Abstract:
Afroalpine plants develop under specific climate with great daily fluctuations and
weak seasonal dynamics of temperature. Do leaf functional traits of the plants
in Mt. Kenya differ from those of temperate plants in NW Caucasus? To answer
this question, we conducted a comparative study at the Teleki valley (4000–4500 m
a.s.l.), Mt. Kenya, Kenya, and Teberda national park (2600–2900 m a.s.l.), the Caucasus,
Russia.
We
measured
leaf
area, fresh and dry mass, C, N, P, δ
13
C, δ
15
N and
derivative traits (specific leaf area – SLA, leaf dry matter content – LDMC, C:N
and N:P ratios) for 48 species at the Teleki valley, and the same traits, except for
the δ
13
C and δ
15
N, for 141 species in the Teberda national park. The CSR-stra tegies
scores were calculated. We applied the Principal Component Analysis to reveal the
main patterns of trait variation. Leaf dry mass of Mt. Kenya alpine plants ranged
from 0.27 mg (Sagina afroalpina) to 14.0 g (Dendrosenecio kenio den dron). Leaf area, mass
and LDMC of alpine plants in both regions did not differ significantly. The SLA
of Mt. Kenya’s plants varied about 20-fold: from 2.6 mm
2
mg
-1
(Festuca pilgeri) to
39.8 mm
2
mg
-1
(Cineraria deltoidea), and Caucasian plants had higher SLA. N and P
leaf concentrations were higher, but C lower in Caucasian plants than in Kenyan.
Leaf N:P ratio was similar for both regions, while C:N ratio was higher in Kenyan
plants. Species of “rosette” trees (Dendrosenecio spp.) differed from other species by
size characteristics (maximal leaf dry mass and area were in Dendrosenecio kenioden
dron), as well as correspondingly higher investment to mechanical tissues (high C:N
ratio, low SLA). By the other functional traits, “rosette” trees were similar to many
other alpine plants. Thus, afroalpine plants of Mt. Kenya are close to temperate
alpine plants by some leaf functional traits, but possess higher stress-tolerance.
