- Boffins trying to domesticate Allanblackia for its oil.
- Phyteuma spicatum must be saved, British folklore depends on it. How about domesticating it?
- Farmers replanting forest in inland Niger delta. Sort of domesticating the forest, you mean?
- And here’s another domesticated forest, this time in Kerala.
- Are oysters domesticated? And seaweeds? Lots of uses for seaweeds, after all.
- Why plant breeding is incompatible with organic agriculture. Eh? First of a trilogy.
- Management of plant genetic resources in Brazil deconstructed.
- Oh dear, now boffins say avoiding bycatch may not be good after all.
- CTA calls for research notes in preparation for proposal writing workshop on neglected and underutilized plants.
- New Sight and Life magazine is out, with interesting discussions of Vitamin A supplementation in newborns and HIV patients.
- While at Scidev.net HarvestPlus defends biofortified crops against charge of medicalizing micronutrient deficiency.
Getting to grips with ecological interactions
Something just in from our occasional contributor Jacob van Etten.
Climate change will shift the limits of the suitable areas of many wild animals and plants, including crop wild relatives. Some species may adapt by gradually moving into areas which resemble their current home area. In other cases, no bridges exist to connect old and new suitable areas and a helping hand may be needed. Translocating species, or “assisted migration” has complex risks and ethical implications. Another approach would be to intensify ex situ collection efforts aimed at those species vulnerable to climate change. “Niche modeling”, which matches species to specific climatic conditions is helpful to locate problem areas.
All of this assumes that currently animals and plants are mainly held in place by climatic factors. ((There are other issues with niche models as well and more sophisticated approaches are being developed.)) But what if this is not the case? Imagine the aftermath of a glaciation. The ice retreats and species start to move towards the poles to occupy new territory. Two competing species, A and B, start to expand their range, but A is a better disperser than A. Since species A arrives first in most places, competing species B is absent, but not because the area is not suited climatically for species B. This would seriously confuse a niche model and its ability to predict future distributions after climate change.
Gilman and co-authors review the evidence on how interactions between different species influences the impact of climate change on species in a recent paper. ((Gilman, S., Urban, M., Tewksbury, J., Gilchrist, G., & Holt, R. (2010). A framework for community interactions under climate change Trends in Ecology & Evolution DOI: 10.1016/j.tree.2010.03.002)) Experiments with fruit flies, literature reviews and modeling studies all show that biotic interactions are crucial in predicting the effects of climate change. However, most models to predict the effects of climate change on species survival ignore these interspecific interactions. The complexity of webs of ecological interactions makes it difficult to draw general conclusions.
Gilman et al. suggest a divide-and-conquer approach to solve the puzzle. They propose to split communities in small modules of 2-4 interacting species, each characterized by a different network of interaction (mutualism, predation, competition, etc.). Through coupled modeling and empirical studies focused on such modules, Gilman et al. hope that some general trends will emerge. Lots of work needs to be done, however, before ecologists will be able to distinguish those trends. Gilman et al. also note that putting the modules together in communities may not be straightforward.
Obviously, this approach requires massive data collection and experimentation, premised on the idea that in the end some pattern will emerge from the data and that it will be possible to predict community level phenomena from the constituent elements. In spite of the importance of all this work to gain insight in the workings of ecological communities, there is no guarantee that we will end up being able to predict species extinction before it happens. In my view, ecological interactions are just too complex to draw any hard conclusions from bottom-up studies. For instance, pollinator networks can change from year to year. And only part of this information on ecological interactions is relevant to predict species survival/extinction. The approach proposed by Gilman et al. seems to steer towards a mismatch between ecological work and the hard questions of management, conservation and policy making.
How can the ecological interactions relevant under climate change be understood without losing ourselves in the details while working with available data? The decreasing costs of DNA analysis and the push for citizen science for conservation will hopefully make more data on gene flow and species occurrence available for monitoring purposes. Would it be possible to infer interactions from these data?
In molecular biology inferring complex interactions from massive data is very common. Vera-Licona and Laubenbacher (2008) apply mathematical methods originally developed for the inference of biochemical networks to ecological interactions. The method makes it possible to pinpoint the sources of remaining uncertainty. It seems that the method is being picked up by others. My feeling is that work along these lines will become important to bring ecology closer to management practice.
The birthplace of the Dashehari mango
Our dear friend and colleague Bhuwon Sthapit has prepared this post for us with input from Dr H. Ravishankar, Dr BMC Reddy, Dr S Rajan and farming communities. Thanks, everyone!
