ECOLOGICAL STUDIES ON ACACIA SALIGNA PLANTS GROWN IN SAND DUNE AREAS AT NORTH COASTAL ZONE, EGYPT

Abstract

During 2013 the highest value of relative humidity (%) was in July and the lowest value of relative humidity (%) was in March. But during 2014, the highest value of relative humidity (%) was in August and the lowest value of relative humidity (%) was in May. Effective wind percent: The highest value of effective wind percent (%) was in July coming from NNW direction, and the lowest value of effective wind percent (%) was in July coming from SSE direction. 1.1. Wind speed: Wind speed (m/s) before the trees was significantly low between seasons, where the summer was the highest and the autumn was the lowest. Furthermore, the locations on the dune differed significantly in wind speed, the crest of dune was the highest and the leeward slope was the lowest in wind speed. The crest of dune was the highest wind speed in the summer and the leeward slope was the lowest wind speed in the spring. Wind speed (m/s) between the trees was significantly between seasons, where the summer was the highest and the autumn was the lowest. However, wind speed differed significantly over the locations on the dune, where, the crest of dune was the highest and the foot of dune was the lowest wind speed. The crest of dune was the highest wind speed in the summer and the foot of dune was the lowest wind speed in the autumn. 1.2. Sand drift potential: Resultant sand drift potential (RDP) differed between months; where, during February RDP recorded 728.12 VU and coming from direction W and movement to direction ENE and it was the highest value in all months. But, in November RDP was the lowest value in all months it recorded 19.39 VU, coming from NW direction and movement to direction