Spatial variations in throughfall in a Moso bamboo forest: sampling design for the estimates of stand‐scale throughfall

Abstract

Abstract:We investigated the spatial and seasonal variations in throughfall (Tf) in relation to spatial and seasonal variations in canopy structure and gross rainfall (Rf) and assessed the impacts of the variations in Tf on stand-scale Tf estimates. We observed the canopy structure expressed as the leaf area index (LAI) once a month and Tf once a week in 25 grids placed in a Moso bamboo (Phyllostachys pubescens) forest for 1 year. The mean LAI and spatial variation in LAI did have some seasonal variations. The spatial variations in Tf reduced with increasing Rf, and the relationship between the spatial variation and the Rf held throughout the year. These results indicate that the seasonal change in LAI had little impact on spatial variations in Tf, and that Rf is a critical factor determining the spatial variations in Tf at the study site. We evaluated potential errors in stand-scale Tf estimates on the basis of measured Tf data using Monte Carlo sampling. The results showed that the error decreases greatly with increasing sample size when the sample size was less than ¾8, whereas it was near stable when the sample size was 8 or more, regardless of Rf. A sample size of eight results in less than 10% error for Tf estimates based on Student's t-value analysis and would be satisfactory for interception loss estimates when considering errors included in Rf data.

Requirements for throughfall monitoring: The roles of temporal scale and canopy complexity

“…The virtual sampling of these simulated throughfall fields has several advantages compared to pure empirical approaches (e.g. Holwerda et al, 2006;Ritter and Regalado, 2010;Shinohara et al, 2010;Ziegler et al, 2009). First, we can test various sample supports by aggregating values of the simulated field.…”

Derivation of two-way volume equation for bamboo, Phyllostachys pubescens

“…The abandonment and expansion of P. pubescens stands is likely to increase the risk of sediment disasters (Hiura et al 2004), whereas other researchers found bamboo to be effective in controlling landslides (Zhou et al 2005). The replacement of natural or plantation forests by bamboo forests can change the terrestrial water cycle (Onozawa et al 2009a, b;Shinohara et al 2010). Moreover, such range expansion of P. pubescens stands may have effects on carbon storage and decomposition in forest ecosystems (Inoue and Suga 2009;Inoue et al 2011).…”

Deriving a reduction factor for woody part of culm for bamboo Phyllostachys pubescens

“…Recently, however, abandoned stands of P. pubescens have been invading neighboring stands, expanding their ranges, and changing landscape patterns (e.g., Isagi and Torii 1998;Hayashi and Yamada 2008;Suzuki and Nakagoshi 2008;Someya et al 2009). Such replacement of natural or plantation forests by bamboo forests can change terrestrial water cycles (Onozawa et al 2009a, b;Shinohara et al 2010). The carbon stock for P. pubescens stands (e.g., Chen et al 2009;Du et al 2010) is comparatively smaller than that for the stands of tree species such as Cryptomeria japonica D. Don and Chamaecyparis obtusa Endl.…”