美濃羽靖・中司駿：深層学習を用いた針葉樹の樹種判別,森林計画誌56：13～23,2022 本研究では,深層学習を用いて野外で撮影した針葉樹の葉画像から樹種判別を試みた。京都府立大学構内および京都府立植物園内に成立する針葉樹8種からそれぞれ300枚の葉を撮影,画像サイズ 256×256 pixelの葉画像を28,800枚作成した。深層学習の学習フレームワークにはCaffeを学習アルゴリズムにはAlexNetおよびGoogLeNetを用いた。訓練事例と未知事例の比率が9：1でデータの水増しなし（LM-1）・あり（LM-2）,同比率が8：2で水増しなし（LM-3）・あり（LM-4）の四つの学習モデルを作成した。学習モデルの性能評価は,各学習モデルにおいて10回のシミュレーションを行い,未知事例に対しての平均正答率を算出,その判別精度を評価指標とした。学習結果より,最も平均正答率が高かったモ...

Independently from its origin, trichloroacetic acid (TCA) as a phytotoxic substance affects coniferous trees. Its uptake, distribution and degradation were thus investigated in the Norway spruce/soil-system using 14C labeling. TCA is distributed in the tree mainly by the transpiration stream. As in soil, TCA seems to be degraded microbially, presumably by phyllosphere microorganisms in spruce n...

Japanese pine sawyer beetle (Monochamus alternatus) is an economically important pest in coniferous trees. Ophiostoma ips was isolated from the beetle and identified based on analysis of morphological properties and the β-tubulin gene sequence. The fungus easily produced perithecia with a long neck on malt extract agar and its ascospores were rectangular shaped. This is first report of Ophiosto...

Pine wilt disease caused by pine wood nematodes is endemic to North America. Pine wood nematodes have already spread to East Asia, including China, Taiwan and Korea in addition to Japan. The pine wood nematode, Bursaphelenchus xylophilus, was discovered in Portuguese pine forests in 1999. If it were to become established in the pine forests in Europe, it could become one of the most serious thr...