Hydro-chemical cycle of forest ecosystem in the Norikura Highlands-1.Chemical characteristic and seasonal change of throughfall in forest ecosystem-

Abstract

Because of precipitation serves as a major vehicle of nutrient input into the forest ecosystem, the accurate measurement of its volume and ion concentration is of prime importance in an evaluation of any bio-geochemical cycle. Therefore, chemistry of the precipitation and throughfall of forest ecosystem was investigated in the Norikura Highlands. The investigation period was from January, 2003 to October, 2006. The throughfall volume in growing season and dormant season were 86 % and 93 % of the precipitation volume. Throughfall pH increased with increasing K + concentration showed that H + was held within the canopy by cation exchange reaction. And the concentration level of K + , Mg 2+ and Ca 2+ in the throughfall was much higher than that in the precipitation. It was the cause of canopy leaching. In growing season, proportions of canopy leaching of K + , Mg 2+ and Ca 2+ were 95 %, 70 % and 43 % of the throughfall deposition respectively. At Coniferous site, the flux of dry deposition was higher in dormant season than growing season. It is suggested that aerosol of the atmosphere and leaf area might be influenced.

Atmospheric Deposition and Interactions with Pinus pumila Regal Canopy on Mount Tateyama in the Northern Japanese Alps

“…Concentrations of K + , Ca 2+ , and Mg 2+ in the throughfall were high compared to those in the BD with NTDs of 0.97, 0.13, and 0.13 kg ha -1 mo -1 (3-year average), respectively. This result is consistent with those from other studies that have shown that, in various forest types, a large proportion of the ions in the throughfall originated from canopy leaching (Cronan et al, 1983;Parker, 1983, Okochi et al, 1995Houle et al, 1999;Muramoto et al, 2007). As shown in Figure 4, NTDs of most ions except Na + increased as the drenched duration of the canopy increased.…”

“…The leaching did not increase with rainfall, but increased as the duration of the fog and dew increased. continent has been reported (Kume et al, 2009(Kume et al, , 2011, most of the previous studies have been conducted below the tree line (e.g., Muramoto et al, 2007), and there have been no systematic observations above the line, especially for P. pumila vegetation.…”

Canopy Rainfall Interception and Fog Capture by Pinus pumila Regal at Mt. Tateyama in the Northern Japan Alps, Japan

“…]; and mountain deciduous broad-leaved forest is 19% [Betula platyphylla, 1610 m a.s.l.] [Muramoto et al, 2007]). The high interception ratio of the P. pumila canopy may be attributed to the high leaf area density.…”