‘Dashehari’ is one of the most popular mango varieties of North India, widely acclaimed for its exquisite taste and pleasant aroma. It is also my favorite. Naturally, I was excited to visit the Dashehari Village in Malihabad where the 200 years-old mother tree of the variety, a cultural heritage of the community, still lives.
It is believed that the trees on 80% of the area covered by mango in northern India can be genetically traced back to this very tree. The heritage is exciting, but the risks resulting from massive uniformity of orchards and lack of home gardens to harbour other interesting types of mangoes are terrifying.
Legend has it that a Pathan of Khalispur village of Malihabad Tehsil, transporting choicest mangoes for trade, happened to halt for rest in a hut of a poor Momedian, a monk. The Momedian helped travelers by offering water and shelter and the travelers reciprocated with ripe mangoes.
At the time of departure, the Pathan and the monk had an argument. In a fit of rage, the Pathan shoved one of his choicest ripe mangoes into the soil instead of gifting it to the monk, who however maintained the utmost calm and restraint. In the ensuing rainy season, a mango sapling emerged from the spot, which was duly nurtured to a robust tree by the Momedian. After about twelve years, the tree profusely flowered and yielded fruits of excellent quality.
The news of this unique mango reached the Nawab who owned the land. Being aware of the importance of genetic wealth, he took due care to protect and conserve this exquisite mango variety, which later became the popular ‘Dashehari’ variety of North India.
The tree is still very healthy and impressive, about 10m tall, having a mean canopy spread of 21.0 m and a trunk circumference of about 3.0 m (see picture 1).
The tree has a robust trunk with twelve main scaffolding branches originating and radiating at 1.5 m height almost parallel to the ground.
The tree has spreading canopy architecture with impressive fruiting at the time of the visit, completely overshadowing neighboring trees.
A scientist from the Central Institute of Sub-tropical Horticulture in Lucknow told me that fruits of this Dashehari tree are oblong, elliptical and medium size (13cm long and 8 cm breadth) weighing 130 to 260 g.
It has attractive yellow pulp, firm and non-fibrous, with very sweet taste (researchers told me that it has oBrix score of 21-23 as measure of sweetness in fruits) and pleasant aroma. CISH collected scion material of the tree for clonal propagation in 1977 and thereafter elite clones spread to northern Indian farmers from a network of private and government nurseries.
This cultural heritage tree belonged to the great-grandfather (Mr Ishtida Hussain) of farmer Mr Shamir Zaidi, now 30 years old, who has named his house in honour of the variety — Dashehari Kothi. Mr Kamil Khan, an 87 years old but rather progressive orchardist of the small hamlet of Kakori (close to Dusseheri village) of Malihabad Tehsil shared local legends with the visitors. He told us that the tree, under natural care, is free from stemborer and termites attacks, both common problems of mangoes. It is also free from Loranthus infestation. This tree has yielded on an average 80-190 kg in the last eight years, with a moderate biennial bearing habit.
In September 2009 the area was registered with Geographical Indication No 125 in the name of “Mango Malihabad Dusseheri” by India’s Geographical Indication Registry. The communities around the mother tree have also been selected for the UNEP/GEF Project “Conservation and sustainable use of wild and cultivated fruit tree diversity: Prompting sustainable livelihoods, food security and ecosystems services” in Malihabad, Lucknow. Communties such as Sarsanda, Kasmandi Kalam and Mohammad Nagar Talukedari have 7-29 cultivated varieties each.
They are also blessed by rich diversity in seedling mango trees, with an estimated population of 3000 to 5000 mango seedling trees. Almost all current commercial mango varieties in India are selected from the seedling population. Potentially research can identify many more consumer- and farmer- preferred diversity of mangoes and innovative farmers can work together with researchers and nurserymen to identify, select and popularize the elite materials from existing farmer’s orchards. The project aims to empower farming communities and local institutions to identify unique varieties from the orchards and scale up genetic resources and associated traditional knowledge for sharing wider benefits to farmers and consumers.
Almost all orchards in Malihabad are dominated by Dashehari (80%), with over 10-20 varieties of other cultivated types, but few trees of each. Around the orchards farmer maintain many seedling types and all of these trees produce diverse fruits with diverse shape, size, color and taste. There is thus scope to increase diversity in the market by sharing information with consumers in urban areas to stimulate demand for other varieties there, and thus minimize the risks posed by uniformity while also providing livelihood security for mango growers.
Nibbles: CIAT, Apples, Poverty, Protected areas, Honey, Juniper, Irish oak
- Learn about CIAT’s reseach via the posters they put on slideshare. Couple on their beans and cassava genebank.
