Initial seedling emergence of hairy birch and silver birch on abandoned fields following different site preparation regimes

Experiments were carried out at four sites in Sweden to investigate the possibility of establishing hairy birch (Betula pubescens Ehrh.) and silver birch (Betula pendula Roth) on abandoned fields using natural regeneration and (or) direct seeding. The effects of six soil preparation methods (no preparation, ordinary ploughing, rotary cultivation, deep ploughing, inverted ground, removal of top-soil) and five additional treatments (no treatment, herbicide, peat litter, wood-ashes, slaked lime) on seedling emergence percentages (SEP) and vegetation cover percentages (VCP) were studied. SEP-values were estimated in June (SEP(J)) and October (SEP(O)). The experimental designs used were: 1) split-plot design with whole plots in a randomized complete block design (RCBD); 2) RCBD. The SEP-values observed with no preparation were close to 0% while the SEP-values obtained with mechanical soil preparation methods mostly were much higher (p0.014). Seedbeds with top-soil in the surface, created by ordinary ploughing or rotary cultivation, and seedbeds with mainly bare mineral soil in the surface, created by deep ploughing, inverted ground or removal of top-soil, obtained SEP-values of equal merit on silty soils, reaching SEP(O)-values up to 15%. The latter seedbeds obtained the best results on sandy soil, with as high SEP(O)-values as 47% after removal of top-soil. Seedbeds with top-soil in the surface were quickly colonized by ground vegetation, reaching VCP-values between 70% and 100%. Herbicide spraying with glyphosate and application of peat litter to the seedbed surface promoted seedling emergence. However, herbicide spraying before soil preparation was of little effect when followed by mechanical soil preparation.     

Early performance of native birch (<Emphasis Type="Italic">Betula</Emphasis> spp.) planted on cutaway peatlands: influence of species,stock types and seedlings size

The poor reputation of birch in Ireland is gradually changing, and the interest shown in it by foresters is growing, as is the recognition of the many advantages that this genus offers, especially from an afforestation and ecosystem development point of view. The potential of native birch species was investigated on industrial cutaway peatlands in the Irish midlands. Field experiments were established to evaluate differences (in terms of survival, growth attributes and form) between B. pendula and B. pubescens, between bare-root and container planting, and between small and medium size seedlings. After five growing seasons, B. pendula was found to be the superior species especially on well drained and shallow peat sites. Bare-root B. pendula will grow faster with reasonable form but containerised birch may be favoured on more difficult sites (with deeper and wetter peat). Larger seedlings performed better, regardless of species. This study demonstrated good growth potential for planted birch on cutaway peatlands and that this species should be integrated in further planting programmes.     

Changes in stem taper for birch plants growing in tree shelters

Plantings with pendula (Betula pendula Roth) and pubescent (Betula pubescens Ehrh.) birches were studied on five localities (Lat. 57–60 ° N) in Sweden. Seedlings were planted in 1988 or 1989. The experiment contained 50 plants per parcel and five replications per treatment. Among treatments harrowed area and birches covered with tree shelter were included. In spring 1993 five plants growing on harrowed area, with and without tree shelter, respectively were randomly chosen on each parcel. A total of 25 birches per treatment, species and locality were used. The trial was replicated in 1994 and 1995. The plant height was estimated and diameter at 20 and 60% of tree height was measured each year for 4 yr. The stem taper was calculated by the quotient D₆₀/D₂₀. The stem taper for birches without tree shelter was 0.5 for both species on all localities. The quotients for birches, which have grown in tree shelter, were 0.6–0.75 the first years of the trial. Then the quotients decreased and 2–3 years later they were on the same level as for birches planted without tree shelters. The results of the studies indicate that tree shelters should be removed two to three years after the plant has reached the top of the shelter. The height of the tree shelter might be shortened to 0.8–1.0 m to stabilise the plant earlier than with the conventional shelter height of 1.2 m.     

Effects of thinning on growth of six tree species in north-temperate forests of Lithuania

This paper summarises the results from 35 years-observed thinning experiments on 256 permanent sample plots in 10–60 year-old stands of ash, aspen, birch, oak, pine and spruce in Lithuania. Thinning enhanced crown projection area increment of residual trees. The largest effect was observed in stands of aspen and birch (growth increase by 200%), followed by ash and oak (over 100%), and spruce and pine (about 80%). Thinning also promoted dbh increment, especially in younger stands, and the increase of dbh increment was positively correlated with the thinning intensity. The strongest reaction was exhibited by oak and aspen, while ash, birch and conifers reacted to a lower extent. Low and moderate intensities of thinning stimulated volume production in younger stands while the opposite was observed in older stands with increasing removals. Spruce stands exhibited relatively strongest increase of volume increment and pine, –the weakest, while the effect on deciduous species was intermediate. The results demonstrate that significant increase in volume increment is achievable with thinning of only young forest stands, e.g. 10–20 year-old pine, birch and ash, or 10–30 year-old oak, aspen and spruce.     

