森林生態系多様性基礎調査(日本版国家森林資源調査)データ(NFIデータ)を真値と仮定し,植生図が整備済みの範囲(2019年11月時点で整備済みであった2,112面)全てを対象に日本全体における植生図の図化精度を求めた.NFIデータと植生図を重ね合わせ,両者の一致の有無を調べた.森林と非森林で比較し,次いで針葉樹人工林とその他森林で比較を行った.植生図と比較するデータとして第3期(2009~2013年)の森林生態系多様性基礎調査のデータを用いた.植生図の凡例を用いて,森林・非森林ならびに針葉樹人工林・その他森林の分類を行った.植生図とNFIデータの一致度を定量化するために判定効率表とKappa係数を用いた.本研究の結果から,NFIデータを真値とした場合における植生図の精度(Kappa係数)は,森林・非森林において0.86,森林における針葉樹人工林・その他森林については0.59であった.平面直角座標系の系毎にKappa係数を算出したところ,相対的に精度の高いエリア,低いエリアが示された.本論によって植生図の精度検証を全国スケールで実施することができた.

近年,新たなリモートセンシングのプラットフォー ムとしてUAV(Unmanned Aerial Vehicle)が大変大 きな注目を受けている。UAVの利点として「再測の 時間間隔を自分で決めることができる」,「低高度飛行 によって対象物に,より近づくことができ,空間分解 能の高いデータを取得できる」,「運用コストを低く抑 えることができる」などが挙げられている(Anderson and Gaston,2013)。森林リモートセンシングにおいて もUAVは既に幅広く活用されており,今後の展開が おおいに期待されている(村上,2018)。 UAV空撮画像は,Metashape(Agisoft 社)や Pix4 Dmapper(Pix4D社)といった SfM(Structure from Motion)ソフトウェアを用いて三次元点群を生成さ せることが多い。それらのマニュアル(例えば,Pix4 Dmapper のマニュアル)では,対地高度一定で撮影 を行うこと,と指示されている。これはつまり空撮対 象エリアの地形に起伏がある場合,地形に沿ってUAV を飛行させることを要求するものである。言い換える と,対地高度一定での飛行が求められている(図-1 参照)。この対地高度を一定に飛行させるためには, その地点の標高を考慮して,その標高値に撮影高度 (対地高度)を加えなければならない。 対地高度一定のUAV空撮を現場で確実に行うため に著者らは検討を重ねた結果,UAV空撮を実行する アプリのひとつであるLitchiに着目した。今回,Litchi を利用した空撮計画の策定手法について紹介する。 なお,本論のGIS環境はArcGIS Pro(ver.2.4,ESRI 社)である。そのため,本論におけるGIS は ArcGIS Pro を意味しており,処理の名称はArcGIS Proのもの に該当する。ユーザによってGIS 環境は異なると思 われるので,使用するGIS が異なる場合は同等の作 業内容で置き換えてもらいたい(GIS によっては同様 の機能がない場合もありうる)。また,設定する座標 系は平面直角座標系,地理座標系(経度,緯度)であ る。測地系は JGD2011もしくはWGS84とする。本論 における手順の流れを図-2に示す。

まず,森林・林業基本計画における森林の有する多 面的機能の発揮に関わる目標にふれたい。スギ,ヒノ キの人工林について,将来的には自然条件が良く,林 業経営に適した地域のみで残し,将来的には660万 ha まで減らしていく。それ以外の地域では針広混交林化 等を目指していく。これを達成するには様々な対策, 政策が必要であるが,その中心は森林計画制度である。 全国44の広域流域ごとに主伐量,間伐面積などの目標 を決め,それをもとに地域森林計画を158の流域ごと に目標を決める。さらに市町村森林整備計画で様々な 施業の規範を作る。また,伐採造林届出などの規制的 な手法,補助金などの誘導的な手法を利用していく。 しかし,これらの手法だけではなかなか思うようには いかない現状にある。 次に,森林管理の課題である。森林所有者の四分の 一は不在村で,そのうち24%は森林相続の手続きを何 もやっていない。所有者の中でも,森林経営を縮小し たい,今後やっていくつもりはない,と回答した人は 60%にものぼる。登記簿上の所有者に郵送,通知をし たが到達しなかったという事例が全体の23%で発生し ており,所有者不明の森林が数多く存在する。日本の 森林の三分の一程度は経営計画が立てられているが, 残りの三分の二については経営計画が立てられていな い。林業経営に興味がない,次世代の経営者不足,そ もそも森林所有の意識がない,などの問題があり政策 が打ちづらい現状にある。森林法は森林所有者が森林 をしっかり管理することを前提としており,その前提 が崩れると目標への誘導は難しくなる。そのため,従 来の手法だけでなく新しい手法を考える必要がある。 先述の針広混交林化には,裏を返せば今後儲けるこ とのできない森林を作っていくということでもあり, 所有者の負担が大きいことになる。また,林業のサイ

