山村における森林経営の実態調査 : 京都府天田郡夜久野町

本調査地区の林野面積は, 総面積の90.2%, 3,272.07町歩の広面積に及んでいる。耕地に利用しうる土地が限度に達しているこの地区では, 広面積を占める林野の利用を一層高度に進めることが, 土地産業として残されている唯一の途と考えられる。この林野面積は, 公有林34.4%, 私有林44.1%にわけられる。私有林は, その所有面積が零細で, 山林所有者数の76.3%が5町歩未満の山林所有関係にあり, このような零細な所有山林は, 営農資材の自給や, 家計の万一の場合に備えるために農業経営組織の一環として経営されねばならぬ。公有林は整理統一されたいきさつからも合理的経営によつて, 単位面積当りの生産量を高めて, 土地の高度利用の増大を図るとともに, できるだけ地元農民が公有林の恩恵に浴することがでるよう経営計画をたてることが大切である。In the district where this survey was made, forestland occupies 90.2% of the total area, reaching to as large as 3,272.07 chobu (3,245.04 hectare). Having a limited area for farmland which is already fully utilized, only way left to develop land productivity is considered to be in the more advanced utilization of the forestland. The forestland consists of the public forest which occupies 34.4% and the private forest 44.1%. The private forest is split into small individual ownerships. Of all the forest owners, 76.3% hold only less than 5 chobu (4.96 hectare) per person. These small forest owners have to use their forest as one of the elements of their farm projects, in such a manner as to obtain from these their farming necessities or to cover their financial needs at time of emergencies. In view of the circumstances under which the public forest have been renovated, it is imperative that effort must be direced towards the higher utilization of land by increasing the productivity of unit area through adequate maintenance, carried out on a scheme which enable famers in the district to profit on the public forest as much as possible

スギ苗のつぎ木増殖に関する基礎的研究(林学部門)

スギ育林学上の重要な問題は優良個体の増殖である。増殖方法は種子による増殖とクローンによる繁殖の二つがあるが, 優良木のほとんどは老齢のものが多く, 一般には結実量が少なく, またさし木による発根が困難で増殖の大きな障害となっている。したがってこの問題を解決する一手段として, まずつぎ木を行ないそれを利用することによって, さし木の発根能力の向上をはかることを目的として, 1960年以来本研究に従事してきた。つぎ木は林木増殖の有効な手段としてきわめて重要な位置をしめているにもかかわらず, 部分的な現象のみが強調され, 総合して確立されたものではなかった。この研究は, まずスギのつぎ木によるゆ合現象を形態学的, 生理学的な面から明らかにし, 早期ゆ合と早期生長に対してもっとも適切と思われるつぎ木方法を確立させ, さらに品種間の親和性からつぎ木材料を検討し, そしてつぎ木をくり返すことによって発根能力をどの程度高められるかを総合的に究明しようとしたものである。Some reasons why there are difficulties in propagating SUGI (Cryptomeria japonica D. Don), are because most of the superior seed trees are old so that they generally don\u27t bear a good many seeds and we can\u27t expect a good rooting on cuttings, either. As one of the efficient steps to solve these problems, this research started in 1960 to increase the rooting ability of cuttings, using clone of the seed tree which had been grafted once before. This paper deals with the synthetical study of the technical method and various conditions to get an optimum result for grafting trees. 1) Six different types of grafting, (Cleft-Grafting, Wrinkle-Grafting, Bark-Grafting, Veneer-Grafting, Side-Grafting and Inarching-Grafting) which was considered to be effective for the purpose of this research, were used and the propriety of these steps were investigated. Consequently, the Cleft-Grafting method showed the best record in the survival percentage and the growth of the scion after grafting. Soft X-ray photograph of the coalescent condition of the grafted part also showed the same result. 2) To find out the necessary and the sufficent condition for the survival of scion, relation between the growth of the callus and these factors such as moisture content, transpiration and suction amount of the scion and the water movement traced by P^ were investigated and it was considered that 2-3 weeks after grafting were the most important period for survival so that successful grafting depend on how to care the tree on that period. It was presumed to be the optimum condition for grafting to control the environment as the temperature around 25℃, the humidity above 70%, and the relative illumination around 50%. 3) High survival percentage and the maximum growth of scion after grafting was generally obtained when the scion was taken from the young seed tree under 50 years of age or from the lately grown part of the old mother tree and cut it into 5 to 10cm long and prune the lateral branches of the scion into 50% length. Latest grown part of the 2-3 years old seedling plant about 30 to 70cm height was found to be the best kind of stock when 30% of total length of the lateral branches were pruned from the top or 50% of each branches were pruned. Besides that, it was recognized that the lateral branches of the stock were indispensable on and after the second year after grafting. 4) Generally speaking, compatibility between the scion and the stock was always at issue but among 12 varieties which were used in this research, these four such as Sanbu-Sugi, Yanase-Sugi, Yaku-Sugi and Yamaguni-Sugi, which had wide insertion angle, made bigger growth in height whether they were used as scions or as stocks. This was due to the differences of the photosynthetic amount. 5) It was proved when the scion was taken from the old seed tree which was about 200 years of age, rooting percentage was only 10% but if the scion was taken from the branch which had been grafted once before, rooting rate became high, up to 50%. However, this was also pointed out that these grafting and cuttings combination was useful only for the first time and it was no use doing it over again to make the rooting percentage much igher

