摘要:

During three consecutive years, 1978–1980, cloudberries (Rubus chamaemorusL.), cranberries(Vaccinium oxycoccusL. &Vaccinium microcarpumTurcz.) and lingonberriesVaccinium vitis‐idaeaL.) growing wild in Swedish forests and mires were inventoried in the annual National Forest Survey. Both the coverage and fertility of these were estimated. Observations from 42 000 test sites (314 m2each) were processed according to geographical region, composition of tree and field layer, altitude and occurrence of draining ditches. Cloudberries cover 425 000 hectares or 1.5 % of the total investigated area (28.6 million hectares). The corresponding values for cranberries and lingonberries are 136000 hectares (0.5 %) and 1362000 ha (4.8%) respectively. Open mires have a greater degree of coverage by cloudberry and cranberry than wet forests on peat. The reverse situation is true for lingonberry. The total berry yield on peatland was estimated to 116.6 million kg (freshweight), distributed as 75.7 million kg cloudberries, 20.8 million kg cranberries and 20.1 million kg lingonberries. The corresponding production of lingonberries on mineral soils was 188.8 million kg. Both in wet forests and on mires, drained areas show lower berry production for the three species, with one exception. Lingonberries yielded better on drained mires. Productive stands of cloudberries and cranberries ought not to be drained for economic reasons.

ISSN:0282-7581    

DOI:10.1080/02827588609382406

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Data on stem volume of intra‐ and interprovenance hybrids ofPicea abiesfrom three field trials, 20–28 years of age, are presented. The mating design is factorial in all trials and the two oldest have the same 33 families. The variation in general combining ability of the mother trees was significant at the youngest trial, while that of the father trees was significant at all trials. The variation in specific combining ability was significant in all trials. The variance component for general combining ability was 1.4–3.7 times larger than that for specific combining ability. A strong genotype × environment interaction was noted both for parental general combining ability and family means. The largest gains in breeding will be obtained by producing commercial seed of selected families.

ISSN:0282-7581    

DOI:10.1080/02827588609382407

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Data on some 30 characters related to stem quality of intra‐ and interprovenance hybrids ofPicea abiesfrom three field trials. 20–28 years of age, are presented. In all three trials the mating design is factorial and the two earliest trials have the same 33 families. For the majority of the characters significant variation of the GCA was noted and in some cases SCA was also significant. Generally the variance components were several times larger for GCA than for SCA. The largest GCA components were noted for basic density, and the sum of the branch diameters divided by the breast height diameter. Three clones with offspring of superior quality and stem volume were identified. For most characters there was no significant difference between the two mating types, Swedish×Swedish and Swedish×central European families. A significant genotype×environment interaction was noted for several characters but the variance components were low, not exceeding 5%.

ISSN:0282-7581    

DOI:10.1080/02827588609382408

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The climatic influence on plant litter decomposition has been successfully correlated on a regional level by using estimated actual evapotranspiration (AET) and annual mass loss. This approach was applied to decomposition studies carried out in a transect along Sweden with litter incubated in four different forest types. A unified needle litter was used and among 14 Scots pine sites about 80% of the mass‐loss rate could be explained. A simple model was made on the influence of both climate and nutrient concentrations (nitrogen and phosphorus) on mass‐loss rate. About 90% of the first‐year mass loss could be explained by this approach. As early decomposition stages were studied (<40%) no influence of lignin was observed.

ISSN:0282-7581    

DOI:10.1080/02827588609382409

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The carbohydrate reserve of bareroot Scots pine(Pinus sylvestrisL.) seedlings was evaluated as means of describing seedling quality and capacity to withstand stress during nursery lifting, outplanting and acclimatization at the planting site. Carbohydrate concentrations in needles were followed through four spring storage treatments and the postplanting success and growth of seedlings monitored at two sites. The reduction in total glucose concentration in needles was affected by storage time and temperature. Depletion of carbohydrate reserves decreased needle growth, reduced the number of terminal buds, disturbed leader shoot formation, and consequently reduced shoot length. The depletion of reserves below a threshold concentration of ∼2 % total glucose during storage resulted in significant seedling mortality. A simple model for estimating the depletion of carbohydrate reserves based on dark respiration was evaluated as a measure of the accumulated strain during the storage. The application of carbohydrate analyses as a routine test of seedling quality in a nursery is not currently feasible because of the insensitivity and laboriousness of the method.

