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Frankia and Alnus

There’s a lengthy review of an interesting-sounding book — People and Forests: Yunnan Swidden Agriculture in Human-Ecological Perspective 1 — in the latest Agriculture, Ecosystems and Environment (though the book seems to have been published in 2001). You do need a subscription, but that turned out to be a blessing in disguise, because in an effort to get around the problem I did some googling, and that not only revealed a very similar review (I know because I had access to the AEE piece at work) by the same person 2. It also led me to a resource I hadn’t come across before: People, Land Management and Ecosystem Conservation (PLEC) News and Views.

The March 2004 issue, which includes the book review, is devoted to “agrodiversity.” Here’s an excerpt from the introduction, by Miguel Pinedo-Vasquez, PLEC Scientific Coordinator (at the time), which certainly struck a chord:

Smallholder agrodiversity strategies have proved to be effective in dealing with widespread declines in the value of agricultural products, yet they continue to be underutilized by most programmes that aim to reduce rural poverty, environmental degradation, erosion of biological diversity, and other problems affecting rural communities.

Here’s more about PLEC from the website of the Department of Anthropology of the Australian National University:

PLEC is a global network, set up by the United Nations University in 1992. From 1998 until 2002 it was funded by the GEF through UNEP. It brings together over 200 professionals, including more than 130 scientists and researchers, together with 190 skilled expert farmers, and 180 undergraduate and graduate students. PLEC members work out of 65 institutions in Brazil, China, Ghana, Guinea, Jamaica, Kenya, Mexico, Papua New Guinea, Peru, Thailand, Tanzania, Uganda, Britain, the United States and Australia. From 1992 until 2002 it was coordinated scientifically by Em. Prof. Harold Brookfield, who is now Senior Adviser.

Conservation through agriculture underpins PLEC’s approach to conserving and utilising biological diversity. Most biodiversity projects relate to protected areas or crop plants alone. PLEC is unique still in its strong and pervading management approach to biodiversity in the context of the livelihoods and social organization of smallholder farmers. Through generations of innovation and experiment, they have nurtured a great diversity of plants and animals, both wild or domesticated, and accumulated rich knowledge of the managed biodiversity.

PLEC also has its own website, where you can subscribe to an electronic list.

Anyway, back to the book about swidden cultivation in Yunnan which started all this. One of the reasons the review caught my attention was the mention of the use of Alnus nepalensis in local agroforestry systems, and in particular the description of that tree as a nitrogen fixer. I had totally forgotten about the phenomenon of “alder-type” actinorhizal symbiosis between some plants and fungi of the genus Frankia. Fungi are agricultural biodiversity too!

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Dragon’s blood set to dry up

Having been involved in the botanical exploration of the Indian Ocean island of Socotra back in the early 90s, and also — more recently — having done some ecological niche modeling, I was fascinated to see these interests coincide in a recent paper in Biological Conservation. Italian and Yemeni researchers 3 have modeled the distribution of the Socotran endemic Dracaena cinnabari, the Dragonblood Tree, to predict what might happen to it with climate change. It’s not good. This flagship species, whose resin has been the source of a dye and medicine since antiquity, is looking at a halving of its potential area of distribution, due to drier conditions, and only a couple of its current localities will fall within what will remain suitable. Fortunately, they are near a protected area, and the authors recommend that its boundaries be expanded to include them.

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Wild relatives to the rescue (again)

You may remember the recent warnings about a new strain of wheat stem rust called Ug99 making its way from the Rift Valley of Africa across the Red Sea to Yemen, thus threatening the very home of wheat in the Middle East. Jeremy blogged about it a couple of months back. Well, resistance to the disease has now been found in about 70% of the 100-odd samples of a wild wheat (Aegilops sharonensis) collected in southern Lebanon and Israel, according to a paper in Plant Disease. Four of the samples actually have resistance to a whole range of fungal diseases:

Co-author of the paper, Yehoshua Aniksterat, of the Israel-based Institute for Cereal Crops Improvement at Tel Aviv University, told SciDev.Net that although it could be difficult — and take up to five years or more — they may be able to transfer genes from wild to cultivated wheat.

The map below is what GBIF knows about the geographic distribution of A. sharonensis 4.

sharonensis.jpg

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Rusty conclusions about iron deficiency

Iron deficiency anaemia is a big problem. WHO estimates that about 2 billion people — that’s roughly one in three — lack enough iron in the diet. And the consequences are grave for health and the economies of developing countries. So of course people are focused on ways to combat iron deficiency. Two hog the limelight: supplementation by adding iron to the diet and biofortification, breeding to add more iron to the staples that make up the diet. A recent paper in The Lancet reviews the story of iron deficiency and how to treat it. 5 Perhaps not surprisingly, the study concludes that “targeted iron supplementation, iron fortification of foods, or both, can control iron deficiency in populations”. And yet, having said that “dietary iron bioavailability is low in populations consuming monotonous plant-based diets,” the authors do not appear to have seriously considered the idea of trying to attack that monotony instead. Maybe enriching and diversifying those plant-based diets to include more dark green leafy vegetables and more pulses would be as effective, with additional benefits in other realms. But that kind of intervention isn’t nearly as glamorous, and gets little attention.

Of course, it could be that solving the problem of iron deficiency will just give rise to other difficulties. Another paper suggests that iron deficiency protects us against some of the epidemic contagious diseases that have hitched along as people crowded together in agriculturally-fed cities. 6 Maybe iron deficiency — at least in moderation — is a good thing?