Abstract. We explore the use of active volcanoes to determine the short- and
long-term effects of elevated CO2 on tropical trees. Active
volcanoes continuously but variably emit CO2 through diffuse
emissions on their flanks, exposing the overlying ecosystems to elevated
levels of atmospheric CO2. We found tight correlations
(r2=0.86 and r2=0.74) between wood stable carbon isotopic
composition and co-located volcanogenic CO2 emissions for two of
three investigated species (Oreopanax xalapensis and
Buddleja nitida), which documents the long-term photosynthetic
incorporation of isotopically heavy volcanogenic carbon into wood biomass.
Measurements of leaf fluorescence and chlorophyll concentration suggest that
volcanic CO2 also has measurable short-term functional impacts on
select species of tropical trees. Our findings indicate significant potential
for future studies to utilize ecosystems located on active volcanoes as
natural experiments to examine the ecological impacts of elevated atmospheric
CO2 in the tropics and elsewhere. Results also point the way toward
a possible future utilization of ecosystems exposed to volcanically elevated
CO2 to detect changes in deep volcanic degassing by using selected
species of trees as sensors.
Fungal community composition and function after long-term exposure of northern forests to elevated atmospheric CO2 and tropospheric O3
