摘要:

Display activity, lek population size, and day‐time movements of capercaillie (Tetrao urogallus)on 3 experimentally logged leks were compared with 2 untreated control leks in a coniferous area in southeastern Norway, during 1980–87. The treatments were clearcut‐ting and thinning of lek areas and parts of surrounding day territories. We recorded considerable changes in display activity and day territories, but the demographic responses were less obvious. A negative effect on population size was recorded only at the most thoroughly logged lek. The findings indicate that large clearcuts (>20 ha) and thorough thinnings (leaving <4–500 stems/ha) promote solitary display, which may have long‐term evolutionary and ecological consequences.

ISSN:0282-7581    

DOI:10.1080/02827588909382551

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In a 136 km2coniferous area in southeastern Norway, 13 of 24 past leks, known from the 1930–40s, went extinct and 5 new leks were established, by 1985. There was no difference in extinction rate between clearfelled (7 of 13) and untreated (6 of 11) leks. Number of leks, number of cocks per lek, and total number of cocks were reduced by 33, 53, and 69%, respectively, compared with a 69% reduction in suitable habitat (forest. older than 70 years). We argue that the overall population decline merely was due to a general fragmentation of suitable habitats, rather than direct clearfelling of lek areas.

ISSN:0282-7581    

DOI:10.1080/02827588909382552

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Height increment among full‐sib families of lodgepole pine plus trees were assessed during different growth phases of the first and second year in nursery. The percentage of the total variance in seedling height and increment due to general combining ability was similar for all growth phases (4–6%). Specific combining ability was significant only at 5 weeks in year 1 (16.2%). Maternal effects were significant at 5 weeks both in year 1 (10.0%) and year 2 (2.5%). Total increment each year was not maternally influenced. The variance component of general combining ability and also the coefficient of variation for height were of a similar size among the corresponding half‐sib families in a 10‐year‐old field test, while the family ranking differed. Present results indicate that breeding should follow methods that make use of general combining ability.

ISSN:0282-7581    

DOI:10.1080/02827588909382553

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Two‐ and eight‐year‐oldPinus sylvestris, originating as controlled crossings from southern and northern Finland, were studied in order to determine their susceptibility to damage byMicrotus‐species. For characteristics that indicate climatic adaptedness (bud set, needle stage) there was a clinal change from north to south according to origin. These differences were not correlated with susceptibility to vole damage. Nor was the total phenol content of the saplings correlated with resistance to such damage. Between families, however, there were statistically significant differences in susceptibility to damage. Some families showed both rapid rate of growth and high resistance.

ISSN:0282-7581    

DOI:10.1080/02827588909382554

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

After‐effects of maternal soil treatment, controlling for photoperiod and weather conditions, were tested in a nursery experiment withPinus sylvestrisL. seedlings. Three full‐sib crosses were replicated in 4 different soil treatment plots of a grafted experimental seed orchard (63"54'N). Weight of filled seeds, percentage of empty seeds, first year hypocotyl and epicotyl length, and autumn frost hardiness (from artificial freeze testing) were evaluated. Systematic effects from maternal soil treatment were small compared to family differences for all characters studied. However, epicotyl length of the progenies showed a positive relationship with N needle content of the mother grafts. The results also indicated an important interaction between maternal soil treatment and autumn frost hardiness of the families. It is suggested that the altered mother tree treatment could lead to a change in progeny performance, corresponding to a 1.5 degree difference in latitudinal origin of natural stand seedlings. The results demonstrate the advantages of providing the mother tree with uniform conditions in early progeny testing.

ISSN:0282-7581    

DOI:10.1080/02827588909382555

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Cambial electrical resistance (CER) of Norway spruce (Picea abiesKarst.) was measured in relation to wood temperature. The linear function obtained was used to correct CER values from field experiments to a standard temperature. A fairly good correlation was obtained between the growth rate and CER of both dominant and suppressed trees. The average value of CER in a sample of spruce trees was relatively low in summer, increased by 100% in the autumn and started decreasing again the following March. Drought stress in a field experiment resulted in a significant increase in CER, which was inversely correlated with bark moisture. A review of the literature concerning the use of CER is presented, and the relevance of estimating CER is discussed, particularly regarding stress and diseases.

ISSN:0282-7581    

DOI:10.1080/02827588909382556

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The study discusses two approaches to predict e effect the effect of neighboring trees on the 5‐year basal area growth of Scots pine. The first approach relies on empirical competition indices and the second on an ecological field theory. The growth models account for 82–84% of the within‐stand variation in basal area growth. The directional distribution of competitors has a slight influence on the tree growth, besides the number, size and distance of the neighbors. To demonstrate the use of spatial growth models, three simulation studies are presented. The first one examined the effect of the spatial pattern of trees on the volume increment of the stand, the second one the usability of variation in the stand basal area as a measure of grouping, and the third one the effects of harvest roads.

ISSN:0282-7581    

DOI:10.1080/02827588909382557

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The paper presents and tests a method for comparing real thinning with strip roads and a simulated selective thinning pattern without strip roads in the same tree stand. The simulation method includes growth models for single trees, and a computer program for carrying out different selective thinning patterns. Simulation proved to be a more reliable method than the simple comparison between the stand growth on 15 m wide zones including and excluding the strip road. The method reduces the effects of random and systematic differences, especially on the small experimental plots. The material of young and middle‐aged Norway spruce stands (19 plots) showed that the growth loss is 0–10% during the first ten years, depending on the width of the strip road and the density of the stand.

ISSN:0282-7581    

DOI:10.1080/02827588909382558

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The possibility of using infrared thermography as seedling vitality test before planting was investigated. The temperature of seedlings of Scots pine and Norway spruce was determined in the laboratory before planting using the AGA Thermovision System. It was found that the field performance conformed to the IR measurements of the seedlings. The “cold”; (high‐transpiring) seedlings performed better than the “warm”; (low‐transpiring) ones. Some of the measurement problems discussed concern illumination and the interpretation of the thermo‐grams because of the small size of conifer needles. The IR measurements might be a tool in a future system for grading seedlings.

ISSN:0282-7581    

DOI:10.1080/02827588909382559

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The effects of stand density, thinning and pruning on the quality of sawn timber of Scots pine(Pinus sylvestrisL.) were studied based on a computer model. Procedures for the tree growth and crown structure produce a tree, whose properties in terms of location, dimensions and quality (living, dead) of branches are known for any moment of the selected rotation. Consequently, the size, quality (living, dead) and location of knots in sawn timber are recognizable allowing the grading of sawn pieces. The model computations showed that the natural dynamics of the crown system in narrowly‐spaced stands could yield sawn timber nearly of the same quality as resulted from pruning in widely‐spaced stands. Thinning increased the branch growth and the branchiness of the wood yielding lower grade for sawn pieces, respectively.

ISSN:0282-7581    

DOI:10.1080/02827588909382560

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor