Articles containing the keyword 'willow'

Possibilities of developing suitable willow (Salix spp.) clones for short-rotation forestry on mined peatlands in the north-western area of Finland were studied in a field experiment in which 300 willow clones were tested during 1985–87. Most of the tested clones started to grow from cuttings on limed and fertilized peat soil. Salix viminalis L. clones of southern origin had a higher leafless above ground biomass production than the well adapted control clone and the local Finnish willows, but their winter hardiness was not satisfactory. The growth habit of some southern willows was also better than that of the control clone. It was also possible to select clones with good sprouting capacity. There were few Salix myrsinifolia Calisb. clones of Finnish origin, which had better cold tolerance than all other willows tested and higher biomass production than that of the control clone. The most critical factor to be selected for this is the optimal combination of winter hardiness and biomass production. This is attempted by selecting clones on the basis of this experiment for a breeding program.

The PDF includes a summary in Finnish.

• Lumme, E-mail: il@mm.unknown
• Törmälä, E-mail: tt@mm.unknown

The solubilityof various phosphorus and potassium compounds in a sedge peat soil was studied in an incubation experiment aimed at screening potential fertilizers for the cultivation of fast-growing willows. (KPO₃)n proved not to be a source of the slow-released K regarded as most desirable for this kind of cultivation as it was hydrolysed completely in the soil during incubation. Phosphorus from easily soluble or hydrolysable compounds (superphosphate, KH₂PO₄, (KPO₃)n) was bound in the soil largely by Al and Fe and elevated the level of readily soluble P considerably, whereas rock phosphates were found to be practically unchanged after incubation and did not contribute to the readily soluble P in the soil. Apatites proved to be quite insoluble and are therefore assumed to be unsuitable as P fertilizers for fast-growing willows, which have a high nutrient demand.

The PDF includes an abstract in Finnish.

• Lumme, E-mail: il@mm.unknown
• Yli-Halla, E-mail: my@mm.unknown

Salix 'Aquatica Gigantea', widely experimented and promising species for temperate zone short rotation forestry, has since 1950 recorded in Finland 23 times with different clone numbers. Salix x dasyclados Wimm., by morphological, cultivational and productivity characteristics similar willow has been recorded 16 times.

The nomenclature and origin of both willows have remained unclear in field research. Recent observations, based on morphological analyses and chromosome studies suggest that ’Aguatica gigantea’ and most S. x dasuclados clones can be collected under one Siberian species: Salix burjatica Nasarov. The true Salix x dasyclados Wimm. is a female hybrid S. x viminalis x cinerea, famous West-European basket willow that has been very little experimented in Finland.

The PDF includes an abstract in Finnish.

• Pohjonen, E-mail: vp@mm.unknown

The interactive effects of water stress and temperature on the CO₂ response of photosynthesis was studied in Salix sp. cv. Aquatica using the closed IRGA system. A semi-empirical model was used to describe the CO₂ response of photosynthesis. The interactive effect of water stress and temperature was divided into two components: the change in CO₂ conductance and the change in the photosynthetic capacity. The CO₂ conductance was not dependent on the temperature when the willow plant was well watered, but during water stress it decreased as the temperature increased. The photosynthetic capacity of the willow plant increased along with an increase in temperature when well-watered, but during water stress temperature had quite opposite effect.

The PDF includes a summary in Finnish.

• Smolander, E-mail: hs@mm.unknown
• Lappi, E-mail: jl@mm.unknown

Downy birch (Betula pubescens Ehrh.) trees growing on a drained peatland were cut during dormancy. The properties of the one-year old shoots produced by the stumps were measured in the autumn after one growing season. The one-year old willow shoots (a mixture of Salix phylicifolia L., S. pentandra L. and S. caprea L.) were collected from an abandoned field.

The basic density of unbarked shoots was 443 kg/m³ for birch and 346 kg/m³ for willow. The basic density of the bark was much higher than that of the wood. The effect of shoot length on the properties was small with the exception of cellular proportions. The fibre percentage increased and vessel percentage decreased with increasing shoot length.

The PDF includes a summary in Finnish.

• Bhat, E-mail: kb@mm.unknown
• Ferm, E-mail: af@mm.unknown
• Kärkkäinen, E-mail: mk@mm.unknown

A review is made into the experiences and possibilities of willow breeding, with a particular consideration of their application under Finnish conditions.

In comparison with other tree genera, Salix has many advantages in breeding. The great number of species, large genetic variation between and within species and frequent crossability offer good possibilities for improvement by hybridization. The dioecious flowering, plentiful seed production and short generation cycle are valuable properties for breeding by controlled pollination. Individuals with desirable characteristics can be easily propagated vegetatively from cuttings. The propertied stated above are also characteristic of poplars, the breeding of which has resulted in great success. Corresponding results can be therefore expected from willow breeding, which has recently been initiated in several countries.

