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The effects of forest edges adjacent to open lands are well established. However, knowledge about the edges between two different forests, which represent relatively smaller changes in microclimatic conditions due to continuous canopy cover, is limited. Here, we investigated the activity-density of ground-dwelling invertebrates across the zone between conifer and hardwood forests. Most of the major invertebrate groups (Coleoptera, Formicidae, Prostigmata, Gamasida and Oribatida) were more active in the hardwood forests than in the conifer forests, and none of the groups revealed higher activity-densities in the conifer forests than in the hardwood forests. Especially, Formicidae and Prostigmata decreased their activity-densities from the forest edges towards the interior parts of the conifer stands. These suggest that many invertebrates leak from the hardwood to the conifer forests. We indicate that the responses of the major invertebrate groups to the distance from forest edges towards the interi...

This paper describes the synthesis of and mesomorphic property and gelation ability for 2-Alkoxy- 6-[4-(2-perfluorohexyl)ethylthiophenyl]naphthalene (compounds 1-n). Compounds 1-n show excl...

We used leaf-litter and bark-litter bags to examine the colonization patterns of microarthropods in arboreal and soil microhabitats of a Cryptomeria japonica plantation. The mass loss of leaf-litter was slower in the arboreal environment than in the soil environment. The variation in leaf-litter mass among litter bags increased markedly with increasing decomposition in the soil, and was smaller in the arboreal environment. The colonization processes of microarthropods differed between the arboreal and soil leaf-litter bags. In the arboreal bags, Collembola, Gamasida, and Prostigmata had a peak density in the summer of the second year after establishing the bags whereas Oribatida maintained relatively constant densities until 15 months. In the soil bags, Collembola colonized the litter first, and Gamasida and Prostigmata subsequently colonized the more decomposed litter. The vertical colonization patterns of the major microarthropods were consistent at all heights on the tree trunk. Slow decomposition in arboreal litter reflected severe conditions for most decomposers throughout the experimental study. In contrast, severe conditions of arboreal litter may lead to a relatively stable resource for limited microarthropods that have physiological tolerance for unfavorable conditions. Because of the traits of these fauna, the arboreal litter may thus be utilized seasonally by Collembola and Gamasida, but continuously by Oribatida. We suggest that soil microarthropods would be more affected by successional changes than by seasonal changes, because of faster decomposition of the litter, whereas arboreal microarthropods would be more affected by seasonal changes because of slow decomposition processes in the arboreal environment.

We compared the efficiency of washing versus the Tullgren method for extracting microarthropods from dead leaves and branches in the canopy of Cryptomeria japonica trees. Oribatida and Collembola were consistently the numerically dominant taxa of microarthropods, but the relative abundance differed between the two extraction methods. Oribatida accounted for more than 70% of all the microarthropods collected by the washing method but less than 30% by the Tullgren method. Collembola accounted for less than 10% collected by the washing method but about 60% by the Tullgren method. The density of Oribatida was higher when collected by the washing method than by the Tullgren method, and vice versa for the density of Collembola. Our results suggest that the washing method is appropriate for collecting Oribatida and other microarthropods, whereas the Tullgren method is better for collecting Collembola from the canopy litter of C. japonica trees.

The ultrasonic motor has nonlinearity characteristics, which varies with driving conditions associated with the variations of temperature and applied load torque of ultrasonic motor. The nonlinearity characteristics for actuators are problems in accurate position control. To improve the control performance of the ultrasonic motor, we apply two-control inputs H ∞ controller for position control of the ultrasonic motor. Applying an H ∞ methodology we derive a stabilizing controller to meet design objectives and robust stability and performance against such variations. The validity of the proposed method is confirmed by experimental results.

We assessed the vertical distribution of litter and its seasonal patterns in the canopy and on the forest floor (soil), as well as litterfall (the flux of litter from the canopy to the soil) in a 33-year-old plantation of Japanese cedar (Cryptomeria japonica D. Don). The masses of total litter, dead leaves, and dead branches in the canopy of C. japonica trees averaged 34.09, 19.53, and 14.56 t dry wt ha−1, respectively, and were almost constant during the study period. The total masses of the annual litterfall were 4.17 and 5.88 t dry wt ha−1 year−1 in the two consecutive years of the study. The mass of the soil litter averaged 7.95 t dry wt ha−1 during the same period. All relationships between the mass of canopy litter and tree-size parameters (diameters at breast height and at the lowest living branch) were linear in a log-linear regression. Compared with the results for this plantation at a younger stage (16 years old), our results suggest that the total mass of dead leaves attached to each tree increases markedly with increasing age, but that the trajectory of this increase as a function of tree size may change from an exponential to a saturation curve with increasing stand age.

The ultrasonic motor has nonlinear characteristics, which vary with driving conditions and possess variable dead-zone in the control input that is associated with the applied load torque. The dead-zone has a problem in accurate positioning actuator. To improve the control performance of the ultrasonic motor, the dead-zone nonlinearity should be eliminated. This article proposes a new position control scheme for the ultrasonic motors that eliminates the problem due to dead-zone by employing fuzzy neural network (FNN). To achieve the accurate position control when drive conditions vary, FNN can adjust the membership function for the antecedent part. The training of FNN is achieved using online backpropagation algorithm. The dead-zone is compensated by FNN, and PI controller performs the accurate positioning of the drive system. The validity of the proposed method is confirmed by experimental results.

In a Cryptomeria japonica plantation, we examined the composition and seasonal abundance of microarthropods in communities associated with “habitat substrates” in the canopy (defined as dead leaves, dead branches, and living leaves) and compared them with those in soil communities. Habitat substrates and microarthropods were periodically collected by the branch-clipping and washing method from the canopy and by the Tullgren method from the soil. Oribatida, Collembola, and larvae of the Chironomidae, most of which are detritivorous or fungivorous, were dominant in the canopy. The dominant oribatid and collembolan families differed markedly between the canopy and the soil. Numbers of all microarthropods per unit dry weight of leaf or per unit area of branch ranged from 4.2 to 11.7 g−1 dry wt on dead leaves, 0.13–0.48 cm−2 on dead branches, and 1.3–6.4 g−1 dry wt on living leaves. In the soil, the number of individuals per unit ground area ranged from 24 000 to 220 000 m−2. The total abundances of microarthropods on dead leaves and dead branches were almost constant throughout the year. These results suggest that the arboreal litter characteristic of C. japonica canopies is utilized consistently by large numbers of detritivorous and fungivorous microarthropods, and that the decomposition of dead foliage and branches is initiated in the canopy.