摘要:

In commercial sawn wood (green lumber) (50 × 150 mm) the pinewood nematode,Bursaphelenchus xylophilus(PWN) was found more frequently and in greater numbers in bluestained sections of lumber boards. The nematode population was dominated by third dispersal juvenile stage (J111). At 70°C a sawmill kiln was more effective in eradicating PWN from infested boards as compared to a laboratory heating oven. In pieces of boards (50 × 150 × 45 mm) all nematodes were killed in 30 minutes in the sawmill kiln, whereas in the laboratory oven, even after 9 hours, living nematodes were present. In 60 cm boards all the nematodes were killed in 2 hours in the sawmill kiln. The results suggest kiln‐heating to be a very effective means of control of PWN in lumber, high temperature being the main contributor to the death of the nematodes. A high frequency of J111of PWN in lumber appeared to be of no importance for this efficiency.

ISSN:0282-7581    

DOI:10.1080/02827589209382703

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Lygusbugs are known to cause growth disorders on young Scots pine seedlings. The affect of timing of the damage on the disorder symptoms was studied on 2–3‐year‐old pine seedlings by exposing the seedlings toLygusbugs at different times between June and September. Early season exposure was found to cause the strongest visible deformations on current year buds and the following year shoots. Latent bud damage, that inhibited budset in the subsequent growing season, was found on seedlings that were exposed to bugs in late July and early August. No growth disorders were detected on the seedlings exposed to bugs late in the season.

ISSN:0282-7581    

DOI:10.1080/02827589209382704

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The susceptibility of a 20‐year‐old Scots pine stand to Scleroderris canker caused byGremmeniella abietinawas monitored in relation to stocking density. The data included five densities varying from 800 to 5 000 trees/ha. The degree of damage, as indicated by the proportion of brown needles and the number of dead trees, correlated positively with the stand density. The proportion of dead trees was low at densities below 1 100 trees/ha, but increased linearly with increasing density.

ISSN:0282-7581    

DOI:10.1080/02827589209382705

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Increased mechanization in the forestry means usually increased traffic on a ground which is also used as a growth substrate. In this state‐of‐the‐art article it is found that the traffic could have an areal extent of 10–30% of the site area mainly due to yarding at clear‐felling and thinning. In the future there could be up to 6 machine entries on the site till a stand age of 50 year.

ISSN:0282-7581    

DOI:10.1080/02827589209382706

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Lime (1 000 kg/ha), NH4NO3(150 kg N/ha) or a combination of both, were added to plots in two middle‐aged coniferous forest stands. Lysimeter studies were performed during four to six years after treatment.

ISSN:0282-7581    

DOI:10.1080/02827589209382707

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In a 38‐year‐old Scots pine(Pinus sylvestrisL.) stand, located in Central Sweden, the accumulation of15N‐labelled fertilizer nitrogen in the foliage was monitored for 6 years. The nitrogen sources used were double‐labelled ammonium nitrate, urea and ammonia solution. Ammonium nitrate was surface broadcast, while the urea and ammonia solution were applied by concentrated deep‐point‐placement.

ISSN:0282-7581    

DOI:10.1080/02827589209382708

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Bacteria inhabiting the xylem of Norway spruce(Picea abies(L.) H. Karsten) were investigated. The trees had been wounded and artificially inoculated with fungi and bacteria obtained from wounds of naturally infected spruce. One and five growing seasons after inoculation the Gram‐negative bacterial population present in the stem of inoculated trees were analysed.

ISSN:0282-7581    

DOI:10.1080/02827589209382709

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Effects of drought on the formation of mycorrhizas byHebeloma crustuliniforme(HC),Paxillus involutus(PI),Laccaria proxima(LP) and Thelephora terrestris (TT) onPicea sitchensiswere studied during well‐watered, moderate and severe drying cycles, and these results were related to the growth and nutrition of the seedlings. TT formed abundant mycorrhizas in all water regimes, Pl showed some preference to the moderately droughted regime, and HC and LP formed most mycorrhizas with the well‐watered seedlings. The differences in the mycorrhizal colonization were not reflected in the growth of plants, but the seedlings with high proportions of mycorrhizas tended to have high N and P concentrations and contents.

ISSN:0282-7581    

DOI:10.1080/02827589209382710

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A method for estimating frost hardiness in seedlings ofLarix leptolepisin their first stage of acclimation is demonstrated. Cuttings of the shoot tip were frozen linearly from +2°C to ‐36°C. The viability was determined by TTC‐assay. Data were fitted to a logistic regression model, and hardiness was calculated from the fitting parameters. It was shown that hardiness is influenced by the duration of the fertilizer application period. No effect of the nutrient status of N, P or K in the shoots was found.

ISSN:0282-7581    

DOI:10.1080/02827589209382711

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Survival and growth were assessed for 17 provenance hybrids and three natural populations ofPinus sylvestris(L.) planted in three field trials in central and northern Sweden. Restricted to the high mortality site the 18‐year hybrid survival percentage increased by three units per degree north latitude and one percent per 100 m higher altitude of the mother. The hybrid height was less influenced by the geographical origin than hybrid survival. For both traits the natural populations were better than or equal to hybrids with the same geographical mean origin. The variance component of the mother was mostly 2–3 times larger than the provenance component. The effect of the grandmother was nonsignificant for both traits.

ISSN:0282-7581    

DOI:10.1080/02827589209382712

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor