Norway Spruce, in a windy, alluvial coastal situation. 42 years old from the ring count, spread at the base 12 metres, and conical from there, height 12 metres. The week before another Norway, sheltered by other giants in a garden, on clays, 28 years old spread 14 metres most of the way up, height 24 metres.

 

Or is there something in this that might point you in the right direction? https://www.sorbus-intl.co.uk/hi-tech/survey-equipment/traditional-survey-equipment/iml-multi-tool

 

Many thanks for the advice Jules - always useful.

 

In fact I have confirmed data on approximately 250 mature trees that are within my data set. The issue is that the wider data set contains ~14,500 trees, so my sub-sample is only representative of ~1.5% of the larger data, which could be a difficult sell.

 

I will take a look at all my other surveys as you suggest, and focus only on the specific species I am concerned about. Thanks for the idea.

[10 Bears]

I could be tha Fibonacci sequence applies, the so called golden ratio that appears in nature regularly.

 

Interesting idea, but personally I think Da Vinci's rule would be more likely to be a factor, but some provisional calculations I did weren't too convincing so I moved on.

 

Thanks for the comment though.

[daltontrees]

It seems inconsequential.

 

Nothing is ever as it seems...

 

Especially if you're used to Redwoods. What would the ratio be for one of those monsters?