Haruo Sawada

Five-year study on the autumn food habits of the Asiatic black bear in relation to nut production

We studied the autumn food habits of the Asiatic black bear (Ursus thibetanus) from 1993 to 1997, based on 202 fecal samples in the Chichibu Mountains, central Japan. Nuts occupied the highest proportions of autumn foods (59.9–85.8% important values). Although the proportion of nuts of Quercus crispula, Fagus crenata and Fagus japonica varied greatly between the years, acorns of Q. crispula were most prevalent in four of the five years. We also determined the relative nut production of these three species by counting the number of nuts or cupules on the ground. Black bears consumed the nuts according to their relative availabilities. Nuts of Q. crispula appeared to be the most important food because: (i) these nuts were eaten in the highest proportion in four of the five study years; and (ii) even in poor years the bears consumed acorns of Q. crispula, whereas nuts of Fagus spp. were not consumed. We discuss the significance of alternative foods for black bears in relation to food tree diversity in the forest and the necessity for long-term studies examining the food habits of Asiatic black bears.

Full polarimetric PALSAR-based land cover monitoring in Cambodia for implementation of REDD policies

Abstract Forest cover monitoring plays an important role in the implementation of climate change mitigation policies such as Kyoto protocol and Reducing Emissions from Deforestation and Forest Degradation (REDD). In this study, we have monitored land cover using the PALSAR (Phased Array type L-band Synthetic Aperture Radar) full polarimetric data based on incoherent target decomposition. Supervised classification technique has been applied on Cloude–Pottier decomposition, Freeman–Durden three component, and Yamaguchi four component decomposition for accurate mapping of different types of land cover classes. Based on confusion matrix derived from the predicted and defined pixels, the evergreen and sparsely deciduous forests have shown high producers accuracy by Freeman–Durden three component and Yamaguchi four component classifications. The overall accuracy of Maximum Likelihood Classification by Yamaguchi four component is 94.1% with 0.93 kappa coefficient as compared to the 90.3% with 0.88 kappa coefficient by Freeman–Durden three component and 89.7% with 0.88 kappa coefficient by Cloude–Pottier decomposition. High accuracy of classification in a forested area using full polarimetric PALSAR data may have been because of high penetration of L-band SAR. The content of this study could be useful for the forest cover mapping during cloudy days needed for proper implementation of REDD policies in Cambodia.

Steep slopes promote downhill dispersal of Quercus crispula seeds and weaken the fine-scale genetic structure of seedling populations

The seed dispersal patterns and genetic structure of plant populations in mountainous forests may differ from those on flat sites, because some seeds that fall from adults are likely to roll downhill, and thus cause the seed shadows from different mother trees to merge. In the study reported here we used six polymorphic microsatellite markers to track seed dispersal and examine the fine-scale spatial genetic structure of adults and first-year seedlings of Quercus crispula in 2500 m2 plots on four slopes. In each of the four plots, leaves of adults, seedlings and endocarps of hypogeal cotyledons attached to the seedlings were genotyped to identify the seedlings’ mother trees. The results showed that steeper slopes result in larger dispersions and smaller genetic structure of seedlings. These findings are a crucial step towards an understanding of the effect of topography on tree regeneration.RésuméLes modes de dispersion des graines et la structure génétique des populations d’arbres peuvent être différents en forêts de montagne par rapport à ceux en forêts de plaine. En effet, les graines qui tombent des arbres adultes roulent probablement vers le bas de la pente entraînant un regroupement des descendances de différentes mères. Dans cette étude, nous avons suivi la dispersion des graines de Quercus crispula et nous avons examiné à l’aide de six marqueurs microsatellites polymorphiques la structure spatiale génétique des arbres adultes et de leurs descendants (semis de 1 an) sur des placeaux de 2500 m2 dans quatre pentes. Dans chacun des placeaux, les feuilles des arbres adultes et des semis ainsi que les endocarpes des cotylédons attachés aux semis ont été génotypés de manière à identifier les mères des semis. Les résultats montrent que les pentes fortes contribuent à une forte dispersion et à une faible structuration génétique des semis. Ces résultats sont une étape importante pour la compréhension des effets de la topographie sur la régénération des arbres.

PALSAR 50 m Mosaic Data Based National Level Biomass Estimation in Cambodia for Implementation of REDD+ Mechanism

Tropical countries like Cambodia require information about forest biomass for successful implementation of climate change mitigation mechanism related to Reducing Emissions from Deforestation and forest Degradation (REDD+). This study investigated the potential of Phased Array-type L-band Synthetic Aperture Radar Fine Beam Dual (PALSAR FBD) 50 m mosaic data to estimate Above Ground Biomass (AGB) in Cambodia. AGB was estimated using a bottom-up approach based on field measured biomass and backscattering (σo) properties of PALSAR data. The relationship between the PALSAR σo HV and HH/HV with field measured biomass was strong with R2 = 0.67 and 0.56, respectively. PALSAR estimated AGB show good results in deciduous forests because of less saturation as compared to dense evergreen forests. The validation results showed a high coefficient of determination R2 = 0.61 with RMSE  = 21 Mg/ha using values up to 200 Mg/ha biomass. There were some uncertainties because of the uncertainty in the field based measurement and saturation of PALSAR data. AGB map of Cambodian forests could be useful for the implementation of forest management practices for REDD+ assessment and policies implementation at the national level.

