leaf adaptation in begonia involucrata
DESCRIPTION
The adaptation of drip-tips in Begonia Involucrata with relation to elevational gradient & leaf sizeTRANSCRIPT
A U S T E N H I L D I N G , L I S A C O L O M B O , T H E R E S A T H A O N G U Y E N , S O F I A R O I T M A N
T H E A DA P TAT I O N O F D R I P - T I P S I N B E G O N I A I N VO LU C R ATA W I T H R E L AT I O N TO A N E L E VAT I O N A L G R A D I E N T & L E A F S I Z E
E L E VAT I O N A F F E C T S T E M P E R AT U R E & P R E C I P I TAT I O N , W H I C H A R E T H E T WO M A I N FAC TO R S T H AT I N F LU E N C E P L A N T M O R P H O LO GY ( L E C . 3 TC E , 2 014 )
• D R I P - T I P S A R E A N I M P O RTA N T A DA P TAT I O N I N W E T E N V I RO N M E N T S ( M A L H A D O E T . A L . , 2 012 )
•
1. K E E P T H E L E A F D RY !
• H E L P P R E V E N T G ROW T H O F E P I P H Y L L S ( D E A N & S M I T H , 197 8 )
• H E L P M A X I M I Z E L I G H T A B S O R P T I O N F O R P H OTO SY N T H E S I S ( M A L H A D O E T . A L . , 2 012 )
• I N C R E A S E T R A N S P I R AT I O N - FA S T E R G ROW T H ( D E A N & S M I T H , 197 8 )
!2. H E L P P R E V E N T S P L A S H E RO S I O N ( W I L L I A M S O N , 19 81 )
D R I P T I P S
B E G O N I A I N VO LU C R ATA “A N G E L - W I N G B E G O N I A”
•A N U N D E R S TO RY P L A N T !
•H A S A VA R I AT I O N O F N U M B E R I N D R I P -T I P S !•P R E S E N T T H RO U G H O U T T H E 15 2 0 - 17 0 0 E L E VAT I O N !!
•D O E S E L E VAT I O N A F F E C T T H E N U M B E R O F D R I P - T I P S I N B E G O N I A I N VO LU C R ATA ? !•D O E S T H E R AT I O O F D R I P - T I P TO L E A F A R E A I N C R E A S E W I T H E L E VAT I O N ? !•I S T H E R E A C O R R E L AT I O N B E T W E E N L E A F S I Z E & N U M B E R O F D R I P - T I P S ?
M E T H O D S
Analyze 30 leaves for each number of drip-tip (1- 4) from 1520-1700 meters
one drip-tiptwo drip-tips
three drip-tipsfour drip-tips
Measure the width and length of each B. involucrata leaf collected using a calliper
Use ImageJ to calculate the drip-tip and the non drip-tip areas of the leaf
Total Area (mm) = (Length/2)*(Width/2)*Pi
Proportion= Drip Tip Area / Leaf Area
Drip-Tip Area (mm^2)= Total Area * Proportion
Count every B. involucrata leaf and note drip-tip in this elevation range to see if there was a relationship between the number of drip-tips and elevational gradient.
A Linear Regression Test showing the relationship of of number of drip-tips per leaf across the elevational gradient
!Number of leaves found across the elevation gradient with the different number of drip-tips
0"
0.002"
0.004"
0.006"
0.008"
0.01"
0.012"
0.014"
0.016"
0.018"
1520" 1540" 1560" 1580" 1600" 1620" 1640" 1660" 1680" 1700"
Leaves&with&1&Drip&Tip& Rsquare&=&0.005&P&=&0.07&N&=&30&
Eleva=on&
Drip&Tips&Area/Leaf&Area&Prop
or=on
&
A Linear Regression Test showing the relationship of the ratio of drip-tip area to leaf area for 30 leaves with 1 drip-tip across the elevational gradient.
0"
0.05"
0.1"
0.15"
0.2"
0.25"
0.3"
0.35"
0.4"
0.45"
0.5"
1520" 1540" 1560" 1580" 1600" 1620" 1640" 1660" 1680" 1700" 1720"
Leaves&with&2&Drip&Tips& Rsquare&=&0.09&P&=&0.09&N&=&30&
Eleva<on&
Drip&Tips&Area/Leaf&Area&Prop
or<on
&
A Linear Regression Test showing the relationship of the ratio of drip-tip area to leaf area for 30 leaves with 2 drip-tips across the elevational gradient.
