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Koike T.,Hokkaido University | Mao Q.,Hokkaido University | Inada N.,Hokkaido University | Kawaguchi K.,Hokkaido University | And 3 more authors.
Asian Journal of Atmospheric Environment | Year: 2012

We studied the effects of elevated ozone ([O 3]) and CO 2 concentrations ([CO 2]) on the growth and photosynthesis of the hybrid larch F 1 (F 1) and on its parents (the Dahurian larch and Japanese larch). F 1 is a promising species for timber production in northeast Asia. Seedlings of the three species were grown in 16 open top chambers and were exposed to two levels of O 3 (<10 ppb and 60 ppb for 7 h per day) in combination with two levels of CO 2 (ambient and 600 ppm for daytime) over an entire growing season. Ozone reduced the growth as measured by height and diameter, and reduced the needle dry mass and net photosynthetic rate of F 1, but had almost no effect on the Dahurian larch or Japanese larch. There was a significant increase in whole-plant dry mass induced by elevated [CO 2] in F 1 but not in the other two species. Photosynthetic acclimation to elevated [CO 2] was observed in all species. The net photosynthetic rate measured at the growing [CO 2] (i.e. 380 ppm for ambient treatment and 600 ppm for elevated CO 2 treatment) was nevertheless greater in the seedlings of all species grown at elevated [CO 2]. The high [CO 2] partly compensated for the reduction of stem diameter growth of F 1 at high [O 3]; no similar trend was found in the other growth and photosynthetic parameters, or in the oth Source


Kochi K.,Hokkaido University of Science | Kochi K.,Saitama University | Mishima Y.,Hokkaido University of Science | Nagasaka A.,Hokkaido Forestry Research Institute
Limnology | Year: 2010

In forested streams, surrounding riparian forests provide essential supplies of organic matter to aquatic ecosystems. We focused on two pathways of particulate organic matter inputs: direct input from upper riparian forests and indirect lateral input from bank slopes, for which there are limited quantitative data. We investigated the inputs of coarse particulate organic matter (CPOM) and carbon and nitrogen in the CPOM into the uppermost reaches of a headwater stream with steep bank slopes in Hokkaido, Japan. CPOM collected by litter traps was divided into categories (e. g., leaves, twigs) and weighed. Monthly nitrogen and carbon inputs were also estimated. The annual direct input of CPOM (ash-free dry mass) was 472 g m-2, a common value for temperate riparian forests. The annual lateral CPOM input was 353 g m-1 and 941 g m-2 when they were converted to area base. This value surpassed the direct input. Organic matter that we could not separate from inorganic sediments contributed to the total lateral input from the bank slopes (124 g m-1); this organic matter contained relatively high amounts of nitrogen and carbon. At uppermost stream reaches, the bank slope would be a key factor to understanding the carbon and nitrogen pathways from the surrounding terrestrial ecosystem to the aquatic ecosystem. © The Japanese Society of Limnology 2009. Source


Konno S.,Senshu University | Araya K.,Senshu University | Teramoto C.,Senshu University | Wakita Y.,Hokkaido Forestry Research Institute | And 3 more authors.
Engineering in Agriculture, Environment and Food | Year: 2010

In order to separate haskaop berry and leaf during harvest, a vertical separation column was envisaged. The air drag coefficients of berry and leaf were measured to determine the proper air velocity in the separation column. The results show that the air drag coefficient of a berry set horizontally in the air flow was 0.959-2.21, and that of a berry set vertically was 0.322-0.977. The air drag coefficient of the leaves was 0.622-2.36. The minimum terminal velocity of berries (horizontally, 9.1 ms -1 and vertically, 11.0 ms -1) was significantly different from the maximum terminal velocity of the leaves (2.35 ms -1). Therefore, it should be possible to separate the berries and leaves using the air velocity from trial experiments in the separation column. Source


Konno S.,Senshu University | Araya K.,Senshu University | Teramoto C.,Senshu University | Wakita Y.,Hokkaido Forestry Research Institute | And 3 more authors.
Engineering in Agriculture, Environment and Food | Year: 2011

In order to separate haskaop berries from other materials during harvest by vacuum suction, a vertical separation column was built where specific weight separation would take place. The results showed that the most suitable configuration of the separation column without damage to berries was one with an inlet pipe through the berry bin. This generated vertical air flow throughout the separation column. Thus, leaves were always suspended in the column. When berries entered the column, air velocity decreased, and berries fell into the berry bin. The required air velocity in the transportation pipe was more than 22 ms-1 to move the heaviest berries. The required air velocity in the separation column was more than 4 ms-1 where the heaviest leaves could remain aloft and be separated from the berries. Source


Johns R.C.,Natural Resources Canada | Johns R.C.,Japan Forestry and Forest Products Research Institute | Tobita H.,Japan Forestry and Forest Products Research Institute | Hara H.,Hokkaido Forestry Research Institute | Ozaki K.,Japan Forestry and Forest Products Research Institute
Ecological Research | Year: 2015

Few herbivores are well adapted to feeding on all foliage age classes available and most have evolved traits that are attuned to the characteristics of either developing or mature foliage; however, recent evidence has shown a number of insect herbivores that may mix different-aged foliage as a means of enhancing fitness. We carried out a series of laboratory and field experiments to investigate whether larvae of Asian gypsy moth [L. umbrosa (Butler) = L. dispar hokkaidoensis Goldschmidt] (Lepidoptera: Lymantriidae) engage in and benefit from foliage-age dietary mixing in common conifer species that naturally occur in its native range of Hokkaido, Japan. In a laboratory experiment, early instar larvae were observed on both developing and mature foliage when both age classes were available; however, larval survival and weight were highest on hosts with developing foliage available (larch, fir, and pine), whereas all larvae died on spruce where only mature foliage was available. In contrast, laboratory and field experiments indicated that late-instar larvae often consumed both developing and mature foliage on all conifer species studied, although there was general preference bias towards mature foliage. Field bioassays indicated that late-instar larvae provided both foliage age classes (a ‘mixed’ diet) had similar performance to those provided only developing or mature foliage. Results of this study indicate that larvae obtain limited performance benefits from mixing different foliage age-classes into their diet, other than perhaps the benefits accrued from having a broader resource pool available on a single host tree. © 2015, Her Majesty the Queen in Right of Canada as represented by: The Minister of Natural Resources. Source

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