On the Ecology of Mountainous Forests in a Changing Climate: A ...

208 Appendix
• Prentice & Helmisaari (1991) judged Fagus silvatica to be very tolerant, which
means that Fagus would dominate the forests also in dry central alpine valleys,
where it is absent in reality. On the other hand, their value of 0 for alder most
probably is exaggerated, implying that alder can grow only at sites with soil
moisture permanently at or above field capacity.
• The values by Jahn (1991) are not differentiated enough (only three tolerance
classes).
Finally, the drought tolerance classes [1..5] obtained like this (kDrT', Tab. A-10) were
converted linearly to evapotranspiration deficits (corresponding to uDrStr) by assuming
that a tolerance class of 5 corresponds to 30% evapotranspiration deficit (cf. Prentice &
Helmisaari 1991), i.e. kDrT = 0.3 (Tab. A-10).
Tab. A-10: Drought tolerance of tree species according to Landolt (1977, 1 = tolerant, 5 = intolerant, x =
indifferent), Prentice & Helmisaari (1991, 0 = intolerant, 0.36 = tolerant), Jahn (1991, 1 = tolerant, 3 =
intolerant), and Ellenberg (1986, 1 = intolerant, 5 = tolerant). All data were converted to the scale [1…5]
where 1 = intolerant and 5 = tolerant (columns with headers in italics).
Species
Landolt
(1977)
Prentice &
Helmisaari
(1991)
Jahn
(1991)
Ellenberg
(1986)
Landolt
(1977)
classes
Prentice &
H. classes
Jahn
(1991)
classes
Abies alba 4 2 3 2 3 3 0.18
Larix decidua 3 2 2 3 3 2 0.12
Picea excelsa 3 0.12 2 1 3 3 3 1 0.06
Pinus cembra 3 5 3 5 0.30
Pinus montana 2 1 5 4 5 5 0.30
Pinus silvestris x 0.24 1 5 5 4 5 5 0.30
Taxus baccata 2 0.06 2 4 4 2 3 4 0.24
Acer campestre 3 1 4 3 5 4 0.24
Acer platanoides 3 0.24 1 3 3 4 5 3 0.18
Acer pseudoplatanus 3 3 3 3 1 3 0.18
Alnus glutinosa 5 0 1 1 1 1 0.06
Alnus incana 4 0 1 2 1 1 0.06
Alnus viridis 4 2 2 3 2 0.12
Betula pendula x 0.24 1 2 5 4 5 2 0.12
Carpinus betulus 3 0.24 2 3 3 4 3 3 0.18
Castanea sativa 3 1 4 3 5 4 0.24
Corylus avellana 3 0.24 3 4 4 0.24
Fagus silvatica 3 0.36 2 2 3 5 3 2 0.12
Fraxinus excelsior 2–4 0.12 3 2 3 3 1 2 0.12
Populus nigra 4 1 2 1 0.06
Populus tremula 3 0.12 3 3 3 3 0.18
Quercus petraea 2 0.36 2 3 4 5 3 3 0.18
Quercus pubescens 2 1 4 4 5 4 0.24
Quercus robur 3 0.24 1 5 3 4 5 5 0.30
Salix alba 4 1 2 1 0.06
Sorbus aria 2 2 4 4 3 4 0.24
Sorbus aucuparia 3 0.06 2 4 3 2 3 4 0.24
Tilia cordata 2 0.36 2 4 4 5 3 4 0.24
Tilia platyphyllos 3 2 3 3 3 3 0.18
Ulmus scabra 4 0.12 3 3 2 3 1 3 0.18
kDrT'
kDrT
kBrow, kLy & kLa parameters
No coherent data could be found on the browsing susceptibility of tree species (except for
scarce data in Ellenberg 1986 and Dengler et al. 1990); thus the values from Kienast
(1987) were used (section 3.4, Tab. 3.11).
For deriving the light parameters (kLy, kLa), the following sources were consulted:
Amann (1954), Landolt (1977), Bernatzky (1978), Ellenberg (1986) and Jahn (1991).
Amann (1954) gives qualitative descriptions for a few species (see footnotes in Tab. A-
11). Ellenberg (1986) is the only author who differentiates light tolerance values for
saplings (pp. 915ff.) and older trees (p. 82) for most species used in FORCLIM
(Tab. A-11). Hence, it was decided to use mainly Ellenberg's values, but to modify
them where inconsistencies became apparent; for example, Amann (1954) and Prentice &
Helmisaari (1991) agree that Acer spp. and Fraxinus excelsior are more shade tolerant as
saplings than as adults, which is not reflected in Ellenberg (1986).