Vegetation state changes in the course of shrub encroachment in an African savanna since about 1850 CE and their potential drivers.

Shrub encroachment has far-reaching ecological and economic consequences in many ecosystems worldwide. Yet, compositional changes associated with shrub encroachment are often overlooked despite having important effects on ecosystem functioning.We document the compositional change and potential drivers for a northern Namibian woodland transitioning into a shrubland.

Optimal leaf water status regulation of plants in drylands.

Leaf water potential regulation is a key process in whole plant and ecosystem functioning. While low water potentials induced by open stomata may initially be associated with greater CO supply and a higher water flux from the rhizosphere to the canopy, they also inhibit cell growth, photosynthesis and ultimately water supply. Here, we show that plants regulate their leaf water potential in an optimal manner under given constraints using a simple leaf water status regulation model and data from a global dryland leaf water potential database.

Iso/Anisohydry: Still a Useful Concept.

The iso/anisohydry concept characterizes plants according to their water status regulation. Coexisting definitions and misconceptions have recently led to considerable criticism. We discuss here reasons for the misconceptions, and propose a robust definition of iso/anisohydry using the leaf turgor loss point to integrate the complex interplay of plant hydraulic traits.