Australian Flora FoundationFINAL REPORT

Life histories and reproductive strategies of halophytic plants: suitability of Frankenia (Frankeniaceae)

for revegetation in Australia.

Prepared by:Dr Lyndlee C. Easton

School of Biological SciencesFlinders University

GPO Box 2100, Adelaide 5001

25th June 2008

Project summary

This PhD project provided information on the life histories and reproductive strategies of Australian plant species in the genus Frankenia.

Global distribution

Mediterranean coastal, and arid inland regions

Specialised soil types e.g. saline and gypseous soils

Australia has the greatest number of species of Frankenia

Project summary

• Small shrubs, sub-shrubs or herbs,

• Habitats: coastal cliffs, sand dunes, coastal salt marshes, margins of salt lakes and salt pans.

Project summary

Frankenia were investigated because they occur naturally in harsh environments

(1) Use in revegetation projects - coastal zones or salt affected regions

(2) Plant cultivation - tolerance to saline and drought conditions.

Project summary

This project provided key data on interspecific variation in reproductive strategies

Variation in seed mass/number per fruit

Significance on germination success under different environmental conditions

Ambient temperature

Salinity levels

Soil properties

Seed mineral content

Project Aims

Two primary aims:

1. To examine germination across Frankenia for seed age, light requirements, temperature preferences, salinity tolerance, and soil characteristics at the seed and seedling stage

Practical significance - halophytic and saltmarsh plants (e.g. Frankenia) play a major role in reclamation programs associated with increasing salinity problems, and/or mine-site revegetation.

Project aims

2. To examine variation in seed mass and number among species of Frankenia to test hypotheses concerning the consequences of these variations for seedling establishment under different ambient conditions.

Practical significance - produced basic information on the reproductive biology of Frankenia, including some that are of conservation significance several species have limited or disjunct distributions or are little known e.g. F. plicata is of particular conservation significance in South Australia

Project Aims(1) Investigate germination requirements for Frankenia in relation to seed age, light

requirements, temperature preferences, salinity tolerance, and soil characteristics.

(2) Investigate two divergent reproductive strategies – notably seed packaging strategies – in relation to environmental variables.

Project Results.

Project Aims(1) Investigate germination requirements for Frankenia in relation to seed age, light

requirements, temperature preferences, salinity tolerance, and soil characteristics. (2) Investigate two divergent reproductive strategies – notably seed packaging strategies –

in relation to environmental variables.

Project results

(1) Overall, larger-seeded Frankenia species were demonstrated to be advantageous for rapid germination after transitory water availability, and for providing resources to seedlings if resources became limiting before their successful establishment.

Project Aims(1) Investigate germination requirements for Frankenia in relation to seed age, light

requirements, temperature preferences, salinity tolerance, and soil characteristics. (2) Investigate two divergent reproductive strategies – notably seed packaging strategies –

in relation to environmental variables.

Project results

(1) Overall, larger-seeded Frankenia species were demonstrated to be advantageous for rapid germination after transitory water availability, and for providing resources to seedlings if resources became limiting before their successful establishment.

(2) Smaller-seeded species delayed germination until both soil-water availability and cooler temperatures persisted over a longer time period, improving chances of successful establishment for the more slowly growing seedlings that are more reliant on their surroundings for resources

The results of each facet of this project was documented as chapters of my PhD thesis entitled:

Easton, L.C. (2008) ‘Life history strategies of Australian species of the halophyte and arid zone genus Frankenia L. (Frankeniaece)’. Flinders University, Adelaide, Australia.

Each chapter was written as a manuscript for publication in peer review journals. The publication status of each manuscript is included in the manuscript abstract.

1. For the results of salinity levels and seed mass on germination in Australian Frankenia species, please refer to manuscript ‘A’.

Easton, L.C. & Kleindorfer, S. (2009) Effects of salinity levels and seed mass on germination in Australian species of Frankenia l. (Frankeniaceae). Experimental and Environmental Botany. 65:345-352.

Germination rates (c)

0

5

10

15

20

25

0%F. p. gunnii

10% 20% 30% 0%F. p.

pauciflora

10% 20% 30% 0%F.

serpyllifolia

10% 20% 30%

Tim

son

's I

ndex

Day 2

Day 4

Day 6

Day 8

Germination rates (a)

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0%F. cinerea

10% 20% 30% 0%F. cordata

10% 20% 30% 0%F. fecunda

10% 20% 30%

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dex

Day 2

Day 4

Day 6

Day 8

Germination rates (b)

0

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25

0% F. foliosa

10% 20% 30% 0% F. interioris

10% 20% 30% 0% F. laxiflora

10% 20% 30%

Day 2 Day 4 Day 6 Day 8

Figure 1. Germination rates, calculated using a modified Timson Index at Days, 2, 3, 6, and 8 at salinity levels of 0%, 10%, 20%, and 30%. Germination rates (a) comprises F. cinerea, F. cordata and F. fecunda. Germination rates (b) comprises F. foliosa, F. interioris and F. laxiflora. Germination rates (c) comprises F. pauciflora var. gunnii (SA varieties), F. pauciflora var. pauciflora (WA varieties) and F. serpyllifolia. Germination rates (d) comprises F. sessilis, F. setosa and F. tetrapetala.