長老ケ岳植物概要(林学部門)

この報告は, 京都府下丹波地方における長老ケ岳の植物調査をした結果について述べたものである。調査の結果, 117科, 342属, 577種の植物を見いだした(表-1)。This paper deals with the results investigated of plants of the Tyorogadake in northern part of Kyoto Prefecture. As the results of this investigation, the writers have been found 577 species of plants which belongs to 342 genus, 117 families (See Table 1)

大気の汚染が林木に及ぼす影響について (I)(林学部門)

大気汚染が林木(スギ)に及ぼす影響について, 樹葉の分光反射特性を利用した赤外カラー画像のバイバンド比(R/G)を総合的な活力指標として, これに影響を及ぼすと考えられる元素含有量とその分布状態および生長をとりあげて検討した。その結果の概要は次のとおりである。(1)大気汚染度とバイバンド比には相関関係があり, 汚染地区の活力低下が認められた。(2)樹葉に含まれる全硫黄量は汚染度の高い林分ほど多い傾向を示した。(3)重金属(Pb・Cd・Zn)は汚染林分の外皮において高い含有量を示した。これは大部分浮遊ばい塵に含まれた重金属類が付着したものと考えられる。(4)汚染地区林木の内皮におけるカリウム含有量は, 対照地区との比較において著しく低い値を示した。As the synthetical index of the tree vitality, we investigated the infrared bi-band ratio (R/G) of the leave of SUGI (Cryptomeria japonica D. Don), which based on the characteristics of the spectral reflectances, so as to clarify the influence of air pollution on the forest trees. Moreover, we examined some factors, those were supposed to concern the vitality, volume increments, chemical elements, and their distribution. Results were as follows; 1. The bi-band ratio had a positive corelationship between air pollution, and the trees, in the polluted areas, showed the vital decay. 2. Total sulfer contents in the leave also had a positive correlationship between air pollution. 3. High contents of heavy metals (Pb, Cd, Zn) were found at the outer bark of the trees, in the polluted areas. It was assumed that this was caused by the catchement of the floating dust. 4. Potassium contents of the inner bark, in the polluted areas, were lower than the control

六甲山系における山腹植栽工林地の土壌回復について(林学部門)

六甲山系は過去において大規模な人為的干渉を受け, 殆んど全山が裸地と化したところである。その後, 明治の末期より山腹植栽工が施工され, その結果, 現在は緑が回復し立派に成林している。したがって, これらの森林は植生および土壌の経時的遷移について調査しうる貴重な場所と考えられるので, 今回とりあげて, 相互の様相を考察した。その結果要約すれば次のとおりである。1)全般に土層が薄く, 砂質で土壌水分は乏しい。層位もやや不明瞭である。しかし植生遷移の進行に伴なって, 土壌も僅かではあるが遷移の様相を呈している。2)本地域の土壌はいずれも強酸性で無機養分も激しい溶脱化のため乏しい。3)全般的に土壌の理化学性はよくない。この程度の経過年数では, たとえ地上部の緑が回復しても, 土壌はまだまだ未熟であって, 良好な植物群落-土壌系の発達には長期間が必要でその維持, 管理は容易でないと考える。In the past time, the Rokko Mountains were almost bared by human activities. But, nowadays, as everybody knows, the Rokko Mountains are almost covered by vegetation. This is the fruit of the planting works at the end of Meiji era. Accordingly, this present pine forests are very valuable material for researching the correlation between the plant succession and the soil succession. The results obtained are summarized below. 1) As a whole, the soil in this area is thin in the thickness, sandy in the texture and low in the moisture content. The layering in the profiles is not clear. But, as the plant succession goes on, it assumes an aspect of the soil succession. 2) The soil is more acid and small content of mineral nutrients by high leaching. 3) Though the vegetation looks recovered, the physical and chemical properties of the soil are not yet favorable condition in such a period, about 70 years. In other word, much more time is necessary for the development of the favorable plant community-soil system, and it is very difficult to keep up and control the conditions

京都における大気汚染と樹木の活力度との関係 (IV) (林学部門)

本報告は大気汚染と樹木の活力度との関係について, サクラの葉を供試材料として実施した京都府南部地域における調査研究の成果の概要である。活力度評価の指標とした葉のバイバンド比(R/B)とその要因としてとりあげた大気の汚染度(SO_3,NO_2), 葉面付着汚染物質量, 葉中全硫黄含有量とはいずれも正の相関関係が認められた。各要因がバイバンド比に及ぼす影響度の順位とその妥当性を回帰分析によって検討した結果, 各要因の基準変量への寄与率の順位は, 葉面付着汚染物質量78.4%, SO_3 11.7%, NO_2 1.4%, 葉中全硫黄含有量0.2%で, これらの寄与率合計91.7%となった。したがって, ここで用いた要因で指標に対する影響力のほぼ全体の大きさとその順序を知ることができた。したがって今回の実験では, 用いた光学的手法の有効性を再確認することになった。This paper presents a part of investigation on quantifying the vital decay of trees by air pollution through the optical analysis. In this paper, we have examined using the leaves of SAKURA (Prunus yedoensis Matsum.) in southern district of Kyoto prefecture. Results were as follows : As a synthetical index of tree vitality, the bi-band ratio (R/B) has showed positive correlationships between some factors such as air pollution (SO_3,NO_2), amount of dust on leaf surface, total sulfer contents in the leaves. We have done the multiple regression analysis so as to clarify the effectiveness of each factors against the bi-band ratio. The ranking of proportion of each factors against the bi-band ratio was as follows; 1. dust on leaf surface 78.4% 2. SO_3 11.7% 3. NO_2 1.4% 4. total sulfer contents 0.2%-total proportion 91.7%. In consequence, we got to infer the loading of each factors to the vital decay. This analysis brought the reaffirmation of applicability of the optical analysis

天の橋立公園のマツ並木の環境調査 (1) : 土壌および地下水について(林学部門)

