Assessing the Potential of Multi-spectral and Multi-temporal Satellite Images for Classification and Mapping of Plant Communities in a Temperate Region

Classification and mapping of plant communities is an essential step for conservation and management of ecosystems and biodiversity. We adopt the Genus-Physiognomy-Ecosystem (GPE) system developed in previous study for satellite-based classification of plant communities. This paper assesses the potential of multi-spectral and multi-temporal images collected by Sentinel-2 satellites. This research was conducted in five representative study sites in a temperate region. It consists of 44 types of plant communities including a few land cover types as well. The plant community types were enumerated in the study sites and ground truth data were prepared with reference to extant vegetation surveys, visual interpretation of high-resolution images, and onsite field observations. We acquired all Sentinel-2 Level-1C product images available for the study sites between 2017-2019 and generated monthly median composite images consisting of ten spectral and twelve spectral-indices. Gradient Boosting Decision Trees (GBDT) classifier was employed as an efficient and distributed gradient boosting technique for the supervised classification of big datasets involved in the research. The cross-validation accuracy in terms of kappa coefficient varied from 87% in Oze site with 41 land cover and plant community types to 95% in Hakkoda site with 19 land cover and plant community types; with average performance of 91% across all sites. In addition, the resulting maps demonstrated a clear distribution of plant community types involved in all sites, highlighting the potential of Sentinel-2 multi-spectral and multi-temporal images with GPE classification system for operational and broad-scale mapping of land cover and plant communities.

CONTRIBUTION OF THE GENETIC IMPROVEMENT OF TALL FESCUE (Festuca arundinacea SCHREB.) IN ARGENTINA: SYNTHESIS OF ACHIEVEMENTS AND ADVANCES

Tall fescue (Festuca arundinacea Schreb.) is represented in Argentina by adapted populations of the continental morphotype, which are long persistent. It is the main perennial forage species cultivated in the temperate region of the country, producing forage for extensive grazing. The development of fescue plant breeding and its contribution to the achievement of higher productivity and better nutritional value with modern synthetic cultivars was the aim of this project. The characters considered were: adaptation and persistence in adverse environments, digestibility, leaf softness and tolerance to rust. The most representative cultivars of the stages and selection criteria considered in this work were: Pergamino El Palenque MAG, Palenque Plus INTA, Brava INTA, Baguala and Luján INTA. Key words: tall fescue, plant breeding, cultivars, germplasm.

Searching for a sign of exotic Aedes albopictus (Culicidae) introduction in major international seaports on Kyushu Island, Japan

Background The Asian tiger mosquito, Aedes albopictus, has spread around the world. The migration was mainly mediated by maritime transportations. This species is known as an efficient vector for arboviruses, and it was responsible for the recent dengue outbreak in Tokyo, Japan. As the vector competence varies among geographical populations, and insecticide resistant populations have emerged, it is important to reveal their movements. The present study uses molecular techniques to search for a sign of introduction of an exotic population in three major international seaports on Kyushu Island. Methodology/principal findings Adults of Ae. albopictus were sampled around the international seaports of Fukuoka, Kitakyushu, and Nagasaki. Pairwise fixation indexes were estimated between the sampled populations based on 13 microsatellite markers. There was no clear genetic differentiation between distant and port populations in Kitakyushu and Nagasaki. However, the analysis found one distinct group near the container terminal in Fukuoka, which handles international freight containers mainly from adjacent countries. DNA samples were also obtained from Goto, Tsushima, Honshu, Ryukyu, Thailand, and the Philippines; and a cluster analysis and discriminant analysis revealed that the distinct group in Fukuoka did not belong to these groups. Combined with the results of phylogenetic analysis based on CO1, these results implied that this group originated from one Asian temperate region outside of Japan. Neutrality test and mismatch distribution analysis suggested that the establishment of this group was not recent. Conclusions/significance The present study found a sign of Ae. albopictus introduction from a temperate region of Asia through maritime freight container transportation. The genetically distinct group found in Fukuoka likely originated from a temperate region outside of Japan. Maritime container transportation may introduce to Japan mosquitoes with greater vector competence/insecticide resistance. This is the first study to describe the spatial population structure of Ae. albopictus in Japan using molecular techniques.