Effects of understorey vegetation on tree establishment and growth in a silvopastoral system in northern Greece     

Stergios Gakis  Konstantinos Mantzanas  Dimitrios Alifragis  Vasilios P. Papanastasis  Athanasios Papaioannou  Dimosthenis Seilopoulos  Panagiotis Platis 《Agroforestry Systems》2004,60(2):149-157

The interaction between understorey plants and trees in a young silvopastoral system was studied in a sub-humid Mediterranean environment with cold winters in northern Greece. The experimental design was a split-split plot with three replications and included: three understorey treatments (grass, legume and control), two tree species (Acer pseudoplatanus and Pinus sylvestris) and two spacings (2.5×2.5 m and 3.5×3.5 m). The competition between herbaceous plants and trees resulted in significant differentiation in tree growth while their spacing did not produce any significant differences. The influence of trees on herbage yield either by plant species or spacing was not significant. During the early stages of establishment, a significant positive correlation was observed between sycamore growth and soil moisture, leaf weight, leaf area and leaf number as well as nitrogen and potassium concentration in leaves. Six years after planting the height increase of the sycamore trees was largest in the control treatment (415%), lowest in the grass treatment (134%) and intermediate (192%) in the legume treatment. Much higher was the increase obtained for the diameter, 161%, 207% and 536% respectively for the grass, legume and control treatments. The Scots pine trees grew faster than sycamore over the course of the experiment. Height increased by 397%, 351% and 400% and diameter by 518%, 443% and 683% respectively for the grass, legume and control treatments. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

合理年采伐量信息管理系统     

王晶  苏顺 《林业勘查设计》2006,(2):103-104

为了配合“十一五”期间年森林采伐限额的编制工作,开发了合理年采伐量信息管理系统,本系统对于未来我国森林资源的经营管理和林业建设有着重要意义。以科学发展观和可持续发展的理念统领和指导编限工作,立足资源、国情、林情,求真务实,统筹协调,编制出符合我国实际、科学、合理的“十一五”期间的年森林采伐限额。本系统是对采伐限额的编制的全自动管理,实现了从数据输入、校对、档案管理、统计计算、打印输出一体的信息管理,各级间的数据也可通过磁盘或网络传输,大大地提高了信息的实效性和准确性。  相似文献   

Kebon tatangkalan: a disappearing agroforest in the Upper Citarum Watershed,West Java,Indonesia     

ParikesitEmail author  K.?Takeuchi  A.?Tsunekawa  O.?S.?Abdoellah 《Agroforestry Systems》2005,63(2):171-182

A comprehensive study was carried out on a typical indigenous agroforestry system, called kebon tatangkalan, in the changing agricultural landscape of the Upper Citarum Watershed, West Java, Indonesia. The main objectives of the study are to elucidate the structural patterns, multidimensional functions, and dynamics of this multi-layered agroforest. The study has identified 12 groups of different plant assemblages indicating that this type of agroforest contributes considerably to the heterogeneity of the agricultural landscape in the study area. Multivariate analysis suggests that elevation and slope are the biophysical factors that correlate most significantly with the distribution of plant species in kebon tatangkalan. The presence of this man-made vegetation is currently declining from the landscape due to population growth and rapid regional economic development. Serious effort to revitalize this traditional agroforest is needed to prevent its disappearance. Introduction of highly productive species and establishment of integrated policies in regional land-use planning and management are measures that should be taken into account in preserving this traditional agroforestry system.  相似文献   

森林防火指挥系统、ArcGIS和Google Earth结合在新一轮退耕还林工程中的应用     

阳昭 《内蒙古林业调查设计》2020,43(2):82-85

在永平县新一轮退耕还林工程作业设计和管理中,利用森林防火指挥系统、ArcGIS10.2和Google Earth的功能优势互补、取长补短,完成工程地块定位、落实勾绘、面积求算、编辑成图等工作。结果表明以上3种软件(系统)结合易学易用、工作效率高、成本低、结果准确、在无地形图识图能力的情况下也能进行工程小班、地块空间位置定位识别、管理。文章简述了地块勾绘,数据格式转换,创建自定义地理(坐标)变换,投影变换,设计小班、地块数据编辑成图的方法和步骤,以期在同类工程中得到应用。  相似文献   

林业科技创新、推广与示范体系建设     

龙云英  郑亚东  丁思统 《江西林业科技》2001,(5):36-37

论述了林业科技创新、推广与示范体系建设在林业开发中的重要性，总结了上饶市的实践经验与体会。  相似文献   

内蒙古可持续发展指标体系设计及评价方法研究   总被引：2，自引：0，他引：2  

邹积君  藏克冰  刘贵富  刘继先 《森林工程》2002,18(6):9-10

通过对内蒙古可持续发展评价指标体系和方法的初步研究，设计出了包括可持续发展综合指数1个目标层、人口状况等5个准则层和人口自然增长率等28个评价指标的层次性指标体系，并利用均方差权数决策方法，对区域可持续发展进行全面分析和定量评价。  相似文献   

Optimum planting density for Japanese oak (Quercus mongolica var.grosseserrata) based on spacing experiment with systematic design     

Morio Imada  Takashi Kunisaki  Nobuya Mizoue  Yukio Teraoka 《Journal of Forest Research》1997,2(2):89-93

A spacing experiment for Japanese oak (Quercus mongolica var.grosseserrata) with Nelder's design have been studied at the Kyushu University Forest in Hokkaido, since 1975. The oak seedlings were planted according to systematic spacings which were 20 levels varying gradually from 40,816 to 1,086 seedlings per hectare with concentric circular arcs (22 in number) and spokes (41 in number). In 1992 when the planted oak seedlings were 18-year-old, DBH, crown diameter, total height and clear length of the survival trees were measured. Based on the results obtained from analyzing the relationships between planting density and the mean values of each block, the optimum planting density should be 7,241 seedlings per hectare. The title is tentative translation from the original Japanese title by the authors of this paper.  相似文献   

面向控制系统的系统逻辑分析和设计方法     

欧松 《中南林业科技大学学报(自然科学版)》1994,(2)

本文应用离散事件系统（ＤＥＤＳ）对系统进行分析，求出了状态转移函数，找出了状态转移规律的给定模式，并根据结定模式的逻辑关系，匹配出梯形图程序．为实现系统分析和系统程序设计的规范化提供了依据．  相似文献   

1-没食子酸甘油酯的研制及其抗氧化性能的研究     

宋振华  肖尊琰 《林产化学与工业》1988,(3)

在实验室条件下,以没食子酸和甘油为原料合成了1-没食子酸甘油酯(GG),做为油脂或油脂食品的抗氧化剂,保护油脂不因氧化腐败,延长贮存时间。合成途径是在日本高砂光正等人工作基础上进行了若干改进,使得率由45.7％提高到72.9％。以菜子油和豆油做底物,丙酯(PG)和2,6-二特丁基对甲酚(BHT)做对比抗氧化剂,用增重法评价其抗氧化性能,柠檬酸和酒石酸做增效剂,评价其增效作用,研究了浓度和分散度对诱导期的影响,探讨了结构因素对性能的影响。实验室结果表明:在本实验条件下,活性次序是GG>PG>BHT,随着浓度的增加,活性增大顺序是GG>PG>BHT。酒石酸对GG有增效作用,柠檬酸无效。溶解度对诱导期没有影响,说明了性能差异产生的原因。通过研究为简化合成途径,进行工业化生产提供了依据,并在此基础上为合成新型抗氧化剂找到一种可行方法。  相似文献   

中国林业科技实力评价     

李智勇 《林业科学》1991,27(5):517-525

本文采用指标评价分析法构建了中国林业科技实力评价指标体系,并就人员、经费、课题、成果、科研仪器设备、科技信息、论文发表数、技术贸易和国际科技合作与交流9个主要指标进行了评价,结果是林业科技基础良好,实力较弱且组合效益欠佳。研究亦指出,人员“结构性断层”与“结构性老化”现象应予注意。  相似文献