DOI: 10.5061/dryad.f4m6k
title: Data from: Spatial variability in soil organic carbon in a tropical montane landscape: associations between soil organic carbon and land use, soil properties, vegetation, and topography vary across plot to landscape scales

description: Presently, the lack of data on soil organic carbon (SOC) stocks in
 relation to land-use types and biophysical characteristics prevents
 reliable estimates of ecosystem carbon stocks in montane landscapes of
 mainland SE Asia. Our study, conducted in a 10 000 ha landscape in
 Xishuangbanna, SW China, aimed at assessing the spatial variability in SOC
 concentrations and stocks, as well as the relationships of SOC with
 land-use types, soil properties, vegetation characteristics and
 topographical attributes at three spatial scales: (1) land-use types
 within a landscape (10 000 ha), (2) sampling plots (1 ha) nested within
 land-use types (plot distances ranging between 0.5 and 12 km), and (3)
 subplots (10 m radius) nested within sampling plots. We sampled 27
 one-hectare plots – 10 plots in mature forests, 11 plots in regenerating
 or highly disturbed forests, and 6 plots in open land including tea
 plantations and grasslands. We used a sampling design with a hierarchical
 structure. The landscape was first classified according to land-use types.
 Within each land-use type, sampling plots were randomly selected, and
 within each plot we sampled within nine subplots. SOC concentrations and
 stocks did not differ significantly across the four land-use types.
 However, within the open-land category, SOC concentrations and stocks in
 grasslands were higher than in tea plantations (P &lt; 0.01 for
 0–0.15 m, P = 0.05 for 0.15–0.30 m, P = 0.06 for 0–0.9 m depth). The SOC
 stocks to a depth of 0.9 m were 177.6 ± 19.6 (SE) Mg C ha−1 in tea
 plantations, 199.5 ± 14.8 Mg C ha−1 in regenerating or highly disturbed
 forests, 228.6 ± 19.7 Mg C ha−1 in mature forests, and
 236.2 ± 13.7 Mg C ha−1 in grasslands. In this montane landscape,
 variability within plots accounted for more than 50 % of the overall
 variance in SOC stocks to a depth of 0.9 m and the topsoil SOC
 concentrations. The relationships of SOC concentrations and stocks with
 land-use types, soil properties, vegetation characteristics, and
 topographical attributes varied across spatial scales. Variability in SOC
 within plots was determined by litter layer carbon stocks (P &lt; 0.01
 for 0–0.15 m and P = 0.03 for 0.15–0.30 and 0–0.9 m depth) and slope
 (P ≤ 0.01 for 0–0.15, 0.15–0.30, and 0–0.9 m depth) in open land, and by
 litter layer carbon stocks (P &lt; 0.001 for 0–0.15, 0.15–0.30 and
 0–0.9 m depth) and tree basal area (P &lt; 0.001 for 0–0.15 m and
 P = 0.01 for 0–0.9 m depth) in forests. Variability in SOC among plots in
 open land was related to the differences in SOC concentrations and stocks
 between grasslands and tea plantations. In forests, the variability in SOC
 among plots was associated with elevation (P &lt; 0.01 for 0–0.15 m
 and P = 0.09 for 0–0.9 m depth). The scale-dependent relationships between
 SOC and its controlling factors demonstrate that studies that aim to
 investigate the land-use effects on SOC need an appropriate sampling
 design reflecting the controlling factors of SOC so that land-use effects
 will not be masked by the variability between and within sampling plots.
description: SOC stocks, soil
 properties, topographical attributes and vegetation characteristics of a
 tropical montane landscapePlease see ReadMe
 file.Blecourt_data_SOIL.xlsx