Germination rates (d)

0

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25

0% F. sessilis

10% 20% 30% 0% F. setosa

10% 20% 30% 0% F. tetrapetala

10% 20% 30%

Day 2 Day 4 Day 6 Day 8

2. For soil characteristics associated with the habitats of central and southern Australian Frankenia species, please refer to manuscript ‘B’. Easton, L. C. & Kleindorfer, S. (in review) Soil characteristics associated with the habitats of central and southern Australian Frankenia L. species (Frankeniaceae). Plant and Soil.

Figure 3. Scatterplot generated by the first 2 Discriminant Function scores calculated to identify soil characteristics that maximise the differences between the 41 Frankenia populations included in this study. Open circles represent larger-seeded species. Closed triangles represent smaller-seeded species. Label numbers represent species as follows: (1) F. connata, (2) F. cordata, (3) F. eremophila, (4) F. foliosa, (5) F. gracilis, (6) F. latior, (7) F. pauciflora var. fruticulosa, (8) F. pauciflora var. gunnii, (9) F. planifolia, (10) F. plicata, (11) F. serpyllifolia, (12) F. sessilis, (13) F. subteres.

-5.00 0.00 5.00 10.00

Discriminant Function 1

-5.00

-2.50

0.00

2.50

5.00D

iscr

imin

ant F

unct

ion

2

1

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444

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5 555

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66

7 77

8

8

8

88

8

889

1010

11 11

1111

12

12 1313

3. For the germination requirements for individual Australian species of Frankenia, please refer to manuscript ‘C’. Easton, L.C. & Kleindorfer, S. (in review) Germination requirements for Australian species of Frankenia L. (Frankeniaceae).

17oC

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cin con fec fol lax mag p(SA) p(WA) cor ere grac int plan serp ses set tet

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23oC

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cin con fec fol lax mag p(SA) p(WA) cor ere grac int plan serp ses set tet

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29oC

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cin con fec fol lax mag p(SA) p(WA) cor ere grac int plan serp ses set tet

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Total rates

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cin con fec fol lax mag p(SA) p(WA) cor ere grac int plan serp ses set tet

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Figure 1. Germination rates for Frankenia species, as calculated by a modified Timson Index, by Day 8. Abbreviations are as follows; ‘cin’ F. cinerea, ‘con’ F. confusa, ‘fec’ F. fecunda, ‘fol’ F. foliosa, ‘lax’ F. laxiflora, ‘mag’ F. magnifica, ‘p(SA)’ F. pauciflora var. fruticulosa, ‘p(WA)’ F. pauciflora var. pauciflora, ‘cor’ F. cordata, ‘ere’ F. eremophila, ‘grac’ F. gracilis, ‘int’ F. interiores, ‘plan’ F. planifolia, ‘serp’ F. serpyllifolia, ‘ses’ F. sessilis, ‘set’ F. setosa, ‘tet’ F. tetrapetala. Grey shading represents smaller-seeded species. Black shading represents larger-seeded species

4. For seed mineral nutrient contents of Australian species of Frankenia, please refer to manuscript ‘D’. Easton, L.C. & Kleindorfer, S. (in prep). Seed mineral nutrient contents in Australian species of Frankenia L. (Frankeniaceae). Plant Sciences.

0.00 5.00 10.00

Discriminant Function 1

-6.00

-4.00

-2.00

0.00

2.00D

iscr

imin

ant F

unct

ion

2

1

2

2

3

4

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44

5

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5

67

7

7

88

9

9 10

1010

11

11

1212

121313

14

15 1515

151616 17

18

18

18

Figure 1. Scatterplot generated by the first 2 Discriminant Function scores calculated to identify the seed mineral nutrient content interactions that maximise the differences between Frankenia populations included in this study. Solid circles are larger-seeded species. Open triangles are smaller-seeded species. Label numbers represent species as follows: (1) F. cinerea, (2) F. cordata, (3) F. eremophila, (4) F. fecunda, (5) F. foliosa, (6) F. glomerata, (7) F. gracilis, (8) F. interioris, (9) F. irregularis, (10) F. laxiflora, (11) F. magnifica, (12) F. pauciflora var. gunnii, (13) F. pauciflora var. pauciflora, (14) F. planifolia, (15) F. serpyllifolia, (16) F. sessilis, (17) F. subteres, (18) F. tetrapetala.

5. For the results of the interaction effects of seed mass and temperature on Australian species of Frankenia, please refer to manuscript ‘E’. Easton, L.C. & Kleindorfer, S. (2008) Interaction effects of seed mass and temperature on germination in Australian species of Frankenia L. (Frankeniaceae). Folia Geobotanica. 43: 383-396

Partial Eta Squares

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Day

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29

Figure 2. Partial Eta Square values for each 2-day time interval showing the proportion of the germination rates accounted for by the interaction of seed mass and species at 17°C, 23°C, and 29°C.

6. For the effects of seed mass, seed age, light and temperature on Frankenia serpyllifolia and F. foliosa, please refer to manuscript. Easton, L.C. & Kleindorfer, S. (2008) Germination in two Australian species of Frankenia L., F. serpyllifolia Lindl. and F. foliosa J.M.Black (Frankeniaceae) – effects of seed mass, seed age, light, and temperature. Transactions of the Royal Society of South Australia 132(1): 29-40.

Seed Age (yrs)

1 7 20

% G

erm

inat

ion

0

20

40

60

80

100Small seeds Large seeds

Fig. 3. Germination success for F. serpyllifolia (larger-seeded species) and F. foliosa (smaller-seeded species) after 21 days for seed age categories 1-, 7-, and 20-years.

Thank you