How much do rural communities benefit from trees?

It never rains but it pours. Ian Dawson follows up his post last week on tree genetic resources and climate change with a piece on how tree genetic resources contribute to livelihoods. Maybe we can now persuade him to mash the two up? And get his own blog :)

In another recent publication on tree genetic resources, complementing that on climate change, Ian Dawson and co-authors reviewed the extent of the benefits received by rural communities from trees. These are not well quantified, but they are important to understand better, in order to determine if, when, and how to intervene to best benefit people. Factors that make quantification difficult include the many products and services provided by trees, informal trade and the lack of coordination between agriculturalists and foresters when assessing the same trees in forests and farmland.

The review considers the value of tree products and services for tropical rural communities from the perspective of three production categories: non-timber forest products (NTFPs) harvested from trees in natural and managed forests and woodlands; trees planted (or wild trees retained) in smallholder agroforestry systems; and cultivated tree commodity crops. These categories are not the whole story, but are able to provide an overview of benefits.

Although there is much literature on the importance of NTFPs, until a decade ago relatively few studies quantified value in robust ways that allowed cross-study comparisons, and therefore wider conclusions to be drawn. More recently, this has been rectified by the collection of comprehensive comparative socio-economic data sets in the context of projects such as the Poverty Environment Network (PEN). These suggest that the conventional wisdom that the commercialisation of wild NTFP harvesting is not only good for livelihoods, but also supports forest conservation, is rarely borne out in practice. A good example is the argan tree (Argania spinosa) in Morocco, which produces one of the world’s most expensive cosmetic and cooking oils: its commercialisation has certainly benefited the local economy, but it has also led to forest degradation that jeopardises future harvests. Similarly, there is surprisingly little evidence that promoting cultivation of alternative sources of NTFPs is effective as a means of relieving pressure on wild stands. Cultivation may, for example, lead to the neglect of management of forest stands, and the creation of markets that unintentionally capture forest as well as planted sources.

Turning to agroforestry, practices that integrate trees in farms have been widely promoted and adopted, especially by tropical smallholders, with a wide range of tree species used. In general, however, little attention has been paid to the genetic quality of the trees planted for soil fertility replenishment and fodder production, although this is less of a problem in the the cases of timber and fruit production. More focus on genetic quality could result in significant productivity gains for smallholders, though a possible downside might be more homogenous farm landscapes. On the other hand, without improvements in tree yield and quality, farmers may choose not to plant trees at all on their land.

Tree commodity crops are the final production category analyzed in the study. The top 5 — palm oil, coffee, cocoa, tea and rubber — had an export value of around US $80 billion in 2010. It is difficult to determine how much of this value can be attributed to smallholder production, but 90% of cocoa and 65% of coffee worldwide may be grown by small-scale farmers. A major challenge in the sustainable use of tree commodity crops is conserving wild stands containing genetic diversity potentially important for future crop development, especially when the biggest producer countries are not those where the crop originates. For example, most coffee production takes place in Brazil, but wild Coffea arabica is found in the rapidly-shrinking montane forests of Ethiopia. How can a link between the two countries be established that supports conservation in Ethiopia? A useful starting point is to carry out ‘option value’ analyses of the wild resource for breeding purposes to make the case for support of conservation.

To sum up, tree-based production systems are often promoted by development practitioners because of their perceived biological, economic and social resilience, but this cannot be taken for granted. A number of supporting components are needed to ensure that improved management of tree genetic resources translates into enhanced livelihoods. These include a better understanding of the genetic aspects of production for NTFPs, a stronger emphasis on the genetic quality of the trees planted by smallholders in agroforestry systems, and more attention to wild and semi-wild stand conservation for tree commodity crops. More work is also needed to develop tree commodity crop cultivars that perform well in diverse farm systems, exploiting the available genetic variation in the genepool.

Brainfood: Homegardens, AnGR genomic conservation, Forest services, Desert wheat, Wild artichoke, Enset ethnobotany, Turkish sheep, Eggplant evaluation, Bolivian maize, Cattle & fire

How are forest genetic resources involved in responding to climate change?

