•Allen, W. 2000. Restoring
•Work done on upper part of Kaupulehu
–North and upslope from Kona
–Fenced in 1956
–20” rain per year
–On lava flow (1800’s)
–Originally native dry forest
•Causes of damage
–Cattle grazing
–Feral ungulates (cattle, pigs,
goats)
–Non-native grasses
•West
(dry) side:
–fountain
grass Pennisetum setaceum
•East
(wet) side:
–kikuyu
grass Pennisetum clandestinum
–Grass-fed fires
•Extent of damage
–90% of dry forest is gone
–40% of rain forest is gone
•Initial restoration and
investigation
–Kaupulehu is fenced and buffered from
fire by lava flow
–Endangered spp. raised from
seeds collected on site, outplanted
–Rodents suspected because of
lack of seedlings
•Bait
traps used
–Fountain grass cut in 1995
•Initial restoration and
investigation, 2
–Fountain grass down to 10% by
1996.
–By 1997, canopy tree seedlings
had increased from 0 to 838 in 53 plots
•Diospyros sandwicensis (lama) (persimmon)
–Subsequent drought slowed
regeneration
•Sub-canopy
microhabitat still not there
•Shading
and drip irrigation proposed
•Cabin, R.J., S.G. Weller, D.H. Lorence, S. Cordell, L.J. Hadway,
R. Montgomery, D. Goo, A. Urakami. 2002.
Effects of light, alien grass and native species additions on Hawaiian
dry forest restoration. Ecological
Applications 12 (6): 1595-1610.
•Experiment done on lower part
of Kaupulehu
–Fenced in 1997
–Same problems: heavy grazing,
fountain grass
•Experimental design
–Two
blocks
•50% shade
•Full sun
–Fountain
grass control
•Bulldoze
•Herbicide
•Plastic mulch
•Trim
–Species
additions
•Outplanting
•Seeding
•Control
•Herbicide was 1% Roundup as
grass was cut in January and as it grew back in April
•Mulch site was cut to ground
and covered with black plastic (for 120 d), which was removed at the start of
the experiment
•Trim: fountain grass was cut
down to 60 cm.
•Outplanting: 44 plants (7 spp)
put into 1.8 x 1.8 m plot (32 cm spacing)
•Seeding: mix of 12 native spp, pre-soaked,
(numbers per spp varied)
–Watered more heavily at first,
then once a week
•Planting done on 17 May
•Experiment conducted for 20
months
Results
•Fountain grass cover greatest
in trimmed sites, lowest in bulldozed sites
•Native cover the reverse
•Native cover high in shaded
plots
•Most natives in outplanted plots, next seeded, then control
•Native and grass cover
negatively correlated
•Greatest outplant
survival in shade, herbicided plots, plastic mulch
Synthesis
•Dry forest restoration should
focus on:
–Reduction or removal of
non-native ungulates
–Control of dominant introduced
grasses*
–Use or creation of favorable microsites
–Re-introduction of selected
native species
–Fire must be controlled*
•In addition, seed dispersal is
poor
–Little wind dispersal
–Almost no animal dispersal
•Loss
of native bird population in
–Seeds short-lived