Posts tagged ‘tree’
Forest mensuration (measuring trees and forests) has come of age. I have written a few posts about forest mensuration and also how to use a smartphone to measure tree height – see links below. I recently came across some really impressive apps for use by foresters and woodland owners to measure trees and areas, and to calculate stand basal area, using an iPhone smartphone.
The Relascope (Spiegelrelaskop), invented by Austrian forester Walter Bitterlich (1908-2008), is a specialist and expensive instrument used by foresters to estimating tree height, distance to tree (although this is complicated), and the basal area of a stand (the sum of the cross-sectional area of trees, taken as a dbh and calculated inside the bark). Although a superb instrument and highly accurate in trained hands, the Spiegelrelaskop is not likely to be used by many private woodland owners as it is unaffordable to many (£1500/$2400). Other relascope types are available, see How to use a wedge prism relascope to measure basal area, but the development of powerful forest mensuration tools for smartphones, which most people carry today, is very welcome.
The apps that I’ve been trying are available free from the Apple app store, developed by Taakkumn Watakushi from Fukushima in Japan. I have no hesitation in recommending these two apps as I’m not aware of anything else like these that are available for foresters. He also provides a compass surveying app (iCompass Surveying) that enables areas to be measured but I have not tested it.
iHypsometer - click to read more on the developer's website
The iHypsometer is a free (in the ‘Lite’ version) tool for estimating tree height. It works on the same principles of trigonometry that I explained in How to measure tree height using a smartphone but it copes with sloping ground (i.e. when the base of tree is not level with your feet) and it completes all the tricky maths for you. It requires that you have a ‘friend’, whose height you should measure, and who should stand next to the tree, although I find that a stick cut to a suitable height works just as well. Angle measurement works in the same way as I described in How to measure tree height using a smartphone except that it uses the short side of the phone. The only feature that I would like the developer to improve is to use the longer side of the phone for sighting along, as I have found in other apps that this provides much greater accuracy. Visit the iTunes app store to download iHypsometer
iBitterlich - click to read more on the developer's website
The iBitterlich is a free app for calculating forest stand basal area. It uses the view from the camera on an iTouch (latest model)/iPhone 3G and up/iPad, on which it overlays buttons where the number of trees of different categories of dbh can be counted simply by pressing them. In the screenshot (below) I was looking at the second tree that I had counted as a ‘+3′, and I had already counted 4x ‘+2′ and 11x ‘+1′ trees in my sweep, that at this point was almost complete at 320 degrees.
iBitterlich iphone app screenshot. This tree is a '+3'. Basal area and Stand volume are displayed at the top.
After finishing a 360 degree sweep of the forest stand and counting all the trees, the average tree height is entered in another field, and form factor can be adjusted. The stand volume m3/ha and basal m3/ha are then displayed at the top of the screen. Visit the iTunes app store to download iBitterlich
Have you tried these apps in the forest and did they work for you? Are you aware of similar apps from other developers? Is there a similar set of apps for the Android platform? Do let me and readers know by sharing your views via a comment.
Gabriel Hemery
Other posts about forest mensuration
The authors recently travelled to East Sussex on the hunt to find some of England’s last remaining mature elm trees.
East Sussex is one of the last strongholds for the elm, where it is assisted in its battle to survive the continuing onslaught of Dutch Elm Disease by a special project run by East Sussex County Council; who employ a dedicated Dutch Elm Disease Officer.
The elm that was
This is the latest in my Elm series; my last image being Ghost elm.
I captured the shadow of a very large and healthy Cornish elm Ulmus minor subsp. angustifolia growing in East Sussex. It is one of the last large elm trees remaining alive in England, following the spread of Dutch Elm Disease, which has all but wiped out the majestic elm. The dark chasm depicts figuratively the loss of the elm in the English rural landscape.
