Aromatic agrobiodiversity was in the news and the peer-reviewed literature today. Rosemary (Rosmarinus officinalis) got a good write-up in ScienceDaily. It turns out that one of chemicals found in its spiky leaves — carnosic acid — can protect the brain from free radicals, but is only activated by the damage caused by these compounds. Otherwise it just sits there doing nothing, which is what you want in a drug. Anyway, there are lots of different varieties of rosemary, and different levels of carnosic acid among them. There are also wild populations in the Mediterranean, as of other herbs as well, and people who make a living harvesting them from the garrigue. That can sometimes be overdone, resulting in damage to the plants, and to the environment, due to increased soil erosion when it rains. So a study from Spain just published in the journal Catena is welcome. It quantified how much harvesting of various aromatic shrubs (lavender, oregano, sage and santolina) you can do before the soil starts to suffer. The recommendation is to leave 50% of the plant biomass in the field.
The growing fields
From a comment here I found my way to mandevu.net and the latest post there on how farmers in Cambodia cope with unexpected conditions, complete with video. What happened was that the floods came early to the village. That destroyed most of the rice crop. So how did the villagers cope? Well, in many ways, all of which involve the careful management of rice agricultural biodiversity. But I’m not going to steal mandevu’s thunder. Go there and see for yourself.
By the way, mandevu notes he has three readers. Well, we have five or six. And I’m happy to try and send a couple his way for first hand reports from the field. We’d do that for anyone with as much interesting material. Just point it out.
It’s good for you, mate
I’ve tasted mate tea, made from the herb Ilex paraguariensis, and I have to say it is a mystery to me how so many Argentinians (and others) could be totally hooked on the stuff. Maybe because they knew all along it was so good for them. ((A comprehensive review was published in the Journal of food Science.)) Now science agrees. Elvira de Majia, of the University of Illinois, discovered that mate drinkers in her lab had greater activity in an enzyme that increases HDL (good) cholesterol while lowering LDL (bad) cholesterol. On that basis, and mate’s many other health benefits, she secured a deal with Argentina to study in detail 84 different varieties of mate, including wild populations. According to the press release:
“Our studies show that some of the most important antioxidant enzymes in the body are induced by this herbal tea,†said de Mejia of her study in September’s Planta Medica. ((Which is here, but you need to be a subscriber.))
“Because Argentina has the different mate varieties, we’ll be able to do more comparisons and characterizations between the different genotypes and the benefits of different growing conditions—whether in sun (on a plantation) or in shade (under the rainforest canopy),†she added.
There’s also interest in adding the active ingredient(s) to processed food. There always is.
Cherry blossom on the move
Andy Jarvis writes:
We’ve long known that climate change is shifting the seasons, and plants appear to be flowering earlier in spring. But a recent study of flowering in 17 species and varieties of cherry trees in Japan had some interesting results that highlight the value of agricultural biodiversity. ((Abraham J. Miller-Rushing et al. (2007), Impact of global warming on a group of related species and their hybrids: cherry tree (Rosaceae) flowering at Mt. Takao, Japan. American Journal of Botany 94:1470-1478.)) The authors have observed that cherry trees on average flower 5.5 days earlier today compared with 25 years ago, and attribute this to an increase in temperature of 1.8°C in February-March. Another example of changing phenology. But what is most interesting is the divergent response between varieties and species – some are flowering 3-5 days earlier per 1°C temperature change, while others as many as 9 days earlier per degree change. Interestingly, these are traits that required climate change to express themselves, and must have impacts on production in addition to the aesthetics of the entire mountain no longer flowering at once.
There must be other places where blossom is important that have long term records like this.
Cutting down on cow emissions
Methane is a powerful greenhouse gas and ruminant farm animals belch out a huge amount of the stuff. No wonder people are scouring agrobiodiversity for animal feeds that minimise emissions. A paper in Animal Feed Science and Technology ((C.R. Soliva, A.B. Zeleke, C. Clement, H.D. Hess, V. Fievez and M. Kreuzer. In vitro screening of various tropical foliages, seeds, fruits and medicinal plants for low methane and high ammonia generating potentials in the rumen. Animal Feed Science and Technology. Corrected Proof, Available online 18 October 2007. http://dx.doi.org/10.1016/j.anifeedsci.2007.09.009)) has come up trumps. The researchers found differences in methane production not just among tropical feed species, but also among accessions of Acacia angustissima and Sesbania sesban. Something to add to the list of evaluation descriptors.