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COMPARATIVE ANALYSES ON THE LITTER IN KOREAN PINE MONGOLIAN SCOTS PINE AND dahurian larch PLANTATIONS(Ⅱ)CONTENT AND RETURNING AMOUNT OF NUTRIENT ELEMENTS

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Journal of Northeast Forestry University 1995年第1期6卷 12-17页

作者：王克张羽 Northeast Forestry University China

Comparative analyses were conducted on the nutrient element content and returning amount of main fractional compositions of litter in Korean pine (KP), Mongolian Scots pine(MSP) and dahurian larch (DL) plantations in Laoshan Plantation Experiment Station of Maoershan Experiment Forest Farm of Northeast Forestry University. The results are as follows: (1) The nutrient element content and returning amount in litter varies among different fractional compositions and tree species, the total returning amount of all nutrient elements and the returning amount of K, Ca, Mg, N and P are DL>MSP>KP, the returning amount of Cu is DL>KP>MSP, the returning amount of Fe and Mn are MSP>DL>KP, (2) To KP and DL plantations, the main nutrient element returned is dead needles; dead branches, bark scales and dead cones account for a little proportion; whereas to MSP plantation, besides dead needles,dead branches and bark scales also play an important role in the return of nutrient elements; (3)A little deal of dead leaves can provided a great deal of returning amount of nutrient elements.

关键词： Korean pine Mongolian Scots pine dahurian larch Plantation Litter,Nutrient elements Returning amount

GROWTH AND YIELD MODELS FOR dahurian larch PLANTATIONS

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Journal of Northeast Forestry University 1991年第1期2卷 24-29页

作者： Li Changshcng Jiang Yiyin Yeh-chu Wang Northeast Forestry University Northeast Forestry University China

Growth and yield models were developed for individual tress and stands based on 336 temporary plots with 405 stem analysis trees of dahurian larch ( Larix gmelinii( Rupr. )Rupr.) plantations throughout Daxing'anling mountains. Several equations were selected using nonlinear regression analysis. Results showed that the Richards equation was the best model for estimating tree height, stand mean height and stand dominant height from age; The Power equation was the best model for prediction tree volume from DBH and tree height; The logarithmic stand volume equation was good for predicting stand volume from age, mean height, basal area and other stand variables. These models can be used to construct the volume table, the site index table and other forestry tables for dahurian larch plantations.

关键词： Growth and yield model Richards equation Plantations dahurian larch

THE SEASONAL DYNAMICS OF NUTRIENT CONTENTS IN MANCHURIA ASH-dahurian larch MIXED STAND

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Journal of Northeast Forestry University 1995年第3期6卷 105-108页

作者：国庆喜 Northeast forestry university Harbin P. R. of China

The yield increasing mechanism of the manchurian ash (Fraxinus mandchurica) and dahurian larch(Larix gmelini) mixed stand was studied on nutrition status of soil and leaves. The results showed that nutrient contents of leaves and contents of the available nutrients of soil in the mixed and pure stands varied with seasons of the year. The available phosphorus contentS of the soil in the larch belt were much higher than those in the manchurian ash belt during growhg season, with the highest value of 3.5 mg/100g, 2~3 times of the latter. The nitrogen contents of leaves of the manchurian ash trees nearest from dahurian larch belt wer 12.7%~80.8% higher than those of its pure stand, and phosphorus 13.4%~140. 8%. The different uptake thythm of the nutrients modified the interspecific competition. The general conclusion is that the high contents of available phosphorus of the soil in dahurian larch belt improved the growing condition of nearby manhurian ash trees.

关键词： Mixed stand Manchurian ash Nutrient dynamics dahurian larch

STUDIES ON OPTIMUM MODELS FOR CULTIVATING dahurian larch SEEDLINGS ON FRIGID REGIONS

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Journal of Northeast Forestry University 1996年第2期7卷 6-10页

作者：宋景和 Northeast Forestry University Harbin P. R. China

The optimum models for cultivationg the seedlings of dahurian larch (Larix gmelim Rupr. ) were studied in the central nursery of Tahe Forestery Bureau from 1989 to 1993. The resultswerc as follows The optimum models of the main morphological standards of the seedlings were30000 kg /hm2 of' decomposed' ash for improviong soil, 70,000 kg/hm2 of excrement and 1,500 kg/hm2of' calcium superphosphate as basal fertilizer , and 500 kg/hm2 of (NH4)2HPO4 and 220 kg/hm2 of'urea as top dressing. During growth perlod of the seedlings, the growth was greatly checked when thesoil water suction (SWS) was uithin 50 ~ 73. 3 kPa or below 10 kPa but greatest when SWS waswithin 30 ~ 40 kPa in initial growth stage and within 10-20kPa in last growth stage. The method for determining the optimum sowing time is to measure the depth of soil thawing, accumulated temperature abovc 5℃ both at 5 cm of the depth of of soil and in atmosphere. In Tahe region, the optimumsowing trme for dahurian larch for Dahuria larch is about on May 10 when the depth of soil thawing, the accumulatedtemperature above 5℃ at 5 cm of the depth and the accumulated temperature above 5℃ in atmosphere reaches 40 cm. abovc 46℃ and abovae 56℃ respectively. The optimum seedlings density forthis region is 600-800 individuals/m2.

关键词： dahurian larch Seedling Phenological rule, Community effect, Soil, water management Standard quantitative model

DYNAMIC THINNING SYSTEM FOR larch PLANTATION

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Journal of Northeast Forestry University 1994年第2期5卷 17-21页

作者：陈祥伟王常海丁宝永张世英 Northeast Forestry University China

Systematic researches were carried out in dahurian larch (Larixgmelini) plantation in the spring of 1958 at Maoershan Forest Farm attached to Northeast Forestry University. First of all, a new tree classificdtion method. relat11'e classification in small group, was presented. Each small group was composed of one tree in the center and six adjacent trees, which formed a hexagon in space. All these seven trees. then, can be divided into five classes such as class A class B,class C. class D and class E respectiveiy. For the conxenience of comparison. the stand used for the trial was duvided into five experimental plots in which the thinning intensity for each plot was controllca as follows: 10% for the first plot; 20% for the second plot- 30% for the third plot; 40% for the fourth plot and the fifth plot without thinning for comparison. Thinning operation was carried out according to the principle of reserving A-class trees, cutting B- class trees in the intensity as required, releasing C-class trees and removing D and E class *** 14 years study- the result shows that if the stand volume of contrast plot is considered as 100% after the first thinning' the volume of other plots are 114. 9% for the first plot, 128. 4% for the second plot, 133. 1% fOr the third plot and 118. 5% for The fourth plot respectively. Meanwhile, biomass and increment of diameter can also be increased significantly after thinning by this method.

关键词： dahurian larch Plantation Thinning Cutting intensity