Nonrandom processes maintain diversity in tropical forests.
An ecological community's species diversity tends to erode through time as a result of stochastic extinction, competitive exclusion, and unstable host-enemy dynamics. This erosion of diversity can be prevented over the short term if recruits are highly diverse as a result of preferential recruitment of rare species or, alternatively, if rare species survive preferentially, which increases diversity as the ages of the individuals increase. Here, we present census data from seven New and Old World tropical forest dynamics plots that all show the latter pattern. Within local areas, the trees that survived were as a group more diverse than those that were recruited or those that died. The larger (and therefore on average older) survivors were more diverse within local areas than the smaller survivors. When species were rare in a local area, they had a higher survival rate than when they were common, resulting in enrichment for rare species and increasing diversity with age and size class in these complex ecosystems.
Wills
Christopher
C
Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0116, USA. cwills@ucsd.edu
Harms
Kyle E
KE
Condit
Richard
R
King
David
D
Thompson
Jill
J
He
Fangliang
F
Muller-Landau
Helene C
HC
Ashton
Peter
P
Losos
Elizabeth
E
Comita
Liza
L
Hubbell
Stephen
S
Lafrankie
James
J
Bunyavejchewin
Sarayudh
S
Dattaraja
H S
HS
Davies
Stuart
S
Esufali
Shameema
S
Foster
Robin
R
Gunatilleke
Nimal
N
Gunatilleke
Savitri
S
Hall
Pamela
P
Itoh
Akira
A
John
Robert
R
Kiratiprayoon
Somboon
S
de Lao
Suzanne Loo
SL
Massa
Marie
M
Nath
Cheryl
C
Noor
Md Nur Supardi
MN
Kassim
Abdul Rahman
AR
Sukumar
Raman
R
Suresh
Hebbalalu Satyanarayana
HS
Sun
I-Fang
IF
Tan
Sylvester
S
Yamakura
Takuo
T
Zimmerman
Jess
J
D044822:Biodiversity; D017753:Ecosystem; D011156:Population Density; D011157:Population Dynamics; D014197:Trees / Q000254:growth & development; D014329:Tropical Climate