Effects of non-native spruce plantations on small mammal communities in subarctic birch forests

Voles and shrews are key species in northern forest ecosystems. Thus, it is important to quantify to what extent new forestry practices such as planting of non-native tree species impact these small mammals. In northern Norway stands of coastal subarctic birch forests have increasingly been converted to non-native spruce stands during the last century. This leads to changes in the forest floor vegetation and soil conditions that can be expected to negatively impact the community of ground-dwelling small mammals. In this 10-year trapping study we contrasted seasonal small mammal population abundances in spruce plantations with four birch forest varieties. Six different small mammal species were trapped (in descending order of abundance; common shrew Sorex araneus, red vole Myodes rutilus, field vole Microtus agrestis, grey-sided vole M. rufocanus, pygmy shrew S. minutus and water shrew Neomys fodiens). None of the voles appeared to exhibit temporal dynamics resembling population cycles. The three most numerous species were clearly less abundant in the spruce plantations compared to the other forest types. Autumn abundances were most impacted by spruce plantations, indicating that growth rates in the reproductive season were more influenced than winter declines. Species associated with productive forest habitats (i.e. field vole and common shrew) were most impacted by tree species conversion. Still young spruce plantations inter-mixed with birch trees and the ecotone habitat, sustained small mammal abundances comparable to the native birch forests. This implies that managing spruce plantations to maintain a mix of different tree species and high spatial heterogeneity (i.e. more ecotones), will reduce the negative impacts on the small mammal community. On the contrary, if young spruce plantations, as they age become spruce monocultures covering larger parts of the landscapes than they do presently, the negative effects on small mammal communities may be larger than observed in the present study.     

Biomass production, foliar and root characteristics and nutrient accumulation in young silver birch (Betula pendula Roth.) stand growing on abandoned agricultural land

The above-ground biomass and production, below-ground biomass, nutrient (NPK) accumulation, fine roots and foliar characteristics of a 8-year-old silver birch (Betula pendula) natural stand, growing on abandoned agricultural land in Estonia, were investigated. Total above-ground biomass and current annual production after eight growing seasons was 31.2 and 11.9 t DM ha⁻¹, respectively. The production of stems accounted for 62.4% and below-ground biomass accounted for 19.2% of the total biomass of the stand. Carbon sequestration in tree biomass reaches roughly 17.5 t C ha⁻¹ during the first 8 years. The biomass of the fine roots (d < 2 mm) was 1.7 ± 0.2 t DM ha⁻¹ and 76.2% of it was located in the 20 cm topsoil layer. The leaf area index (LAI) of the birch stand was estimated as 3.7 m² m⁻² and specific leaf area (SLA) 15.0 ± 0.1 m² kg⁻¹. The impact of the crown layer on SLA was significant as the leaves are markedly thicker in the upper part of the crown compared with the lower part. The short-root specific area (SRA) in the 30 cm topsoil was 182.9 ± 9.5 m² kg⁻¹, specific root length (SRL), root tissue density (RTD) and the number of short-root tips (>95% ectomycorrhizal) per dry mass unit of short roots were 145.3 ± 8.6 m g⁻¹, 58.6 ± 3.0 kg m⁻³ and 103.7 ± 5.5 tips mg⁻¹, respectively. In August the amount of nitrogen, phosphorus and potassium, accumulated in above ground biomass, was 192.6, 25.0 and 56.6 kg ha⁻¹, respectively. The annual flux of N and P retranslocation from the leaves to the other tree parts was 57.2 and 3.7 kg ha⁻¹ yr⁻¹ (55 and 27%), respectively, of which 29.1 kg ha⁻¹ N and 2.8 kg ha⁻¹ P were accumulated in the above-ground part of the stand.     

