1.

論文(リポジトリ)

論文(リポジトリ)
新本, 光孝 ; 新里, 孝和 ; 安里, 練雄 ; 石垣, 長健 ; 呉, 立潮 ; Aramoto, Mitsunori ; Shinzato, Takakazu ; Asato, Isao ; Ishigaki, Choken ; Wu, Lichao
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.9-14,  2005-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3329
概要: 本研究は、亜熱帯沖縄における天然林の資源植物学的研究の一環として、亜熱帯・沖縄県の主要島嶼の沖縄島、宮古島、石垣島、西表島を対象に既応の著書・文献を用いて分布植物のデータベース化をはかるために森林植物を中心とした全ての在来植物の分布種及び外 来種を明らかにするために行ったものである。琉球列島全体の分布植物は、琉球植物目録(FRSAI、1994)で238科、1688属、5,473種で最も多く、Flora of Okinawa and Southern Ryukyu Island (FOSRI、1976)で239科、1,061属、2,560種、琉球列島維管束植物集覧(FRSAI、1997)、200科、949属、2,275種、琉球植物誌(FR、1975)182科、863属、2,142種の順であった。全体的に総分布種は文献間に差異があり、その主な要因は外来種の分布の取り扱いによるものと思料される。在来植物の種の構成は沖縄島FR 1,451、FRSAI 1,445、CLVFR 1,404、宮古島FR 640、FRSAI 656、CLVFR 633、石垣島FR 1,099、FRSAI 1,132、CLVFR 1,119、西表島FR 1,151、FRSAI 1,139、CLVFR 1,142で各島嶼とも分布種に大きな差異はなかった。また、島嶼別の在来種は沖縄島>西表島>石垣島>宮古島の順であった。宮古島が最も少ないのは、同島の大部分が隆起サンゴ礁の石灰岩でおおわれ、平坦な島であるため、分布植物において山地性植物の森林植物が他島に比べて少ないものと思料される。島嶼別固有植物はいずれの文献も沖縄島に多くの固有植物が分布しVJOO 16種、FR 15種、CLVFR 33種であった。ついで西表島で多くVJOO 13種、FR 10種、CLVFR 9種、宮古島、石垣島では1~3種であった。<br />Within the frame work of a series of plant resource studies on the natural forests in the subtropical Okinawa, the present study was undertaken to clarify the distribution of forest plant for both indigenous and exotic species on the Ryukyu Islands, especially for the 4 main Islands, i.e. Okinawa, Miyako, Ishigaki and Iriomote Islands in the Ryukyus based on the database of the five reference books. The considerable difference was found for the total number of species among the references. The plants distributed in the entire Ryukyu Islands were 238 families, 1,688 genera and 5,473 species based on Flora of the Ryukyus, Southern of Amami Island (FRSAI), which had the highest number of species, while Flora of Okinawa and Southern Ryukyu Island (FOSRI, 1976) recorded 239 families, 1,061 genera and 2,560 species. According to Check List Vascular Flora of the Ryukyu Islands (CLVFR), 200 families, 949 genera and 2,275 species were present. Flora of the Ryukyus (FR) recorded the least species with a total of 182 families, 863 genera and 2,142 species. The methods of the handling of plant distribution to the exotic species may be responsible for the obvious differences in the main factor on the total number of species among these references. For the composition of the indigenous species, in Okinawa Island, 1,451 (FR), 1,445 (FRSAI) and 1,404 (CLVFR) species were recorded; 1,099 (FR), 1,132 (FRSAI) and 1,119 (CLVFR) species in Ishigaki Island; 1,151 (FR), 1,139 (FRSAI) and 1,142 (CLVFR) species in Iriomote Island. No obvious differences were found among the 3 references. Moreover, for the abovementioned indigenous species, the order of species number were Okinawa > Iriomote > Ishigaki > Miyako. As for the least value of indigenous species in Miyako Island, it is thought that the greater part of the Island is covered with the limestone of the upheaval coral reef, and the mountainous forest plant is less than other Islands because of its smooth landform on the Island. Each reference recorded a lot of endemic plants in the Okinawa Island, with 16 species recorded in VJOO, 15 species in FR, and 33 species in CLVFR, while Iriomote Island had the second highest value for endemic plants with 13 species recorded in VJOO, 10 species in FR and 9 species in CLVFR. In Miyako or Ishigaki Islands, few endemic plants were present with a range of 1-3 only. 続きを見る
2.

