Dataset for: Aboveground carbon stocks, woody and litter productivity along an elevational gradient in the Rwenzori Mountains, Uganda

Montane forests are characterized by high biodiversity, endemism and
strong elevational environmental gradients. The latter attribute makes
them also suitable as a ‘natural laboratory’ for studying the effects of
environmental parameters on ecosystem functions. To provide better insight
into the carbon cycle of Afromontane ecosystems, we used an elevational
gradient approach to quantify carbon stocks, woody and litter
productivity, and their constraining factors. Twenty plots were
established, covering five elevations from Kibale Forest at 1250 m to 3000
m in the Rwenzori Mountains. Results revealed aboveground carbon stocks of
between 185.4 ± 48.9 Mg C ha-1 and 70.8 ±18.6 Mg C ha-1 at 1250-1300 m and
2700-3000 m respectively. Aboveground carbon tended to decrease with
elevation, but this trend was not significant. This was due to
similarities in stem diameter combined with different effects of tree
height and stem density. Similarly, woody productivity did not change with
elevation, ranging from 8.3 ± 4.1 Mg C ha-1 year-1 to 3.4 ± 1.5 Mg C ha-1
year-1 at 2500-2600 m and 2700-3000 m respectively. However, litter
productivity decreased linearly by 0.14 ± 0.04 Mg C ha-1 year-1 per 100 m
of elevation increase, ranging from 4.0 ± 0.7 Mg C ha-1 year-1 at
1750-1850 m to 1.2 Mg C ha-1 year-1 at 2700-3000 m. Topsoil
physicochemical properties varied with elevation, but showed no
significant relationship with carbon stocks and woody productivity.
However, litter productivity increased with mean soil temperature, whereas
it decreased with soil total nitrogen.