Effects of log storage and drying on birch (<Emphasis Type="Italic">Betula pendula</Emphasis>) wood proanthocyanidin concentration and discoloration

In conventional drying, sawn birch (Betula sp.) timber darkens and reddens from the inside while the layer a few millimetres under the yellowish surface remains light in color. Lack of information concerning the chemical basis of the discoloration hinders the development of a reliable solution for this problem. In this study, the role of soluble proanthocyanidins in discoloration of birch wood was investigated because the polymerization and oxidation of these compounds are known to yield insoluble reddish compounds. Different periods of log storage affected the synthesis of soluble proanthocyanidins during conventional drying. Concentration of proanthocyanidins also correlated with changes in the color of birch wood. Discoloration appeared differently in conventionally dried and vacuum-dried wood, which indicates that the discoloration mechanism in these drying methods may differ chemically, and/or the compounds that take part in discoloration may be different at different drying temperatures.     

Impact of tree coppicing on tree-crop competition in parkland and alley farming systems in semiarid Burkina Faso

The aim of this study was to evaluate the effects of tree coppicing on tree-crop competition in farmed parkland and in alley farming, both in semiarid Burkina Faso.Azadirachta indica A. Juss (neem) was studied in the parklands, while neem,Albizia lebbeck (L.) Benth. (albizia) andLeucaena leucocephala (Lam.) de Wit (leucaena) were investigated in the alley farming system. The crop was sorghum (Sorghum bicolor (L.) Moench) in both cases.Under non-coppiced neem trees in the parkland, the sorghum yield at 0–3 m distance from the tree (under the tree canopy) was 82% of open field yields at 6–9 m distance, but the difference was not significant (p=0.07). Close to trees (0–3 m distance) which had been coppiced before planting, the sorghum yield was 148% of open field yields. In alley farming, early coppicing was superior; sorghum yields were highest close to trees coppiced early and lowest close to trees coppiced late.

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Résumé La présente étude se propose d'évaluer les effets de la taille sur la concurrence entre arbres et cultures dans les parcs arborés et dans les cultures en couloir, en climat semiaride (Burkina Faso). Les espèces étudiées ont été:Azadirachta indica A. Juss (neem) dans les parcs et neem,Albizia lebbeck (L.) Benth. (albizia) ainsi queLeucaena leucocephala (Lam.) de Wit (leucaena) dans les cultures en couloir. Dans les deux cas la plante cultivée concerné a été le sorgho blanc (Sorghum bicolor (L.) Moench).Sous les neems non taillés des parcs, le rendement du sorgho cultivé de 0 à 3 m de l'arbre (sous le bouppier de l'arbre) a atteint 82% du rendement obtenu en plein champ, soit à une distance de 6 à 9 m de l'arbre (différence non significative,p=0.07). Une taille effectuée en début de campagne a entraîné un accroissement du rendement de 148% pour les cultures situées de 0 à 3 m de l'arbre, par rapport aux rendements en plein champ.Dans les cultures en couloir, on a constaté qu'une taille precoce est préférable, c'est à dire que les rendements de sorgho ont été supérieurs dans les lignes proches des arbres taillés tôt que dans celles proches des arbres taillés tard.

     

New triterpene saponins from the root of Ilex pubescens

Two new triterpene glycosides named ilexpublesnin A (1) and ilexpublesnin B (2) were isolated from the root of Ilex pubescens. Their structures were determined as 3-O-(β-d-xylopyranosyl)-28-O-(β-d-glucopyranosyl)-3β, 19α-dihydroxyurs-23-oxo-12-en-28-oic acid (1) and 28-O-(β-d-xylopyranosyl-(2 → 1)-β-d-glucopyranosyl)-3β, 19α-dihydroxyurs-23-oxo-12-en-28-oic acid (2) on the basis of chemical and spectroscopic methods.     

Cherrybark oak stump sprout survival and development five years following plantation thinning in the lower Mississippi alluvial valley,USA

Cherrybark oak (Quercus pagoda Raf.) stump sprouts were studied for 5 years in a 30-year-old plantation thinned to 70–75% stocking (light thinning) and 45–50% stocking (heavy thinning). Sprouting success, survival, number of sprouts per stump, and sprout height differed little between thinning treatments throughout the 5-year study period. Pre-harvest tree d.b.h. also had no influence on sprout survival and development. A 2-year drought reduced survival and may have influenced sprout development. Sprout clump survival dropped from 90% 1 year following thinning to 46% 3 years after thinning. Although sprout height averaged 337 cm 5 years after thinning, annual sprout growth decreased from 166 cm the first year after thinning to 33 cm in each of the last 2 growing seasons. Results indicated that bottomland hardwood regeneration evaluation models may underestimate the potential of oak stump sprouts to contribute to pre-harvest regeneration assessments. Further study in the role of stump sprouts to regenerate bottomland oak species is needed. The U.S. Government's right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged     