論文(リポジトリ)

論文(リポジトリ)
呉, 立潮 ; 新里, 孝和 ; 新本, 光孝 ; Wu, Lichao ; Shinzato, Takakazu ; Aramoto, Mitsunori
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.15-21,  2005-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3330
概要: 本論文は沖縄の亜熱帯照葉樹林地帯において,天然更新を基盤とする各種天然林施業法に関する研究の一環をなすものである。帯状伐採施業は1994年実行され、保残区残存木の報告に引き続き施業7年後の伐採区について調査した。試験林設定時の伐採区は伐採樹 種53種、891株で、今回は根株(伐採株)の腐朽状態と萌芽幹、実生幹、新規発生木を樹高1.0m以上の全出現個体について毎木調査を行った。根株の枯死率(腐朽状態-d-)は34.7%で,施業試験地が隣接する皆伐施業林の一年後、5年後の枯死率より高くなり,根株枯死率は伐採経年た伴って増大傾向を示した。根株の生育状況は約1/3の完全腐朽(枯死)に対して,多数の根株が生存あるいは萌芽幹を発生しており,そのうち根株の12.8%が萌芽幹発生・原型保持(腐朽状態-a-)、42.6%が萌芽幹発生・部分腐朽(b)、9.9%が萌芽茎発生・完全腐朽(c)であった。施業7年後の二次林の樹種は74種で、そのうち49種が萌芽由来、69種が実生由来となり、伐採前林分(天然林)の53種より増加していた。萌芽力が強い天然林優占種のイタジイは、二次林途中相でも優占していた。実生由来と萌芽由来の間で、平均樹幹密度は実生由来が萌芽由来より高く有意差がみられたが、基底面積は有意差がなかった。胸高直径4cm以下の樹幹密度と基底面積は実生由来が萌芽由来より高く、胸高直径4cm以上の基底面積は萌芽由来が実生由来より高い値を示し、早期の二次林途中相では実生由来の多数個体が下層に出現し、萌芽由来が上層を占めていた。天然林伐採後、先駆樹種が侵入し樹種増加を伴うが、天然林構成種の萌芽由来と実生由来の発生がみられ、帯状伐採施業7年後の再生林は進行遷移に属することが示唆された。<br />The mortality of stumps and growth of a secondary forest in cut area seven years post strip clear-cutting in a natural subtropical laurel forest on Okinawa Island were studied. The results showed the mortality rate of stumps was 34.7%, which was higher than those in a similar secondary forest at the first and the fifth year after clear-cutting (13.2, 20.2%, respectively) in nearby site, confirming that the mortality rate of stumps increased with years in a certain years. In contrast to dead of one-thirds of stumps nearly, majority of stumps remained alive, of which, 12.8% of the stumps were remained initial figure, 42.6% of them partly decaying and 9.9% of them invisible with living sprout. The secondary forest was consisted of a total of 74 woody species, of which, 49 and 69 species, respectively, were found in sprout- and seedling-origins, greater than that in the primary forest (53 species) before strip clear-cutting. The primary dominant species, Castanopsis sieboldii, still dominated the secondary forest. The mean stem number of seedling origin stems by plot was significant (p<0.05) higher than that of sprouting origin ones. However, no significant differences found for the mean basal area by plot between two kinds of stem origins. Seedling stem number in DBH group<4.0cm had higher values than those for sprout's, while sprout origin stems in basal area were roughly seven-fold more than that for seedling's in DBH group>4.0cm. The results indicated that the seedling stems shared the understorey and sprout-origin stems shared the crown canopy in the early succession stage. The secondary forest was dominated by sprout stems rather than seedling-origin ones. The great of woody species with abundant of sprout- and seedling-origin stems suggested the secondary forest seven years after strip clear-cutting occurred in a progressive succession. 続きを見る
3.

