Transcript Salinity Effects on Red Mangrove

“Effects on Red Mangrove’s (Rhizophora
mangle) growth and foliage development with
different salt concentration water
treatments”
Presents: Oscar H. Torres
University of Arizona
Soil, Water, and Environmental Science Department.
Course: SWES 574
Introduction
 Crops productivity’s improvement or maintenance,
has to cope with tolerance of saltier soils and
waters today (Boyer, 1982; Epstein et al., 1980).
 Key: to make selections under salty conditions
found in nature, for genotypes able of exploiting
limited resources can be recognized (Boyer, 1982).
 With these genotypes, large-scale modification of
the environment is less necessary (Boyer, 1982):
area for mangrove reforestation.
Salt stress.
 Serious factor limiting plant growth and
productivity (Boyer, 1982; Zeng et al., 2006).
 Outstanding environmental feature in
mangroves’ swamps and zonations (Lin and
Sternberg, 1993).
Mangroves
 Mangroves: woody plants which dominate
vegetation in tidal, saline wetlands along tropical
and subtropical coasts (Lin and Sternberg, 1993).
 The fluctuation in salinity a spp can withstand will be a
determinant of the distribution and importance of that
spp along salinity gradients (Lin and Sternberg, 1993).
Objective
 R. mangle:
 Detect optimum water Tx
foliage development.
growth and
 Identify strains with best growth.
Methodology.
After Ajmal Khan and Aziz (2001), Hwang and Chen (2001),
and Clough (1984).
Results.
Discussion.
 R. mangle grows in [35/00] (Clough,
1984), vs. growth @ 2 distant [5/00] &
[50/00].
 Experiment hints R. mangle can actively
accumulate biomass in
[]&
[]
salty waters.
[100/00]
Deionized water
 The growth @ [ 0 ] is largely due to the
usage of deionized water (0 ions or
minerals) Turgid effect.
 In all other methodologies reviewed, [ 0 ] Tx
was based in regular tap water.
 Energy used by plant’s equilibrating
osmotic stresses by DI water, could be
seized for growth instead.
Lowest growth [20 ppt] plants?
 Salt stress:
 Causes poor photosynthesis (Hwang & Chen, 2001;
Seeman & Critchely, 1985) or causes indirect reaction of
ions with C metabolism (Seeman & Critchley, 1985).
 Regardless of
finding the # in buds & the
# of new leaves in the same plant, exemplifies the plant’s
need of
leaf’s area: photosynthesis & growth.
Freshwater preference
 Mangroves growing in high saline ambient
preferentially take up fresh water when
available (Hwang and Chen, 2001).
 This opposes the experiment, where
optimal growth was fulfilled at Tx 5 ppt and
50 ppt; freshwater Tx not optimal.
Discrepancies between
greenhouse & wild mangroves.
 Greenhouse mangroves: optimal growth
salinities range from 1.5 ppt to 15 ppt
seawater (Hwang and Chen, 2001).
 In the field, same mangroves grow well @
salinities ranging from 15 ppt to over 30 ppt
(Hwang and Chen, 2001).
Conclusions
 5 ppt & 50 ppt Tx are recommended to
grow R. mangle the swiftest in
Greenhouse conditions.
 20 ppt Tx is not suggested to grow Red
mangroves in the Greenhouse.
Conclusions
 Albeit, at 20 ppt Tx,
buds were got.
# of leaves & leaf
 Current results buttress what Boyer (1982) proposed.
(Growth reached under unfavorable salt conditions
rather in favorable ones).
Thanks for your attention.