林野庁は，森林施業によるイヌワシの採餌環境の創出事業を全国的に実施している。しかし，本種の採餌行動が可能な空間サイズや形状が十分に理解されていないこともあり，その空間特性に基づいた有効な環境創出ができていないことが課題となっている。そこで本研究は，新潟県の1つがいを対象に，採餌場所の特定と，そのサイズと形状の計測を実施し，本種に有効な採餌環境の創出方策の検討に必要な情報を蓄積した。落葉広葉樹林の林冠ギャップは，冬期および夏期におけるイヌワシの採餌場所となる傾向にあった。また，落葉広葉樹林の林冠ギャップは，開空部の広さや形状にかかわらず，イヌワシの採餌場所となる可能性があると推察された。その一方，雪原および疎林は，調査範囲内における現存面積に反してその利用頻度は低く，好適な採餌場所となっていない可能性があった。今後はイヌワシによる雪原および疎林の利用状況を詳細に評価する必要がある。

1660年頃作成の屋久島の古い絵図「屋久島古図」が存在する。この絵図は非常に詳細で，島内の集落名，山頂名，河川名，場所名，スギを含む数種の樹木の存在，島中央への歩道等が書き込まれている。そこで本研究では，この地図を現代図と重なるようにGIS上で補正し，当時のヤクスギ分布を推定した。さらに現代図のヤクスギ分布域との比較から，その間の変化を把握しかつその変化要因を分析し，最後にこの地図の今後の利用可能性を検討した。その結果，この地図は現代図と非常に良く重ね合わせることができ，当時のヤクスギ分布域は島東部の安房川流域に偏り，標高200 m付近の低標高域にも存在していたことが判明した。1660年当時にヤクスギが分布していた地域で，その後の伐採でヤクスギが消失した地域は，低標高の地域と川の近くに多かった。以上からこの屋久島の地図は，作成当時の森林状態を詳細に記録した地図として活用できる可能性が示唆された。

Assemblages of sandy shores are primarily structured by physical environment factors. This structuring provides a unique opportunity to evaluate biogeographic regions. In this study, the shallow subtidal zone (0.2–1.2 m) of 39 sites of sandy shores along the Japan Sea coast of Honshu were surveyed using a sledge net to identify invertebrate assemblages and to elucidate their relationships with environmental factors and geographic distributions. In total, 78 taxonomic units were obtained and six clusters of assemblage were recognized according to the Morisita-Horn dissimilarity index values between the assemblages of these sites. Indicator taxonomic units were identified for the clusters and a distance-based redundancy analysis (dbRDA) demonstrated that a set of five environmental factors (slope angle of the swash zone, sediment grain size, average wave fetch, spring sea surface temperature, and summer Chlorophyll- a concentration) significantly explained variations of the assemblages. Geographical distributions of two of the clusters were localized and mutually exclusive (one in the north and one in the south), while the other four clusters were scattered along the coast. On the dbRDA ordination, these two clusters were plotted on opposite ends of the 1st axis on which spring sea surface temperature and summer Chlorophyll- a concentration showed high contributions. The spatial gap between the two clusters was located in an area between the Noto Peninsula and the Sado Island, central Honshu, which can be proposed as a boundary of geographic regions of sandy shore organisms along the Japan Sea coast.

Estimation of the current successional status of long-lived coniferous forests is difficult especially after several hundred years of human disturbance. However, in Cryptomeria japonica forest on Yakushima Island, the stumps generated by logging activities from the seventeenth to nineteenth centuries remain almost intact without intense rotting. From an inventory of these stumps and long-term monitoring of current stands for more than 25 years, we estimated the forest condition before logging and evaluated the current status of secondary succession. The size structure of Cr. japonica stumps suggested the stumps were composed of two different generations: the stumps of trees present before initiation of logging; and those of trees that regenerated after initiation of logging. In the current forest, the stem number of canopy species is decreasing and that of understory broad-leaved species is increasing. Regenerating Cr. japonica individuals are rare. Before the logging, the forest contained a larger number of larger Cr. japonica trees than the current forest. The results of monitoring the current forest suggested that all coniferous species, including Cr. japonica, were still undergoing self-thinning. The current Cr. japonica forest is in an intermediate stage of secondary succession, but the processes of succession are markedly different between the study plots, depending on their location or previous logging intensity.

The swash zone of sandy shores is a transitional habitat between the sea and land where the physical environment is the primary factor influencing the distribution of shore macrofauna. We constructed cumulative logit models using Bayesian inference to predict the ranked abundance of three species of peracarid crustaceans (Haustorioides japonicus, Excirolana chiltoni, and Archaeomysis kokuboi) that dominate the sandy shores of the Niigata coastline, Sea of Japan. Additionally, we estimated the importance of 14 environmental factors at explaining the variation in abundance. The environmental factors were grouped into three categories: swash zone, landward, and offshore. Optimum models were selected among the null model, the basic model (swash zone factors only), and additional models with landward and/or offshore factors. The optimal model for each of the three species was obtained when landward and/or offshore factors were added to the basic model, suggesting the importance of these regional factors. Combinations of significant factors differed between the three peracarid species. Some differences can be explained by accounting for life history characteristics. The slope of the offshore seafloor was the only common significant factor for the three species. Therefore, a decrease in the size of the shallow area off the sandy shore was associated with a decrease in the density of the three species. Because the peracarid crustaceans play an important role in trophic links in sandy shore ecosystems, our study results predict that an increase of coastal erosion leading to change of near-shore bathymetry will reduce the ecological function of the swash zone.

