Notes from the Field

Last Thoughts

August 29th, 2009 by Joanne Howl

Merril Brook Cabins, Howland, Maine

From Dr. Jon Ranson:

I’ve shared a lot of my own experiences over the past two weeks.  For the moment, I’m going to step aside and ask Sassan Saatchi to share with you his impressions of his work at Howland. 

From Dr. Sassan Saatchi

This has been a very good experience and I think we’ve done well here.  We came out in support of the DESDynI mission.  There are a few specific goals we’re working on.  One is to refine our algorithms to measure forest biomass and structure.  For that reason, we flew radar that’s very close to the DESDynI radar over this area not long ago.  We also flew lidar.  For DESDynI we want to combine the two to make forest structure more accurate.  Our measurements on the ground combined with the data from the lidar and radar flights will help us do that. 


Forests can change quite quickly when under timber management.  This forest was identified as a high biomass site from 2003 remote sensing data.  When the scientists arrived to measure it, they found it had been logged quite recently.  Photo by Sassan Saatchi.

Another one of our goals was to refine a mathematical model that takes the three dimensional structure of the forest and tries to simulate the radar return from it.  The structural measurements we make here will help us test our model and the performance of the satellite instruments prior to launch.

Another project funded by NASA includes 3 major sites: this forest in Howland, a wet tropical forest in Costa Rica and a tropical forest in the Congo basin in Africa. In these three sites we’d like to see how the forest changes in time.  We know that over time some trees will die and some will grow. Changes in the forest have an impact on the carbon forest balance – there are gains by growing or loss of carbon when trees die.  So we like to measure in different years and relate the changes to the satellite data we will collect in different years. Ideally we’d try to measure this forest annually.  So I’ll be coming here for the next 5 years to see how the forest changes in time.  This helps us with DESDynI too – when we get ready to launch, we’ll have refined instruments.

One of the things we found at Howland is that most of the forest here is to some extend disturbed, even the old growth forest.  Some disturbance is natural.  Trees naturally grown and die, trees are blown down by wind.   Some disturbance is from forest management. Where slash cutting is used they pick out the best timber to use, then leave the rest on the floor.  There can be a lot of dead wood in some areas here, possibly 5-10% of the biomass.  But we aren’t measuring it.  One of the challenges is to extrapolate this information so we can understand how much above ground biomass is live and how much lies dead on the forest floor.

The forest changes rather quickly here at times. One of the surprises was that some of the sites we identified as interesting for measurements, based on satellite data gathered in 2003, we found to be recently logged.  They were not longer suitable for our measurements.  A lot of this is private land and is used for timber.  Only a small part is preserved.  Everything around this small Howland preserve is all managed forest.

It’s important to realize that managed forests, even though they are being used, have a level of conservation.  There is good habitat for many animals, such as moose and bears. When people think about habitat, they think wild and unmanaged forests.  But in many areas, especially in the northeast US, most of the forest is managed.  In the middle of the 19th century, the forests weren’t managed.  This area was largely deforested.  In the last 100 – 150 years these forests have grown back.  Now there is a really large area of forest cover here, good habitat – and in large part, management makes this happen. 

Morning on the Penobscot River near the Penobscot Experimental Forest, Howland, Maine.   Photo by John Lee.

I really think this was a wonderful experience.  It had some challenges – some of us got into bees and got stung a few days ago.  It was good to see how they handled that.  They took care of themselves, kept a good attitude and wanted to go back to work.  It’s been a very good team. Everyone works so well together. Even though they were stung or tired, there was a great spirit in all of this team.   For some of our students, this was the first time in the field.  We like to train future environmentalists.  It would be great if some of these students would take this type of work on and get involved in these studies as their career. 

I also want to mention that the people from the University of Maine were very, very good to us.  And so were the folks from the US Forest Service.  I can only say that this was a collaborative effort between many institutions – and it was a great success.  I look forward to my next visit to Howland. 

From Dr. Ranson:

Okay, I’m back for the last word.  I agree with Sassan that the team had great spirit.  We got up early, everyone was ready on time and everyone wanted to be there.  Even on the last day when everyone was really tired, we decided we would go slog through a bog.  Everyone said “yes, count me in”.  It was non-stop work and there were challenges.  But we achieved our goals and then some.  

I was impressed with the quality and the diversity of people we had here. NASA DESDynI provided the primary support  and other scientists participated from their related projects. There were people trained in forestry, natural resources, engineers or physicists, graduate students, managers, university professors, government scientists.  We had young folks working side by side with seasoned scientists.  What a wealth of experiences and knowledge.

I want to thank NASA Headquarters for providing funding for this effort.  And the US Forest Service for the use of their land in Penobscot Experimental Forest.  We certainly appreciate the North East Wilderness Trust and GMO LLC for access to their forest lands.  The University of Maine gave us absolutely fabulous support – thank you so much.  And a special thanks to Bruce Cook for his great success with his first big challenge with NASA.  As soon as he came to work for me, I asked him to organize and do the logistics for this project.  It went great.   As Sassan has said – this is really a collaborative effort.  Everyone’s help is greatly appreciated.

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