Modern Pollen Assemblages Modern Pollen Assemblages Along Transects Across Two Along Transects Across Two

Lowland Tropical LakesLowland Tropical Lakes

Joe N. BurgessM.S. Degree, Spring 2009

Department of GeographyThe University of Tennessee, Knoxville

Study Sites◦Laguna Hule◦Laguna Maria Aguilar

Transects◦1 from Laguna Hule◦2 from Laguna Maria Aguilar ◦Collected by Edward Gray and Glen Hyman in

July and August of 1993

Location of study region in Costa Rica. Source: Horn (2001) Location of study region in Costa Rica. Source: Horn (2001)

Location of Laguna Maria Aguilar and Laguna Hule on the Caribbean Location of Laguna Maria Aguilar and Laguna Hule on the Caribbean slope of Costa Rica. Source: Horn (2001)slope of Costa Rica. Source: Horn (2001)

Location of transect across Laguna Hule along which Teddy Gray and Glen Location of transect across Laguna Hule along which Teddy Gray and Glen Hyman collected 11 dredge samples. Source: Gray (1995)Hyman collected 11 dredge samples. Source: Gray (1995)

Aerial photo of study area. Source: Instituto Geográfico Nacional. Aerial photo of study area. Source: Instituto Geográfico Nacional.

Laguna Hule is the large lake in the lower center of the photograph.

Laguna Mariá Aguilar is the small lake in the upper right corner of the photograph.

Laguna HuleLaguna Hule

Laguna HuleLaguna Hule

Laguna HuleLaguna Hule

Laguna Hule Laguna Hule

Laguna HuleLaguna Hule

Laguna Maria AguilarLaguna Maria Aguilar

Laguna Maria AguilarLaguna Maria Aguilar

Laguna Maria AguilarLaguna Maria Aguilar

Pollen concentration in surface samples of Laguna Maria Pollen concentration in surface samples of Laguna Maria Aguilar Transect AAguilar Transect A

Laguna Maria Aguilar Transect A Pollen Concentration

0

10000

20000

30000

40000

50000

LMA1

LMA2

LMA3

LMA4

LMA5

LMA6

LMA7

LMA8

LMA9

LMA10

LMA11

LMA12

Laguna Maria Aguilar Transect A Pollen Concentration

0

10000

20000

30000

40000

50000

LMA1

LMA2

LMA3

LMA4

LMA5

LMA6

LMA7

LMA8

LMA9

LMA10

LMA11

LMA12

Pollen concentration in surface samples of Laguna Maria Pollen concentration in surface samples of Laguna Maria Aguilar Transect BAguilar Transect B

Laguna Maria Aguilar Transect B Pollen Concentration

0

5000

10000

15000

20000

25000

30000

35000

LMB 1 LMB 2 LMB 3 LMB 4 LMB 5 LMB 6 LMB 7

Laguna Maria Aguilar Transect B Pollen Concentration

0

5000

10000

15000

20000

25000

30000

35000

LMB 1 LMB 2 LMB 3 LMB 4 LMB 5 LMB 6 LMB 7

Pollen percentages in surface samples of Laguna Maria Pollen percentages in surface samples of Laguna Maria Aguilar Transect AAguilar Transect A

Laguna Maria Aguilar Transect A

0%10%20%30%40%50%60%70%80%90%

100%LM

A 1

LMA

2

LMA

3

LMA

4

LMA

5

LMA

6

LMA

7

LMA

8

LMA

9

LMA

10

LMA

11

LMA

12

Other

Ulmus

Mortoniodendron

Iriartea

Urticales

Acalypha

Alchornea

Asteraceae

Poaceae

Laguna Maria Aguilar Transect A

0%10%20%30%40%50%60%70%80%90%

100%LM

A 1

LMA

2

LMA

3

LMA

4

LMA

5

LMA

6

LMA

7

LMA

8

LMA

9

LMA

10

LMA

11

LMA

12

Other

Ulmus

Mortoniodendron

Iriartea

Urticales

Acalypha

Alchornea

Asteraceae

Poaceae

Pollen percentages in surface samples of Laguna Maria Pollen percentages in surface samples of Laguna Maria Aguilar Transect BAguilar Transect B

Laguna Maria Aguilar Transect B

0%10%20%30%40%50%60%70%80%90%

100%LM

B 1

LMB

2

LMB

3

LMB

4

LMB

5

LMB

6

LMB

7

Other

Ulmus

Mortoniodendron

Iriartea

Urticales

Acalypha

Alchornea

Asteraceae

Poaceae

Laguna Maria Aguilar Transect B

0%10%20%30%40%50%60%70%80%90%

100%LM

B 1

LMB

2

LMB

3

LMB

4

LMB

5

LMB

6

LMB

7

Other

Ulmus

Mortoniodendron

Iriartea

Urticales

Acalypha

Alchornea

Asteraceae

Poaceae

Pollen concentration in surface samples of Laguna HulePollen concentration in surface samples of Laguna Hule

Laguna Hule Pollen Concentration

0

5000

10000

15000

20000

25000

30000

35000

40000

LH 1x LH 2x LH 3x LH 4x LH 5 LH 6 LH 7 LH 4 LH 3 LH 2 LH 1

Laguna Hule Pollen Concentration

0

5000

10000

15000

20000

25000

30000

35000

40000

LH 1x LH 2x LH 3x LH 4x LH 5 LH 6 LH 7 LH 4 LH 3 LH 2 LH 1

Pollen percentages in surface samples of the Laguna Hule Pollen percentages in surface samples of the Laguna Hule transect.transect.

Laguna Hule Transect

0%10%20%30%40%50%60%70%80%90%

100%

LH1x

LH2x

LH3x

LH4x

LH5

LH6

LH7

LH4

LH3

LH2

LH1

Other

Ulmus

Mortoniodendron

Iriartea

Urticales

Acalypha

Alchornea

Asteraceae

Poaceae

Laguna Hule Transect

0%10%20%30%40%50%60%70%80%90%

100%

LH1x

LH2x

LH3x

LH4x

LH5

LH6

LH7

LH4

LH3

LH2

LH1

Other

Ulmus

Mortoniodendron

Iriartea

Urticales

Acalypha

Alchornea

Asteraceae

Poaceae

Percentage of fern spores in the surface samples of the Percentage of fern spores in the surface samples of the Laguna Hule transect.Laguna Hule transect.

Laguna Hule Fern Spore Percentages

0%1%2%3%4%5%6%7%8%9%

LH 1x LH 2x LH 3x LH 4x LH 5 LH 6 LH 7 LH 4 LH 3 LH 2 LH 1

Laguna Hule Fern Spore Percentages

0%1%2%3%4%5%6%7%8%9%

LH 1x LH 2x LH 3x LH 4x LH 5 LH 6 LH 7 LH 4 LH 3 LH 2 LH 1

Significance of Study

Rare study of within basin pollen sedimentation in the neotropics

Aids in selection of core sites◦Near shore taxa in abundance closer to shore◦Highest concentration of pollen in the center