Jurnal Ilmiah Nasional Berita Biologi Volume 8 Nomor 1 April 2006 : Fluktuasi Potensial Air Harian Gewang (Corypha Gebanga Lamk.), Jenis Tumbuhan Hijau Abadi di Savana NTT [Diurnal Water Potetntial Fluctuations of Gewang (Corypha Gebanga Lamk.), an Evergreen Plant Species in Savanna Area of East Nsa Tenggara]