政府的有效组织与云南印楝产业的快速发展

云南省地方政府通过捕获信息、科学决策，制定印椿产业发展规划，引导印楝产业科学、合理、有序地发展。文章从3个方面阐述政府的有效组织是云南印椿产业快速发展的基础，即地方政府先期投入作为资金保障；科研先行。引进、筛选优良品种作为技术保障；集中育苗、加强幼苗管护作为管理机制保障。同时，抓住国家的政策机遇，强化印楝系列产品开发，开展国际合作，壮大印楝产业，使云南印楝种植规模迅速成为世界之最。     

印楝素含量与种子形态及成熟期关系的初步研究

对印楝素含量与种子形态表征及成熟期的关系进行了初步研究.种子的长宽比与印楝素含量相关,并且认为它是能反映印楝素含量的主要表征,得出种子长宽比(X)与印楝素含量(Y)的关系为:Y=0.295 0.134X-0.028X2.种子长宽比接近2.39时,种仁的印楝素含量出现峰值,可将印楝种子的形态表征作为初步估测印楝素含量的指示参数,而种子的成熟期与印楝素含量无关.在印楝原料林良种优良母树筛选中应尽量选择各个种源中生长良好、结实量大、种子饱满且长宽比接近2.39的植株.     

会理县印楝产业开发探讨

介绍了印楝的生物学特性和神奇的用途 ,分析了会理县发展印楝产业的优势和条件 ,详细总结了印楝的育苗造林和管理技术 ,并对如何发展印楝产业提出了设想和建议。     

广东引种印楝树的主要病虫害种类及其防治技术

文章从生产实际需要出发,总结近年来对印楝的病虫害观察和防治试验结果,介绍在广东省人工栽培印楝主要病虫害种类及其防治对策,以期在今后发展种植印楝时提供参考。     

影响印楝素稳定性及其含量的主要因素

印楝素的稳定性及其含量的高低受许多因素的影响。印楝素对光敏感，暴露在光下会逐渐失去活性；室温及低于20℃的贮藏温度有利于印楝素的稳定，而高于室内温度会加速印楝素的降解；印楝素在中性条件下比较稳定，室温条件下，在pH值为4～6的酸性水溶液中也稳定，但在碱性和强酸溶液中不稳定；中性有机溶剂对其稳定性有利。微生物的活动会加快印楝素的降解，不同的地理种源和种植土壤对印楝种实中印楝素的含量高低影响很大，在干季所结果实的种子中印楝素含量高于在雨季种植所结果实的种子。而不同组培条件对组培体的印楝素含量也会产生影响。     

快速搅拌法室温浸提印楝油和印楝素

在室温下用间歇式快速搅拌法从印楝种仁中浸提印楝油和印楝素。讨论了料液比以及浸提时间对得率的影响。结果表明:印楝种仁300g,以750mL石油醚做溶剂,在快速搅拌条件下浸提21min时印楝油得率最高;将300g去油后的印楝种仁以900mL甲醇做溶剂,在快速搅拌下浸提21min时印楝素得率最高。由此得出,快速搅拌法浸提印楝油的最佳条件是:溶剂石油醚、料液比1∶2.5(g∶mL,下同)、时间每次7min、浸提3次,出油率30.4%;快速搅拌法浸提印楝素的最佳条件是:溶剂为甲醇、料液比1∶3、时间每次7min、浸提3次,印楝素A的得率为0.438%,印楝素B的得率为0.142%。     

干热河谷地区印楝林农复合栽培模式经济效益分析

以现有5种主要印楝(Azadirachta indica)林农复合模式为研究对象,对5种主要印楝农林复合模式的印楝生长情况以及经济效益进行研究,探讨印楝与其它物种搭配种植对印楝生长结实的影响及其经济效益。结果显示:与印楝纯林相比,印楝与其它物种搭配种植不会显著抑制印楝生长结实,同时提高单位面积的经济效益;以净现值进行比较,5种林农复合模式经济效益从高到低排序为印楝-辣木间作印楝-咖啡间作印楝-甘蔗间作印楝-玉米间作印楝-木薯间作。     

印楝育苗技术

印楝属楝科，是热带、亚热带的一种速生常绿乔木，具有耐干旱、耐瘠薄的特点，原产于南亚，以印度和缅甸的干热地区自然分布最多，世界上有５０多个国家引种栽培。印楝在年降雨量８００～１２００ｍｍ的地区特别适合种植，我国的海南、广东及我省的德宏、元谋等地均已引种成功。印楝植株各部分均可利用，经济价值高，同时它具有杀虫功能，被誉为制造生物农药的最佳原料。 印楝果成熟后易脱落，种子无后熟期和休眠的特点。这给育苗带来不良影响，故须掌握一定育苗技术。笔者在元谋县多次培育过印楝苗，现将实践经验介绍如下：１ 种子处理 把…     

印楝对干热河谷立地条件适应性的初步研究

依据会理县金沙江干热河谷立地环境特点,通过印楝对立地条件适应性试验研究,总结提出了在本区适宜种植区,选择印楝造林地时,北坡（包括东北、西北坡）、土壤粘重板结、土层厚度低于50cm、土壤石砾含量过高、雨季季节性积水的地块,均不宜选择作造林地。本区大面积种植印楝,应以四旁、坡地林网、退耕还林种植为主,成片荒山种植为辅。     

印楝细胞悬浮培养系的建立及悬浮培养

研究了印楝细胞悬浮培养系的建立及印楝细胞悬浮培养的条件。结果表明,印楝细胞悬浮系的建立以B5培养基,NAA2 0～4 0mg·L-1,采用直接倾倒法作为接种方法为好;基于生物量、印楝素含量和印楝素产率综合分析认为,印楝细胞悬浮培养的最佳条件为B5培养基,NAA2～4mg·L-1,蔗糖30g·L-1,培养温度25℃,及根据培养容器的大小选择合适的转速和装液量。     

长白山林区天然次生林胡桃楸的适宜生长空间

利用次生林主林层胡桃楸34株平均木(胸径为11.0～39.1 cm)的树干解析数据,结合反映植物生长空间的冠幅,进行5,10和15年抚育间隔期的单株材积定期生长量、林分蓄积增长量与生长空间关系的研究,建立不同抚育间隔期胡桃楸胸径与适宜生长空间关系的模型;利用林冠下层27株胡桃楸平均木(胸径为4.6～14.3 cm)的树干解析数据,评价适宜生长空间模型应用于被压状态胡桃楸时的生长促进效果.结果表明:1)3参数S型曲线模型和二项式模型分别能够很好反映胡桃楸前5,10和15年间单株材积定期生长量、林分蓄积增长量与冠幅的关系;2)不同抚育间隔期胡桃楸胸径与适宜生长空间关系的模型为幂函数模型(y=a×x~b);3)对数函数模型(y=a×ln(x)+b)能显著反映适宜生长空间下胸径与材积定期生长量的关系;4)适宜生长空间下胡桃楸5,10和15年材积定期生长量至少比生长空间受限条件下的林木提高97.8%,114.4%和128.5%.采用5,10,15年抚育间隔期时,不同胸径胡桃楸的适宜生长空间分别是相应胸径的0.256 6～0.368 7,0.344 1～0.447 1和0.449 1～0.504 6倍.     

肉桂人工林土壤速效养分与酶活性的季节变化

研究了广西高峰林场林龄为3年和6年的肉桂人工林土壤速效养分(水解N、速效P、速效K)和土壤酶活性(过氧化氢酶、脲酶、酸性磷酸酶)的季节变化规律及其相互关系。结果表明：两种林地土壤速效养分含量和土壤酶话性均表现出明显的季节动态．：E壤速效N、P、K含量和L壤脲酶活性均以肉桂生长初期(3月中旬)最高．其次是第一个生长高峰期(6月中旬)或第二个生长高峰期(9月中旬)，最低是生长未期(12月中旬)；而土壤过氧化氢酶和酸性磷酸酶活性以第一个生长高峰期或第二个生长高峰期最高．其次是生长初期,最低是生长末期；士壤速效养分与土壤酶活性的季节变化密切相关。因此，生长初期至第一个生长高峰期是肉桂林地施用N、P、K肥的适当时期。     

