Frost Hardiness of Red Alder (Alnus rubra) Provenances in Britain

The phenology and frost hardiness of shoots of 15 provenancesof Alnus rubra growing in Scotland were measured over one autumn,winter and spring. Dates of budset (in September) and the onsetof rapid frost hardening (in October-November) occurred about2 days earlier for each degree latitude of origin northwards,except for an Idaho provenance. However, all provenances dehardenedat about the same time in March and burst their buds between8 and 14 April. Assuming that rapid frost hardening in the autumnwas triggered primarily by shortening daylengths, Alaskan provenancesof A. rubra seemed better adapted to British conditions thansouthern British Columbian provenances, which have been mostcommonly planted. However, even Alaskan provenances are proneto spring frost damage. Scottish A. glutinosa and Alaskan A.sinuata set buds and frost hardened 1–2 weeks before eventhe Alaskan A. rubra, and burst their buds 2–3 weeks laterin April-May. All three species were hardy to below –30°Cfrom December to mid-March.     

Late Autumn Frost Resistance of Twelve North European Provenances of Quercus Species

Twelve north European oak provenances [11 Quercus robur L. and one Quercus petraea (Matt.) Liebl] were tested for late autumn frost hardiness using visual methods and measurements of relative conductivity. Tissue from buds and twigs from 2-yr-old seedlings was used. The test was carried out in November and December. Temperatures between ?20 and ?32°C were necessary to cause serious damage to tissue, even when tissues were tested only a few weeks after leaf fall. Visual methods proved to be fast and could be applied in practical test applications. Estimation of twig viability was found to be a more reliable variable than bud assessment, which appears to be sensitive and not necessarily related to plant mortality. Relative conductivity is a more labour-intensive method and requires some technical equipment, but it provided the most consistent statistical results. Strong correlation between the visual methods and relative conductivity was demonstrated. Provenances originating from locations close to the Atlantic ocean (The Netherlands, the UK, Denmark and Norway) tended to be less frost resistant than more continental provenances (from Norway, Sweden, Finland and Poland). Frost tolerance was correlated with budset, but not with growth of the provenances. The results confirm the existence of specific ecotypes and suggest a high potential for adaptation in Q. robur.     

Genotype and environment: two factors related to autumn cold hardiness on Persian walnut (Juglans regia L.)

Context

J. regia timber is appreciated for high-value wood products. In new plantations, biotic or abiotic events which could affect wood quality should be monitored. Autumn frosts could affect annual shoot development, with consequent loss of timber value or even tree death. In southern Europe, climate change forecasts include erratic and severe autumn frost events.

Aims

The relationship between genotype and environment regarding susceptibility to autumn frost damage was examined in four provenances of Juglans regia L., planted at two ecologically different sites, one subject to Mediterranean and the other Atlantic weather conditions.

Methods

Annual budsticks from eight trees per provenance were collected in November 2010 from each site. The samples were then submitted to freeze–thaw cycles down to ?8, ?13 and ?18 °C, plus a control treatment (keeping samples at 5 °C). Damage to the stem was assessed using the index of freezing injury calculated from relative electrolyte leakage at each temperature considered. Frost damage to stem, apical and lateral buds was recorded by visual scoring.

Results

Differences in cold acclimation between sites were detected, with provenances exhibiting differences on senescence. A ‘provenance?×?site’ interaction was found in some of the analyses, but the same ranking of susceptibility was detected for all provenances at both sites and in all the tissues analysed. The differences between provenances could be related to their geographical origins, where an altitude gradient was observed.

Conclusions

The genetic component was important in the expression of autumn cold hardiness and, together with productive traits, should be considered in new afforestation projects.     

