miked's picture

Treezilla forum

Welcome to this new forum for discussions around the treezilla.org project which is from the same stable at iSpot and may be of interest to many iSpot users.
Suitable subjects for this forum might be: trees in general and how they can be mapped, useful identification guides for trees, how to set up local groups, places to see interesting trees in UK etc.
We don't currently have a forum facility on treezilla itself so treezilla users can also discuss general issues about that project here.



dan_wrench's picture

Going beyond Treezilla it

Going beyond Treezilla it would be very useful to have a similar system for assessing habitat values. While of course being wary of those who may look at the financial 'value' of a habitat and think that it can be replicated elsewhere for a specific cost...

Dan Wrench
Biodiversity Officer - Shropshire

miked's picture

I think there are one off

I think there are one off overall estimates for these financial 'values' for other habitats. With trees its more tricky as each size/species has a different value and there is often no overall record of these in each urban area.

DavidHowdon's picture

Tree depivation

I think GIGL (the London area records centre) did something along these lines. Not got details to hand but I am sure they would be willing to talk about it.

djs536's picture

Measuring the height of trees

I've begun adding trees to Treezilla but don't have any means of measuring tree height. I wondered if it would be helpful to put a metre measure against the base of the tree before taking a photo and maybe someone would be able to work out the height of the tree somehow? Any helpful suggestions?

DavidHowdon's picture

From memory

Use a stick the same length as from you eyes to the end of your arm stretched out in front of you.

Holding that stick vertically back up until the stick appears the same height as the tree. The distance from you to the tree is approximately the height of the tree.

Or failing that some basic trigonometry should be able to get you the answer in other ways.

miked's picture

There are a bunch of ways of

There are a bunch of ways of measuring tree height. I set up an activity on Open Science Lab to compare the different methods, not sure if the activity is live at the moment. Basically it describes some of the simple methods such as using sticks etc and basic trig (also how this can be combined with using a tape measure) but also trying one of the smartphone methods which may or may not be better.
there are more advanced, expensive, ways of doing it using laser measuring device or clinometer of some kind.
But with any of these it is always best to have an estimate of tree height just by eye to check that the number you get from the device is in the right ballpark. In UK there are plenty of trees in the 5-25m range but very few at 50m tall.