2nd International Congress of Alpine and Arctic Botanical Gardens

Detection of climate change impacts in alpine and
arctic botanic gardens: a phenology program
Andreas GRÖGER
Alpengarten auf dem Schachen/ Botanischer Garten München, Germany
Annette MENZEL
Fachgebiet für Ökoklimatologie / Technische Universität München, Germany
Since decades many Botanic Gardens in the lowlands are conducting standardized phenological observations
of cloned plants, recording timing of leaf unfolding, flowering, fruit ripening, leaf coloring, and leaf
fall (e. g. International Phenological Gardens project, since 1959). But long term observations from higher
elevations, which are affected even more severely by climate change, are still very scarce. Alpine and Arctic
Botanic Gardens (AABGs) offer a perfect field for these studies, allowing to compare the effect of climate
change on genetically identical plants under alpine as well as arctic conditions. Following AABGs agreed to
cooperate in a joint phenological program: Alpengarten auf dem Schachen (Germany), Giardino Botanico
Alpino Viotte (Italy), Jardin Botanique Alpin du Lautaret (France), Tromsø Arctic-Alpine Botanic Garden
(Norway) and Reykjavik Botanic Garden (Iceland).
Effects of climate change on plant life
In 2007, the Intergovernmental Panel on
Climate Change (IPCC) has drawn very different
scenarios. Two years later, rising CO emissions
2
and further results in climate research proof,
that the worst case scenario becomes more than
probable, i.e. an average increase of atmosphere
temperature of more than 4°C until 2100. The
effects on biodiversity will be drastic (Rosenzweig
et al. 2007).
One of the hard hit environments will be subalpine
and alpine biomes. But nevertheless, data
on the effects of climate change to ecosystems
in high altitudes are still quite scarce. In general,
with each °C increase of temperature in the
mountains, the duration of snow cover decreases
by several weeks, the glacier line shifts upward
by 60 to 140 m and the treeline shifts upward by
several 100 m.
The only options for plant species to respond
to these changes are migration to higher altitudes
or higher latitudes (Parmesan & Yohe,
2003) or adaptation (ecological plasticity, microevolution).
Especially temperature and drought
sensitive species and species which are poor
dispersers, will face the risk of extinction. For
some mountain ranges the prognosis of loss
of local plant species exceeds 60%, assuming a
temperature increase of 4°C.
Research and Conservation Activities 47