0"
0.1"
0.2"
0.3"
0.4"
0.5"
0.6"
1500" 1520" 1540" 1560" 1580" 1600" 1620" 1640" 1660" 1680" 1700"
Leaves&with&3&Drip&Tips& Rsquare&=&0.05&P&=&0.196&N&=&30&
Eleva>on&
Drip&Tips&Area/Leaf&Area&Prop
or>on
&
A Linear Regression Test showing the relationship of the ratio of drip-tip area to leaf area for 30 leaves with 3 drip-tips across the elevational gradient.
0"
0.1"
0.2"
0.3"
0.4"
0.5"
0.6"
1520" 1540" 1560" 1580" 1600" 1620" 1640" 1660" 1680" 1700" 1720"
Drip%Tips%Area/Leaf%Area%Prop
or0on
%
Eleva0on%
Leaves%with%4%Drip%Tips% Rsquare%=%0.01%P%=%0.53%N%=%30%
A Linear Regression Test showing the relationship of the ratio of drip-tip area to leaf area for 30 leaves with 4 drip-tips across the elevational gradient.
0"
0.1"
0.2"
0.3"
0.4"
0.5"
0.6"
1500" 1520" 1540" 1560" 1580" 1600" 1620" 1640" 1660" 1680" 1700" 1720"
Eleva&on)
Drip)Tips)Area/Leaf)Area)Prop
or&on
)
All)leaves)together) Rsquare)=)0.001)P)=)0.71)N)=)120)
A Linear Regression test showing relationship between drip-tip to leaf area ratio for all 120 leaves across the elevational gradient
0"
2000"
4000"
6000"
8000"
10000"
12000"
1" 2" 3" 4"
#"of"Drip"Tips"
Leaf"Area"(m
m)"
A"
A" AB"
B"F"="6.67"DF"="3"P"<"0.001"
Comparing total leaf area to number of drip-tips
0"
0.1"
0.2"
0.3"
0.4"
0.5"
0.6"
1" 2" 3" 4"
#"of"Drip"Tips"
Drip"Tips"Area/Leaf"Area"Prop
or1on
"
*"
F"="15.17"DF"="3"P"<"0.001"
Ratio of drip-tip area to leaf area for the 4 leaf types
D I S C U S S I O NN O S TAT I S T I C A L E V I D E N C E T H AT C H A N G E I N E L E VAT I O N H A S A N Y S I G N I F I C A N T E F F E C T O N T H E N U M B E R O F D R I P - T I P S . !N O E V I D E N C E O F A N I N C R E A S E I N R AT I O O F D R I P - T I P TO L E A F A R E A W I T H I N C R E A S E I N E L E VAT I O N . !I N B . I N VO LU C R ATA , T H E R E ’ S N O S I G N I F I C A N T E F F E C T O N L E A F M O R P H O LO GY A S E L E VAT I O N C H A N G E S . !!
D I S C U S S I O N!!W E F O U N D P O S I T I V E CO R R E L AT I O N B E T W E E N L E A F S I Z E & T H E N U M B E R O F D R I P - T I P S . !W E S P E C U L AT E T H AT B E C AU S E T H E L E A F I S L A RG E R , I T I S CO L L E C T I N G M O R E WAT E R S O I T N E E D S M O R E RU N - O F F TO M A X I M I Z E P RO D U C T I V I T Y. !P O S I T I V E F E E D BAC K - M O R E D R I P - T I P S H E L P FAC I L I TAT E G ROW T H ( M A L H A D O , E T . A L . , 2 012 ) !S T RO N G E V I D E N C E P O I N T I N G TO T H E I M P O RTA N C E O F D R I P - T I P S I N W E T E N V I RO N M E N T S . !
C O N C LU S I O N
I N A W E T E N V I RO N M E N T I N T H E F O R E S T U N D E R S TO RY I T I S B E N E F I C I A L F O R P L A N T S TO I N V E S T I N M O R E D R I P -T I P S A S T H E L E A F S I Z E I N C R E A S E S .
C I TAT I O N SMasters, Alan. "Climate and Community". CIEE Tropical Community Ecology lecture. 12 September 2014. !Mahaldo A., et. al. (2012). Drip-tips are associated with intensity of precipitation in the Amazon rain forest. Biotropica 44: 528-537. !Dean, J. M. and Smith, A. P. (1978). Behavioral and morphological adaptations of a tropical plant to high rainfall. Biotropica 10: 152-154 !Williamson, G. B. (1981). Driptips and splash erosion. Biotropica 13: 228-231.
T H A N K YO U !