Types of Leaf Herbivority in Communities

Cameron, Nate , Crystal, Puja, Rachael, Barney

Atlantic Forest, BrazilSEE-U 2000

Introduction

The principle type of herbivores that affect leaves in plant communities are:

• scrapers-start inside of leaf and work way out

•miners-eat only the mesophyll of leaf•cutters-moves from edges to the inside,

leaving plant veins

• suckers-attach to stem to obtain H20 and nutrients

Introduction(II)

These herbivores are found in different plant communities

Some are more predominant than others

The effect of herbivores may decrease productivity of certain plant species.

Hypotheses

Null Hypothesis- the type of herbivore predation is the same between two sample sites.

Alternative Hypothesis-the type of herbivore predation will vary between the two sample sites.

Methodology

Two groups collected data by identifying plant species affected by herbivores

The predominant type of predation was determined for each plant species

A comparison was made between the two sample sites

Frequency Distribution of the Types of Predation Found Between Sites

0

5

10

15

20

25

30

scrapers cutters miners scrapers andcutters

types of predation

nu

mb

er o

f p

lan

t sp

ecie

s

site 1 site 2

,

Chi squared value: 1.59

Number of species vs. types of predation at site 1. (Group A and Group B)

0

5

10

15

20

25

30

scrapers cutters miners cutters andscrapers

types of predation

num

ber

of

spe

cie

s

group agroup b

0.243 = Sorensen index of diversity

Conclusion

The scrapers and cutters were the predominant types of herbivores

Typically, older leaves were more affected by herbivore predation than younger leaves on the same plant

With a Chi-squared value of 1.59 (with 3 degrees of freedom), we accepted the null-hypothesis