Characterization of forests and deforestation in Cambodia using ALOS/PALSAR observation

In this study, we have demonstrated the capability of full polarimetric ALOS/Phased Array L-band Synthetic Aperture Radar data for the characterization of the forests and deforestation in Cambodia, to support climate change mitigation policies of Reducing Emission from Deforestation and Forest Degradation (REDD). We have observed mean backscattering coefficient (σ°), entropy (H), alpha angle (α), anisotropy (A), pedestal height (PH), Radar Vegetation Index (RVI) and Freeman–Durden three-component decomposition parameters. The observations show that the forest types and deforested area are showing variable polarimetric and backscattering properties because of the structural difference. Evergreen forest is characterized by a high value of σ° HV (−12.96 dB) as compared with the deforested area (σ° HV=−22.2 dB). The value of polarimetric parameters such as entropy (0.93), RVI (0.91), PH (0.41) and Freeman–Durden volume scattering (0.43) is high for evergreen forest, whereas deforested area is characterized by the low values of entropy (0.36) and RVI (0.17). Based on these parameters, it is found that σ° HV, entropy, RVI and PH provide best results among other parameters.

Genetic Diversity and Gene Flow of Quercus crispula in a Semi-Fragmented Forest Together With Neighboring Forests

Abstract The genetic diversity and differentiation in Quercus crispula populations in the Chichibu Mountains, central Japan, were evaluated using six microsatellite markers. Gene flow into a 2500-m2 semi-fragment of a natural forest from the neighboring natural forest at a distance of more than 50m was also evaluated using parentage analysis. All five populations in the mountains had similar levels of genetic diversity (He = 0.752-0.792), and the level of population differentiation was low (FST = 0.016). The semi-fragmented stand showed similar genetic diversity with the neighboring unfragmented forests, and Hardy-Weinberg disequilibrium was not found (FIS = 0.083 in adults, 0.025 in seedlings). In the semifragment, 70 seedlings were examined; according to the parentage analysis, eight of the 70 seedlings (ca. 11%) had neither of the parent trees in this fragment. These seeds must have been transported from a distance of more than 50 m; therefore, there could be a possibility that the seeds were dispersed by birds. A similar trend of seed flow into the fragment was also confirmed by genotyping endocarps of hypogeal cotyledons, while more frequent seed flow was found in the neighboring unfragmented forest. Of the remaining 62 seedlings, the maternal trees (but not the paternal trees) of 29 seedlings and both parent trees of 33 seedlings were detected in the semi-fragment. These results indicate that the gene flow among the populations occurs frequently via pollen dispersal and occasionally via seed dispersal and that, at least the current levels of genetic diversity have been maintained in such fragmented forests.

Natural forest biomass estimation based on plantation information using PALSAR data.

Forests play a vital role in terrestrial carbon cycling; therefore, monitoring forest biomass at local to global scales has become a challenging issue in the context of climate change. In this study, we investigated the backscattering properties of Advanced Land Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) data in cashew and rubber plantation areas of Cambodia. The PALSAR backscattering coefficient (σ0) had different responses in the two plantation types because of differences in biophysical parameters. The PALSAR σ0 showed a higher correlation with field-based measurements and lower saturation in cashew plants compared with rubber plants. Multiple linear regression (MLR) models based on field-based biomass of cashew (C-MLR) and rubber (R-MLR) plants with PALSAR σ0 were created. These MLR models were used to estimate natural forest biomass in Cambodia. The cashew plant-based MLR model (C-MLR) produced better results than the rubber plant-based MLR model (R-MLR). The C-MLR-estimated natural forest biomass was validated using forest inventory data for natural forests in Cambodia. The validation results showed a strong correlation (R2 = 0.64) between C-MLR-estimated natural forest biomass and field-based biomass, with RMSE  = 23.2 Mg/ha in deciduous forests. In high-biomass regions, such as dense evergreen forests, this model had a weaker correlation because of the high biomass and the multiple-story tree structure of evergreen forests, which caused saturation of the PALSAR signal.

Structures of the high-temperature forms of the barite-type compounds. I:α-BaSO4

The crystal structure of the high-temperature α-phase of BaS04 has been studied based on a set of single-crystal X-ray intensities collected at 1215°C [cubic, F?3m, a0 = 7.415(3) A , Z = 4, = 3.77 gem ]. The results have confirmed the previously proposed structure. The S0 4 tetrahedra possess a non-centrosymmetric arrangement.

Overview of Japan's spaceborne vegetation lidar mission

Vegetation LIDAR, which measures an accurate canopy height, has been studied by JAXA. Canopy height is a very important parameter to estimate forest biomass, and global measurement of accurate canopy height leads to better understanding of the global carbon cycle. The vegetation LiDAR is designed based on the assumption that it is to be mounted on the Exposed Facility (EF) of the Japanese Experiment Module (JEM, also known as “Kibo”) on the International Space Station (ISS). The vegetation LIDAR uses an array detector (2x2) for dividing the ground footprint, making it possible to detect the slope of the ground for improving the accuracy of canopy height measurement. However, dividing the footprint may cause a reduction in reflected lights and signal-to-noise ratio (SNR); hence, the vegetation LiDAR system needs high sensitivity and low-noise array detector module. We made a prototype of the array detector module and it satisfied the tentative target SNR which we set. This presentation will introduce the mission objectives, the LiDAR system including experimental prototypes of array detector module, and some results of the study.

Role of remote sensing and community forestry to manage forests for the effective implementation of REDD+ mechanism: a case study on Cambodia

In this study, we have shown the importance of remote sensing applications and community forestry for forest management, discussed as a case study on Cambodian forest management. Curbing deforestation is necessary for the effective implementation of Reducing Emissions from Deforestation and forests Degradation (REDD+) mechanism and management of forest resources to support sustainable forest management plans. The updated information of the forest cover and forest biomass using advanced remote sensing techniques can be useful for selecting the suitable sites for planned thinning, reforestation, community forestry, and concession land, which eventually will help in controlling the deforestation in Cambodia. To overcome the limitations of remote sensing, an integrated approach of remote sensing and community forestry to monitor forests from local to national level has also been discussed.