October 2009 Archives

Change of Seasons Aids Aerial Photo Interpretation

By PETER LINEHAN on October 23, 2009 7:12 PM | 0 Comments | 0 TrackBacks
In remote sensing images taken during the summer in the visible spectrum it's hard to distinguish between hardwood and softwood trees and even harder to identify individual species. During leaf-out in the spring it is much easier to determine species composition as the different hardwood species get their leaves at different time and have different colors. Softwoods stand out even more!

The same thing happens in the fall as trees lose their leaves. You don't even need an airplane to see the difference. Just drive by a steep slope when the sunlight is right. It's just like an oblique aerial photo.

Here, looking across Penn National, the pine stand in Meeting of the Pines stands out strongly against the surrounding hillside. This has been the peak week for foliage in southern PA. This picture was taken in the afternoon of 10/22.

P1060898


The Amazing Néré Tree

By PETER LINEHAN on October 21, 2009 11:26 AM | 0 Comments | 0 TrackBacks
One of my favorite trees in Africa is the Néré (Parkia biglobosa). This species is so useful that it has been preserved and cultivated around the villages and throughout the landscapes of west African countries. Below is a superb specimen outside the Environmental Education Center in Kinkon, Guinea in the Fouta Jalon Highlands, where I was visiting in December, 2006.

PICT0416.JPGAnother name is the African locust bean tree. The néré is a legume, and can therefore fix nitrogen. A more important use is to ferment the seeds to make a cooking condiment called soumbala, that is prized in local cooking around the region.

 This pictures shows the flower pods, which are bright red when mature.
Parkia biglobosa flowers

This photo found on Flickr shows soumbala being processed and presented in the market.


Family at the market
Originally uploaded by v3ronique.
The caption says: "Little girl stays very close to her mother while she is making 'soumbala' or "Maggi" at the market. They are made of fermented seeds rolled into a ball and fried. "

This USDA Germplasm Resources Information Network article has botanical information.
This article, in pdf format, has general information about nere and its nursery requirements.

Deforestation Presentation

By PETER LINEHAN on October 7, 2009 12:12 PM | 0 Comments | 0 TrackBacks
This afternoon I will be speaking to the Intro to Forestry class on international forestry in what has become an annual event. I will concentrate on problems of deforestation and desertification in the Sahel region of western Africa. Here is a map of places I have worked over the years:



View My African Places. in a larger map
Summarizing up some of the main reasons for deforestation:
  • Overgrazing is caused by the farmers' strategy of letting livestock roam freely as a sort of bank on the hoof.
  • Poor agricultural practices that result in soil erosion and loss.
  • The emphasis on cash crops, like cotton and peanuts, that require expensive fertilizer input.
  • Periodic droughts. These are a normal part of the environment, but with larger populations there is less flexibility in dealing with the problems.
All of these issues can be overcome with the right strategies and technologies that we will discuss during the presentation.

There has been a lot of upheaval lately in Guinea, the last country I visited. Last year the president died after a long illness. Within a few hours his corrupt regime was replaced by a group of young army officers. They promised to end corruption and restore democracy. The leader of the group, Captain Camara, promised he wouldn't run for president. Now he has changed his mind. Recently his soldiers slaughtered and raped protesters at the national stadium. Here are articles from the New York Times and the BBC. Guinea should be a prosperous and happy country with all the resources at its disposal. I hope this situation can be resolved soon.

Here are pictures from my visit to Guinea at the end of 2006. I volunteered at an environmental education technical school near Pita. It was great to work in French again!

Finally, I was at the Soc. of American Foresters Convention last week. The Peace Corps said that they had many more openings in forestry and natural resources than they do volunteers. This is an excellent way to jumpstart your career. I highly recommend it.

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