Teak (<Emphasis Type="Italic">Tectona grandis</Emphasis> L.) tree growth,stem quality and health in coppiced plantations in Java,Indonesia

Coppicing is an alternative reforestation tool for teak in the tropics, substantially reducing regeneration time/costs and associated demands for labor and seed when available. Growth rates of coppiced material are rapid in most situations, but stem/wood quality is a frequent concern. We compared coppiced teak plantations to paired seed-origin plantations, at ages 3, 8, and 13 years, on Forest State Corporation managed land located in Java, Indonesia. Teak trees were evaluated for height, diameter, lower-bole straightness, and presence of disease in both plantation types and at three ages. Mean height and diameter of trees in coppiced plantations were both significantly greater than that in their paired seed-origin plantations at all three ages. Furthermore, heights and diameters in coppiced plantations were higher than expected based on established growth tables for Java. Coppiced plantations were less symptomatic of disease than seed-origin plantations, which promises better wood production and quality. Lower-bole stems in coppiced plantations developed less straight than those in seed-origin plantations, but these deviations faded with time and will likely become insignificant within a 60-year rotation. Based on these results from existing coppiced plantations in Java, coppiced plantations can make a major contribution to teak production in Indonesia.     

Optimizing the joint production of timber and bilberries

Berries and mushrooms are increasingly appreciated products of Finnish forests. Therefore, there is a need to integrate them in silvicultural planning. Bilberry (Vaccinium myrtillus L.) is an economically important wild berry that is widely collected for household consumption and sale in North Karelia, Finland. In this study, bilberry yield models developed recently were included in a stand growth simulator and the joint production of timber and bilberry was optimized by maximizing soil expectation value (SEV) with 3% discounting rate, assuming that 75% of the bilberry yield is harvested. The effect of bilberry production on the optimal stand management increased with increasing bilberry price. With high bilberry prices (4–8 € kg⁻¹) it was optimal to manage the mixed stand of Scots pine, Norway spruce and birch, and the pure stand of Norway spruce so as to promote bilberry production. In the Scots pine stand, where bilberry yields are higher, bilberry production affected optimal stand management already with a price of 2 € kg⁻¹. Compared to timber production, joint production led to longer rotation lengths, higher thinning intensities, more frequent thinnings, and higher share of Scots pine in the mixed stand. The contribution of bilberries to the total SEV increased with increasing bilberry price and discounting rate. In the mixed stand and pine stand the SEV of bilberry production, calculated with 3% discounting rate, exceeded the SEV of timber production when bilberry price was 4 € kg⁻¹.With 4% discounting rate this happened already with bilberry price of 2 € kg⁻¹. It was concluded that forest management which promotes bilberry yields is the most profitable in pine stands where the potential bilberry yields are high.     

林地土壤及其真菌对毛红椿种子发芽及幼苗保存的影响

[目的]通过不同群落毛红椿天然林林地土壤及其真菌对种子萌发和幼苗存活影响的研究,探讨影响毛红椿天然更新的障碍因素。[方法]在江西九连山国家级自然保护区内的3个毛红椿天然优势群落中,分别取距离毛红椿母树3个不同距离(2.5、5.0、7.5 m)处的根区土壤和远离毛红椿母树(25 m以外)的非根区土壤,以非林地土为对照开展室内模拟播种和以根区土壤真菌的水或根系分泌物悬液对毛红椿幼苗进行灌根接种,观察种子萌发、幼苗存活和幼苗感病情况。[结果]各群落土壤中种子发芽均呈先上升后下降规律,且基本在第8 10天达到高峰;林地土与非林地土种子发芽率差异不显著,但林地根区土幼苗的存活率极显著低于非林地土和林地非根区土;距母树3个不同距离根区土的幼苗存活率差异不显著。灌根接种不同处理间幼苗存活率差异极显著,具体表现为接种RS2、RS5根区真菌的幼苗感病率显著高于根系分泌物及无菌水空白对照,且RS2真菌的根系分泌物悬浮液幼苗感病率显著高于其无菌水悬浮液。[结论]毛红椿种子萌发不受土壤环境的影响,但幼苗建成受根区范围内土壤的影响,根系分泌物和致病菌的互作显著降低幼苗保存率。由此推断,毛红椿根区土壤内存在幼苗的潜在致病菌及根系分泌物可增强其致病性。     

