Adaptations of plant populations to nutrient-poor environments and their implications for soil nutrient mineralisation

In this chapter we attempt to understand the critical adaptations of plant species to nutrient-poor and nutrient-rich habitats and the consequences of the involved plant traits for nutrient mineralisation in the soils on which these species grow. It appears that species from nutrient-poor environments have lower biomass loss rates but also lower maximum growth rates because they allocate more nutrients to other functions than photosynthesis, such as defence and support. Morphological and physiological constraints determine that a high plant growth rate and an economic use of nutrients (through long life spans) cannot be combined in a single plant. The positive correlation between biomass loss rate and maximum growth rate found among a wide variety of plant species has important implications for the effects of plant species on soil organic matter dynamics and nutrient mineralisation. In a garden experiment annual N mineralisation was found to be 30 to 50% lower in plots planted with species from nutrient-poor habitats compared to plots planted with species from more fertile soils.