7年生平欧杂种榛果实生长发育规律的研究

以‘82-11’、‘84-237’和‘84-402’等3个杂种榛优良品系为试材,采用动态监测的方法,研究7年生平欧杂种榛果实生长发育规律。结果表明,3个榛子品系果实重量生长曲线为“慢-快-慢”的“单S”型曲线,其生长过程可分为初始缓慢生长期、快速生长期、第二次缓慢生长期3个阶段。3个榛子品系果仁重量生长曲线为“单S”型曲线,随着果仁的发育,果仁鲜重逐渐增加,果仁重量的增加在果仁发育前期较快,后期较慢。果实发育前期,果实重量的增长主要来自细胞的分裂与膨大,果实发育后期,果实重量的增长主要由果仁的生长引起。     

美国白松生长特性的研究

以山东乡土针叶树种油松和黑松作对比,研究了从美国引种的１２年生美国白松的物候期及新梢、针叶的生长特性。以Ｌｏｇｉｓｔｉｃ方程拟合３种针叶树新梢和针叶的生长,并用数学分析的方法确定各树种新梢和针叶的速生期和速生点。测定了３个针叶树种的径、高年生长量。结果表明,美国白松在山东能够正常生长发育,生长期比油松和黑松短,但生长迅速,年生长量比较大,是一个值得引进并扩大栽培的速生针叶树种     

Acclimation of shoot and needle morphology and photosynthesis of two Picea species to differences in soil nutrient availability

To investigate morphological acclimation to differences in nutrient availability, we compared shoot and needle morphology of Picea glehnii (Friedr. Schmidt) M. T. Mast. and Picea jezoensis (Siebold & Zucc.) Carrière trees growing on nutrient-poor volcanic ash and nutrient-rich, brown forest soil. Trees of both species were shorter and had more open canopies when growing on volcanic ash than when growing on brown forest soil. Nutrient-poor conditions limited height growth less in P. glehnii than in P. jezoensis. In both species, trees growing on volcanic ash had shorter annual increments in the previous year and more needles per shoot length and, hence, a smaller shoot silhouette area (SSA) relative to needle dry mass (NDM) than trees growing on brown forest soil. Soil type had less effect on shoot projected needle area (PNA). Total needle area (TNA) of P. glehnii shoots was similar between soil types, whereas TNA of P. jezoensis was lower in trees growing on volcanic ash than in trees growing on brown forest soil. For both species, low SSA in response to nutrient-poor conditions resulted in low shoot SSA/PNA ratios, indicating high within-shoot self-shading. Shoot SSA/TNA of P. glehnii was lower in trees growing on volcanic ash than in trees growing on brown forest soil, indicating that needles were sun-acclimated. In contrast, shoot SSA/TNA of P. jezoensis was higher in trees growing on volcanic ash than in trees growing on brown forest soil. The contrasting response of TNA to low nutrient availability was associated with species-specific differences in needle morphology. Needles of P. glehnii growing on volcanic ash were slightly shorter, wider, thicker and heavier than those of trees growing on brown forest soil, indicating morphological acclimation to high irradiance. Needles of P. jezoensis growing on volcanic ash were shorter than those of trees growing on brown forest soil, but did not show morphological acclimation to high irradiance in width, thickness or mass. For both species, nutrient-poor conditions decreased maximum photosynthetic rate (Amax) per NDM. However, when expressed per PNA, the decrease in Amax was reduced, and when expressed per SSA, Amax was higher in trees growing on volcanic ash than in trees growing on brown forest soil. On volcanic ash, Amax per NDM was lower for P. glehnii than for P. jezoensis. However, morphological changes at the shoot and needle levels reversed this trend when Amax was expressed per SSA or per PNA. The species-specific differences in morphological response to differences in soil nutrient availability suggest that P. glehnii is more tolerant of nutrient-poor conditions, whereas P. jezoensis is better at exploiting nutrient-rich soils.     

