Research

November 18, 2010

Effects of litter quality and climate change along an elevation gradient on litter mass loss in an alpine meadow ecosystem on the Tibetan plateau

Abstract Knowledge of the response of litter mass
loss to climate warming and litter quality in alpine
ecosystems is still sparse. Here, we conducted a 507-
day litter decomposition experiment along an elevation
gradient from 3200 to 3800 m using different
litter types to determine the influences of litter quality
and climate change on the elemental mass losses and
on the temperature sensitivity of litter mass losses
(annual percentage decomposition (%) per 1C temperature
difference). Mass losses of C, nitrogen (N),
phosphorus (P), potassium (K), sodium (Na), calcium
(Ca), and Magnesium (Mg) decreased with an increase
in elevation. In general, N and Na concentrations in
litter and ratios of C:N and lignin:N were the best
predictors of C mass losses. A higher N concentration
and C:N ratio in litter caused greater C mass losses, but
higher lignin:N ratio in litter resulted in lower C mass
losses. Litter decomposition occurred in a two-stage
process. Carbon mass loss in litter was mainly limited
by soil temperature in the first growing season of the
decomposition period, whereas N concentration and
ratios of C:P and N:P limited carbon mass loss in the
remaining litter during the second growing season of
the decomposition period. Soil moisture appeared not
to affect litter mass loss and the temperature sensitivity
of litter mass loss of grass litter was greater than that of
shrub litter in the alpine region.
Keywords Litter quality Mass loss
Soil temperature Soil moisture Elevation gradient
Alpine meadow
The research has been published on Plant Ecol (2010) 209:257–268
DOI 10.1007/s11258-009-9714-0
Guangping Xu • Yigang Hu • Shiping Wang • Zhenhua Zhang •
Xiaofeng Chang • Jichuang Duan • Caiyun Luo • Zengguo Chao •
Ailing Su • Qiaoyan Lin • Yingnian Li • Mingyuan Du