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Genetic diversity a hidden tool in coping with climate change

Raw material of food systems are key to helping agriculture adapt to volatile weather and rising temperatures

19 January 2015, Rome - Genetic resources have a critical role to play in feeding the world — especially as climate change advances faster than expected — and much more needs to be done to study, preserve and utilize the biological diversity that underpins world food production, according to a new book released by FAO today.

"Time is not on our side" warns the book, Coping with climate change: the roles of genetic resources for food and agriculture. "In the coming decades, millions of people whose livelihoods and food security depend on farming, aquaculture, fishing, forestry and livestock keeping are likely to face unprecedented climatic conditions."

Crops, livestock, forest trees and aquatic organisms capable of surviving and producing in a changing climate will be needed.

The ability of plants and animals raised by farmers to withstand volatile conditions and adapt when the environment changes is a direct result of their genetic diversity, but stronger efforts to study and use that diversity as a coping mechanism — and policies to support that — are required, the book argues.

"In a warmer world with harsher, more variable weather, plants and animals raised for food will need to have the biological capacity to adapt more quickly than ever before," said FAO Deputy Director-General Maria Helena Semedo.

"Preventing further losses of agricultural genetic resources and diverting more attention to studying them and their potential will boost humankind's ability to adapt to climate change," she added.

 Such an adaptive approach will require updating the goals of agricultural breeding programmes — and in some cases introducing varieties, breeds, species, that have not been previously raised.

And improvements to field-based and off-site conservation programmes for domesticated species, their wild relatives and other wild genetic resources important for food and agriculture — along with policies that promote their sustainable use — are "urgently" needed.

Building our knowledge of genetic resources for food and agriculture - where they are found, what characteristics they have (e.g. resistance to drought or disease) and how they can best be managed is also critical, the book says.

In particular, improving knowledge, conservation and use of crop wild relatives is important — they are likely to have genetic traits that can be used to develop well-adapted crops for use in climate change-affected food systems.

"We need to strengthen the role of genetic resources and help farmers, fishers and foresters cope with climate change," says Linda Collette, lead editor of the volume and Secretary of FAO's Commission on Genetic Resources for Food and Agriculture, which starts its biennial meeting today.

Many locally adapted varieties and breeds of crops and livestock — as well as trees, fish, insects and micro-organisms — are poorly documented and may be lost before their potential roles in climate change adaptation are recognized.

Efforts should be made to avoid practices that destroy biodiversity or undermine the health of agricultural ecosystems — for instance the use of broad-spectrum insecticides that impact pollinators.

Guidelines point the way

The commission will also consider the adoption of guidelines for the integration of genetic resources into climate change adaptation plans, developed by FAO taking into account UNFCCC's current guidance. The draft guidelines argue for an increased and explicit use of genetic resources as a part of overall adaptation measures needed to assure food security — in recognition to the critical role that genetic diversity must play there.

The guidelines contain a range of recommendations aimed at helping countries implement policies and strategies for studying, preserving, and utilizing genetic resources to adapt to climate change.

They aim to support governments' use of genetic resources — ranging from seed varieties of major staple crops to the millions of microbes living in the soil, an area where expertise is relatively thin — in their national plans for coping with climate change.

Helping evolution survive

FAO stresses that boosting conservation of genetic diversity on farms and in fields is as critical as maintaining gene banks.

Many life-forms used in agriculture don't have the equivalent of seeds and can only be maintained through human intervention — one example is the banana, a vital staple for millions.

Additionally, on-site (in situ) conservation — including that of crop wild relatives — is a way of "allowing evolution to continue" and thus permit the continued generation of adaptive traits.

In situ conservation can take many forms but closely involving farmers is particularly effective, especially as it is increasingly clear that the consequences of climate change need to be considered at local levels as well as at global or regional ones.

Ethiopia, home to many microclimates, has an advanced and decentralized scheme based on community seed and gene banks through which farmers and researchers cooperate to test, adopt and conserve landraces of the most important crops — teff, barley, chickpea, sorghum and faba beans — that were nearly lost during the 1980s drought.

Research work never ends

Knowledge of agricultural genetic resources needs to grow more quickly, according to FAO — especially in under-studied sectors such as forests, where fewer than 500 tree species out of a total of over 80,000 have been studied in-depth. The gap in knowledge of invertebrates and micro-organisms is even larger.

While often decried as agents of diseases in crops and livestock, micro-organisms provide a myriad of functions — protecting plants from pests, drought, cold and salinity among them.

Meanwhile, proper genetic inventories geared to providing "passport data" on the genetic assets currently stored in seed banks and other ex situ conservation centres are needed in order to access positive adaptive traits that may be needed.

The effects of climate change also mean that it is more important than ever to intensify the exchange and sharing of agricultural genetic resources. Local and national seed fairs do exist, but will need to expand and go international as climate change accelerates.

Genetic resources and the time factor

One aspect of climate change with a direct impact on genetic diversity has to do with changing pressures on biological time. Pollination patterns are a major point of concern, as insects are highly sensitive to temperature and may not always synchronize with newly adopted flowering timing.

Rising temperatures are also likely to favour species that can cope with shorter generational cycles.

For fish, for example, that means fish that feed at lower trophic levels and have relatively short production cycles are likely to be preferred in aquaculture projects. 

At the same time, a two degree Celsius rise in temperature is estimated to allow insects to complete up to five extra lifecycles per season, according to FAO’s book — which also notes that pathogens able to shorten their breeding cycles will likely be able to evolve more rapidly and  pose greater potential challenges to various organisms and ecosystems.

In forested areas, invasive species may also react more rapidly to changing conditions, crowding out extant tree types. On current climate projections, it appears that natural forests will have to migrate 10 times faster than they did at the end of the Ice Ages to keep pace with climate change.

A recent study using of the Arabidopsis thaliana, a weedy relative of mustard and the first plant to have its genome sequenced, showed how seeds stored in banks can also help understand that climate change is moving faster than expected: Variants of the plant taken from Spain did better in Finland than seeds originally taken there.

Photo: ©FAO/Sandro Cespoli
A crop of sorghum in Uruguay, funded by the International Treaty on Plant Genetic resources for Food and Agriculture.