杉木与马褂木、檫树混交林及其纯林生物量和土壤肥力研究

从林分生长、生物量、空间分布格局及土壤养分等方面 ,对营造于福建邵武的 5年生杉木与马褂木、檫树不同模式混交林及其纯林进行了研究。结果表明 :杉木与马褂木、檫树混交林及马褂木、檫树纯林具有较高的林分生产力 ,马褂木纯林 (91.932 t· hm-2 )和杉 2∶马 1(4 5 .2 32 t·hm-2 )混交林生物量 (烘干 )分别是杉木纯林的 4 .5 5倍、2 .2 4倍 ;杉 3∶马 1(36.12 0 t· hm-2 )和杉5∶马 1(34 .2 92 t· hm-2 )混交林生物量 ,分别比杉木纯林大 78.96%和 69.90 % ;檫树纯林生物量(60 .10 5 t· hm-2 )是杉木纯林的 3.31倍 ,杉 2∶檫 1(32 .4 2 6t· hm-2 )、杉 3∶檫 1(2 8.635 t·hm-2 )和杉 5∶檫 1(2 5 .82 3t· hm-2 )混交林 ,分别比杉木纯林大 78.5 4 %、5 7.67%和 4 2 .18%。杉木与马褂木、檫树混交林不仅有利于维护地力 ,促进杉木生长 ,而且可形成较好的林分结构 ,杉 2∶马 (檫 ) 1带状混交模式是值得推广的杉阔造林模式。     

杉木、檫树混交林生长及其土壤肥力变化分析

针对不同比例杉木、棒树混交林的生长及土壤肥力状况进行了调查分析。结果表明：10a生杉檫混交种间关系比例协调．林分较稳定，可以促进两树种的生长。从林分群体结构的整个生长同期展望，4：1杉檫混交是一种比较稳定的高产类型，不同混交比例的土壤理化性质有所变化，杉檫列间比杉木列间土壤变得疏松、湿润、较肥沃。     

杉木,檫树混交林光合成生产力研究

在研究杉木，檫树光合特性的基础上，分别对杉，檫网状混交林及其纯林的光合生产力进行了探讨。林分的物质生产结构，尤其是光合系统中的叶面积密度，叶面积指数及叶的年龄结构，与林分的光合生产力关系最为密切；它们还直接影响林分的光能分布。林分的光合生产力以混交林最高，檫树纯林最低。在混交林内，光合生产力以檫树最高，檫树近旁的第１行杉木最低。在林分或单株标准木范围内，光合生产力与林地生产力在ａ＝０．０５的水平上     

杉木 檫树光合特性研究

在离体条件下,用红外线CO_2气体分析仪,测定杉木(Cunninghamia Ian-ceolata)和檫树(Pseudosassafras Iaxiflora)的光-光合曲线。固定叶位叶的净光合速率随叶龄的增加和冠层光强度的减弱而降低;同一技条上,净光合速率又都随叶着生部位的升高而升高。杉木的耐荫性比檫树强。衫木3年生阳位叶CO_2日交换呈释放过程。林冠光合产物的积累,杉木主要来自冠表1年生阳位叶,檫树为冠表不断产生的技顶功能叶。     

杉木、檫树混交林光合生产力研究

在研究杉木、檫树光合特性的基础上，分别对杉，檫网状混交林及其纯林的光合生产力进行了探讨。林分的物质生产结构，尤其是光合系统中的叶面积密度、叶面积指数及叶的年龄结构，与林分的光合生产力关系最为密切；它们还直接影响林分的光能分布。林分的光合生产力以混交林最高，檫树纯林最低。在混交林内，光合生产力以檫树最高，檫树近旁的第１行杉木最低。在林分或单株标准木范围内，。光合生产力与林地生产力在ａ＝０．０５的水平上，存在极显著正相关关系     

杉木与南酸枣混交林生物量及土壤肥力研究

从林分生长、生物量及土壤养分等方面,对营造于浙江遂昌县牛头山林场的6年生杉木(Cunnighamia lanceolata)与南酸枣(Choerospondias axillaris)不同模式混交林及其纯林进行了调查和对比分析,结果表明,南酸枣与杉木混交后能促进杉木的生长和有利于维护地力,其中以杉∶南=3∶1混交模式生产力和生物量较高,蓄积量为76.42 m3/hm2,生物量为41.512 7 t/hm2,与杉木纯林为相比,分别提高了74.55％和97.27％,南酸枣纯林以及杉木南酸枣混交林的土壤肥力与杉木纯林相比也均有不同程度提高.     