Survival,early growth and impact of damage by late-spring frost and winter desiccation on Douglas-fir seedlings in southern Sweden

Introduction of non-native species, such as Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), can be a means of mitigating the effects of climate change by meeting the growing demand for biomass and high quality wood. The aim of this study was to investigate early growth, survival and damage from late-spring frost and winter desiccation. A provenance trial with four coastal and three interior provenances of Douglas-fir originating from British Columbia, Canada, was established in Southwest Sweden (56°43′N, 13°08′E). Seedling height, length of the leading shoot, and occurrence of frost damage, were measured after one, three, and six growing seasons. Timing of bud break in spring was also observed. The interior Douglas-fir were more frequently damaged by late-spring frost compared to the coastal Douglas-fir. The interior Douglas-fir still had a higher survival after six growing seasons compared to the coastal variety. All provenances were damaged by winter desiccation, but the provenances originating from the coastal area were more severely damaged. Choice of variety may reduce the risk for either late-spring frost or winter desiccation.     

Autumn frost hardiness in Norway spruce plus tree progeny and trees of the local and transferred provenances in central Sweden

Reforestation with provenances from locations remote from the planting site (transferred provenances) or the progeny of trees of local provenances selected for superior form and vigor (plus trees) offer alternative means to increase yield over that obtained by the use of seed from unselected trees of the local provenance. Under Swedish conditions, Norway spruce (Picea abies (L.) Karst.) of certain transferred provenances generally has an advantage in productivity relative to the local provenance comparable to that of progeny of plus trees. The aim of this study was to explore the extent to which productivity gains achieved by provenance transfer or the use of plus tree progeny are associated with reductions in autumn frost hardiness, relative to that of trees of the local provenance. In a field trial with 19-year-old trees in central Sweden, bud hardiness was tested on four occasions during the autumn of 2002. Trees of the local provenance were compared with trees of a south Swedish provenance originating 3 degrees of latitude to the south, a Belarusian provenance and the progeny of plus trees of local origin. The Belarusian provenance was the least hardy and the local provenance the most hardy, with plus tree progeny and the south Swedish provenance being intermediate in hardiness. Both the Belarusian provenance and the plus tree progeny were significantly taller than trees of the other populations. Within provenances, tree height was negatively correlated with autumn frost hardiness. Among the plus tree progeny, however, no such correlation between tree height and autumn frost hardiness was found. It is concluded that although the gain in productivity achieved by provenance transfer from Belarus was comparable to that achieved by using the progeny of plus trees of the local provenance, the use of trees of the Belarus provenance involved an increased risk of autumn frost damage because of later hardening.     

Walnut demonstrates strong genetic variability for adaptive and wood quality traits in a network of juvenile field tests across Europe

Adaptive and wood quality trait data were collected and analyzed on commercially available Juglans regia and J. regia×J. nigra provenances and progenies planted across Europe in a multi-site network. A total of 19 seed sources, replicated 35 times per site, were planted at 13 sites from 5 European countries, encompassing the potential distribution area of timber production plantation sites. The following traits were evaluated: survival, height, diameter at breast height, stem form, apical dominance, vegetative budbreak, along with biotic and abiotic damage. Mean values were significantly different both among provenances/progenies and sites. Most common damage was late spring and early autumn frost. Bud break ranking was significantly correlated with provenance and progeny origin. Although J. regia is fast growing, southern European early budbreak plant material should not be planted under most middle European conditions where late spring frost can be expected, as it has a significant negative impact on architectural (and thus wood quality) traits. Hybrid J. regia×J. nigra progeny performed better than J. regia provenances/progenies for most traits measured. Differences were significantly in favor of hybrids at sites with medium to low fertility, although some locally selected seed sources tended to perform as well as hybrids on high fertility sites.     

