Structure and Demography of Tree Communities in Tropical Secondary Forest Recovering From Logging Keala Cummings and Dr. Diane Thomson 2007 Keala Cummings and Dr. Diane Thomson 2007

Conclusions  Forest not very developed even after 15 years  Mature forests: up to 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 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.

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

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 community  Species composition, abundance and distribution  Estimate rates of  mortality  growth  biomass  biomass accumulation  Short term goals  Establish long-term monitoring plots  Characterize baseline tree community  Species composition, abundance and distribution  Estimate rates of  mortality  growth  biomass  biomass accumulation

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

Distribution of Tree Sizes Results Number of trees Plot 1

Distribution of Tree Sizes Results Number of trees Plot 2Plot 3 Very few mature trees, lots of saplings.

Plot maps Plot 2Plot 3

Figure 3: Plot 2 map showing common species. Red = Psidium, green = Piper. Species diversity Plot 2 Plot 3 Red= Psidium, Green= Piper, Blue= Other Total diversity= 17 spp. (most individuals from a few dominants).

Species diversity 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 2Plot 3 Other species- clustered due to limited dispersal?

Species Composition Blue= Plot 1 Red= Plot 2 Yellow= Plot 3 Individual plots have fairly different compositions.

Stand Characteristics ____________________________________________ __________________________________________________________________________________________________ *Silver et al. (2000) *

Future Questions:  What limits recovery?  Seeds?  Site conditions?  Species composition?  What limits recovery?  Seeds?  Site conditions?  Species composition?

Acknowledgements 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 Effects of Climate and Stand Age on Annual Tree Dynamics in Tropical Second-Growth Rain Forests. Ecology 86(7):  Dunn, Robert R Recovery of Faunal Communities During Tropical Forest Regeneration. Conservation Biology 18 (2):  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:  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):  Chazdon, Robin L., Alvaro Redondo Brenes, and Braulio Vilchez Alvarado Effects of Climate and Stand Age on Annual Tree Dynamics in Tropical Second-Growth Rain Forests. Ecology 86(7):  Dunn, Robert R Recovery of Faunal Communities During Tropical Forest Regeneration. Conservation Biology 18 (2):  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:  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):