Germination and establishment of Sahelian rangeland species : II. Effects of water availability.

In order to understand the vegetation dynamics of Sahelian rangelands, the effects of water availability on germination were investigated under controlled conditions in climate rooms. Mixtures of seeds from species that occur in the same habitats but have different seed characteristics were exposed to different watering treatments. Responses to the treatments in the climate room were comparable to those observed in the field situation.

Germination and establishment of Sahelian rangeland species : I. Seed properties.

In the context of a study on the dynamics of Sahelian rangelands, seed characteristics of about 30 species have been described, with particular attention to germination characteristics. Data on both form and weight of the seeds are presented. Germination was studied under controlled conditions in a climate room.

Competition between two desert varieties of Medicago laciniata (L.) Mill. under controlled conditions.

Two varieties of Medicago laciniata common in the Negev desert of Israel reveal a distinct pattern of distribution within two different plant communities: M. laciniata var. laciniata occupies northern slopes and wadi beds within the association of Artemisia herba-alba, and M.