CR 51:1-10 (2012)  -  DOI: https://doi.org/10.3354/cr01047

ABSTRACT: To detect the effects of a deciduous shrub Salix reinii on microclimate along a gradient of elevation during the snow-free period, we measured ground surface temperature and surface photosynthetically active radiation (PAR) for bare ground and S. reinii patches (henceforth ‘patches’). Measurements were made at low (560 m above sea level), middle (665 m), and high (755 m) elevations on the Mount Koma volcano in northern Japan. Soil water content was also measured for bare ground and under S. reinii patches at the middle elevation, and wind speed was measured on bare ground at all 3 elevations. The forest canopy, dominated by Larix kaempferi, was more developed at lower elevations, and wind speeds there were lower. The PAR value in patches decreased with increasing foliage, which also reduced temperature fluctuations at all 3 elevations. The water content remained higher in patches than on bare ground. These observations show that shrub cover markedly reduces temperature fluctuation and soil desiccation by intercepting solar radiation. Differences in microclimate between the 3 elevations were less in the shrub patches, showing that the patches weakened the effects of elevation and canopy on microclimate at each of the ­elevations surveyed.

KEY WORDS: Microclimate · Ground-surface temperature fluctuation · Photosynthetically active radiation · PAR · Salix reinii shrub patch · Water content in volcanic deposits