Development of bioavailable pools of base cations and P after afforestation of volcanic soils in Iceland

Few long-term studies have been conducted on changes in soil nutrients after afforestation in Iceland, a country with a young history of forest management. While fertilization was shown to improve survival of seedlings in the first years after planting on the nutrient limited soils, knowledge about the nutrients status of the soils that develop under maturing forest stands is still scarce. In a chronosequence study, the development of base cations and Olsen-phosphorus (Olsen-P) in the mineral soil was followed in six forest stands of two different tree species of increasing age (14–97 years): native birch (Betula pubescens) and introduced Siberian larch (Larix sibirica). A treeless heathland was included to present soil conditions prior to forest establishment. The sites are part of the largest forest area in Iceland, located in the east of the country. Results revealed an effect of stand age on all soil nutrients investigated except for potassium (K). Olsen-P increased in 0–10 cm depth of the mineral soil, indicating a better availability and thus improved P supply in maturing forest stands. Calcium (Ca) and magnesium (Mg) concentrations decreased with stand age in 0–10 and 10–20 cm soil depth, while sodium (Na) decreased only in the upper soil layer. Only Olsen-P and K concentrations were higher in the upper soil layer as compared to 10–20 cm depth. This indicates a higher biotic control as opposed to the geochemical control of the other base cations.     

Anti-inflammatory and antinociceptive activity of Thymus pubescens extract

Thymus pubescens is an aromatic and medicinal plant, which has been widely distributed in Iran. The anti-inflammatory and analgesic effects of the T. pubescens aerial parts methanol extract were studied at doses of 50-400 mg/kg i.p. using carrageenan-induced edema, formalin, hot plate and writhing tests. The extract produced a significant decrease in the degree of swelling, 3 h after carrageenan injection and caused graded inhibition of both phases of formalin-induced pain. Moreover, in the hot plate test, it significantly raised the pain threshold. While in the writhing test produced a significant decrease in the number of writhing in comparison with the control group (P<0.001). The results of pharmacological tests performed in the present study suggest that the extract of T. pubescens presents analgesic and anti-inflammatory effects.     

Effect of CCC and daminozide on growth of silver birch container seedlings during three years after spraying

Applications of growth retardants, daminozide and CCC (chlormequatchloride), were studied in order to determine their effects on morphology and post-planting growth of silver birch (Betula pendula Roth) container seedlings. Daminozide was sprayed once (on 28 June at concentrations of 1.0 – 6.0 g l^–1) and CCC was sprayed twice (on 29 June and 27 July at concentrations of 0.5–3.0 gl^–1). Height growth, morphology of seedlings at the end of the growing season, the shoot and root growth potential the following spring and field performance during the following seasons were measured. During the first summer in the nursery, both daminozide and CCC retarded height growth,but daminozide was more effective. The effects of compounds on stem diameter during the summer of application were small. Neither of the compounds affected the field performance of seedlings. The most suitable applications for retardation of height growth, without negative effects on other morphological variables, were 4 g l^–1 (32 mg per seedling) for daminozide and 2 g l^–1 (16 mg per seedling), sprayed in two applications, for CCC.     

Fine root dynamics of shaded cacao plantations in Costa Rica

Root turnover may contribute a significant proportion of recycled nutrients in agroforestry systems and competition between trees and crops for nutrients and water may depend on temporal fine root regrowth patterns. Fine root biomass ( 2 mm) and fine root productivity were measured during one year in plantations of cacao (Theobroma cacao) shaded by Erythrina poeppigiana or Cordia alliodora planted on a deep alluvial soil in Turrialba, Costa Rica. Fine root biomass of approximately 1.0 Mg ha^–1 varied little during the year with maximum values at the beginning of the rainy season of 1.85 Mg ha^–1 in the cacao-C. alliodora system compared to 1.20 Mg ha^–1 for cacao-E. poeppigiana. Fine root productivity of C. alliodora and E. poeppigiana (maximum of 205 and 120 kg ha^–1 4 week^–1, respectively) was greatest at the end of the rainy season, while for cacao it was greatest at the beginning of the rainy season (34–68 kg ha^–1 4 week^–1), which suggests that if nutrient competition occurs between the shade trees and the cacao, it could be minimized by early fertilization during the beginning of the rains immediately after pruning the shade trees. Annual fine root turnover was close to 1.0 in both systems. Assuming that fine root biomass in these mature plantations was constant on an annual basis, nutrient inputs from fine root turnover were estimated as 23–24 (N), 2 (P), 14–16 (K), 7–11 (Ca) and 3–10 (Mg) kg ha^–1 year^–1, representing 6–13% and 3–6% of total nutrient input in organic matter in the C. alliodora and E. poeppigiana systems, respectively.     

