Structure and Demography of

Tree Communities in Tropical

Secondary Forest Recovering From

Logging

Keala Cummings andDr. Diane Thomson

2007

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ConclusionsConclusions Forest not very developed even after 15 years

Mature forests: up to 200-250 species/ha (Phillips, 1994) Small tree size Domination of pioneer species

Biomass within range of literature values

Literature values very variable

Proximity to mature forest?Wind direction?Animal seed vectors?Rainfall?Other environmental factors?

Forest not very developed even after 15 years

Mature forests: up to 200-250 species/ha (Phillips, 1994) Small tree size Domination of pioneer species

Biomass within range of literature values

Literature values very variable

Proximity to mature forest?Wind direction?Animal seed vectors?Rainfall?Other environmental factors?

Background 60% of all tropical forests are secondary or degraded (ITTO

2002).

As mature forest is destroyed, secondary forests become increasingly important in maintaining biodiversity (Dunn, 2004) and in carbon sequestration (Silver, 2000).

Future conservation efforts may need to be primarily directed towards secondary forests.

Tropical secondary forest recovery is not well understood or studied.

60% of all tropical forests are secondary or degraded (ITTO 2002).

As mature forest is destroyed, secondary forests become increasingly important in maintaining biodiversity (Dunn, 2004) and in carbon sequestration (Silver, 2000).

Future conservation efforts may need to be primarily directed towards secondary forests.

Tropical secondary forest recovery is not well understood or studied.

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Background Firestone Center for Restoration Ecology

Located in Dominical, Costa Rica

Donated to Pitzer College by Diane Firestone in 2005

Property previously used for cattle ranching

Secondary forest stands 15 years old

Firestone Center for Restoration Ecology

Located in Dominical, Costa Rica

Donated to Pitzer College by Diane Firestone in 2005

Property previously used for cattle ranching

Secondary forest stands 15 years old

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Project goals

Long term goals

To better understand:

the processes that affect/influence recovery of secondary forest

Their value as habitat for other species

Their contribution to carbon uptake and sequestration

Long term goals

To better understand:

the processes that affect/influence recovery of secondary forest

Their value as habitat for other species

Their contribution to carbon uptake and sequestration

Project goals

Short term goals

Establish long-term monitoring plots

Characterize baseline tree communitySpecies composition, abundance and distribution

Estimate rates ofmortalitygrowthbiomassbiomass accumulation

Short term goals

Establish long-term monitoring plots

Characterize baseline tree communitySpecies composition, abundance and distribution

Estimate rates ofmortalitygrowthbiomassbiomass accumulation

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Methods Established two new 30 x 30 m plots in secondary

forest.

Tagged, mapped and identified all trees (n=530) over 2.0 cm diameter at breast height (dbh).

Measured dbh (size)

Remeasured all trees tagged in third plot during 2006.

Estimated tree biomasses and basal area using published allometric relationships with dbh.

Established two new 30 x 30 m plots in secondary forest.

Tagged, mapped and identified all trees (n=530) over 2.0 cm diameter at breast height (dbh).

Measured dbh (size)

Remeasured all trees tagged in third plot during 2006.

Estimated tree biomasses and basal area using published allometric relationships with dbh.

Distribution of Tree Sizes

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Distribution of Tree Sizes

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Plot 2 Plot 3

• Very few mature trees, lots of saplings.

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(m)

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Plot maps

Plot 2 Plot 3

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Figure 3: Plot 2 map showing common species. Red = Psidium, green = Piper.

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Species diversity

Plot 2 Plot 3

Red= Psidium, Green= Piper, Blue= Other

• Total diversity= 17 spp. (most individuals from a few dominants).

Species diversity

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Note: Red = Psidium, green = Piper, black = Cecropia, sea green = Miconia (#1), blue= Miconia (#2), sky blue = Miconia (#3), lime = Miconia (#4), orange = Tuete, plum = Guanacaste, pink = tree 1, gold = tree 2, tan = tree 3, brown = tree 4, grey = tree 5, rose = tree 6, blue grey = tree 7, white = collective unknowns.

Plot 2 Plot 3

• Other species- clustered due to limited dispersal?

Species Composition

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PsidiumPiperCecropia

Miconia (#

1)M

iconia (#2)

Miconia (#

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iconia (#4)

TueteG

uanacasteTree 1Tree 2Tree 3Tree 4Tree 5Tree 6Tree 7U

nknown

Blue= Plot 1

Red= Plot 2

Yellow= Plot 3

• Individual plots have fairly different compositions.

Table 1. Stand characteristics of Firestone plots. Measurements are for trees 5 cm.

Characteristics Plot 1 Plot 2 Plot 3

Stand age at time of census (yr) 15 15 15

Species density (no. species/900 m2) 11 16 14

Density of trees 5 cm dbh (no. stems/ha) 1100 1733 1756

Basal area (m2/ha) 32.62 24.32 21.34Biomass 2007 (Mg/ha) 176 128 117Biomass 2006 (Mg/ha) 162 - -

Note: Values of biomass for similar forests in literature review: 10-242 Mg/ha

Stand Characteristics

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*Silver et al. (2000)

*

Future Questions:

What limits recovery?

Seeds?

Site conditions?

Species composition?

What limits recovery?

Seeds?

Site conditions?

Species composition?

AcknowledgementsAcknowledgements

I would like to thank the Andrew W. Mellon Foundation for their grant to the Joint Science Department, Scripps. I would also like to thank my advisor and project supervisor, Dr. Diane Thomson, The Firestone Center for Restoration Ecology, Emily Schultz, Sam Scott, Alicia Hill and Al Binder for an amazing summer.

I would like to thank the Andrew W. Mellon Foundation for their grant to the Joint Science Department, Scripps. I would also like to thank my advisor and project supervisor, Dr. Diane Thomson, The Firestone Center for Restoration Ecology, Emily Schultz, Sam Scott, Alicia Hill and Al Binder for an amazing summer.

Literature cited Chazdon, Robin L., Alvaro Redondo Brenes, and Braulio Vilchez Alvarado.

2005. Effects of Climate and Stand Age on Annual Tree Dynamics in Tropical Second-Growth Rain Forests. Ecology 86(7):1808-1815.

Dunn, Robert R. 2004. Recovery of Faunal Communities During Tropical Forest Regeneration. Conservation Biology 18 (2):302-309.

ITTO, Guidelines for the restoration management and rehabilitation of degraded and secondary tropical forests, International Tropical Timber Organization, Yokohama (2002).

Philips, 0. L., P. Hall, A. H. Gentry, S. A. Sawyer, and R. Vasquez. Dynamics and species richness of tropical rain forests. Ecology 91:2805-2809.

Silver, W. L., R. Ostertag, and A.E. Lugo. The Potential for Carbon Sequestration Through Reforestation of Abandoned Tropical Agricultural and Pasture Lands. Restoration Ecology 8(4):394-407.

Chazdon, Robin L., Alvaro Redondo Brenes, and Braulio Vilchez Alvarado. 2005. Effects of Climate and Stand Age on Annual Tree Dynamics in Tropical Second-Growth Rain Forests. Ecology 86(7):1808-1815.

Dunn, Robert R. 2004. Recovery of Faunal Communities During Tropical Forest Regeneration. Conservation Biology 18 (2):302-309.

ITTO, Guidelines for the restoration management and rehabilitation of degraded and secondary tropical forests, International Tropical Timber Organization, Yokohama (2002).

Philips, 0. L., P. Hall, A. H. Gentry, S. A. Sawyer, and R. Vasquez. Dynamics and species richness of tropical rain forests. Ecology 91:2805-2809.

Silver, W. L., R. Ostertag, and A.E. Lugo. The Potential for Carbon Sequestration Through Reforestation of Abandoned Tropical Agricultural and Pasture Lands. Restoration Ecology 8(4):394-407.