ISSN:0282-7581    

DOI:10.1080/02827588609382410

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A dynamic model of branch length and weight growth was developed for two contrasting sites, both with young stands of spruce. At one site sample trees were obtained from both unfertilised plots and from plots with increased growth rate maintained by annual fertilisation. At the second site unfertilised trees and trees subject to single applications of fertiliser were modelled. A model of the same structure was developed for each site and tested by application at the alternate site. In view of the close agreement between sites, model parameters were calculated based on all data combined. The model is driven by height increment and branch age. The sample trees were mostly open grown so that only a tentative estimate of the effects of between tree competition is given. The limitations of the model are stressed.

ISSN:0282-7581    

DOI:10.1080/02827588609382411

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Six short‐term freezing experiments were carried out on 24 one‐year‐old single‐tree open pollinated families ofPinus sylvestris(L.) representing four populations in northerly Sweden (latitude 62°10'N to 66°50'N). Two experiments were conducted in a climate chamber, two in a greenhouse and two outdoors. For freeze testing the plants were exposed to ‐10°C for three hours in a freezing chamber. A freezing experiment in a climate chamber of 28 one‐year‐old full‐sib families (half diallel with two parents from each population) was also carried out. The results were related to the mortality of the same open pollinated families over the first 18 years in the field. The ranking of the populations was the same in all six freezing experiments as in the field. Significant differences in frost resistance between one‐year‐old open pollinated families were found within all populations except the most northern one. The correlations within populations between frost resistance and field mortality varied considerably between populations and freezing experiments. The results from the two greenhouse experiments showed the best correlations with the cumulative field mortality after 18 years. The freezing test of the 28 full‐sib families resulted in the same mutual ranking, according to the general combining ability of parents within populations, as was obtained from the freezing tests of single tree families.

ISSN:0282-7581    

DOI:10.1080/02827588609382412

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Reinvestigation of 90 soil profiles sampled for pH measurements in 1927 revealed a general decrease in pH with 0.3–0.9 units (measured electrometrically on field‐moist samples in water with the same ratio soil/water on both occasions). All soil horizons (A0, A2, B and the subsoil, C, at 70 cm depth) had become more acid beneath all types of canopy (beech, oak, spruce planted during different periods), but the spruce stands were on average more acid than the hardwoods. In the upper soil horizons (A0and A2), old spruce stands were more acid than the young ones at both samplings, but this effect was small in the B horizon and absent in the C horizon. While the tree species effect and age effect in the spruce stands may be called biological acidification, the acidification of deeper horizons, now often below pH 4.5 and in the aluminium buffer range, seems difficult to explain without assuming an influence of acid deposition.

ISSN:0282-7581    

DOI:10.1080/02827588609382413

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Scots pine and different provenances of lodgepole pine were compared in regard to root characteristics and the distribution of biomass within individual trees. Tap root formation was more frequent and the root/shoot ratio was higher on Scots pine than on lodgepole pine but significant variation of these traits was found between provenances of planted lodgepole pine. A non‐destructive method for estimation of root biomass was developed.

ISSN:0282-7581    

DOI:10.1080/02827588609382414

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The probability of achieving an anatomically mature seed crop of Scots pine(Pinus sylvestrisL.) in Northern Finland has been studied on the basis of earlier data and meteorological observations. The meteorological data over the period of 1951–1980 was used to calculate the probability of having a mature seed crop in various parts of Northern Finland. The climatic variables used were: (a) June‐August mean temperature (b)June—September mean temperature, and (c) annual temperature sum (+5°C base temperature). A non‐linear relationship between the percentage of mature seeds in a seed crop and the annual temperature sum was detected, indicating that 50% mature seed crop was achieved at appr. 890 degree days. The results suggest that the probability of having 50% mature seed crop is approximately 0.02–0.03 near the polar timber line. The probability of the occurrence of such years is, however, considerably higher in lowlands and lake districts even near the timber line.

ISSN:0282-7581    

DOI:10.1080/02827588609382415

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor