Results of field sampling at different sites with different land-use. Scores plot of principal component analysis of chromatographic peaks of Plantago lanceolata field-sampled at four plots, two in Augustdorf (Aug) and two in Bielefeld (Bi), each with different land-use. Leaf samples were extracted following the recommended protocol (Table 4) and analysed by LC-MS. N = 73 plant samples were taken. At PC 1, explaining 86% of the variance within the data, samples from Augustdorf with horses and Augustdorf unused/mowed were significantly different and samples from Bielefeld were different to samples from Augustdorf with horses (Kruskal-Wallis test followed by post hoc paired comparisons tests, P < 0.01). All sites and treatments were significantly different at PC 2, explaining 11% of the variance, (Kruskal-Wallis test followed by post hoc paired comparisons tests, χ2 = 488.349, df = 71, P < 0.001).