FLUKTUASI POTENSIAL AIR HARIAN GEWANG {Corypha gebanga Lamk.), JENIS TUMBUHAN HIJAU ABADI DISAVANA NTT

Abstract

A physiological study on Gewang or Tune (Corypha utan Lamk.),a drought resistant and still-wild native palm species in the savanna area of Timor island, East Nusa Tenggara (NTT),shows that this species undergoes a sharp fluctuation in her diurnal water potential (Wd).In two different sites,the early morning Wd shows a less negative values (-1,9 bars to -5,40 bars); however in the afternoon, due to environmental stresses, the Wd drastically dropped to between (-9,7 bars and -17,3 bars).Interestingly,Gewang successfully regulates her Wd during the afternoon and along the night as their d went back normal levels, due to quickly recharged of their Vd to less negative values (-2,1 bar to -8,5 bars).The values of d differs between two sites, however they have similar patterns when comes to recharge their WA.This phenomenon is in line with their relative water content (RWC), as shown a fluctuation following the drops and recharge of Vd.This figure indicates that Gewang may develop mechanism of osmotic adjustment to cope with environmental especially water stress, thus proves her ability to lead as a drought resistant and evergreen species.