Late frost sensitivity of juvenile <Emphasis Type="Italic">Fagus sylvatica</Emphasis> L. differs between southern Germany and Bulgaria and depends on preceding air temperature

Fagus sylvatica, the dominant native forest tree species of Central Europe, is sensitive to late frost events. Advanced leaf flushing due to climate warming may lead to more frequent frost damage in the future. Here, we explore local adaptation to late frost events at both continental and regional scales and test how moderate climate warming (+1.5°C) affects late frost sensitivity. Short-term leaf injury and height growth after a late frost event were quantified in a common garden experiment with 2-year-old F. sylvatica seedlings. The fully crossed three-factorial design consisted of a late frost manipulation, a continuous warming manipulation and selected provenances (three provenances from western Bulgaria and three from southern Germany). Late frost led to leaf injury and reduced height growth (−7%). Provenances differed in their late frost sensitivity at the regional scale, and local adaptation was detected. At the larger scale, the Bulgarian provenances showed reduced height growth (−17%), while the German provenances did not exhibit growth reduction. The warming treatment prevented late frost damage, while height growth declined by 19% in the reference temperature treatment. This surprising finding was attributed to advanced leaf maturity in the warming treatment. The impact of late frost events on F. sylvatica in a warmer world will depend on timing. An event that damages leaves immediately after leaf flushing appears negligible a few days earlier or later, thereby complicating projections. Local adaptation to late frost is evident at a regional scale. Management strategies should aim at maximizing genetic diversity to adapt to climate change.     

Differences between provenances of pinus contort a var. latifolia in resistance to attack by gremmeniella abietina

A provenance trial of lodgepole pine (Pinus contorta var. latifolia) planted in 1969 at Matrand, Eidskog, Norway was apparently attacked by Gremmeniella abietina in 1984/85. In late autumn the damage was recorded separately on the lower and upper halves of the trees. The material ranged in latitude from 40.25°N to 56.28°N, and in altitude from 2 850 to 450 m a.s.l., highest in interior western United States and lowest in western Canada. The most heavily attacked sources were those from southern latitudes and from high elevations. The attack frequency changed gradually from south to north. In order to avoid attack by G. abietina, only well‐adapted provenances should be used.     

The use of field and artificial freezing studies to assess frost tolerance in natural populations of Pinus oocarpa

The susceptibility of Pinus oocarpa to freezing temperatures limits the commercial deployment of the highly productive Pinus patula × P. oocarpa hybrid in South Africa. Identifying P. oocarpa germplasm with increased frost tolerance is important. Twenty-three P. oocarpa provenances, originating from Mexico, Honduras, Guatemala and Nicaragua, were therefore assessed for their tolerance to freezing conditions by analysing field survival after frost events, subjecting needles to freezing temperatures and assessing damage using the electrolyte leakage test, and exposing young plants to freezing temperatures in a semi-controlled environment and scoring tissue damage based on a visual assessment. The performance of many of the provenances represented in the field and artificial freezing studies were similar and there was a strong correlation between provenance ranking in the whole plant freezing and electrolyte leakage test. We therefore support the use of these techniques as a means to assess cold tolerance in P. oocarpa at the provenance level. Provenances from north-western Mexico demonstrated more frost tolerance than those from southern Mexico. Provenances representing Honduras and Guatemala appear to be highly susceptible to frost.     

Phenologies of sixteen European provenances of sessile oak growing in Scotland

Budburst, budset, leaf yellowing, growth, and frost damage wereassessed on 2- to 4-year-old transplants of 16 provenances ofsessile oak (Quercus petraea) collected in six European countriesand grown in Scotland. There were significant differences indates of budburst between provenances. Provenances from Franceand Austria burst bud earlier than the others (P > 0.05). Budburst date was negatively correlated with altitude of provenanceorigin but positively correlated with latitude, indicating thatsouthern provenances burst bud earlier than northern provenancesand are therefore more prone to spring frost damage. Although there were no significant differences of growth betweenprovenances, French provenances tended to grow later in autumnthan provenances originating in other countries. Consequentlyplants from these French provenances were more badly damagedby autumnal frosts (P > 0.05) than plants from other provenances.Budset and leaf yeljowing in late September were positivelycorrelated.     

