Table 1.

Pairwise similarity for trees greater than 10 cm DBH in four second-growth forest plots in Costa Rica in 2004, based on the Chao Jaccard Abundance Estimator ±95% confidence limits (Chao et al. 2005). (Plot age since abandonment is given in parentheses. Values along the diagonal are similarities within each site between 1997 and 2004. Tree species composition differed significantly across plots of different ages, but not over time within plots.)

	Lindero Sur (12)	Tirimbina (15)	Lindero El Peje (20)	Cuatro Rios (25)
Lindero Sur	1.0±0.0	0.48±0.14	0.80±0.12	0.61±0.12
Tirimbina		1.0±0.0	0.48±0.16	0.44±0.15
Lindero El Peje			1.0±0.0	0.75±0.09
Cuatro Rios				1.0±0.0