The effect of land use type on net nitrogen mineralization on abandoned agricultural land: Silver birch stand versus grassland

The effect of land use type on the dynamics and annual rate of net nitrogen mineralization (NNM) in a naturally generated silver birch stand and in a grassland, both on abandoned agricultural land, was assessed in situ in the upper 0–20 cm soil layer using the method of buried polyethylene bags. Annual NNM rate in the birch stand (156 kg N ha⁻¹ year⁻¹) was higher than in the grassland (102 kg N ha⁻¹ year⁻¹); in both cases NNM covered a major part of the plants annual nitrogen demand. The rate of NNM in the upper 0–10 cm soil layer in the birch stand (99 kg N ha⁻¹ year⁻¹) exceeded the respective rate of NNM in the grassland (51 kg N ha⁻¹ year⁻¹) roughly two times. In the grassland the rates of NNM in the 0–10 and 10–20 cm layers were equal; in the birch stand NNM in the 0–10 cm layer was 1.7 times higher than in deeper 10–20 cm layer. The intensity of daily NNM in the upper 0–10 cm soil layer in the birch stand was the highest in June and in the grassland in May, 776 and 528 mg kg⁻¹ N day⁻¹, respectively. In our study no significant correlation was found between NNM and the environmental factors monthly mean soil temperature, soil moisture content and pH.     

Investigation of change in tangential strain on the inner bark of the stem and root ofBetula platyphylla var.japonica andAcer mono during sap season

Although it is well known that sap exudation during early spring in temperate deciduous trees occurs in response to daytime warming and nighttime cooling, the mechanisms of the process are not yet fully understood. Previous theories suggested that changes in stress in the wood caused by daytime heating and nighttime cooling might be linked with sap flow. Consequently, a study of itaya-kaede maple (Aver mono) and shirakamba birch (Betula platyphylla var.japonica) looked at tangential strains. One-hour intervals for 3 years of the tangential strains on the inner bark of stem and root were measured in itaya-kaede maple and shirakamba birch during the sap exudation season. The measurements indicated different mechanisms of sap exudation in these two trees. During the sap exudation season in late March, when the temperature fluctuated around 0°C, the tangential strain in the root of itaya-kaede maple showed expansion in the daytime and contraction at night. Conversely, in early April the tangential strain in the root of shirakamba birch exhibited contraction in the daytime and expansion at night. The changes in tangential strains in itaya-kaede maple were attributed to conditioning, a known concept used to explain the uptake mechanism of soil water in maple and its exudation during early spring. However, because the change in tangential strain in the roots of shirakamba birch was similar to that found during the rampant season, sap exudation was not attributed to conditioning but to the plentiful supply of water from the roots. The implications of these mechanisms are that different sap harvesting techniques may be appropriate for different tree species.     

Effect of seed coverings and seed pretreatments on the germination response of <Emphasis Type="Italic">Alnus glutinosa</Emphasis> and <Emphasis Type="Italic">Betula pubescens</Emphasis> seeds

The germination of common alder (Alnus glutinosa (L.) Gaertn.) and downey birch (Betula pubescens Ehrh.) seeds is often poor in bare-root nurseries. The effect of a variety of seed coverings and a few seed pretreatments on seedling emergence was examined in this study in an attempt to address this problem. Seeds of each species were sown in trays containing nursery soil, covered with grit, gravel, sand, combinations of these coverings, a hydromulch or a sealed plastic cloche and then incubated for 6 weeks at 17–20°C. The grit combined with sand or gravel, the hydromulch and the cloche increased seedling emergence when compared with the standard grit. In another experiment, seeds of each species were fully imbibed (FI) (>50% moisture content, MC), as per standard practice, or adjusted to target MC (TMC) (30–35% MC) levels, and then chilled to release dormancy. Some seeds of each MC treatment were primed at 20°C for 2 days following chilling, after which all seeds were evaluated in laboratory tests and a nursery trial. Germination potential of the FI seeds declined in the lab tests by the second test date, which was reflected in low seedling emergence in the nursery in birch. The primed FI seeds of alder germinated most rapidly in the nursery, but other effects were not significant. Seedling emergence was better in the nursery in response to the TMC than the FI pretreatment in birch.