The Crested Ibis, became extinct in the wild in Japan in 1981; however, a captive breeding facility was established on Sado Island, Niigata Prefecture in 1999 in the hope of conserving the species. Following successful breeding at the facility, a group of birds was released on Sado Island on 25th September 2008, with further reintroductions in subsequent years. Habitat restoration is also necessary to facilitate the re-introduction program of this endangered species. The aim of this study was to detect suitable nesting areas for the released ibises on Sado Island for subsequent nature restoration. Since little ibis nesting information was available for Sado Island, the nesting model was constructed from nesting information from China, from which results were extrapolated for Sado Island. Land usage was assessed using LANDSAT/ETM+ data for China and SPOT/HRG images for Sado Island. In this study, land-use information was used to define the environmental parameters related to nest site selection of the Crested Ibis. For the nesting model, a generalized linear mixed model, with seven environmental factors, was employed. The multi-spatial scale for Crested Ibis nesting was also analyzed. We took the spatial scale into consideration at intervals of 100 m from a buffer size of 100 m to 2500 m. Because nest site selection was influenced by the results of the previous year, nesting location data in 2005 and 2006 were distinguished and models built accordingly. Several important environmental factors were identified for nest site selection: the ratio of broadleaved deciduous forest to coniferous forest; the shape of the forest edge; and, the distance from rice fields and other wetlands. The model's accuracy was verified using the Boyce index, and shows the validity of the model's results. Suitable nesting areas for the Crested Ibis were found mainly on: the Kuninaka plain; the ridgeline between the Kuninaka plain and the Osado or Kosado mountain ranges; the area around Lake Kamo; and, the midwestern area of the Kosado region. Suitable nesting sites for the Crested Ibis were all found to be concentrated in what is known as Yatsuda, a traditional Japanese landscape structure providing a complex mosaic of forest and rice fields with complex ecotones. Eastern Kosado, the region that has been designated by the Ministry of the Environment as the conservation area for the reintroduced birds, was not judged to provide suitable nesting habitat for the Crested Ibis. Unfortunately, no evaluation of habitat suitability was made prior to the release of the first captive-bred Crested Ibis into the wild on Sado Island. Had an evaluation of habitat suitability been performed prior to release, more effective nature restoration could have been planned.

: Appropriate wildlife management is important in order to resolve human-wildlife conflicts. The objective of this study is to clarify the relationship between animal distribution and landscape information. In particular, we evaluated the effect of spatial scale (extent and grain size) in predicting animal distribution. Our target species are Asiatic black bear ( Ursus thibetanus ), Japanese macaques ( Macaca fuscata ), and wild boar ( Sus scrofa ). Honshu (the mainland of Japan) and Niigata Prefecture were defined for two types of spatial extent. Furthermore we detected landscape information from 30 m and 500 m-spatial resolutions for grain size in Niigata Prefecture. Logistic regression analysis was applied for predicting animal distributions. Extent influenced the contribution of selected ecological indicators for animal distribution. For the prediction of Asiatic black bear ’ s distribution, agricultural area, conifer forest, broad-leaved forest and snowy area were preferred predictors at the spatial scale of Honshu. At the spatial scale of Niigata Prefecture, however, agricultural area was avoided, while conifer forest and snowy area were preferred predictors. For the prediction of Japanese macaque ’ s distribution, agricultural area, conifer forest, broad-leaved forest and water area were preferred, while snowy area was avoided at the Honshu scale. However, agricultural area was avoided, while conifer forest and snowy area were preferred at the scale of Niigata Prefecture. For the prediction of wild boar ’ s distribution, agricultural area, urban area, conifer forest, broad-leaved forest and water area were preferred, while snowy area was avoided at the Honshu scale. At the Niigata Prefecture scale, however, only high snow depth area was preferred predictor. Predictions of the distribution of Asiatic black bear at both Honshu scale and Niigata scale were very accurate. Predicting the distribution of Japanese macaques at the Honshu scale had slightly lower accuracy. Predicting the distribution of wild boar at the Honshu scale was reasonable, but that result at the Niigata scale was poor. Effects of grain size in the prediction of animal distribution were not clear. We suggest that the influence of extent in the prediction of animal distribution is important.

林野庁ならびに国土地理院が撮影してきた過去の空中写真の時系列解析により,施業区画(小班)を抽出する手法の開発を試みた。1963年から2002年の7時期の空中写真をオルソフォトに加工し,隣接する2時期をそれぞれ組み合わせ,2時期合成画像を使用して林分分類を行った。輝度値及びDSM(Digital Surface Model)の2時期合成画像の主成分分析により得られた第2主成分画像を用いて伐採地ならびに植栽地の抽出を試みた。今回提案する手法によって,人工林のより正しい施業区画の描画の可能性が示された。出力結果を既存の森林GISと比較したところ,既存の森林GISの区画線の不整合や林齢の不一致を指摘することができ,提案手法の妥当性が確認された。