Climate change and extinction

Predicting the effects of climate change on biodiversity is very much a growth industry, and understandably so. I’ve contributed to it myself (together with lots of friends), as I immodestly noted here in a previous posting. Many studies have predicted drastic increases in rates of extinctions, but then, why have so few species gone extinct during the past 2.5 millions years of recurring ice ages? This “Quaternary conundrum” is addressed in a new paper announced, and available for downloading, here. The conclusion of the 19 co-authors is that current approaches do not adequately take into account the factors which allow species to persist when conditions change for the worse. They make eight recommendations for improving predictions, ranging from better models to better validation of model results. Well worth reading.

Trees in Kenya

There were two interesting articles about trees in Kenya in the Money section of this morning’s Daily Nation. Not online, though, so I’ll have to summarize. One piece describes how farmers in Nyeri are adopting a number of short-statured mango varieties from South Africa and Israel, apparently including things called Apple, Kent, Vydke and Tommy. This is not a mango-growing region, but these particular varieties have been found to be a good fit on the small farms of the area, to yield heavily and early, and to be good for juice. So now there’s no need to truck mangoes in from the coast. Good for Nyeri farmers, perhaps not so good for coast farmers? This may not be a zero-sum game: I don’t know enough about the supply of, and demand for, mango in Kenya to predict what will happen, but I would try to conserve those coastal varieties ex situ somewhere just to be on the safe side.

Then there was also a piece on how the Tree Biotechnology Project has been successful in cloning a number of indigenous trees (including for example Prunus africana, whose bark feeds a large international market for a prostate cancer drug) and providing planting materials to farmers. It seems previously the project’s focus has been on eucalypts. This is expected to take pressure off wild populations and contribute to reforestation, but there was nothing in the Daily Nation article about the downside of planting large areas of genetically identical clones. However, this is clearly a problem the project recognizes, as you can see for example by reading on page 28 of this brief on some of its activities:

Planting large areas of single clones will have the effect of decreasing rather than increasing biodiversity, and the risk of narrowing the genetic base needs to be managed to avoid growing pest and disease problems. Mondi has a policy to restrict planting of a single clone to no more than 5% of any planting area, and the project is adhering to this policy. In order to maintain biodiversity, the project team will select a wide range of local tree species of economic value and will feed these into the clonal production system through adaptive tissue culture research. Once the capacity to adapt the techniques of micro-propagation to different species is fully in place, there will be great potential for the project to multiply and disseminate a wide range of improved germplasm of different tree species, including those that are under threat of over-exploitation and extinction, such as ebony.

Is this good news for bees?

“I’m not convinced that it’s so much worse than what we saw in 2004 and 2005,” said Eric Mussen, a bee specialist with the University of California, Davis.

While bees are undoubtedly in trouble this year, Mussen said, there’s little evidence so far that it’s anything other than the continuation of their long struggle with disease, environmental stress and the hardship of being hauled cross-country in midwinter to pollinate crops in California.

“This time the media just became much more involved in it,” he said.

That’s from an article by Jim Downing in the Sacramento Bee. (I kid you not; it is actually a very good paper, although you may need to register and log in to see the full story, which is why I am quoting from it at some length.) Mussen is just one of the experts who says that the fuss this year about vanishing bees reflects more media interest rather than fewer bees.

“About all we’ve got is anecdotes,” said, Troy Fore, executive director of the American Beekeeping Federation.

There is, in fact, no central agency responsible for monitoring the status of honeybees in the US. News comes by word of mouth, and while some beekeepers are playing down the crisis, hoping that farmers don’t question the pollinating ability of the hives they’ve rented, others are blowing up the problem in a bid for government support.

Years ago, Mussen said, many Central Valley counties employed a bee inspector to check the health of rented hives. That person helped resolve disputes between beekeepers and farmers and served as an informal census-taker.

Today, those inspectors are scarce. One of the few remaining is Clifton Piper, who has checked hives for the Merced County Department of Agriculture since 1973. He isn’t sure about the big picture, either.

“It’s difficult to see just how short the shortage is,” he said. Beekeepers often bolster weak hives with imported packages of bees from Australia, he said. And in cold and rainy weather, it’s hard to tell whether sluggish bees in a hive are sick or simply chilly.

I suppose time, and the price of almonds, will tell.

An appreciation of the importance of crop diversity

There’s an important post entitled Vegetables of Mass Destruction over at The Daily Kos, a blog. Important not so much for the content, most of which is familiar, well-meaning and just a tad parochial, but for the location. The Daily Kos is one of the most popular sites in the blogosphere, averaging around half a million visits a day. If just some of those readers go away with a slightly better appreciation of the value of agricultural biodiversity, that will be A Good Thing. So thanks to cookiebear and The Daily Kos for their support.

How to halt desertification

IRD in France has released the results of a long study of the Jeffara region of Tunisia, which has been very prone to desertification. The study pinpoints the role of agriculture and the use of natural resources as key factors in the spread of deserts, but acknowledges the very complex interactions at work. The press release concludes:

“[D]egradation can be checked by prohibiting the development of endangered natural environments for cultivation. However, real practical alternatives must in that case be proposed to farmers, in the agriculture sector, through maintenance of a certain diversified production in their holdings and enhancing commercial value of high-quality local or regional produce, but also by means of diversification of activities and of sources of revenue other than farming. This diversification would offer people improved flexibility to face up to climatic and economic hazards and enable them to manage better their families’ financial resources. In addition, the effort government has made in water management, through the CES, could be enhanced by schemes for desalinating brackish water and recycling waste water.”

But can they find a way to diversify and add value before the farmlands, soils and water have vanished completely?