論文(リポジトリ)

論文(リポジトリ)
ホサイン, モハメド アムザド ; 松浦, 新吾郎 ; 土井, 光弘 ; 仲村, 一郎 ; 石嶺, 行男 ; Hossain, M.d. Amzad ; Matsuura, Singoro ; Doi, Mitsuhiro ; Nakamura, Ichiro ; Ishimine, Yukio
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.23-26,  2005-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3331
概要: 万田31号は、自然災害を含めて作物、野菜、果物の収量と品質を高めることが報告されている。ここでは、万田31号の使用がほうれん草の生育、収量に及ぼす効果を調べるために琉球大学農学部亜熱帯フィールド科学教育研究センターのガラス室において実験を行 った。まず万田31号(100ppm)を、葉の枚数が3-5枚になった時から十日間隔で三回散布した。対照区では水だけを散布した。万田31号を施用した区では対照区に比べ葉の色はより濃緑色で葉の老化が緩やかであった。1個体あたりの葉の枚数と面積では万田31号施用区が対照区に比較し有意であった。根の乾物量と収量は万田31号施用区で有意に増加した。以上の実験結果から万田31号はほうれん草の生育、収量を高める効果があると考えられえる。<br />Manda 31, a fermented natural plant concentrate, improves yield and quality of crops, vegetables and fruits without any hazard of environment factors. A glasshouse experiments was conducted to evaluate the effects of Manda 31 on growth and yield of spinach at the Subtropical Field Science Center of the University of the Ryukyus, Japan. Manda 31 at 100ppm was sprayed to plant shoots three times at a 10-day interval beginning 3- to 5-leaf stage. Water was adequately sprayed to control plants. Leaf was greener and leaf senescence occurred slowly when spinach was grown with Manda 31. Number of leaves, leaf area, root biomass and yield (shoot biomass) per plant were significantly increased with the Manda 31 application, as compared to control plant. This study indicates that Manda 31 is effective for promoting growth and yield of spinach. 続きを見る
4.

論文(リポジトリ)

論文(リポジトリ)
菊地, 香 ; Kikuchi, Koh
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.27-40,  2005-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3332
概要: 本稿の目的は集落営農によって平地農業地域の生産継続の可能性を土地、資本、労働に加え農業後継者の農業に対する意識をもとに実証的に解明することである。日本の基幹的な農業である水稲作は、一般に立地条件や生産条件で条件不利地と言われる中山間地域だけ でなく平地地域においても厳しい状況に立たされていることが理解できる。<br />The purpose of this paper is to positively clarify the possibilities for continued production in the flatland agricultural regions of agricultural communities. The study is based upon the agricultural knowledge of the future successors, and takes into consideration such factors as land, capital, and labor. It is clear that Japan's core agricultural activity, wet-land rice production, is in jeopardy, not only in the mountainous regions where it is said that the geographical location and production conditions are unsuitable, but also in the flatland areas. 続きを見る
5.

論文(リポジトリ)

論文(リポジトリ)
瀬戸内, 秀規 ; Setouchi, Hideki
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.49-126,  2005-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3334
概要: 本論文は,降伏面の内部の応力変化による塑性変形を表現し得る非古典弾塑性論としての下負荷面モデルに下負荷面の接線方向の応力速度成分つまり接線応力速度による非弾性ひずみ速度を考慮した接線・下負荷面モデルを比例負荷から繰返し非比例負荷に至る広範の 負荷を受ける地盤材料の変形挙動の予測に適用し,実測値と比較することにより本モデルの妥当性を検証したものである.まず,砂における3軸試験装置で得られた排水および非排水条件の繰返し試験,真の3軸試験装置および中空捩り試験装置で得られた排水条件の繰返し等方圧縮,軸対称圧縮およびb-値一定の圧縮・伸張試験,および非比例負荷である真の3軸試験装置で得られた排水条件の平均主応力一定繰返し円形応力負荷試験のシミュレーションを行った.一連のシミュレーション結果から,本モデルが負荷条件によらず地盤材料の変形挙動を統一的に予測できることを実証した.また,円形応力負荷では,負荷過程における非弾性ひずみ速度の方向および大きさを明らかにすることにより,従来の弾塑性構成式は応力速度方向の剛性を非現実的に高く予測することを示し,接線・下負荷面モデルは接線応力速度による非弾性ひずみ速度により応力速度方向の剛性を適切に緩和でき変形挙動の予測精度を向上させることを実証した.さらに,土の異方性を表現する下負荷面の回転を考慮したモデルおよび接線応力速度によって誘導される接線ひずみ速度の方向が下負荷面の接線方向のみでなく下負荷面の外向き法線方向を有するとする拡張接線・下負荷面モデルを導入し,砂の応力プルーブおよび主応力軸回転試験に適用した.その結果,下負荷面の回転の効果を明らかにするとともに,接線応力速度による下負荷面の外向き法線方向の非弾性ひずみ速度の効果によりさらに高精度に非弾性ひずみ速度を予測できることを示し拡張接線・下負荷面モデルの妥当性を実証した.<br />The inelastic strain rate described in the traditional elastoplastic constitutive equation is independent of the magnitude and the direction of stress rate component tangential to the yield surface. Therefore, an unrealistically high stiffness modulus is predicted for nonproportional loading process significantly deviating from proportional loading. The tangential-subloading surface model can describe not only the plastic strain rate due to the stress rate component normal to the subloading surface but also the tangential strain rate due to the stress rate component tangential to the subloading surface. The major advantage of this model is that the model is not restricted to materials obeying isotropic hardening/softening law and also for materials having a simple isotropic shape of loading surface. Further the model is applicable to arbitrary loading conditions including cyclic loading, since the model is based on the subloading surface model and fulfills the mechanical requirements for cyclic plasticity. The validity of the tangential-subloading surface model for the prediction of soil deformation behavior is studied in this research. The model is based on the extended subloading surface model incorporating the evolution rule of the similarity-center of the normal-yield and the subloading surfaces with the rotational hardening and the isotropic and the deviatoric hardenings. The predictions is compared with the test data of sands subjected to various loadings ranging from proportional to cyclic nonproportional loading, while the unique sets of material parameters are used, and the calculations are performed from the unique initial states in spite of the variety of test types. Further, the concepttangential stress rate relaxationon the relaxation relevant to the deviatoric part of the component of stress rate tangential to the subloading surface is applied for the prediction of deformation behavior of soils subjected to stress probe and principal stress axes rotation. The validity of the concept is verified by comparing with the test data. Then, it is concluded that the tangential-subloading surface model can simulate reasonably well the arbitrary loading behavior including cyclic nonproportional loading and the concept of the tangential stress rate relaxation is of importance for describing more realistically nonproportional loading behavior. 続きを見る
6.

論文(リポジトリ)

論文(リポジトリ)
田幸, 正邦 ; 城間, 郁子 ; 上地, 俊徳 ; Tako, Masakuni ; Shiroma, Ikuko ; Uechi, Shuntoku
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.139-143,  2004-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3557
概要: ローゼラ小麦アミロペクチン(平均重合度,18,000±2,200;数平均鎖長,19.2±1.7)水溶液の流動曲線は,広い濃度範囲(3.0~7.0%)で擬塑性流動を示した.ローゼラアミロペクテンの貯蔵弾性率は,濃度 の増大に伴って低温側でもそれほど増大しなかった.また,貯蔵弾性率は温度の上昇に伴って徐々に城少した.損失正切(tanδ)は7.0%,0℃でも高い値(2.0)を示した.ローゼラアミロペクチンの貯蔵弾性率は尿素(4.0M)の添加によってわずかに増大し、温度の上昇に伴って徐々に城少した.また、ローゼラアミロペクヂンの貯蔵弾性率は,アルカリ溶液(0.05M NaOH)でもわずかに増大し,温度の上昇に伴って徐々に城少した.以上の結果から,ローゼラアミロペクテンの分子銀は,水溶液で二次結合(分子銀内または分子銀閣)を形成しない事が示唆された.<br />The non-Newtonian behavior and dynamic viscoelasticity of wheat (Rosella) amylopectin in aqueous solution were investigated. The flow curves, at 25℃, of Rosella amylopectin showed shearthinning behavior at various concentrations (3.0, 5.0 and 7.0%). The storage modulus of Rosella amylopectin showed a little high values and decreased gradually during increase in temperature even at 7.0% solution. The tan d showed a value of 2.0 at 7.0% even at low temperature (0℃) and increased a little with increase in temperature. The storage modulus of Rosella amylopectin (7.0%) increased a little upon addition of urea (4.0 M) and decreased gradually with increase in temperature. The storage modulus was a little higher in 0.05 M NaOH solution (7.0%) than in aqueous solution. The results obtained suggested that the wheat (Rosella) amylopectin molecules might be involved in little secondary association in aqueous solution. 続きを見る
7.