Variation in the date of budburst in <Emphasis Type="Italic">Quercus robur</Emphasis> and <Emphasis Type="Italic">Q. petraea</Emphasis> across a range of provenances grown in Southern England

The widely observed advance in spring budburst across a range of temperate forest species due to climatic warming has received considerable attention. This change in forest phenology has important implications for the choice of species and provenances currently being planted, which need to be suited to both current and future climatic conditions. Using a provenance trial in the south of England, this study assessed variation in the timing of budburst across 23 different European provenances of oak (Quercus robur L. and Q. petraea (Matt.) Liebl.) over 8 years of observations. The order in which the different provenances reached budburst was related to provenance source latitude: the southern provenances were always earlier than those from more northerly latitudes. The statistical technique partial least squares regression was used to identify critical periods of both chilling and warming. A General Linear Model and three-dimensional temperature response surfaces were used to analyse the temporal trends in budburst. There was a negative correlation between the date of budburst and mean daily air temperature in both the chilling and warming periods for all provenances, which was statistically significant for a majority. Spring warming had a larger effect on budburst than winter chilling with a mean spring temperature-driven advance of 3.61 days/°C (standard error = 0.17 days/°C) and mean winter period temperature-driven advance of 0.99 days/°C (standard error = 0.17 days/°C). Surprisingly, there was no statistically significant interaction between mean air temperatures during the chilling and warming phases on the date of budburst.     

闽楠种源苗期生长性状地理变异研究

为研究不同产地闽楠（Phoebe bournei）幼苗生长性状的变异规律及其与地理、气候因子的关系,以来源于6个省区的12个种源的种子培育的幼苗为试验材料。研究分析了闽楠幼苗苗高、地径、生物量等性状的种源差异,苗期生长性状与种源产地气候或与地理因子间的相关性以及各性状的相关性。结果表明：参试种源间生长差异显著,这些差异主要由遗传因素制约;地径、地下生物量与经度呈显著负相关关系,地径与海拔呈显著正相关关系;各观测性状与无霜期呈显著或极显著相关关系;苗木苗高、地径、生物量等性状之间呈显著或极显著相关关系。根据聚类分析结果,供试的12个种源可划分为优、良、中、差4类,其中广西、贵州种源具有较明显的生长优势。综合分析结果表显示：闽楠各种源间存在明显的遗传分化,地理隔离导致幼苗的生长性状变异丰富,西南地区种源普遍生长较好。     

No difference in frost hardiness between high and low altitude Pinus sylvestris (L.) offspring

Seedlings representing offspring from 46 Swedish natural stands of Pinus sylvestris (L.) from latitude 63° to 68° and altitude 75 to 675 m were artifically frost hardened and tested for autumn frost hardiness using artifical freeze testing in a programmable freezing chamber. A clinal variation in frost hardiness was observed over latitude. Altitude had no effect on the frost hardiness. The results are discussed in relation to the reproduction‐ and migration biology of P. sylvestris.     

A study on the geographic variation and selection of the best provenance ofLarix olgensis

On the basis of the results from the geographic provenance test of nine years oldlarix olgensis in Liangshui Natural Reserve of our university, a study on the geographic varition and the primary selection of the best provenance ofLarix olgensis was carried out. The main results are as follows: I.The different provenances ofLarix olgensis have rich and wide genetic variation, and exist a linear correlation with latitude and longitude in collection area. General trends are enumerated below: Provenances at lower latitude and more west longitude have lighter thousand seed weight, short growth period, higher increment, wide branches, rich leaves and crown as well as worst adaptabillity. It is a dual-way variation along with two directions of latitude and longitude, and also embodies a change gradually in climate condition from south to north. The temperatures in seed production site, especially the mean temperature in January and ≥10 °C accumulated temperature, are important factors that produce geographic variation forlarix olgensis. 2. The variation of different provenances in periodic biological phenomena and growth rhythm trends are that: 1 both of the provenances from Changbai Mt. (III) and Dashitou(IV) at low latitude belong to the centralized growth type, and have shout growth period, the difference between these two provenances is that the provenance from Changbai Mt. grows well in all time, Dashitou provennce is well only in later period; 2 the provenance from Baidao Mt. (II) at middle latitude belongs to even growth type and has longer grpwth period, this provenance has higher increment in early and later periods relatively; 3 Xiaobeihu provenance at high latitude is a growth type among II. III and IV provenances and has a general growth period, the provenance grows better in middle time and worse in later time. 3. The best provenance in Liangshui Natural Reserve and its meighbourhood is Dashitou Procenance, which growth in height, diameter and volume has exceeded 16. 28%, 46. 27%, 30. 58%, 78. 20, 82. 00% as well as 392. 00% by comparison with the mean value of the contrast and the worst provenance respectively, The result from the height growth of three, five, seven and nine years oldLarix olgensis by using the method of order correlation analysis demonstrates that it is possible to make early selection of the provenance. Meanwhile, data from juvenile and mature oflarix olgensis plantation also prove the reliability of the early selection. 4. The provenance heritabilities of nine years oldlarix olgensis in Liangshui Natural Reserve are follows: The heritability of the height growth (h²) is 0.79; The heritability of the diameter breast height (h²) is 0.791; The geretic gain is 24.5% and 40.36% respectively.     

