Tallgrass needs microbes, according to an article in Nature News 31 October 2013 and Science 1 November 2013 vol. 342 621-624 DOI: 10.1126/science.1243768. The USA Midwest was once dominated by tallgrass prairies, but these have largely been replaced by cultivated farms as settlers moved across North America. Whilst agriculture has produced abundant crops, poor farming practices have contributed to degradation of the land, as happened in the Dust Bowl disasters of the 1930s. There are now numerous attempts at restoring tallgrass ecosystems, so a group of scientists in the USA have studied soil from relics of the prairie grasslands in cemeteries and reserves that have never been cultivated. They used gene sequencing technology to identify which bacteria were dominant in the soil and found a group of bacteria named Verrucomicrobia was abundant in prairie soil. These bacteria are poorly understood as they are slow-growing and difficult to cultivate in the laboratory. However, it seems they thrive in soil with poor nutrients, but are less common on land that has been farmed and artificially fertilised.
The scientists also collected data on climate variations across the Midwest, and combined this with their soil microbe analyses to predict the historical composition of the soil microbes across the entire region once covered by tallgrass prairie. The research team suggest: “Maps of the soil microbial communities that once existed in this ecosystem may provide targets to help improve the long-term success of prairie restoration efforts, as restoration efforts are often more successful when they also try to restore below-ground communities”.
Editorial Comment: The importance of soil microbes has been experienced by those trying to re-plant forests in Australia, where they have had the same problem – the trees would not thrive unless tree seedlings were planted along with soil taken from existing forests. We now know that trees need to establish a relationship with soil fungi and microbes in order to grow well. This study of the relationship between plants and microbes is a reminder that nothing in the living world functions alone, and that is exactly what you would expect if God created complete functioning ecosystems in a few days, rather than individual organisms struggling to survive over millions of years. (Ref. ecology, angiosperms, microbiology)
Evidence News 24/13, 4 December 2013