What is biodiversity and why do we need it?
There is a complex balance between food production and safeguarding the world’s biodiversity. Biodiversity represents the variety of life on our planet, including ecosystems, species, and genes. Biodiversity can be a complex web of relationships between animals, plants, bacteria, and other life, the loss of one link in these webs may impact the survival of the others.
Every species within an ecosystem fulfils a particular role, many of which can benefit humans. These roles include; the production of resources such as soil and fuel, the protection of fresh water, air purification, and moderating the climate, as well as other more conceptual assets such as recreation, tourism, and cultural resources (1, Fig 1). Many of these functions are fundamental for human survival. Evidence suggests the more diverse an ecosystem is, the greater its resistance to stress and change. Alterations to an ecosystem can impair its ability to provide these functions.
How is biodiversity affected by food production?
Satellite data shows that 28% of the Earth’s surface is used for food production. The relationship between food production and biodiversity is complex and reliant on farming techniques (2). Food production is often started by the removal of natural vegetation to plant crops or creating pasture for livestock. This change in land use causes a dramatic loss of biodiversity through habitat loss and by isolating populations in fragments of suitable habitat.
The use of insecticides and herbicides reduce biodiversity through direct toxic effects (3, Fig 3). Many widely used insecticides are known to affect a broad range of insects, not only the target species. They can also pass their toxicity through the food chain by being eaten by a predator.
Is there space for both food production and biodiversity?
Many of the benefits of biodiversity can present a useful tool on farmland, including: pest control, reduced reliance on outside resources such as imported feed and chemical fertilisers, and crop pollination (1). The cost of replacing these should biodiversity be lost would be staggering, for example the value of pollinating insects such as honeybees was estimated at £208bn in 2005. It not only makes sense to maintain biodiversity for the love of nature, but it also makes economic sense.
However, it’s also important to consider that maintaining biodiversity isn’t easy. Maintaining biodiversity takes space which could be dedicated to improving food security for the ever increasing human population (2). Intensified farming methods have their benefits; it’s estimated that in the USA there is a loss of 37% of all crops to pests, causing a loss of $122bn every year. Pesticides can provide an attractive way to combat this. Herbicides and pesticides also reduce the costs of manual labour by reducing the amount of time required to physically remove weeds and pests from fields.
There are both costs and benefits to maintaining biodiversity against maximising food production. However, more and more farmers are utilising the benefits of maintaining biodiversity despite these costs. Here are three examples of farming techniques in recent media that have shown both a positive effect on biodiversity and yield, demonstrating that biodiversity and food production can go hand in hand.
Firstly, the use of regenerative practices to improve plant diversity and decrease reliance on manufactured animal feed. This management technique involves leaving grasslands to recover between visits by grazing livestock to allow for the plant communities to regrow. This technique can produce 10-15% more grass biomass, which can reduce the farmers’ reliance on fodder whilst maintaining livestock production. However, this technique requires more pasture land; the livestock will require another field to graze while the other fields recover.
Secondly, another use of biodiversity in food production is the use of natural predators to control pests. The introduction of native plants to farmland can attract the predators of crop pests as well as natural pollinators. This technique can be cost effective by reducing reliance on pesticides and the manual labour of applying them.
Furthermore, farming techniques that not only improve plant diversity around the crops but within them have shown benefits to food production. A recent study has highlighted the costs of monoculture – the farming of a single crop species in a field. Mixing crop species together, or even increasing the genetic diversity within a single crop species, can reduce damage by pests (Fig 3). Improving plant diversity on farmland can act as a natural pesticide.
What does the future hold?
As the human population continues to increase, so does our demand for resources. Maximising food production whilst maintaining biodiversity presents many challenges (2), but as the previous case studies have shown, a shift towards a balance between food production and biodiversity is beneficial for both.
Though much biodiversity has already been lost to existing farmland, a deeper appreciation for biodiversity can help shape future developments. In September 2014 the Australian Government presented opportunities to create farmland in savannahs in northern Australia (4). These savannahs occupy the same amount of space as France and Germany combined, and are one of the few remaining large, intact natural spaces in the world. Without proper management of any proposed farming, they risk the loss of 50% of 40 different species and vegetation communities (5).
As our knowledge of the benefits of biodiversity grows, we need to develop more sustainable farming techniques (2,5, Fig 5). Empirical evidence can be presented to policy makers, such as the United Nations 2030 Agenda for Sustainable Development to shape the future of food production. Proper management of existing farmland can maximise food production, maintain biodiversity, and provide food security for billions of people around the world.
- Tscharntke, T., Klein, A., Kruess, A., et al. “Landscape perspectives on agricultural intensification and biodiversity – ecosystem service management”, Ecology Letters. 2005, 8, 8, 857-874.
- Holt, A., Alix, A., Thompson, A., et al. “Food production, ecosystem services and biodiversity: We can’t have it all everywhere”, Science of the Total Environment. 2016, 573, 1422-1429.
- Oerke, E. “Crop losses to pests”, The Journal of Agricultural Science. 2006, 144, 1, 31-43.
- Joint Select Committee on Northern Australia. Pivot North. Inquiry into the Development of Northern Australia – Final Report. 2014. The Parliament of the Commonwealth of Australia, Canberra, ACT.
- Moran-Ordonez, A., Whitehead, A., Luck, G. “Analysis of trade-offs between biodiversity, carbon farming and agricultural development in Northern Australia reveals the benefits of strategic planning”, Conservation Letters. 2016, DOI 10.1111/conl.12255.