title: Good-bye to tropical alpine plant giants under warmer climates? Loss of range and genetic diversity inLobelia rhynchopetalum.
abstract: The main aim of this paper is to address consequences of climate warming on loss of habitat and genetic diversity in the enigmatic tropical alpine giant rosette plants using the Ethiopian endemicLobelia rhynchopetalumas a model. We modeled the habitat suitability ofL.rhynchopetalumand assessed how its range is affected under two climate models and four emission scenarios. We used three statistical algorithms calibrated to represent two different complexity levels of the response. We analyzed genetic diversity using amplified fragment length polymorphisms and assessed the impact of the projected range loss. Under all model and scenario combinations and consistent across algorithms and complexity levels, this afro-alpine flagship species faces massive range reduction. Only 3.4% of its habitat seems to remain suitable on average by 2,080, resulting in loss of 82% (CI 75%-87%) of its genetic diversity. The remaining suitable habitat is projected to be fragmented among and reduced to four mountain peaks, further deteriorating the probability of long-term sustainability of viable populations. Because of the similar morphological and physiological traits developed through convergent evolution by tropical alpine giant rosette plants in response to diurnal freeze-thaw cycles, they most likely respond to climate change in a similar way as our study species. We conclude that specialized high-alpine giant rosette plants, such asL. rhynchopetalum, are likely to face very high risk of extinction following climate warming.
authors.affiliation: Natural History Museum University of Oslo Oslo Norway.
authors.forename: Desalegn
authors.initials: D
authors.lastname: Chala
authors.affiliation: Natural History Museum University of Oslo Oslo Norway.
authors.forename: Christian
authors.initials: C
authors.lastname: Brochmann
authors.affiliation: Swiss Federal Research Institute WSL Birmensdorf Switzerland.
authors.forename: Achilleas
authors.initials: A
authors.lastname: Psomas
authors.affiliation: Department of Arctic and Marine Biology UiT - The Arctic University of Norway Tromsø Norway.
authors.forename: Dorothee
authors.initials: D
authors.lastname: Ehrich
authors.affiliation: Natural History Museum University of Oslo Oslo Norway.
authors.forename: Abel
authors.initials: A
authors.lastname: Gizaw
authors.affiliation: Natural History Museum University of Oslo Oslo Norway; Institute of Resource Assessment University of Dar es Salaam Dar es Salaam Tanzania.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Masao
authors.affiliation: Natural History Museum University of Oslo Oslo Norway; Norwegian Institute for Nature Research Oslo Norway.
authors.forename: Vegar
authors.initials: V
authors.lastname: Bakkestuen
authors.affiliation: Swiss Federal Research Institute WSL Birmensdorf Switzerland.
authors.forename: Niklaus E
authors.initials: NE
authors.lastname: Zimmermann
keywords: Lobelia rhynchopetalum; afro‐alpine; climate change; giant rosette plants; loss of genetic diversity; model algorithms; model complexity; range loss; tropical alpine plants