A new report released on 22 February by the United Nations presents sombre findings and suggests that natural support systems for the human diet are deteriorating around the world. Agriculture is one of the main factors associated with the decline. In particular, land-use changes and unsustainable management practices, including over-exploitation of soil and over-reliance on pesticides, herbicides, and other chemicals.
Biodiversity aids the planet by proving ecosystem services such as pollination, pest control, soil formation and maintenance, carbon sequestration, purification and regulation of water supplies, as well as reducing the threat of natural disasters and providing habitats for beneficial species. Moreover, maintaining global biodiversity is vital to meeting the Sustainable Development Goals, a list of 17 goals covering social and economic development issues ― from poverty, clean water, and sanitation to global warming.
To examine how biodiversity as a whole contributes to food and agriculture, scientists analysed reports submitted by 91 countries on the state of their biodiversity for food and agriculture and its management. According to the new report, the growing practice of monoculture ― cultivating a single crop within a given area ― now dominates global food industries. The authors also note that many species indirectly linked to food production, like pest-eating birds and mangrove trees that help purify water, are in decline.
Another study published earlier this month highlighted the global shift towards a small number of crop species and lineages that now dominate agricultural land around the world ― which is bad news for sustainability. A total of nine plant species (sugar cane, maize, rice, wheat, potatoes, soybeans, oil-palm fruit, sugar beet and cassava) make up nearly two-thirds of total crop production and are farmed using large amounts of pesticides, mineral fertilizers, and fossil fuels. Moreover, wild food sources have become more scarce.
Around 20 per cent of the earth’s surface covered by vegetation has become less productive and there has been a “debilitating” loss of soil biodiversity, forests, grasslands, coral reefs, mangroves, seagrass beds and genetic diversity in crop and livestock species.
One of the main drivers affecting biodiversity for food and agriculture is population growth and urbanization. Many people are no longer in touch with rural communities and increasingly opt for processed foods rather than fresh foods. Furthermore, there is a growing reliance on a narrow range of cereal crops (maize, wheat and rice)” as well as meat-based diets.
Pressure on producers to “continuously grow or keep only a limited range of species, breeds and varieties of crops, livestock, trees, fish, etc.” has contributed greatly to global biodiversity loss, which has weakened the resilience of production systems. This poses huge risks in terms of susceptibility to pests and disease.
The other main drivers adversely affecting biodiversity for food and agriculture identified in the report are
- Over-exploitation and over-harvesting
- Changes in land and water use and management
- Pests, diseases, and invasive alien species
- Climate change
- Pollution and external inputs
- Natural disasters
- Markets, trade and the private sector.
Biodiversity for food and agriculture and the ecosystem services it supports are “fundamental to efforts to increase the resilience, sustainability and productivity of food and agricultural systems, sustain livelihoods and enhance food security and nutrition around the world.”
Thus, strategies should be implemented to promote diversification, in addition to “integrating intercrops, hedgerows or cover crops, particularly legumes, into a system can reduce drought stress by helping to conserve water in the soil profile and help to replenish depleted soil fertility.” The report also suggests that using diverse species of forage plants in pastureland can reduce damage from pests and the invasion of weeds.
But to realise these changes, producers must first understand the benefits and adopt a willingness to change. Some progress has been made ― including greater uptake in sustainable forest management, ecosystem approaches to fisheries, aquaponics and polyculture ― but efforts thus far are insufficient, according to the authors.