““Effects on Red Mangrove’s (Effects on Red Mangrove’s (Rhizophora mangleRhizophora mangle) ) growth and foliage development with different growth and foliage development with different

salt concentration water treatments”salt concentration water treatments”

Presents: Oscar H. TorresPresents: Oscar H. TorresUniversity of ArizonaUniversity of ArizonaSoil, Water, and Environmental Science Department.Soil, Water, and Environmental Science Department.Course: SWES 574Course: SWES 574

IntroductionIntroduction Crops productivity’s improvement or maintenance, Crops productivity’s improvement or maintenance,

has to cope with tolerance of saltier soils and waters has to cope with tolerance of saltier soils and waters today (Boyer, 1982; Epstein today (Boyer, 1982; Epstein et alet al., 1980).., 1980).

Key: to make selections under salty conditions Key: to make selections under salty conditions found in nature, for genotypes able of exploiting found in nature, for genotypes able of exploiting limited resources can be recognized (Boyer, 1982).limited resources can be recognized (Boyer, 1982).

With these genotypes, large-scale modification of With these genotypes, large-scale modification of the environment is less necessary (Boyer, 1982): the environment is less necessary (Boyer, 1982): area for mangrove reforestation. area for mangrove reforestation.

Salt stress.Salt stress.

Serious factor limiting plant growth and Serious factor limiting plant growth and productivity (Boyer, 1982; Zengproductivity (Boyer, 1982; Zeng et al et al., 2006).., 2006).

Outstanding environmental feature in Outstanding environmental feature in mangroves’ swamps and zonations (Lin and mangroves’ swamps and zonations (Lin and Sternberg, 1993).Sternberg, 1993).

MangrovesMangroves

Mangroves: woody plants which dominate Mangroves: woody plants which dominate vegetation in tidal, saline wetlands along tropical vegetation in tidal, saline wetlands along tropical and subtropical coasts (Lin and Sternberg, 1993).and subtropical coasts (Lin and Sternberg, 1993).

The fluctuation in salinity a spp can withstand will be a The fluctuation in salinity a spp can withstand will be a determinant of the distribution and importance of that determinant of the distribution and importance of that

spp along salinity gradientsspp along salinity gradients (Lin and Sternberg, 1993).(Lin and Sternberg, 1993).

ObjectiveObjective

R. mangleR. mangle::

Detect optimum water Tx growth and Detect optimum water Tx growth and foliage development.foliage development.

Identify strains with best growth.Identify strains with best growth.

Methodology.

After Ajmal Khan and Aziz (2001), Hwang and Chen (2001), and Clough (1984).

Results.Results.

Discussion.Discussion.

R. mangleR. mangle grows in [35/00] (Clough, grows in [35/00] (Clough, 1984), vs. growth @ 2 distant [5/00] & 1984), vs. growth @ 2 distant [5/00] & [50/00].[50/00].

Experiment hints Experiment hints R. mangleR. mangle can actively can actively accumulate biomass in [ ] & [ ] accumulate biomass in [ ] & [ ] salty waters. salty waters.

[100/00][100/00]

Deionized waterDeionized water

The growth @ [ 0 ] is largely due to the The growth @ [ 0 ] is largely due to the usage of deionized water (0 ions or usage of deionized water (0 ions or minerals) Turgid effect. minerals) Turgid effect.

In all other methodologies reviewed, [ 0 ] Tx In all other methodologies reviewed, [ 0 ] Tx was based in regular tap water.was based in regular tap water.

Energy used by plant’s equilibrating Energy used by plant’s equilibrating osmotic stresses by DI water, could be osmotic stresses by DI water, could be seized for growth instead.seized for growth instead.

Lowest growth [20 ppt] Lowest growth [20 ppt] plants?plants? Salt stress:Salt stress: Causes poor photosynthesis (Hwang & Chen, 2001; Causes poor photosynthesis (Hwang & Chen, 2001;

Seeman & Critchely, 1985) or causes indirect reaction of Seeman & Critchely, 1985) or causes indirect reaction of ions with C metabolism (Seeman & Critchley, 1985). ions with C metabolism (Seeman & Critchley, 1985).

Regardless of finding the # in buds & the Regardless of finding the # in buds & the

# of new leaves in the same plant, exemplifies the plant’s # of new leaves in the same plant, exemplifies the plant’s need of leaf’s area: photosynthesis & growth.need of leaf’s area: photosynthesis & growth.

Freshwater preferenceFreshwater preference

Mangroves growing in high saline ambient Mangroves growing in high saline ambient preferentially take up fresh water when preferentially take up fresh water when available (Hwang and Chen, 2001).available (Hwang and Chen, 2001).

This opposes the experiment, where This opposes the experiment, where optimal growth was fulfilled at Tx 5 ppt and optimal growth was fulfilled at Tx 5 ppt and 50 ppt; freshwater Tx not optimal.50 ppt; freshwater Tx not optimal.

Discrepancies between greenhouse Discrepancies between greenhouse & wild mangroves.& wild mangroves.

Greenhouse mangroves: optimal growth Greenhouse mangroves: optimal growth salinities range from 1.5 ppt to 15 ppt salinities range from 1.5 ppt to 15 ppt seawater (Hwang and Chen, 2001). seawater (Hwang and Chen, 2001).

In the field, same mangroves grow well @ In the field, same mangroves grow well @ salinities ranging from 15 ppt to over 30 ppt salinities ranging from 15 ppt to over 30 ppt (Hwang and Chen, 2001).(Hwang and Chen, 2001).

ConclusionsConclusions

5 ppt & 50 ppt Tx are recommended to 5 ppt & 50 ppt Tx are recommended to grow grow R. mangleR. mangle the swiftest in the swiftest in Greenhouse conditions.Greenhouse conditions.

20 ppt Tx is not suggested to grow Red 20 ppt Tx is not suggested to grow Red mangroves in the Greenhouse. mangroves in the Greenhouse.

ConclusionsConclusions

Albeit, at 20 ppt Tx, Albeit, at 20 ppt Tx, ## of leaves & leaf of leaves & leaf buds were got. buds were got.

Current results buttress what Boyer (1982) proposed. Current results buttress what Boyer (1982) proposed. (Growth reached under unfavorable salt conditions (Growth reached under unfavorable salt conditions rather in favorable ones).rather in favorable ones).

Thanks for your Thanks for your attention.attention.