Today willows have no practical significance for forestry in Finland. There are, however, some suitable Salix species, both indigenous and exotic, for starting material for breeding, and plenty of favourable sites for willows. Therefore, the beginning of breeding research with willows should be well justified also in Finland.

The PDF includes a summary in English.

• Malmivaara, E-mail: em@mm.unknown
• Mikola, E-mail: jm@mm.unknown
• Palmberg, E-mail: cp@mm.unknown

The winter food of moose (Alces alces L.) was examined in 1967-68 in the Saariselkä fell area in the communes of Inari and Sodankylä, in the northern parts of the communes of Salla and Savukoski, and in the central part of the commune of Salla in eastern Lapland in Finland.

In northern parts of Salla and Savukoski 25 moose were followed during 3.-13.4.1968. This area is typical wintering terrain of moose in north-east Lapland. According to the estimate, 45% food taken by the moose was Scots pine shoots and needles, 28% birch, 17% juniper sprigs and needles, 9% willow, and 1.5% bear moss. According to observations of the researchers in 26.1.-16.5.1968, moose seemed to avoid birch, even if it was available in the area, and eat Scots pine shoots and needles and juniper.

Moose seemed to prefer willow in as a winter feed in the southern part of the area studied, where it accounts according to the present and earlier studies 50-90% of the winter food. In the northern wintering areas of moose, where willow is not as common, willow seemed to account for less than 10% of the winter food. There Scots pine is the most important winter food for moose.

The PDF includes a summary in English.

• Pulliainen, E-mail: ep@mm.unknown
• Loisa, E-mail: kl@mm.unknown
• Pohjalainen, E-mail: tp@mm.unknown

There is demand for cultivated willow in toy and barrel making, and handcrafts in Finland. In Europe, Salix sp. have been cultivated on several kinds of sites. In Finland, suitable sites for willow plantations could be found, for instance, by the rivers and brooks, on other alluvial lands, wet meadows and other humid lands unsuitable for agriculture. The article suggests that the cultivation of willow should begin on the agricultural lands, because the choice of origin of the willow cuttings is less important when it is grown on fields, and the areas are more accessible. The desired qualities for cultivated willow are good growth rate and robust stems, frost resistance and resistance to annual cuttings. Of the different species, especially suitable is Salix sect. Amygdalinae. In field tests, all the tested Salix species have been frost resistant, which makes it possible to cut the stems annually.

The PDF includes a summary in German.

• Nordberg, E-mail: sn@mm.unknown

Salix viminalis L. is an important shrub that has potential for use as a bioenergy crop, for phytoremediation of heavy metal contaminated soil and sewage sludge treatment. It is mainly distributed in the northeast of China, but the species has not yet been used a resource here. We examined the genetic diversity and population structure of populations from the Ergun basin and West Liao basin using 20 microsatellite markers. A high level of genetic diversity (N_a = 16.45, H_e = 0.742) was detected for S. viminalis, and populations from the Ergun basin exhibited higher genetic diversity and private alleles numbers than the West Liao basin. The 12 populations could be divided into two clusters by both Bayesian analysis and UPGMA clustering which were consistent with the populations derived from the two basins. Moderate population differentiation (F_ST = 0.076) was shown in S. viminalis, and AMOVA analysis confirmed that most of the genetic variation (86.13%) was attributed to individual differences within populations, while 11.49% was attributed to differences between basins and 2.38% to differences within each basin. Significant correlations of F_ST/(1–F_ST) with log (geographic distance) among 12 populations (r = 0.634, p < 0.00) and 10 populations within the Ergun basin (r = 0.482, p = 0.0002) indicated that geographical distance was the principal factor influencing genetic structure. As most of genetic variation exist within populations, so protection measures should be focused on populations with higher genetic diversity and unique alleles, such as Tuli, Mordaga downstream, Zhadun1 and Genhe.

• Zhai, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China; School of Architectural and Artistic Design, Henan Polytechnic University, Century Avenue, Jiaozuo, Henan, 454000, PR China E-mail: lkyzff@163.com
• Liu, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China E-mail: liu-jx295@163.com
• Li, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China E-mail: zhenjianli@163.com
• Mao, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China; Research Institute of Economic Forest, Xinjiang Academy of Forestry, Anjunanlu, Urumqi, Xinjiang, PR China E-mail: 350512173@qq.com
• Qian, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China E-mail: qianyq@caf.ac.cn
• Han, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China E-mail: hdd@caf.ac.cn
• Sun, State Key Laboratory of Tree Genetics and Breeding; Research Institute of Forestry, Chinese Academy of Forestry; Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Haidian District, Beijing, 10091, PR China E-mail: lkyszy@126.com

• Mola-Yudego, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: blas.mola@uef.fi

• Repo, The Finnish Forest Research Institute, Joensuu Research Centre, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: tapani.repo@metla.fi
• Laukkanen, University of Joensuu, Department of Physics, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: jl@nn.fi
• Silvennoinen, University of Joensuu, Department of Physics, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: rs@nn.fi