Diversity may reduce our reliance on fertiliser

January 14, 2016 by Thomas Deane
Grasslands in the Burren are some of the most species diverse on the planet.

Ecologists have, for the first time, teased out the many interacting factors that explain why species diversity and productivity vary so greatly between different grassland ecosystems across the globe.

The findings suggest that promoting diversity here in Ireland - and further afield - could help to boost in a similar way to how have in the past. Reducing our reliance on fertilisers will be critical if we are to intensify agricultural practices sustainably in the future.

The team of ecologists, which included researchers from Trinity College Dublin, published findings in the leading international journal Nature today.

Grasslands occur over one third of the world's ice-free land. We rely on them for food, for raising livestock for meat and dairy products, for supporting animal and plant biodiversity, and for removing carbon dioxide from the atmosphere.

Agriculture in Ireland is highly reliant on pastures which range from low diversity pastures on heavily fertilised soils to some of the highest diversity pastures in the world, which exist on nutrient-poor soils in the Burren.

This research suggests that across all types of pasture, increases in can lead to increased productivity of pastures. However, fertilisation of species rich pastures, while resulting in higher productivity, also leads to reductions in biodiversity. There are two routes open for management of pastures for higher productivity: increasing species diversity and increasing fertilisation.

Professor of Zoology in the School of Natural Sciences at Trinity College Dublin, Yvonne Buckley, said: "We have traditionally relied very heavily on fertilisers for increasing productivity in grasslands but by paying attention to species diversity grasslands can produce the multiple benefits that we need, such as habitat for critical pollinators, while still maintaining productivity."

"In a world where fuel prices are increasing rapidly and pushing up the cost of fertilisers, the use of species diversity to increase and maintain productivity will become increasingly critical. We need to understand the effects of species diversity in Irish in order to set an appropriate course for sustainable intensification."

In ecological terms, the findings show that local climatic suitability and soil suitability determine how many species will be present in a grassland, and how much biomass it will produce. However, the same conditions are not necessarily good for diversity and .

For example, under a certain set of environmental and soil conditions there is clear evidence that biomass increases as diversity also increases. However, there is a complex relationship between biomass and species diversity as more fertile soils promote higher biomass, which in turn reduces the number of species able to persist. However, in most scenarios, more species will lead to a higher biomass.

Professor Buckley added: "This research reconciles decades of debate as to which mechanism was strongest and explains over 60% of the variation in diversity seen between sites worldwide."

Explore further: Non-native species are transforming grassland ecosystems

Related Stories

Non-native species are transforming grassland ecosystems

July 17, 2015

Non-native 'space invaders' are transforming the world's precious grassland ecosystems, with new research showing that they do far better than native plant species in the presence of fertiliser and large herbivores like kangaroos, ...

Unprecedented worldwide biodiversity study

July 16, 2015

Humans depend on high levels of ecosystem biodiversity, but due to climate change and changes in land use, biodiversity loss is now greater than at any time in human history. Five University of Alberta researchers, including ...

Biodiversity enhances carbon storage of tropical forests

December 2, 2015

Tropical forests store 25% of the global carbon and harbour 96% of the world's tree species. But it was not clear whether this high biodiversity really matters for high carbon storage. Now, researchers of the ROBIN project ...

Herbicides may not be sole cause of declining plant diversity

February 4, 2014

The increasing use of chemical herbicides is often blamed for the declining plant biodiversity in farms. However, other factors beyond herbicide exposure may be more important to species diversity, according to Penn State ...

Recommended for you

Mating induces sexual inhibition in female jumping spiders

October 18, 2017

After mating for the first time, most females of an Australian jumping spider are unreceptive to courtship by other males, and this sexual inhibition is immediate and often lasts for the rest of their lives, according to ...

Understanding the coevolving web of life as a network

October 18, 2017

Coevolution, which occurs when species interact and adapt to each other, is often studied in the context of pair-wise interactions between mutually beneficial symbiotic partners. But many species have mutualistic interactions ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.