In:
Journal of Ecology, Wiley, Vol. 103, No. 4 ( 2015-07), p. 891-903
Abstract:
Tropical montane forests house unusual and diverse biota and are considered highly vulnerable to climate change, particularly near the trade wind inversion ( TWI ) – the upper end of the cloud belt that defines tropical montane cloud forest ( TMCF ). The upper cloud belt has two possible futures: one hypothesis postulates a ‘lifting cloud base’, raising both the upper and lower ends of the cloud belt; the other expects the upper end of the cloud belt will change independently, with a ‘shifting TWI ’. We used a ˜5900‐year‐long palaeorecord of vegetation and fire from a small forest hollow at 2455 m in the C ordillera C entral, D ominican R epublic. The site sits near the upper limit of TMCF taxa and the TWI and allows us to evaluate the relationship between vegetation dynamics and two potential drivers of TWI elevation – the I ntertropical C onvergence Z one ( ITCZ ) and the E l N iño/ S outhern O scillation ( ENSO ). Vegetation changed from cloud forest (˜5900–5500 cal. years BP ) to alpine grassland (˜4300–1300 cal. years BP ), to pine savanna (˜1300–600 cal. years BP ) and finally to closed pine forest (after ˜600 cal. years BP ). Habitat distribution models for TMCF and pine forest taxa show that these state changes were strongly associated with position of the ITCZ (cloud forest x R 2 = 0.63; pine forest x R 2 = 0.53), providing support for the shifting TWI hypothesis. We find a negative relationship between fire and TMCF and a hump‐shaped relationship between fire activity and pine. Synthesis . Shifts up‐ and downslope of the upper limit of the cloud belt over the last 5900 years produced major vegetation changes. Fire also played a significant role, in particular when pine occupied the site after ˜1300 years ago and from 1965 AD when fire suppression led to a rapid return of cloud forest taxa. Our results strongly suggest that latitudinal shifts in the ITCZ position have controlled the upper limit of cloud forest in the C aribbean and understanding how the ITCZ will respond to climate change will be critical for tropical montane conservation strategies.
Type of Medium:
Online Resource
ISSN:
0022-0477
,
1365-2745
DOI:
10.1111/jec.2015.103.issue-4
DOI:
10.1111/1365-2745.12423
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
3023-5
detail.hit.zdb_id:
2004136-6
SSG:
12