四川盆地丘陵及盆周低山区杉木实生林生长特点及提高产量的途径

四川盆地丘陵及盆周低山区杉木实生林受气候等环境条件的影响,速生期早而短,若立地条件差则很多林木因早熟而达不到培育目标。本研究在调查杉木主要分布区林分生长状况基础上,通过树干解析、生长过程对比分析,弄清了该地区杉木林分速生期持续的年限,并提出了以间作、合理施肥、合理密植为提高产量的主要措施。试验证明,这些措施具有明显的效果,既改良了林地土壤的理化性质、提高了土壤肥力,又延长了林分的速生期,提高林分蓄积并改善了木材的规格质量,其经济效益和社会效益都十分明显。     

Plasticity of shoot and needle morphology and photosynthesis of two Picea species with different site preferences in northern Japan

We compared shoot and needle morphology and photosynthesis in Picea glehnii (Friedr. Schmidt) M.T. Mast. and Picea jezoensis (Sieb. et Zucc.) Carr. trees planted on immature volcanic ash and well-developed brown forest soils to investigate whether species differences in morphological and physiological plasticity affected tree growth on different soil types. Height growth of P. glehnii was reduced by about 10% on volcanic ash compared with forest soil, whereas that of P. jezoensis was reduced by more than 60%. Needle morphology of P. glehnii was unaffected by soil type. In contrast, needles of P. jezoensis trees growing on volcanic ash were shorter, narrower and thicker, with less dry mass and area, than those of trees growing on forest soil, and specific needle area was lower, indicating lower foliar light-interception efficiency. In both species, changes in needle morphology with increasing irradiance were similar in trees growing on both soil types, indicating that plasticity of needle morphology was unaffected by soil type. In both species, shoot mass and shoot silhouette area were lower and needle mass per unit shoot mass was higher in trees growing on volcanic ash than in trees growing on forest soil. Trees of both species had more needles per unit shoot length, lower shoot silhouette to projected needle area ratios and lower shoot silhouette areas per unit shoot mass (SAM) on volcanic ash than on forest soil, indicating lower shoot-level light-interception efficiency. For P. glehnii, the response of shoot morphology to increasing irradiance was similar on both soil types, with the exception of SAM, which showed lower plasticity in trees growing on volcanic ash. In contrast, shoot-level morphological plasticity of P. jezoensis was reduced in trees growing on volcanic ash. Light-saturated maximum photosynthetic rate (P(max)) of P. glehnii was unaffected by soil type, whereas mass-based P(max) of P. jezoensis was lower in trees growing on volcanic ash than in trees growing on forest soil. In P. jezoensis trees growing on forest soil, area-based P(max) increased with increasing irradiance, but this response was not observed in trees growing on volcanic ash. As a result, area-based P(max) at the top of the canopy was 39 to 54% lower in trees growing on volcanic ash than in trees growing on forest soil. Our results indicate that constraints on morphological acclimation to high irradiances may contribute to reduced height growth of P. jezoensis on volcanic ash.     

ECONOMIC ASPECTS OF POPLAR GROWING FOR MATCHWOOD PRODUCTION

Some economic aspects of poplar growing in South Africa are discussed. A volume yield table for Populus deltoides Bartram ex Marshall is presented and the average costs of poplar growing are reproduced. Various types of rotations are calculated and the profitability of poplar growing in South Africa is analysed.     

Effects of compost additive in sphagnum peat growing medium on Norway spruce container seedlings

Sphagnum peat has been the most commonly used growing medium in containers in tree nurseries worldwide for its good growing properties. As a result of increasing costs and environmental incentives, seedling-growers are seeking more local growing medium components such as composts. Composts are, however, diverse products with varying chemical, physical, and hygienic properties and therefore require thorough testing before real-world use. In this study, a commonly used compost (raw materials: sewage sludge, biowaste, peat, wood chips) was tested for feasibility as a component (0–30 vol.%) of a sphagnum peat container medium for growing Norway spruce (Picea abies (L.) Karst.) container seedlings in a forest-tree nursery. In proportions of up to 30% in peat, the compost additive used was shown to be a feasible material for seedling growing in forest nurseries. On average, the seedlings grew best in pure peat, but the compost additions to peat showed no marked reduction in seedling growth in greenhouses, nor were there any effect on seedling growth in the first summer after outplanting. However, a slightly elevated risk of seed non-germination and of seedling mortality was observed when the growing media contained compost in proportions of 20% or more. The compost additive in peat also changed the bulk density, structure, and chemical properties of the medium during nursery growing. The results suggest that seedling watering and fertilisation should be adjusted for each growing medium mix separately to achieve correct water, oxygen, and nutrient availability in containers during nursery growing.