The relationship between diversity and productivit in plant communities: facts and artefacts.

2 pages. http://www.aloj.us.es/grnm210/pdf/Maranon97.pdfOnce ecologists have found patterns in nature they are able to generate testable exp1anatory theories (Weiner 1995). One such commonly found pattern is that when exploring an environmental gradient, the relationship between plant species richness and above-ground biomass tends to be unimodal. This trend was first described by AI-M uf ti el al. (1977), although only 14 sample plots were used, and the curve was fitted by hand. Despite the small data set and the rudimentary quantitative analysis used, this study formed the basis for an intuitive, conceptual model that explained the hump-backed curve of diversity in terms of infiuences by 'stress', disturbance and competition (Grime 1979).Peer reviewe