Sam and Louis, it's really good to see this paper and all the hard work you must have done to measure the root characteristics in grasslands. Your findings show clear differences between the two sward types and your calculation of seasonal turnover of roots is a very helpful contribution. May I just ask about the root lengths you present in Figure 2? The lengths seem very high and, if they are correct, then I suggest you could better present them  in units of km/m2. I hope your paper is well received by Plant & Soil, David