I used burn and dodge tools in Adobe Lightroom to create the effect of a chasm in the ground. I left a subtle hint of colour amongst the darkness to help suggest depth (visible at full size). Some small adjustments of greens and yellows helped enhance the already strong tree shadow in the grass. Taken with a Lumix GF2 with 7mm lens (14mm at 35mm equivalent), f11, ISO100.
Gabriel Hemery
Like this:
Afterlife tool and spoke
Winter ash gale bend and yield
Oak a merest nodGabriel Hemery
During the recent winter gales in England I was inspired to write a Haiku poem. The amazing flexibility of the ash Fraxinus excelsior tree means that its wood is widely used in tool handles, sporting goods such as hockey sticks, and in the spokes of wooden wheels. In this short film made amidst a woodland gale, an ash tree waves and yields by amazing degrees in the gusting wind. Nearby (just visible distant far left) a stoic English oak Quercus robur tree hardly moves.
Gabriel Hemery
Like this:
Like most people I love watching a good film or movie, in the cinema or at home. I have to admit a strange affliction however: I just cannot avoid spotting out-of-place trees in films and TV dramas. Try as I might, rows of ‘alien’ Sitka spruce of Douglas Fir which were introduced to Europe only in the last two hundred years or so, just shout out to me when appearing in the landscape of period dramas or Medieval action movies such as Robin Hood. I see red; my saturation in the fiction spoilt as I am jolted back to reality. My poor family.
I feel for the film maker, I really do. They already have to contend with vapour trails in the sky from jets, with tyre tracks or inappropriate architecture. It may be difficult to film in any modern woodland and to fool the expert forester eye, and perhaps it doesn’t matter in that most people will never notice.
On a more positive note this got me thinking about the tree in film. The films where trees take a starring role and that leave you richly rewarded.
Avatar (2009)
The most recent example would be James Cameron’s epic eco-tale Avatar. The indigenous Na’vi on the moon Pandora, are invaded by resource-seeking humans in 2148 A.D. The message is unashamedly one of environmentalism. The trees in a rainforest take a central role, most especially one mother tree called the Hometree which allows the Na’vi to communicate with Eywa; their guiding force or deity. The film is a masterpiece; it’s no surprise that it is one of the biggest-grossing films ever made. It is not my favourite tree film though, much as I enjoyed its special effects. Perhaps the environmental message was a little too overt for me.
The man who planted trees (1988)
The story of Elezeard Bouffier, a fictional character and star of Jean Giono’s classic tale The man who planted trees, first published in 1954, is well-known and much-loved the world over.
Many people may not be aware however that a beautiful animated film was made, based on the book, by the amazing Frédéric Back. Lasting just 30 minutes you cannot help but be mesmorised by the wonderful animation and captivated by the story that is told. This film is widely thought of as a masterpiece.
Unfortunately the film is currently difficult/expensive to purchase, even online. However, visit a website dedicated to the animator and you can watch some video clips: www.FredericBack.com
Silent Running (1972)
A science fiction classic, that deserves much greater recognition, is Silent Running Directed by Douglas Trumbull in 1972. Trumbull was the special effects maestro behind 2001: A Space Odyssey (1968). It tells the story of a future where all plant life on Earth is extinct, and an astronaut is given orders to destroy the last of Earth’s flora that has been preserved in a greenhouse onboard a spacecraft.
Crew member, Freeman Lowell, a ‘forest ranger’ of the future, becomes a renegade when he questions an order to destroy the forests preserved in the domes.
“Hey, wait a minute, wait a minute… I don’t think you guys understand what this means, please don’t blow up the domes.”
“… they are not replaceable!”
The special effects, which even though made over 30 years ago. are impressive. Together with the sound effects, music score and superb acting by the cast, in particular by Bruce Dern in the lead, a powerful sensory experience is created on film. Without wishing to spoil the movie, you can expect murder, tension, starring roles from three robots and a really imaginative film that will leave you pondering the meaning of life and our environmental responsibilities long after the credits have finished rolling.
DVDs of the film are easy to come by on many online stores, and the film is available remastered and on blueray.
Gabriel Hemery
