Lethal effects of experimental warming approximating a future climate scenario on southern African quartz-field succulents: a pilot study.
New Phytol
; 165(2): 539-47, 2005 Feb.
Article
en En
| MEDLINE
| ID: mdl-15720664
ABSTRACT
Here we examine the response of succulents in a global biodiversity hot spot to experimental warming consistent with a future African climate scenario. Passive daytime warming (averaging 5.5 degrees C above ambient) of the natural vegetation was achieved with 18 transparent hexagonal open-top chamber arrays randomized in three different quartz-field communities. After 4-months summer treatment, the specialized-dwarf and shrubby succulents displayed between 2.1 and 4.9 times greater plant and canopy mortalities in the open-top chambers than in the control plots. Those surviving in cooler ventilated areas and shaded refuges in the chambers had lower starch concentrations and water contents; the shrubby succulents also exhibited diminished chlorophyll concentrations. It is concluded that current thermal regimes are likely to be closely proximate to tolerable extremes for many endemic succulents in the region, and that anthropogenic warming could significantly exceed their thermal thresholds. Further investigation is required to elucidate the importance of associated moisture deficits in these warming experiments, a potential consequence of supplementary (fog and dew) precipitation interception by open-top chambers and higher evaporation therein, on plant mortalities.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Plantas
/
Temperatura
/
Efecto Invernadero
Tipo de estudio:
Clinical_trials
País/Región como asunto:
Africa
Idioma:
En
Revista:
New Phytol
Asunto de la revista:
BOTANICA
Año:
2005
Tipo del documento:
Article
País de afiliación:
Sudáfrica