Volume 9 Special Volume: The Hula Peatland: Past, Present and Future (2011/2012) Article 2

Dynamics of vegetation development on drained peat soils of the Hula Valley, Israel

by Z. Henkin, M. Walczak and D. Kaplan

Published online: 21.11.2011

Summary

Lake Hula and its neighbouring peatland in the upper Galilee, Israel were drained during the 1950s. For about 40 years after drainage most of the area was under continuous intensive cultivation with rain-fed winter crops and irrigated summer crops. In 1994 an area of about 110 ha of mainly peat soil was re-flooded and 350 ha surrounding it were partly taken out of intensive agricultural use. The surrounding area was still cultivated under rain-fed conditions in the cool winter season, but left fallow during the hot, dry summer. The summer vegetation was mowed periodically to promote the development of a continuous sward cover for recreation and control of wind erosion. The goal of this research was to study the relationship between dynamic changes in the soil and water conditions and the composition and species distribution of the spontaneous summer vegetation. During four consecutive years the vegetation dynamics were characterised by increasing dominance of  and Sorghum halepense. Cyperus rotundus, which was common under irrigated cultivation, partly disappeared under the new non-irrigated regime. The density and growth rate of the vegetation mainly reflected differences in the water table depth, which varied between 0.5 m and 3 m. Three years after re-flooding, soil salinity was high in areas where the water table was higher than 0.5 m and in dry patches where almost no cover of vegetation was found. In these sites the concentration of mineral nitrogen (N-NO₃ and/or N-NH₄) was especially high. A continuous vegetation cover developed on the peat soil in areas where the depth of the water table was between 1 m and 2 m. Mowing the vegetation periodically in summer suppressed the growth of tall, weedy species and promoted the dominance of Cynodon dactylon creating a dense, productive sward.

Citation

Henkin, Z., Walczak, M. and Kaplan, D. (2011): Dynamics of vegetation development on drained peat soils of the Hula Valley, Israel. Mires and Peat 9: Art. 2. (Online: http://www.mires-and-peat.net/pages/volumes/map09/map0902.php)

Reviewers

IMCG and IPS acknowledge the work of the reviewers.