論文(リポジトリ)

論文(リポジトリ)
ホサイン, モハヤド・アムザド ; 松浦, 新吾郎 ; 土井, 光弘 ; 仲村, 一郎 ; 石嶺, 行男 ; Hossain, Amzad ; Matsuura, Singoro ; Doi, Mitsuhiro ; Nakamura, Ichiro ; Ishimine, Yukio
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.145-149,  2004-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3558
概要: 万田31号は,作物の収量と品質を高める発酵自然植物凝集物である.万田31号がウコンの生育および収量に効果的であるかを調べるために,1999年5月から2000年2月にかけて琉球大学の亜熱帯フィールド科学教育研究センターの実験圃場で試験した.試 験区を葉,土壌,葉と上壌の3つに分け. 100ppmの万田31号を15日間隔で10回施用した.ところが,1999年9月22日に強い台風が発生し,すべての圃場のウコンが大きな被害を受けた.しかしながら,台風後のウコンの回復力に万田31号施用区と無施用区では大きな違いが見られ,興味深い結果を示した.万田31号施用区と無施用区における台風後のウコンの被害の回復,生育および収量について調査した.その結果,万田31号施用区では,新しい分けつの発生と新芽が台風後15日目に確認でき,約70%の植物体は,万田31号の施用を続けることでウコンは順調に回復し,台風後,12月まで生育は良好であった.一方,万田31号施用区に隣接している無施用区においては,施用区から4~11m離れた畝のウコン収量は,11m以上離れたウコンの収量よりも有意に高く,18m以上離れた畝の植物体は,台風後40日以内に枯死した.総じてウコンの収量は,万田31号施用区が無施用区に比べて約3倍高かった.これらの結果は,万田31号は台風によるストレスに効果的で,しかも,万田施用区近隣の植物体にまで有利に働くと考えられる.万田31号の効用は,激しい降雨による流水によって隣接する圃場へ移動すると推察された.<br />Manda 31 is a fermented natural plant concentrate, which improves yield and quality of crops, vegetables and fruits without any hazard of environment factors. A series of experiments was conducted at the Subtropical Field Science Center of the University of the Ryukyus in 1999-2000, actually to examine the efficacy of manda 31 on growth and yield of turmeric. Manda 31 at lOOppm was applied 10 times to leaf, soil or leaf and soil at a 15-day interval until November. A strong typhoon, occurred on September 22, 1999, caused severe damages of turmeric plants in all fields equally. It was unbelievable that there were some differences in damage recovery and growth of turmeric plants between manda 31 applied field and commercial field (Manda 31 not applied), after typhoon occurred. Hence, in this paper, we compared damage recovery, growth and yield of turmeric between manda 31 applied field and commercial field. New tillers and leaves of turmeric plants developed within 15 days of typhoon occurred in the manda 31 applied field, and continued the process up to November. Around 70% of damaged plants recovered due to continuous application of manda 31, and the plants remained green up to December. It was also unbelievable that the plants in some rows in commercial field, which were adjacent to the manda 31 applied field (up to 18 m from manda 31 applied field), produced some new tillers and leaves, and remained green until November. On the other hand, the plants in this field, which were greater than 18 m from manda 31 applied field, withered within 40 days of typhoon occurred. Turmeric yield was around three times higher in manda 31 treated field than that in commercial field. Yield in the first four rows (4-11 m from manda 31 treated field) of commercial field was significantly higher than that in far rows (>11 m). Effect of manda 31 was not observed on plants in rows with greater than 18 m from manda 31 applied field. These results indicate that the manda 31 is effective in stress condition of plant, and plants in neighboring field of manda 31 applied field may be benefited with manda 31. It was assumed that manda 31 moved with heavy rainfall to the neighboring field. 続きを見る
8.

論文(リポジトリ)

論文(リポジトリ)
新里, 孝和 ; 呉, 立潮 ; 新本, 光孝 ; Shinzato, Takakazu ; Wu, Lichao ; Aramoto, Mitsunori
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.151-157,  2004-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3559
概要: 本論文は亜熱帯照葉樹林地帯において,天然更新を基盤とする各種天然林施栗法に関する研究の一環をなすものである.天然林施栗試験林は沖縄島北部と西表島西部にあり,沖縄島北部では琉球大学農学部附属亜熱帯フィールド教育研究センター・与那フィールドに皆 伐施栗(1992年度),択伐施栗(1993年度),帯状伐施葉(1994年度)が設定された.帯状伐施業は天然林の面積3,600m^2で,斜面方向に10m幅の6帯状試験区A~Fが区画され,樹高1.2m以上の立木について樹種,樹高,胸高直径の毎本調査が行われた.保残区の直径分布はL字型を示し,材積64.7%のイタジイが優占した天然林であった.毎本調査の後レ6帯状試験区は交互にA,C,Eの伐採区とB,D,Fの保残区に区分され,伐採区は全立木が地上20cm高で伐採された.各帯状試験区には10m×10mの方形調査区2個,計10個が設定された.本論文では帯状伐施栗林設定7年後の保残区について,設定時の天然林残存本51種邱O個体の生育状態が調査,解析された.残存本の生育状態は7タイプに類型化され,胸高直径と生活形から考察された.生育状態は残存本の64.7%が健全で,35.3%が支降水であった.支障本35.3%の内訳は,枯死15.8%,頂端部の枯損12.9‰倒木6.6%であった.生存状態は胸高直径と生活形に関係していた.胸高直径1-2cmの小径群は枯死率がもっとも高く,胸高直径12cm以上の大径群は頂端部の枯損率が高くなった.生活形ではシシアクテのような低木種は枯死本のほとんどを占め,優占種であるイタジイは枯死率が6.3%で低く健全率が71.9%と高かった.シシアクチやタシロルリミノキのような林冠下に生育する低木種の枯死率が高いのは,伐採による生育環境の急激な変化,例えば強い光,乾燥,風の影響,また林冠木の折損枝の落下圧,さらに残存本の成長や新規発生木による密度圧などが考えられる.帯状伐施薬は森林の循環利用にとってきわめて有効であるが,その施栗法の確立のためには,保残区の残存本の生育,伐採区の二次遷移,根株の萌芽や実生,侵人種の更新,それらの相互作用など継続的な調査が必要である.<br />The effect of strip clear-cutting on surviving states of the primary trees 7 years post-cut in a subtropical laurel forest in Okinawa was studied. In the 3,600 m2 study area, six permanent plots named A to F were established by sequence in January 1995. A tree census was conducted; all trees with height equal to or higher than 1.2 m in the study plots were numbered and recorded with species name, height, and diameter at breast height (DBH). Strip clear-cutting was conducted after the tree census in February; the trees in plots A, C, E were clear-felled at the base at 20 cm height above the ground, versus the other trees in plots B, D and F, which remained. In the present study, a new tree census was performed in December 2002. The primary trees consisted of 51 tree species 550 tree stems in plots B, D and F were checked. Examined and measures were the surviving state, DBH and height. The current state of the primary trees was divided into seven types. The results showed the majority of stems (64.7%) remained in regular state without obvious damage, while 35.3% of them were in disturbance, i.e. 15.8% of them were dead, 12.9 % of them were living in standing state with breakdown at treetop or with withered tops, and 6.6% of them were living in falling state. The surviving states of primary trees differed by DBHs, life forms and tree species. The smallest DBH group (1-2 cm) had the highest mortality rate, versus the big DBH group (>12 cm) which had the highest rate of breakdown at treetop. Ardisia quinquegona, a kind of nanophanerophyte species, had the majority of the dead stems, while the dominant species, Castanopsis sieboldii, had the low mortality (6.3%), with most stems (71.9%) in regular state. 続きを見る
9.

論文(リポジトリ)

論文(リポジトリ)
上野, 正実 ; 川満, 芳信 ; 孫, 麗亜 ; 平良, 英三 ; 内間, 亜希子 ; Ueno, Masami ; Kawamitsu, Yoshinobu ; Sun, Liya ; Taira, Eizo ; Uchima, Akiko
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.17-22,  2004-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3562
概要: 土壌状態や作物状態を詳細に把握してサトウキビ栽培を支援する情報システムを間発した.現行の品質取引で品質評価に利用されている近赤外分光分析装置(NIR)を効果的なデータ収集装置として使用した.品質取引において自動的に得られる精度と単収をデータ ベース化した.NIR測定システムの機能をジュース成分と土壌成分の評価もできるように拡張し,ショ精,グルコース,P,K,Mgおよび他のミネラル成分を一定精度内で測定できることを確認した.本システムで得られる大量のデータによってデータベースを極めて低コストで作成できることを示した.南大東島のサトウキビ生産システムにこのようなデータ収集システムを備えたモデル情報システムを組み込んだ.さらに,このシステムの目的を実現するために地理情報システム(GIS)を用いて単収と精度の空間分布の解析を行った. NIRとGISの組み合わせはサトウキビ生産システムの構造を解析するのに非常に有効であることが明らかとなった.いくつかの事例研究によって個々の農家の栽培と経営の改善におけるこのシステムの有用性を示した.<br />An information system was developed to assist the sugarcane cultivation by precisely grasping the conditions of soil, crop and others. Near Infrared Reflectance (NIR) spectroscopy for evaluating the cane quality in the current payment system was employed as an effective data collecting system. Sugar content and unit yield obtained automatically in the payment system were used to make a database. The function of NIR measurement system was extended to evaluate the components of cane juice and soil. It was confirmed that sucrose, glucose, P, K, Mg and other minerals could be measured within a certain accuracy level. A large volume of data collected by the system enabled us to make a database with quite low cost. A model information system equipped such data collecting system was installed into the sugarcane production system in Minami-Daito Island. Spatial analyses on the unit yield and sugar content were carried out using Geographic Information System (GIS) in order to achieve the purpose of the system. Combination of NIR and GIS was quite effective to analyze the structure of sugarcane production system. The availability of the system to improve the farming and management of individual farm was demonstrated by some case studies. 続きを見る
10.

論文(リポジトリ)

論文(リポジトリ)
イテャワンデイ, イン ; 篠原, 武夫 ; ダルスマ, ドゥドゥン ; Ichwandi, Iin ; Shinohara, Takeo ; Darusman, Dudung
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.33-41,  2004-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3564
概要: インドネシア開発計画の初期投資において大面積の天然林を有する同国は,国の収入を生み出すため,林業部門を振興した.この目標を実現するために,同国政府は国内投資促進のための税の優遇措置,丸太輸出の規制および禁止,輸出用製材品への高い税と最低価格 の設定,輸出促進といっ力経済手段を伴う政策を打ち出した.その結果,森林伐採梅と製材・合板業は数と生産能力の両面で急速に増加した.発展を続ける木材産業の成功は持続可能な森林資源経営によってもたらされているのではない.森林伐探梅の履行初めに導入されたインドネシア択伐法は大面積の天然林の劣化をもたらしている.木材産業は高い生産能力を有しており,短期間で供給できる丸太を求めているが,しかし天然林は持続的でない森林施薬の結果,かなり減少している.新しい政府の政策によって天然林資源と同様に木材産業も安定的に育成されるにちがいない<br />To finance the beginning of Indonesian development plans, Indonesia, which has a large natural forest, promoted forestry sector for generating national income. To realize this goal, Indonesian government issued some policies with economic instrument such as tax holiday for domestic investment, restriction and ban of logs export, a high tax and a minimum price on exported sawntimber, and export promot ion. As a consequence, forest concession and then sawntimber and plywood industries grew rapidly, both on number and capacity. Success on developing timber-based industries has not been followed by the successful management of forest resources. A Selective cutting (TPTI), which was introduced at the beginning of the implementation of forest concession, caused natural forest degradation on a large area. A high installed production capacity of timber-based industries needs logs, which are in short supply because natural forest has declined considerably as a result of unsustainable forest practices. Some new government policies must be set up to ensure the Indonesian timber-based industries as well as natural forest resources. 続きを見る