Diego Barranco-Elena

1 Introduction Multivariate ordination techniques such as nonmetric multidimensional scaling (NMDS), principal component analysis (PCA), and constrained methods like redundancy analysis (RDA) or distance-based RDA (dbRDA) are central to ecological data analysis.

1 INTRODUCTION The proliferation of lesser-known weeds, such as Centaurea diluta Aiton (North African knapweed), is being exacerbated by changes in European Union legislation which have resulted in limited availability of herbicides and reduced frequency of tillage, thus diminishing weed control options for farmers.1, 2 Centaurea diluta, which is endemic to North Africa and south-western Europe, has become one of the principal concerns for farmers in southern Spain, particularly in cereal...