4.4 | Short term vs long term acclimation
In the absence of large-scale manipulative experiments with mature trees
in the tropics, studies of climate change effects rely on seedling or
sapling temperature and/or CO2 manipulations (e.g.
Winter & Virgo 1998; Winter, Garcia, Gottsberger. & Popp 2001;
Lovelock, Winter, Mersits & Popp 1998; Cheesman & Winter 2013; Slot &
Winter 2017a, 2018; Fauset et al. 2019), or on manipulation of
individual leaves or branches of mature trees (Körner & Würth 1996;
Lovelock, Virgo, Popp & Winter 1999; Doughty 2011; Slot et al. 2014,
but see Smith et al. 2020). Inferring long-term acclimation potential
from manipulated pre-existing canopy leaves is challenging because newly
developed tissue tends to exhibit stronger acclimation responses than
pre-existing leaves. This was confirmed in our study; stronger
acclimation was accomplished when plants were measured at their growth
conditions than when fully-formed leaves were re-measured after the
plants were switched between treatments. Acclimation of newly developed
tissues is more relevant for long-term predictions and simulations.