四川低海拔区杉木萌生林经营前景研究   总被引：2，自引：0，他引：2  

胡庭兴  袁洪光 《四川林业科技》1995,16(2):16-25

通过对四川省低海拔区杉木萌生林生长特点的分析，确定在中、上立地条件下，杉木第一代萌生林的成熟龄在１４～１６年左右。从胸径和树高生长看，第一代萌生林以留萌一株为好，但从单位面积蓄积看，以留萌两株为佳，在距地面高度不大的情况下，不同的采伐方式和伐桩高度对萌生林生长影响不大。一代萌生林的木材力学学性质与全国同年龄实生杉木的性质十分接近。详细的经济分析表明，在低海拔地区经营第一代杉木萌生林具有良好的前景。  相似文献   

杉木幼林不同抚育方法效果的评价   总被引：11，自引：0，他引：11       下载免费PDF全文

张先仪  盛伟彤  邓宗付  李旭明  张小文 《林业科学研究》1994,7(4):394-398

在江西分宜县上村林场地位指数≥１６，没有或极少五节芒、茅草和水竹的地段，对杉木幼林采用以下抚育方法：①全面刀抚；②全面刀抚加局部松土除草；③全面松土除草。连续３ａ试验观测，结果表明：①和②法比③法植被覆盖度分别大５％～２５％，侵蚀量少４０％以上；３种抚育方法对林水生长均无显著差异，单位面积的抚育用工量，①法仅为②、③法的１／３左右。所以综合看来，以①法效果为佳。  相似文献   

Role of canopy interception on water and nutrient cycling in Chinese fir plantation ecosystem     

Wenxing Kang  Xiangwen Deng  Zhonghui Zhao 《Frontiers of Forestry in China》2007,2(4):448-452

The role of canopy interception on nutrient cycling in Chinese fir plantation ecosystem was studied on the basis of the position data during four years. Results indicate that the average canopy interception amount was 267.0 mm/year. Canopy interception play a significant role in water cycle and nutrient cycle processes in ecosystem, and was an important part of evaporation from the Chinese fir plantation ecosystem, being up to 27.2%. The evaporation from the canopy interception was an important way of water output from ecosystem, up to 19.9%. The flush-eluviation of branches and leaves caused by canopy interception brought nutrient input of 143.629 kg/(hm² · year), which was 117.2% of the input 63.924 kg/(hm² · year) from the atmospheric precipitation. The decreased amount of 80.1 mm precipitation input caused by canopy interception reduced the amount of rainfall into the stand surface and infiltration into the soil, reduced the output with runoff and drainage, and decreased nutrient loss through output water. Therefore, the additional preserve of nutrient by canopy interception was 8.664 kg/(hm² · year). __________ Translated from Scientia Silvae Sinicae, 2006, 42(12): 1–5 [译自: 林业科学]  相似文献   

Using near-infrared hyperspectral images on subalpine fir board. Part 1: Moisture content estimation     

Ataollah Haddadi  James Burger  Brigitte Leblon  Zarin Pirouz  Kevin Groves  Joseph Nader 《Wood material science & engineering》2015,10(1):27-40

Abstract

In this study, moisture content (MC) images of subalpine fir (abies lasiocarpa Hook) boards were derived from near-infrared hyperspectral images in the 947–1637 nm range. One hundred and seven cubic samples with the size of 4 cm were prepared from 14 boards. All samples were dried to various MCs during several steps until being completely dried. Hyperspectral images and weight measurements were acquired over each sample at each drying step. The samples have MC ranging from 1% to 137% (dry basis). The images were first calibrated into reflectance. Then, bad pixels were found and replaced by a corrected value using a median filter. A modified version of the boxplot method was used to find abnormal spectra that were then removed. The remaining spectra were converted into absorbance spectra. They were then split into a calibration and a validation data-set according to the boards they were extracted from to build and validate a partial least squares (PLS) regression model between the near-infrared absorbance spectra and the measured MCs. The PLS model was applied first to the sample images, then to the whole board images in order to produce 2D images of MC.  相似文献   

杉木人工林不同造材方式的效果分析   总被引：1，自引：1，他引：1  

林金叶 《福建林业科技》2006,33(1):90-93

以福建顺昌130株杉木人工林采伐样木资料为基础,采用7种不同的造材方式进行实际造材,对不同造材方式的出材率和平均销售单价进行比较,分析结果表明,不同造材方式出材率、平均销售单价之间均有显著差异。采用第7种造材方式(遇到根部有缺陷的,则截1 m段头,4 m段造材,根部无缺陷的,则不截头,4 m段造材)出材率和平均销售单价均最大,为最佳的造材方式。  相似文献   

杉木人工中幼林二元立木材积数学模型的选择     

陈绘画  王子荣 《浙江林业科技》1995,15(4):55-60

对多种二元立木材积方程的拟合和比较，认为形数由平均实验形数推算而得时，以迈耶的６参数方程拟合杉木人工中幼林二元立木材积的效果最佳。  相似文献   

杉木种子园建园技术研究初探     

董元华  李昌廷  杨曾顺 《西部林业科学》1996,(2)

本文着重论述杉木种子园建园中关于建园材料、园址选择、规划设计、子代测定、建园技术、技术档案的收集等问题。  相似文献   

杉木主要材质性状配合力研究^*   总被引：12，自引：2，他引：12       下载免费PDF全文

支济伟  陈益泰  骆秀琴  张寿槐  管宁  张国武 《林业科学研究》1994,7(5):531-536

对杉木７×７半双列杂交试验林进行８个材质性状的测定和配合力分析。结果表明，所有材质性状的一般配合力方差均达到极显水平。木材径向干缩系数，顺纹抗压强度和纤维长度的特殊配合力方差达到极显水平。除径向干缩系数和顺纹抗压性状以外，一般配合力方差的分量远大于特殊配合力方差的分量（随机模型），表明基因加性效应对这些性状的表达起主要作用。木材密度、径向干缩系数、顺纹抗压强度和纤维长度的广义遗传力较高（分别为  相似文献   

杉木幼林地水土流失规律的研究   总被引：10，自引：0，他引：10  

俞新妥  杨玉盛 《林业科学》1993,29(1):25-32

在4个坡度级的山场上建立12个径流小区,连续4年对炼山的杉木幼林地定位观测,分析了杉木幼林从炼山起至郁闭止,林地的水、土、肥流失的季节和年度的变化规律,划分了水土流失时期,分析坡度与流失的关系。结果指出,炼山后第一年水、土、肥流失最严重,泥沙冲刷量达24.81t·ha~(-1),以后逐年递减,至第4年趋于稳定,与不炼山的接近。常规幼林抚育措施加剧了林地水土流失,建议调整幼林抚育方式和季节,并采取必要的生物措施。  相似文献   

杉木间伐材生产层压板工艺研究   总被引：3，自引：0，他引：3  

宋孝金 《福建林业科技》1994,21(4):13-18

本文探讨了利用小径杉木间伐材生产建筑模板用材──层压板的生产方法与工艺条件；并研究了各种工艺参数对产品性能的影响，确定了生产层压板的较佳工艺条件。  相似文献