Sites In Hokkaido Research Articles

Microplastics in snow from protected areas in Hokkaido, the northern island of Japan

Snowfall is regarded as a carrier of airborne microplastics (MPs). Deposited snow can function as a temporary reservoir for atmospheric MPs. Nevertheless, knowledge and understanding of MPs in snow remain sparse. This study investigates the abundance, composition, size (> 30 µm), and shape of MPs in snow specimens from various nature preservation areas and also from urban sites in Hokkaido. Various polymeric-type MPs with mostly fragmentary shapes were detected among the specimens. More than half of MPs were in the smallest size class (30–60 µm), implying the presence of more MPs below the limit (< 30 µm). Concentrations of MPs ranged from 1.5 × 102 to 4.2 × 103 particles/L. The results demonstrated that microplastic abundance generally decreases concomitantly with increasing remoteness of sampling sites. Observed features of MPs at different locations and their relation to geographical settings have indicated that the ubiquitously observed fine particles (mainly alkyd, ethylene–vinyl acetate, and polyethylene) are attributable to long-distance atmospheric transportation, whereas the rubber and larger particles especially found near highways and cities are from local sources of plastic. Taken together, these findings suggest important implications for elucidating the nature and distribution of atmospheric MPs.

Modeling forest above-ground biomass using freely available satellite and multisource datasets

Achieving the 2 °C global warming target will require all stakeholders, from local to global, to accelerate carbon reduction plans. To properly estimate carbon amounts sequestered and stored by forests, these stakeholders need accurate maps of forest above-ground biomass (AGB). However, AGB maps are developed solely by researchers using methodologies that are typically difficult for non-researchers to understand. To ensure that non-researchers can prepare such maps, freely available open-source datasets are needed along with a simple AGB estimation method. Remote sensing data have become widely used, and some satellite images are provided as open-source data. However, few AGB estimation studies have relied exclusively on freely available datasets. This study, therefore, examined the capability of using open-source satellite and multisource datasets to estimate AGB for two contrasting test sites in Hokkaido, Japan, and for the two sites combined (the unified sites). Test site 1 contained three forest types on a hilly terrain, while test site 2 contained one dominant forest type on a flat terrain. The datasets used were L-band backscatter, a canopy height model, slope, aspect, annual mean temperature, annual precipitation, and forest type. Three machine-learning algorithms and one parametric algorithm were compared. The results showed that the machine-learning models outperformed the parametric model in all instances, reproducing low and high AGB values properly with reduced saturation issues. A variable importance analysis revealed that in the best-performing machine-learning models, forest type and annual precipitation were the two most important variables for test site 1 and the unified sites, and another climatic factor, annual mean temperature, rose in rank for the unified sites. These variables had relatively large intra-variability and inter-variability in common, both of which appear to have offered advantages in modeling AGB for the sites where AGB variability was large. In contrast, the synthetic aperture radar (SAR)-based variables (the backscatter and the canopy height model) ranked lower in relative importance. This may reflect the negative influence of hilly terrain of test site 1 (and the unified sites) on the precision of SAR-based datasets. For test site 2, with its flat terrain, these SAR-based variables were the two dominant variables. Our results show the promise of freely available satellite and multisource datasets for modeling AGB and the important roles that non-SAR-based variables may play in large-scale AGB mapping that includes varied terrain.

Integrative approach clarifies the distinct taxonomic account of gryloblattids endemic to Hokkaido, Japan, with a description of two new species (Insecta, Grylloblattodea)

Galloisiana yezoensis Asahina, 1961 was described on the basis of female specimens from the Ishikari Mountains, Hokkaido, Japan, and has been known as the only species of Grylloblattidae in Hokkaido. In preliminary research, several species closely related to G. yezoensis were collected from various sites in Hokkaido. In the present study, the taxonomic status of G. yezoensis and its relatives was reexamined through molecular and morphological analyses approaches. As a result, the phylogenetic tree of the COII region, and mitochondrial DNA, suggest that G. yezoensis and its relatives form a unique clade distinct from the Galloisiana clade. We therefore establish a new genus, Arctigalloisianagen. nov., with two new species, A. poropnetopasp. nov. and A. yubariensissp. nov. The type species is Arctigalloisiana yezoensiscomb. nov., and its male is described here for the first time.

Region-specific linear site amplification model for peaty organic soil sites in Hokkaido, Japan

We develop a site amplification model for a regional geologic condition that includes surficial deposits of peaty organic soils in Hokkaido, Japan. We use ground motion data from national Japanese networks along with local data from the study region. We apply a non-reference site approach to infer site effects from misfits of reference ground motion models to data from 10 subduction zone earthquakes. Application of this approach requires removal of source-specific biases and careful consideration of source-to-site path effects. These considerations are essential to avoid mapping source- or path-related model misfits into estimates of site response. We consider three subduction ground motion models as reference models. By paying special attention to the conditions for which the path models are effective, and making adjustments for between-island path misfits (Hokkaido to Honshu and vice versa), we identify regional site effects that are insensitive to the ground motion models used in their derivation. Observed site responses are characterized by strong resonances at first-mode site frequencies, and as a result the regional model is conditioned on peak frequency from horizontal-to-vertical spectral ratios.

Phylogeographic analysis of Ligidium japonicum (Isopoda: Ligiidae) and its allied species reveals high biodiversity and genetic differentiation in the Kanto region, Japan

AbstractResearch of the diversity and evolutionary history of Japanese soil invertebrates is scarce. Molecular data analysis can help to elucidate species classifications and evolutionary processes. We analyzed the mitochondrial cytochrome oxidase subunit I (COI) and nuclear 28S rDNA genes and the morphology of the male pleopod 2 endopod of Ligidium japonicum and its allied species from 67 sites in Hokkaido, Honshu and Shikoku, where only L. japonicum is thought to occur. We found males of the L. japonicum complex with a pleopod 2 endopod morphology matching that of the L. japonicum syntype specimens, except for the number of denticles at the inner margin. There were also more than five species that differed morphologically from the L. japonicum complex, and most of these species had allopatric distributions despite the absence of obvious barriers. A time‐calibrated molecular phylogeny implied that the L. japonicum complex of the Kanto region first differentiated allopatrically in the mountains; this was followed by independent dispersal of three lineages to the Kanto Plain and Boso Peninsula, where secondary contact occurred. Two of the three sympatrically distributed L. japonicum complex lineages had a significant difference in the number of denticles at the inner margin of male pleopod 2 endopods. This variation implies the presence of cryptic species within the L. japonicum complex.

Response of an Indicator Species, Dryopteris crassirhizoma, to Temporal and Spatial Variations in Sika Deer Density.

Simple SummaryDeer can affect forest ecosystems through foraging behavior. Using indicator species that are sensitive to temporal and spatial variations in deer density has the advantage of managing deer effectively and practically. We examined the response of Dryopteris crassirhizoma to the variations in sika deer density in Hokkaido, Japan. We showed that the grazing intensity of D. crassirhizoma was sensitive to short-term decreases in deer density and positively related to spatial variation in deer density within regions. Dryopteris crassirhizoma can be a useful indicator species and using grazing intensity could help managers rapidly determine their management direction and decide where to focus their efforts.Identifying appropriate indicator species for the impact of deer on forest vegetation is crucial for forest management in deer habitats and is required to be sensitive to temporal and spatial variations in deer density. Dryopteris crassirhizoma was selected as a new indicator to evaluate the response to these variations. We examined the population-level characteristics, morphological characteristics at the individual level, and grazing intensity of D. crassirhizoma at temporally different deer density sites in Hokkaido, Japan. The response of D. crassirhizoma to spatial variation in deer density was also examined within and between two regions in Hokkaido, Japan. Although the population-level characteristics and morphological characteristics did not significantly respond to short-term decreases in deer density, grazing intensity significantly decreased with decreasing deer density. The grazing intensity was also positively related to the spatial variation of deer density within both regions, but the estimated coefficient of the grazing intensity differed between regions. We concluded that D. crassirhizoma can be a useful indicator species of the impact of deer on forest vegetation. The grazing intensity of the indicator species was sensitive to temporal and spatial variations in deer density within the region.

Le Paléolithique supérieur dans l’île d’Hokkaïdo

Since the discovery of the first Paleolithic site in Hokkaido, we consider that the time in the half more than centuries already passed, and float today. However, our research is still a way. By today, we have not discovered the trace about a Pithecantropines (Homo erectus) and a Paleanthropic man (Homo sapiens neanderthalensis) at all in this region. We know that a Neanthropic man (Homo sapiens sapiens) dominated all the continents except Antarctica in the final time of the Pleistocene era. And they passed along the dried shoal which appeared to the north in the same time from the Asian Continent to the Island of Hokkaido, and reached it to this place. The first attainment time is an age which exceeds 20,000-years before a little from the present. We are not checking a fact which exceeds it you to be much. However, the habitants of these beginnings left the trace of the activity of them in large numbers, so that he was wonderful to inside of this island. The studies-of-prehistory research in Hokkaido has little proof of the natural science field concerned on age determination or chronology. This has serious restriction. However, the tephra-chronology of volcanic ashes has played the big role uniquely. The eruption of the Eniwa volcano of the Hokkaido central part is especially a very important index. This volcano blows off ash fall (En-a) in large quantities, and covered all large ranges. This deposited volcanic-ashes layer plays a big role to discernment of an old industry and a recent industry on the cultural chronology. The obsidian from this island and nearby hard shale was used for many industries of this Upper Paleolithic cultures as main materials. Although obsidians in the island where the different four outcrops are known well. This rock was mined in large quantities, and was carried in various places. As well as many examples in the world, we divided this rock, and the human beings of the prehistoric age were demanded for it, and it was often utilized. In it, especially the outcrop of Shirataki was located in the northern part of Hokkaido, and was very important. Large quantities of obsidian from Shirataki outcrop is discovered in a large number of Paleolithic sites within a segment 700km in diameter at least. It covered the territory in Hokkaido and circulated further also except this island. This fact circulated as important trade materials on stone-tool fabrication among the human-beings groups from whom this island's every place differed. In this time, human beings’ activity in Hokkaido is a clear proof, which was not isolated at all. As for the studies of the prehistorians of Hokkaido distinguish, the exception put the technical process of eight different microblade productions. The technical process of some of them was limited only to the specific narrow area. Or it is proved that other technical processes are widely connected with the human-beings group of the Asian Continent on the contrary. At present, our research grasps the whole second-half Paleolithic culture, and has not yet established the year system edited by locally complete. The oldest industry of this area composed the typical stone tool of second-half Paleolithic culture from the beginning, and was accompanied by the manufacturing technique of a braid and microblade. The feature is the example in which the ruins of Kashiwadai-I were most excellent. These ruins correspond at time older than deposition of the Eniwa volcano tephra. It is located at the chill time in the second half of a Würm glacial period. The second continuing step is an industry of succession newer than this volcano tephra. It is raised as an example with Ôsatsu-16 typical ruins etc. The third phase is an industry of the end term of second-half Paleolithic culture. It is simultaneously located in the dawn of Jōmon culture. The feature of this cultural aspect is a transitional cultural stage which earthenware appears and is called what is called “Sub-Neolithic-Culture”. We can check having passed expansively, while the aspect of this last continues within a short period of time relatively.

Updated distribution of anopheline mosquitoes in Hokkaido, Japan, and the first evidence of Anopheles belenrae in Japan

BackgroundIn Hokkaido, northern island of Japan, at least seven cases of falciparum malaria were reported by 1951. A survey conducted at that time was unsuccessful in implicating any mosquito species as the possible vector. Although active anopheline mosquito surveillance continued until the middle of the 1980s, there is very limited information on their current status and distribution in Japan. Therefore, this study is an update on the current status and distribution of anopheline mosquitoes in Hokkaido based on a 15-year entomological surveillance between 2001 and 2015.MethodsA survey of mosquitoes was conducted at 22 sites in Hokkaido, Japan, from 2001 to 2015. Adult mosquitoes were collected from cowsheds, lakesides, shrubs, and habitats ranging from open grassland to coniferous forest using a Centers for Disease Control and Prevention (CDC) miniature light trap enhanced with dry ice, aspirators, and sweeping nets. Larvae were collected from lakes, ponds, swamps, stagnant and flowing rivers, and paddy fields. All specimens were morphologically identified and subjected to polymerase chain reaction (PCR)-based sequence analysis of the internal transcribed spacer 2 ( ITS2) region of rDNA. Phylogenetic trees were reconstructed using the neighbor-joining method with the Kimura 2-parameter model on MEGA X version 10.2.2.ResultsA total of 46 anopheline specimens were used for the phylogenetic analysis. During the survey, a new member of the Anopheles hyrcanus group, An. belenrae, was discovered in eastern Hokkaido in 2004. Anopheles belenrae has since then been consistently found and confirmed to inhabit only this area of Japan. Four members of the An. hyrcanus group, namely An. belenrae, An. engarensis, An. lesteri, and An. sineroides, have been found in Hokkaido. The results also suggest that An. sinensis, formerly a dominant species throughout Japan, has become a rarely found species, at least currently in Hokkaido.ConclusionThe updated distribution of anopheline mosquitoes in Hokkaido, Japan, showed considerable differences from that observed in previous surveys conducted from 1969 to 1984. In particular, areas where An. sinensis was previously distributed may have been greatly reduced in Hokkaido. The phylogenetic analysis revealed a novel An. hyrcanus group member identified as An. belenrae, described in South Korea in 2005. It is interesting that An. belenrae was confirmed to inhabit only eastern Hokkaido, Japan.Graphical abstract

Differences in Rhinoceros Auklet diet and chick body mass at 4 breeding sites in Hokkaido

北海道周辺の異なる海洋環境に位置する4つのウトウCerorhinca monocerata繁殖地において，2016–2017年に雛に持ち帰った餌と雛の体重（成長段階で補正）を調べた．松前小島，天売島，トド島の3繁殖地はそれぞれ対馬暖流の南部，中北部，北部に位置しており，トド島はオホーツク海の東樺太海流に由来する冷水塊にも近い．また，大黒島は沿岸親潮および親潮が流入する太平洋側に位置する．主な餌種は繁殖地間で異なっており，天売島およびトド島ではホッケPleurogrammus azonus 0歳，松前小島ではスケトウダラGadus chalcogrammus 0歳，大黒島ではサケOncorhynchus keta 0歳だった．加えて，イカナゴ属Ammmodytes spp. 0歳もしくは1歳以上はすべての繁殖地である程度利用されていた．エネルギー密度が高いホッケ0歳をよく持ち帰ったトド島では，1給餌あたりの餌重量も大きく，結果として雛の成長段階補正体重も重かった．海水温の違いがトド島と天売島におけるホッケの利用割合の違いや，大黒島内におけるサケ0歳の利用割合の年変化を説明するかもしれない．また，サケ稚魚ふ化放流事業に由来した餌資源量の地域差も，繁殖地間のサケ0歳の利用割合を説明するかもしれない．さらに，イカナゴ属は，北海道周辺の沿岸に広く分布するのでいずれの繁殖地でも一定割合利用されたのかもしれない．本研究は，海流による海水温の差や人為的影響が餌資源量の海域間差をもたらし，それが各地域で繁殖するウトウの餌ひいては雛の体重に影響していることを示唆する．

The Last Glacial Maximum Microblades from Kashiwadai 1 in Hokkaido, Japan

ABSTRACT Although microliths are regarded as small standardized tools for complex composite technology, it is still not fully understood whether this schematic understanding developed in Old World prehistory can apply to the Late Pleistocene microblades in northeastern Asia. Here, referring to the definition of the Old World microliths, we explore the morphometric traits of the Late Pleistocene microblades in northeast Asia through an examination of the laminar blank production technology from the Last Glacial Maximum (LGM) microblade assemblage recovered from the Kashiwadai 1 site in Hokkaido, northern Japan. Metric and nonmetric data obtained from numerous laminar blanks reveal that microblades are comparable to bladelets without backing, as defined in the Old World records. The core reduction sequence reconstructed from the refitted specimen reveals that microblades are produced from blade core gradually reduced by careful core preparations, best labeled as the integrated laminar technology conceptually related to post-LGM bifacial microblade core technologies.

Palaeoproteomic identification of breast milk protein residues from the archaeological skeletal remains of a neonatal dog

Accurate postmortem estimation of breastfeeding status for archaeological or forensic neonatal remains is difficult. Confident identification of milk-specific proteins associated with these remains would provide direct evidence of breast milk consumption. We used liquid chromatography coupled to tandem mass spectrometry (MS) to confidently identify beta-lactoglobulin-1 (LGB1) and whey acidic protein (WAP), major whey proteins associated with a neonatal dog (Canis lupus familiaris) skeleton (430–960 cal AD), from an archaeological site in Hokkaido, Japan. The age at death of the individual was estimated to be approximately two weeks after birth. Protein residues extracted from rib and vertebra fragments were analyzed and identified by matching tandem MS spectra against the dog reference proteome. A total of 200 dog protein groups were detected and at least one peptide from canine LGB1 and two peptides from canine WAP were confidently identified. These milk proteins most probably originated from the mother’s breast milk, ingested by the neonate just before it died. We suggest the milk diffused outside the digestive apparatus during decomposition, and, by being absorbed into the bones, it partially preserved. The result of this study suggests that proteomic analysis can be used for postmortem reconstruction of the breastfeeding status at the time of death of neonatal mammalian, by analyzing their skeletal archaeological remains. This method is also applicable to forensic and wildlife studies.

Long-term marine resource use in Hokkaido, Northern Japan: new insights into sea mammal hunting and fishing

ABSTRACTBased on examinations of archaeofaunal remains from 153 components from 122 sites in Hokkaido, Northern Japan, this study highlights that northern fur seals were the most important game for sea mammal hunting from the early Early Jomon (7000 calBP) and proposes a hypothesis that offshore hunting technology for hunting adult fur seals was established prior to the late Early Jomon (5800 calBP). This study also reveals that the importance of fishing for subsistence rapidly increased during the very end of the Final Jomon (2600 calBP) and the Early Epi-Jomon (2400 calBP–1800 calBP). Fishing focusing on bastard halibut and swordfish was actively conducted for status-building by Early Epi-Jomon fishers in some areas. Mortuary analyses indicate that ritual leaders were not necessarily capable fishers and/or hunters in the Jomon communities. However, during the Early Epi-Jomon, only successful fishers and/or hunters had the power to control rituals and the long-distance trade.

Comparison of the intestinal helminth community of the large Japanese field mouse (Apodemus speciosus) between urban, rural, and natural sites in Hokkaido, Japan

Anthropogenic ecosystem modification has affected over 80% of the global land cover. Interest in its effects on wildlife has been growing over the past several decades, specifically in regard to biodiversity and ecosystem function. Parasites are of particular interest, because they directly impact animal health, and can be transmitted to humans through the process of zoonosis. However, most studies so far tended to focus on only one or two parasites with few looking at the entire community, thereby limiting our understanding of the effects of ecosystem modification on parasitic organisms. In this study, we estimated the intestinal helminth diversity and species richness of the large Japanese field mouse (Apodemus speciosus), as well as the prevalence and abundance of each species in two modified ecosystems, a rural agricultural area and an urban park. We then compared them to a natural area to see how they have been altered. We found that diversity, prevalence, and abundance were all highly altered within both modified ecosystems, but generally to a greater degree within the urban park. However, there was great variation in the direction and degree of response of each helminth species, suggesting that generalized trends may be difficult to ascertain. Furthermore, it is important to analyze the entire helminth community, because interspecific interactions and the effect that ecosystem modification has on them may help determine what species persist.

Late Jomon male and female genome sequences from the Funadomari site in Hokkaido, Japan

The Funadomari Jomon people were hunter-gatherers living on Rebun Island, Hokkaido, Japan c. 3500–3800 years ago. In this study, we determined the high-depth and low-depth nuclear genome sequences from a Funadomari Jomon female (F23) and male (F5), respectively. We genotyped the nuclear DNA of F23 and determined the human leukocyte antigen (HLA) class-I genotypes and the phenotypic traits. Moreover, a pathogenic mutation in the CPT1A gene was identified in both F23 and F5. The mutation provides metabolic advantages for consumption of a high-fat diet, and its allele frequency is more than 70% in Arctic populations, but is absent elsewhere. This variant may be related to the lifestyle of the Funadomari Jomon people, who fished and hunted land and marine animals. We observed high homozygosity by descent (HBD) in F23, but HBD tracts longer than 10 cM were very limited, suggesting that the population size of Northern Jomon populations were small. Our analysis suggested that population size of the Jomon people started to decrease c. 50000 years ago. The phylogenetic relationship among F23, modern/ancient Eurasians, and Native Americans showed a deep divergence of F23 in East Eurasia, probably before the split of the ancestor of Native Americans from East Eurasians, but after the split of 40000-year-old Tianyuan, indicating that the Northern Jomon people were genetically isolated from continental East Eurasians for a long period. Intriguingly, we found that modern Japanese as well as Ulchi, Korean, aboriginal Taiwanese, and Philippine populations were genetically closer to F23 than to Han Chinese. Moreover, the Y chromosome of F5 belonged to haplogroup D1b2b, which is rare in modern Japanese populations. These findings provided insights into the history and reconstructions of the ancient human population structures in East Eurasia, and the F23 genome data can be considered as the Jomon Reference Genome for future studies.

ラムサール条約登録湿地「濤沸湖」の維管束植物相

ラムサール条約登録湿地「濤沸湖」の維管束植物相

Discovery of the Jomon era maize weevils in Hokkaido, Japan and its mean

Recent research on plant and insect impressions on Jomon-period pottery strongly suggests not only the presence of household pests such as the maize weevil (Sitophilus zeamais), but also the existence of storage facilities for acorns and nuts inside pit houses. The presence of insect pests provides indirect evidence for human-mediated crop propagation on a large scale. The evidence also suggests the possibility of introduction of maize weevils into north-eastern Japan by the Jomon people via the transportation of infested foodstuffs. However, this ‘diffusion by man’ hypothesis has remained unproven because it is possible that these insect pests and their preferred foods originated locally. Aiming to resolve this issue, we examined pottery vessels discovered at a Jomon site in Hokkaido that contain the remains of adult maize weevils. The geographical and temporal distribution of these vessels suggests a possibility of the human-mediated diffusion of maize weevils and chestnut cultivation across oceanic barriers by the Jomon people. Ultimately, we could not prove this hypothesis because of lack of entomological evidence, but we could prove that colonization of the cultivated plants had played a role in the spread of stored food pests. A lot of discoveries of the maize weevil by further impression survey will be expected as a clue to trace the relationship history between people, cultivated plant and pest insects.

Inelastic soil amplification in three sites during the Tokachi-oki MJMA 8.0 earthquake

Earthquake case histories of soil response in the last half century have revealed the nonlinear behavior of soils under strong shaking. Over the years numerous efforts have been made to represent realistically soil behavior in the nonlinear range. In the aftermath of an international benchmark exercise (PRENOLIN) aimed at verifying 23 nonlinear codes and then validating them against the recorded seismic responses of two soil sites, this paper investigates the response of 3 soil sites in Hokkaido, Japan, shaken by the Tokachi-oki 2003 earthquake. Surface and deep (“in-borehole”) accelerographs recorded the event at each site. The objective of our study is to see if available nonlinear codes, without any after-the-event calibration and with imperfect knowledge of the soil layer properties, can lead to practically acceptable results. Before embarking into the nonlinear analyses, the linear response to an aftershock is first simulated with reasonable success. Then, using three different nonlinear 1D soil-amplification codes, which incorporate different constitutive relations, numerical wave propagation analyses are performed for each site, excited with the motion recorded in each borehole (at the depth of the presumed bedrock). Computed results in the form of acceleration time histories and response spectra for the ground surface are systematically compared with the respective recorded motions. It is found that the numerical codes perform generally quite satisfactorily. Exceptions are discussed in the light of the other research findings.

北海道におけるアメリカ・カナダ産ストローブマツの適応性〜江別市に設定した３５年生産地試験地の結果〜

北海道におけるアメリカ・カナダ産ストローブマツの適応性〜江別市に設定した３５年生産地試験地の結果〜

Environmental factors determining the distribution of highland plants at low‐altitude algific talus sites

AbstractAlgific talus is a micro‐scale habitat type where highland plants (subalpine and alpine species) are found, disjunct from their typical range, in lowland forests. On algific talus, cold airflows from the interstices between talus fragments create a local microclimate colder than surrounding forests. Despite of the widely‐known occurrence of unique vegetation on algific talus, critical environmental factors determining the distribution of highland species in this habitat type are unclear. In order to reveal the environmental factors enabling highland species to inhabit algific talus, we investigated the vegetation and environments of 26 algific talus sites and four reference (non‐algific talus) sites in Hokkaido, northern Japan. Several algific talus sites were dominated by highland species, while some algific talus sites and all non‐algific talus sites were dominated by lowland species. Community analysis based on detrended correspondence analysis (DCA) and canonical corresponding analysis (CCA) revealed that the algific talus sites dominated by highland species had lower ground temperature, more acidic soil, larger canopy openness, and less diverse vegetation than the sites dominated by lowland species. Highland plants might be maintained under conditions stressful for lowland plants, resulting in less competitive situation. Generalized linear models (GLM), used to evaluate the response of individual highland species to environmental factors, revealed that preferable environmental conditions for highland plants are highly species specific. These results indicate that the maintenance of diverse environments is crucial for the conservation of the unique vegetation and local populations of highland species in algific talus areas.

The growth until 5 years old of the hybrid larch progeny “Clean Larch” in 4 planting test sites in Hokkaido

The growth until 5 years old of the hybrid larch progeny “Clean Larch” in 4 planting test sites in Hokkaido