(Article of periodic en Français - 1983)

Document title

Phytomasse et production végétale en Tunisie présaharienne

Authors(s) and Affiliation(s)



Phytomass measurements were carried out within about thirty ecological systems (mainly steppe vegetation types) of the Presaharian zone of Tunisia. The mean above-ground phytomass of perennial species is between 500 and 700 kg dry matter/ha. About thirty species contribute to it. 90 % of this phytomass is constituted by chamaephytes and small phanerophytes. The belowground phytomass seems to be slightly inferior to the above-ground one. The fluctuations of above-ground phytomass were studied during several years. Depending on the system and the year, the production (without grazing) ranged from about zero to 2,250 kg dry matter/ha/year. This production is a function of the total annual rainfall, but chiefly of the seasonal distribution of rainfall: the variation in production changes from 1 to 3 for the same annual rainfall. The water use efficiency is between 2 and 5 g dry matter/kg HO that is lost due to evapotranspiration. Due to the low soil nutrient level, water is not the principal limiting factor in very wet years. The above-ground phytomass decreases greatly in summer. There is no accumulation of litter from one year to the following one.


Article of periodic

published at : Acta oecologica. Série Oecologia plantarum Montreuil

Editor :

Millesime : 1983, vol. 4, no2 [pp. 133-152]

Bibliographic references : 39 réf.



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