杉木巨尾桉混交林林分生物量及土壤肥力研究

对杉木纯林、杉木巨尾桉混交林的林分生物量、土壤肥力和生物多样性的研究结果表明：杉桉混交林林分的总蓄积量比杉木纯林高出26．41％，生物量则是纯林的1．6倍，大大地提高林分生产力。两种林分林地土壤结构稳定性相差不大，混交林土壤肥力略有下降，但混交林增加了群落的生物多样性，取得了良好的生态效益。因而营造杉木巨尾桉混交林是科学经营杉木连栽地的有效措施之一。     

杉木拟赤杨混交林土壤肥力研究

杉木是我国南方重要的速生用材树种，但长期的连栽会引起地力衰退。通过对杉木拟赤杨混交林土壤的物理性质和化学性质等进行研究，认为混交林土壤结构状况，水分物理性质均比杉木纯林得到较大程度的改善，同时０－２０ｃｍ土层有机质，全Ｎ，全Ｐ比杉木纯林增加１２．４３％，１４．２９％和７．３２％；水解Ｎ，速产Ｐ，速效Ｋ分别增加１５．４９％，７．８９％和６．７８％，混交林土壤肥力状况明显优于杉木纯林。     

闽南山地马尾松火力楠混交林的生物量和土壤肥力研究

基于对闽南山地马尾松火力楠混交林及马尾松纯林的大量调查，分析了经营混交林与纯林对生物量及土壤肥力所产生的影响。结果表明：与马尾松纯林相比，马尾松火力楠混交林对生物量积累具有显著的促进作用，对林地土壤具有明显的改良作用，土壤水分、养分状况明显改善。建议今后应尽量避免连茬经营人工纯林，提倡营造针阔混交林。     

Millettia ferruginea from southern Ethiopia: Impacts on soil fertility and growth of maize

Growing agricultural crops under Millettia ferruginea (Hochst.) Baker, a tree that is endemic to Ethiopia, is an age-old practice in the country, but the beneficial effects of the tree on crops have not been scientifically quantified. To achieve this, four isolated and nearly identical Millettia trees growing on similar site conditions were selected and canopy coverage of each tree was divided into four radial transects. Four plots of 0.5 × 0.5 m were established on each radial transect at 0.5 to 1, 2.5 to 3, 4.5 to 5, and 6.5 to 7 m away from the tree bases. The control plot was established at 29.5 to 30 m. Composite soil samples from each of the four plots located at a comparable distance and at two soil depths, 0 to 10 and 20 to 30 cm, were collected and analyzed. The level of surface soil P, organic C, exchangeable base-forming cations and cation exchange capacity were all significantly higher (P < 0.000 to P < 0.015) under the trees than in the open field. Nutrient levels declined with depth and increasing distances from the tree trunk. Soil pH values did not show significant horizontal or vertical variations in all the soil samples analyzed. Maize plants grown on soils collected from underneath Millettia trees resulted in significantly better growth responses and higher dry matter yield as compared to the control (P < 0.001). Socioeconomic studies indicated that Millettia trees have good standing in the region both because of their desirable biological characteristics and because of their economic benefits.This revised version was published online in November 2005 with corrections to the Cover Date.     

杉檫人工混交林地表可燃物水分析出规律的研究

设立标准地,测定杉檫人工混交林内地表可燃物水分与林内气象因子及地表可燃物负荷量的关系,运用SPSS软件分析,得出多元线性回归方程。并结合偏相关分析它们对地表可燃物水分析出规律影响的权重。结果表明权重大小顺序为:相对湿度、风速、温度、地表可燃物负荷量。     

Productivity,soil fertility and soil erosion under cassava based agroforestry systems

The interactions between component species in three-tier agroforestry systems were studied on sloping laterite soils of South India for three years. The wood yield of Eucalyptus was found to increase in association with the intercrops, with cassava + groundnut resulting in the best growth of Eucalyptus. Green forage yield of Leucaena was adversely affected by cassava but was improved by inclusion of a short duration seasonal crop. Both spread and mean length of lateral roots of Eucalyptus and Leucaena were restricted by cassava intercropping. Both the tree species were found to reduce the tuber yield of cassava and also the pod yield of both the seasonal crops when grown in association. Monocropping with cassava was found to improve the fertility and an increase in phosphorus and potassium contents of the soil was observed when grown in association with Eucalyptus and Leucaena. Soil fertility fell considerably after three years of cultivation of the tree species. The nutrient uptake by cassava was low when grown in association with perennial species. Both run off and soil loss were effectively reduced when cassava was grown in staggered mounds under Eucalyptus and Leucaena.     