- Trying to speed up apple breeding.
- Biodiversity interventions find it difficult to fight poverty. How about agrobiodiversity interventions?
- More bad news: protected areas don’t work anyway. At least for trees in Burkina Faso.
- Boffins trying to spot contraband honey. There’s contraband honey?
- Gin drinkers told to start worrying.
- Forest of Belfast project to wind up, but not before finding really old oak.
Why the sorghum crop failed in Kongwa — it’s not what you think
The average agricultural research paper describes some kind of formal experiment, whether in the lab or the research station or even farmers’ fields, and that is as it should be. To know if something really works, you need to be able to keep everything else the same. But there are experiments going on all the time out there, in real life, if you but know how to look. There is surely room in the scientific literature for more of the kind of case study reported in a recent paper in Food Security entitled “The underlying cause of the 2009 sorghum failure in Kongwa district and its implications for Tanzania’s vulnerability to climate change.” ((Page, S., Karanja, D., Mbwaga, A., Letayo, E., & Nsemwa, L. (2010). The underlying cause of the 2009 sorghum failure in Kongwa district and its implications for Tanzania’s vulnerability to climate change Food Security DOI: 10.1007/s12571-010-0059-2))
Through a series of in-depth household and farm surveys the authors seem to have been able to identify the reason why the sorghum crop failed in Kongwa in 2009, and use that information to make general recommendations about what should be done to prevent this happening again in the future, not just in that area but elsewhere in Tanzania.
So let’s set the scene. People in Kongwa are poor, most living on less than $1 a day. They are on the edge of subsistence. They used to grow mainly maize, increasing the area of sorghum when the early rains were poor. Since about 2003, however, sorghum has been the main crop. They grow a suite of local sorghum landraces called Lugugu: long-duration, good-tasting and hard-grained, which means they can be stored for a long time if need be. They also have access to three improved open-pollinated varieties from ICRISAT ((Released in 1986, 1995 and 1999 — why nothing since, one is tempted to ask.)): shorter-duration, which means they can cope with drought, but softer and thus more susceptible to storage pests, and also prey to the parasitic herb Striga. But then there are two Striga-resistant varieties on the market, bred by World Food Prize winner Gebisa Ejeta and released in Tanzania in 2002. Often, the early varieties are grown as a cash crop, sold to buy maize, which is the preferred food still.
In 2009 the rains started badly, and farmers were encouraged by local politicians, in their inimitable way, to “plant drought-resistant crops.” Of course they did, as they would have done anyway, but crop production was nevertheless below requirement. Why?
In fact, it seems that overall the rains, although relatively poor, should have been more than enough for the short-duration varieties. Problem was, there was no seed of these varieties at the optimum time for planting them. And when it finally arrived, too late to take advantage of what early rain there was, it was infected with Covered Kernel Smut. There was no seed at all of the Striga-resistant varieties in the area.
This is not a new problem. Shortage of improved sorghum seed was identified as a constraint as far back as 1987. But none of the village-based seed production projects that have been carried out has had much of an impact, clearly. At least not after the donor funding ceased. And, unfortunately
…the Government of Tanzania has actively discouraged farmers from conserving local sorghum landraces and this has resulted in increasing dependence on so-called improved varieties and is a long term threat to household food security.
Actively discouraged from keeping their long-duration but storable varieties; actively encouraged to plant new varieties that are more drought-tolerant, sure, but can’t be stored, cost money that they don’t have and whose seed is not available anyhow, or at least not in time. Who’d be a Tanzanian farmer?
Now, it seems that “the short rainy season that characterised the 2008–09
cropping season may become the norm,” so some answers need to be found. Better water management is one. And improvement of local seed storage practices. Also,
…attention should be paid to conserving indigenous landraces and breeding improved short season varieties that can be stored for longer periods using traditional, on-farm practices, as this would reduce the need for expensive and unsustainable external seed multiplication systems.
And, I would add, perhaps look into the feasibility of push-pull control measures for Striga.
But mostly the study seems to me a damning indictment of the existing seed system, and of it’s seeming lack of integration with the breeding sector. What good is breeding those “improved short season varieties that can be stored for longer periods using traditional, on-farm practices” if they don’t get to the farmers in time? Indeed, why has storability not been a breeding objective? Well, perhaps it has, and weevil-resistant stuff is on the way. But will it ever get to the farmers?
Now, talk of an integrated germplasm pipeline — from genebank to breeder to farmer — is all the rage these days, and about time too. The case is only strengthened by studies such as this. You don’t always need a replicated trial to do useful science.