According to Ian Dawson, one of the authors of a recent review in Forest Ecology and Management 1, led by Rene Alfaro, it depends…

ResearchBlogging.orgThe evidence for the negative effects of climate change on forests globally is mounting, with a good example being the outbreak of mountain pine beetle in British Columbia, Canada, believed to be caused by unusually warm winters. It has attacked more than 13 million hectares of lodgepole pine forests over the last decade. Such climate-influenced pest and disease attacks may be particularly problematic for trees, as pests and diseases with shorter generation intervals can evolve more quickly in response to new environmental conditions than their hosts can.

Phenotypic plasticity (the capacity of a particular genotype to express different phenotypes under different environmental conditions), genetic adaptation and seed and pollen migration all have a role to play in responding to climate change, but the speed at which environments alter may be greater than the ability of trees to cope through natural processes, and human help may sometimes be needed. Just as natural responses to climate change depend on genetic resources, so too do human-mediated responses such as altered forest management practices, the facilitated translocation of tree planting material and tree breeding.

Forest managers, however, sometimes question whether interventions formulated to respond to climate change are economically justified, and tropical foresters are likely to consider commercial agriculture and unplanned logging more important production threats. In this setting, appropriate management interventions that are good practice under ‘business as usual’ scenarios are likely to be more effective than those specifically to address climate issues.

For the future, field trials established across different environments are required that allow a better understanding of adaptive variation in tree species, including in drought, pest, disease and fire tolerance and resistance. Another interesting question to address is what role epigenetics (check out the term on Wikipedia) has in responding to climate change by providing a temporary buffer against environmental variability, giving the genome time to ‘catch up’ with change.

When dealing with trees that might only be harvested 100 years after they are planted, estimating the level of future climate uncertainty is obviously crucial. Otherwise, the planting of the wrong species at a site could be catastrophic perhaps decades into the future, as observed when 30,000 ha of maritime pine plantations were destroyed in France during the winter of 1984/1985, following the introduction from the 1940s of non-frost-resistant material from the Iberian Peninsula. New breeding approaches to those currently used are also required, as current methods, with the long generation times of trees, are often too slow to respond to change.

Brainfood: Lima been diversity, Cassava diversity, Urban soils, Oil palm seed supply, Ginger ploidy, Certification, Gene flow, Maize & drought, Coffee seed storage, Pathogens on seeds, Wheat breeding, Intensification tradeoffs

The future of genebanks unfolds, a bit

The potential benefits of recent developments in DNA sequencing technologies to both collection management and use will also be explored during the course of the project.

That was from an article a couple of days ago on the future of the UK’s vegetables genebank. Well, we learned yesterday that for rice, at least, that brave new world is almost at hand:

…access to 3,000 genomes of rice sequence data will tremendously accelerate the ability of breeding programs to overcome key hurdles mankind faces in the near future.

That would be DNA sequences from 2,466 of the International Rice Genebank Collection’s (IRRI) accessions, plus 534 accessions housed at the CAAS genebank, amounting to 13.4 terabytes of data. This begins the long road to sequencing the whole IRRI collection of about 100,000 accessions, the rationale for which was recently set out:

In this paper, we will discuss how genotyping and sequencing can be integrated into the activities of a modern gene bank to revolutionize the way scientists document the genetic identity of their accessions; track seed lots, varieties, and alleles; identify duplicates; and rationalize active collections, and how the availability of genomics data are likely to motivate innovative collaborations with the larger research and breeding communities to engage in systematic and rigorous phenotyping and multilocation evaluation of the genetic resources in gene banks around the world. The objective is to understand and eventually predict how variation at the DNA level helps determine the phenotypic potential of an individual or population. Leadership and vision are needed to coordinate the characterization of collections and to integrate genotypic and phenotypic information in ways that will illuminate the value of these resources. Genotyping of collections represents a powerful starting point that will enable gene banks to become more effective as stewards of crop biodiversity.

Alas, the news came a few days too late for the Pahiyas Festival:

Clearly, rice is the main inspiration of this delightful affair. The rice grains, rice plants and rice seedlings on display may all seem the same, but a closer look will reveal that they are not. Some seeds are longer, some are rounder and some are lighter in color than others, reminding us of just how rich and diverse our rice varieties are.

Maybe next year.

Meanwhile, if you want to celebrate instead by cracking open a nice bottle of wine from the Quinta do Crasto estate in Portugal, well, they’re using high-resolution genotyping there as well to figure out just exactly what clones they have in their fields. What’s that you say? You don’t drink wine? How about a nice bar of quality heirloom chocolate, also thoroughly genotyped, then? Truly the future is upon us.