杉木乳源木莲混交对地力影响的初步研究

对１０年生乳源木莲与杉木的混交林及杉木纯林的林地枯枝落叶量及分解速率、土壤理化性质等进行调查分析。结果表明：混交林结构林地物理性质优于杉木纯林，土壤水稳性团聚体组成多，土壤疏松多孔；土壤有机质、全Ｎ、全Ｐ分别比杉木纯林提高１２．２％、１１．８％和４．５％，土壤速效养分（Ｎ、Ｐ、Ｋ）亦分别提高２９．６％、１０．５％、１０．１％，该混交对地力改良有积极作用。     

辽西地区不同人工林地土壤肥力变化研究

为研究辽西地区人工林对石灰性褐土土壤质量的定向改良作用,以油松×沙棘混交林、山杏纯林、油松纯林3种人工林地为研究对象,对在石灰性褐土上的人工林土壤肥力进行了分析。结果表明,油松沙棘混交林能够显著提高有机碳含量,比荒地高42.8%;油松沙棘混交林、油松纯林土壤碱解氮分别比荒地增加34.6%和33.6%,人工林对土壤全氮含量影响不显著;油松沙棘混交林的土壤速效磷和水溶性磷分别比荒地提高14.9%和128.57%;人工林增加了土壤速效钾含量;林木的改良土壤作用主要表现在土壤表层。     

长沙市城乡交错带五种林分土壤肥力评价

基于野外调查和土壤样品分析数据,应用内梅罗综合指数法,讨论了长沙市城乡交错带五种典型林分类型（枫香纯林、马尾松-阔叶树混交林、湿地松纯林、杉木-桤木混交林、樟树纯林）土壤的综合肥力状况。结果表明,各林分林地均属于有机质、速效磷含量中等,速效钾含量缺乏。五种林分土壤综合肥力系数的大小顺序为马尾松-阔叶树混交林〉杉木一桤木混交林〉樟树林〉枫香林〉湿地松林。     

马尾松苦槠混交林生长状况与土壤肥力分析

对福建省光泽县杉木人工林采伐迹地上营造的7 a生马尾松纯林和马尾松苦槠混交林(混交比例1∶1)的生长量和土壤肥力进行研究。研究结果表明:在下坡位,混交林的林分生长量大于马尾松纯林,蓄积量为30.33 m3·hm-2,比马尾松纯林增加17.47%;在中坡位,混交林的蓄积量略高于马尾松纯林;在上坡位,混交林的生长量小于马尾松纯林,林分蓄积量为11.89 m3·hm-2,仅为马尾松纯林的76.02%。混交林和纯林蓄积量、表层(0-10 cm)土壤有机质和全氮等指标均随着坡位的下降而增加。马尾松苦槠混交林的表层(0-10 cm)土壤有机质、全N等指标在下坡和中坡位均略高于马尾松纯林,在上坡位则略低马尾松纯林。     

周山森林公园不同林木生长对土壤氮的动态影响

在河南洛阳周山森林公园,2009年不同时期对紫叶李(Prunus cerasifera Ehrhart)和塔柏(Sabina chinensis)不同立地林地土壤全氮含量进行了测定,结果表明:紫叶李林地土壤中全氮的含量高于塔柏林地含量,无论平地坡地皆是如此。在不同月份或季节,前者全氮的含量高于后者,且波动幅度较后者大。同时土壤中全氮含量也受地形的影响,平地的全氮含量高于坡地。不同深度,0~10cm土层,平地和坡地的差距最大,随着土层深度的增加,差距逐渐缩小,20~30cm土层,已无明显差异。总体来看,紫叶李平地和坡地土壤氮元素的含量变化要比塔柏平地和坡地土壤氮元素含量变化显著。