天の橋立のマツ並木は近年環境の悪化にともなって樹勢が衰え, 今後の対策が憂慮されている。そこで現況を十分把握したうえで, 保護対策をたてなければならない。本報告は生立基盤である土壌と地下水について調査を行った。その結果を要約すれば次のとおりである。(1)土壌は砂土が大部分を占め, その粒子間に構造は認められず, 粘性も弱く, 土壌化は殆ど進んでいないIm-s型土壌である。(2)土壌の三相組成では固相が50%以上も占め, 液相や気相の割合が非常に少ない。そして, 容積重は100g/100cc以上で非常に重く, 孔隙率は40∿50%と少ない値を示す。また, 最大容水量や最小容気量も著しく小さい値で理学的性質は極めて悪い。(3)炭素, 窒素などの養分要素の含有率も非常に少なく化学的性質からみても瘠悪な土壌である。(4)地下水位は非常に高く60∿120cmであって, すべての地点で塩分濃度は低く真水同様の値であることが注目される。According to the deterioration of environmental conditions, recently the vitality of MATSU trees, stand AMANO-HASHIDATE, is going to weaken. So we must grasp the present conditions fully, and need to consider the preservation treatments. We investigated the soil and the ground water as the foundation of growth. The results obtained are summarized below. 1. The soil is almost occupied by fine-grained sand and has no structures between particles, and weak cohesion. So we classify it as Im-s type soil, which the formation of soil doesn\u27t progress. 2. Concerning about the relative contents of solid, water, air, solid occupies more than 50%, and the percents of water and air are very small. So the bulk density is very high (more than 100g/100cc) and the percents of porosity is low (40-50%). Maximum water capacity and minimum air capacity also show so small. Therefore the physical properties of the soil are supposed very bad. 3. Nutrients, such as carbon, nitrogen and other elements, aren\u27t almost contained in the soil, so the chemical properties of the soil are also bad. 4. Ground water level is remarkably high (60-120cm under surface). Characteristically, the ground water shows low salinity, almost fresh water, every sampling points

山腹植栽工によって成立した植物群落における遷移に関する研究 I : 牛伏川流域のニセアカシア林での事例(林学部門)

牛伏川流域のニセアカシア林は約70年前の明治42年より大正7年にわたっての山腹植栽の施工地として現在に至っている林分である。昭和51年および昭和52年にかけて, その植生および士壤調査を行なう機会に恵まれ, 現在成立している植物郡落がいかなる経緯で存在し, またどのような過程を経て遷移していくかについて考察してみた。その結果, 以下に示す事項が認められた。1.施工時に導入されたアカマツ・ヒメヤシャプシおよびヤマハンノキは残んど残存しておらず, 補助的に導入されたニセアカシアが山腹施工地の全域にわたって優占している。2. (1)に至るについて有余曲折があったと考えられるが最大の成因となるのは, 昭和20年前後の混乱期に薪炭材採取のために伐採が行なわれたことがあげられ, 萌芽更新の旺盛なニセアカシアが急速に全域を被覆したと考えられる。3.これらニセアカシア林の中で, それぞれの環境の差異によって群落を構成する種の質および種数に明らかな差が認められる。4.これらの林分を次の三つのタイプに分けることができる。すなわち, a)階層構造の発達はもちろんであるが, ニセアカシアとともに郷土種が高木層を形成している。b)高木層はニセアカシアにより占められるが亜高木層および低木層は郷土種が優占する。c)高木層はニセアカシアにより占められるが群落の階層構造が発達せず, 草本層のみが形成されている。5.土壌調査結果から, 地表の植生が回復したかに見えても, 地表下の土壌条件は全く未熟であると判定される。したがって, 以上の事実を認識したうえで, これらの林分を取り扱うのでなければ, 容易に荒廃化する危険性を秘めていると考えられる。We have done some vegetation and soil research for NISEAKASHIA (Robinia pseudo-acacia) stand at Ushibuse river basin in Nagano Prefecture, that were estabulished by excuting the hill-side planting works about 70 years ago. We studied for the succession of these living plant communities, the results are summerized as follows : 1. Main leading plants, that is, AKAMATSU (Pinus densiflora), HIMEYASHABUSHI (Alnus pendula), and YAMAHANNOKI (Alnus firsuta), not remain in the present state, but NISEAKASHIA, that was assistantly lead on planting, dominate at the whole range of the hill-side works. 2. In this NISEAKASHIA stand, it is recognized that the quality and quantity of species forming the plant community are aparently distincted by the environmental difference of each plant communities. 3. There are 3 types of plant communities in this NISEAKASHIA stand that is, (a) the native species with NISEAKASHIA are forning in the tree stratum, (b) the native species are forming in the range up to the subtree stratum, (c) the native species are only recognized in the harb stratum. 4. From the results of soil research, it is recognized that the soil conditions are not mature at all, though it seems to recover the vegetation on the surface of the earth