Forest Successional Processes in the E. S. George Reserve,

Livingston County, Michigan

Ivette Perfecto

John Vandermeer

The transformation of the Oak-dominated forests

• Oak-domination is an anthropogenic product of Native American agriculture and hunting activities.

• Red maple (Acer rubrum) survived in swamps and is now spreading.

• American beech (Fagus americana) and sugar maple (Acer saccharum) were eliminated from vast areas.

The transformation of the Oak-dominated forests

• Since sugar maple and American beech are not very common in these forests, we expect recruitment limitation to occur.

• We also expect a fat-tail distribution of seed dispersal (as suggested by Clark et al., 1998)

No. seeds

Distance

The transformation of the Oak-dominated forests

Oak

Red Maple

Sugar Maple American Beech

OBJECTIVES

• 1) Estimate the possible time-course of replacement of oaks by red maple.

• 2) Estimate the possible long term time-course of replacement of red maples by American beech and sugar maple.

SITE AND METHODOLOGY

Wetlands

Old fields

Forest

Main plot

Esker plot

Hourglass plot

West woods plot

Patterson lake plot

E. S. George Reserve

three 100 X 70 M2

Plus one 100 X 70 M2 plot

at the Patterson Lake

Facility

one 16

hectares

62 surviving offspring:

from seedling to 10 cm dbh

2 largest are 70 and 78 years old

60 hectares were surveyed

DISTRIBUTION OF BEECH

Wetlands

Old fields

Forest

Main plot

Esker plot

Hourglass plot

West woods plot

Patterson lake plot

SUGAR MAPPLE

Data to be Collected • Continue the censuses of small plot (summer 2003-2004)

• Locate and tag all seedlings and saplings near remnant reproductive red maples (summer 2003-2004)

• Seed traps near the two reproductive red maples (fall 2003)

• Sugar maple seedlings will be planted in forested areas (mainly in the Patterson Lake Nature Center, if it remains available) to verify that suitable microhabitats

Analyses • Seed traps we will provide an accurate estimate of

the seed shadow of the two remnant sugar maples.

• The data will allow us to determine if there is a "fat tailed" distribution.

• Spatial simulation model by Higgens et al. (2001)

Analyses • With the 2004 re-census it will be possible to

estimate both the mortality rate of all trees and the growth rate of all trees.

• Estimates of the time course of the replacement of the oaks and hickories by the red maple.

• Here the modeling framework will be a simple

stage structured model (Caswell, 2001).

Future Research • Depending on the results, the new proposal

to NSF may include aspect of dispersal limitation and neutral competition (Hubble et al, 1999; Vandermeer et al, 2000) as mechanism for the maintenance of diversity.

• Comparison between these mechanisms in tropical and temperate forests.