Erica Schwarz CARSON:“carson_index” — 2008/5/27 — 14:41 — page 500 — #10500Index
invasible tropical systems (Contd.)
opportunities for spread of aggressive exotics
414–15
Singapore, exotics correlate with canopy
openness 415
fragmented forests 415
subject to edge encroachments 415
islands 414
examples 414
seen as invasible species hotspots 414
managed ecosystems 415–16
cost of controlling weeds 415–16
disturbance/canopy opening, spread of invasive
species 415
invasive African grasses 415
vulnerable to spread of exotics 416
weed encroachment and abandonment of
swidden fields 416
open-canopied forests 414
invasive species, threat to rainforests 447
invasiveness–enemy release hypothesis 419
investment in growth vs. defense against herbivores
trade-off 251
island biogeography theory 151 , 155, 157
and destruction of tropical forests 476
model influences on conservation
science 476–7
does not work well with forest fragments 476
island rainforests 450
island syndrome 327
two major hypotheses 323
absence of interspecific competitors 323
bottom-up vs. top-down controversy 323
reduction in predation 323
Jaccard index 13, 399
Janzen–Connell effects 156
driven by periodic outbreaks of specialist insects
237
failure to find does not reject hypothesis 236
few studies of among and within latitudes
235–6
density-dependent mortality 236
may be stronger in tropical forests 235, 236
seasonality effects in tropical forests 236
repelled recruitment syndrome 236
Janzen–Connell hypothesis 5, 103
a community-level hypothesis 232–3, 236
density- and distance-dependence in temperate
forests, evidence for 235–6
difficult to test and falsify 236–7
effect of dense rare species aggregations 236
distance-dependent prediction of 211
few studies in abiotically stressful habitats 236
impact of enemies on aggregated adults and of
outbreaks, neglected 234–5
aggregation of conspecifics in double jeopardy
235
outbreaks of specialist insects and defoliation
235
pre-dispersal seed predation effects 235
resource concentration hypothesis 234–5
latitudinal gradient in species richness 235
majority of studies in tropical habitats212–16,
235
predictions concerning seedlings 106–7
rejection very difficult 237
a special case of keystone predation? 233
testing impeded 237
community-level evaluations 233
studies to test diversity prediction 232–3
underlain by complex trade-offs 233–4
low light vs. pest pressure 234
shade tolerance 233–4
vulnerability to predation and rapid growth
trade-off 233
Janzen–Connell hypothesis, testing and falsifying
210–41
challenges/issues associated with testing,
evaluating and falsifying 232–7
exclusion experiments 236
testing for repelled recruitment syndromes 236
review of studies testing for 211,212–16, 216,
218–31, 232
areas needing further attention 217, 232
conclusions from the study 217, 232
evaluation of density dependence 217
evidence consistent with density or distance
dependency 211
majority focused on a single species 211
most species studied from lowland tropical
forests 217
species in different life-history classes tested
217, 232
summarize results on a per species basis 217,
218–31
seven studies tested impact on species diversity
217
juveniles, distribution, abundance and shade
tolerance 163