Provenance variation in growth and wood properties of juvenile Cyclocarya paliurus

Cyclocarya paliurus is a highly valued and multiple function tree species. There has been increasing interest in planting and managing C. paliurus for timber production and medical use owing to loss of harvestable acreage. Seed from six provenances was collected from the main natural range of this species. Significant variation in growth and wood properties was measured among the six provenances at age 7 years. Provenance mean height and DBH varied significantly from 730–991 and 6.7–10.0 cm, whereas provenance means of wood basic density and crystallinity ranged from 463–554 kg m^?3 and 51.4–74.1 %, respectively. Mean provenance microfibril angle (MFA) at breast height ranged from 18.1° to 23.2°, while MFA at breast height varied from 11.0° to 34.5° among growth rings which showed a consistent pith-to-bark trend of declining angles. There was no significant relationship of growth rate with latitude or longitude of seed sources, however, provenances from low latitude and longitude grew faster at the trial site. Wood quality was significantly related to latitude of seed sources, showing a positive correlation for both wood basic density and wood crystallinity, but a highly negative association with MFA. Significant correlations between wood properties measured indicated that there exists a great opportunity to improve wood quality of C. paliurus through selection of juvenile trees with low MFA.     

Phenotypic Differences Between Natural and Selected Populations of Picea Abies. I. Frost Hardiness

The frost hardiness of non-juvenile Norway spruce [Picea abies (L.) Karst.] populations growing in northern Sweden (63°54' N) was monitored during 1996-1997. The investigated progenies originated from 12 natural populations and six seed orchards located between 58° N and 68° N in Sweden. Frost hardiness of needles was assessed by measuring chlorophyll fluorescence and electrolyte leakage after freezing. The loss of frost hardiness in 1-yr-old needles during spring occurred slightly earlier in populations originating north of 63°30' N than in those originating further south. Dehardening was slightly delayed in selected populations compared with natural populations of similar origin. The level of frost hardiness during autumn was higher in populations originating north of 63°30' N than in those originating south of this latitude, but there were no clear differences in frost hardiness between selected and natural populations of similar origin. The results are discussed in relation to climatic factors and inherent growth rhythms.     

Study on the provenance ofFraxinus mandshurica

This paper studied that the significant difference exists among the ten provenances of 9-year-oldFraxinus mandshurica stand. The rule of geographic variation is that dual continuous changes with longitude and latitude, and the provenance in the southwest range grows rapidly. There are positive significant correlation when the tree growth is influenced by ≥10°C accumulated temperature, duration of sunshine and annual precipitation. So it is suggested that Lushuihe and Maoershan provenances should be employed first in Maoershan Forest Farm and its neighborhoods. (Responsible Editor: Zhu Hong)     

European silver fir (<Emphasis Type="Italic">Abies alba</Emphasis> Mill.) provenances from Calabria,southern Italy: 15-year results from Danish provenance field trials

Height after 15 years, bud burst and mortality varied significantly among 13 southern Italian (Calabrian), a central Italian, a German (Schwarzwald), a Romanian (Carpathian), and a Danish provenance of silver fir (Abies alba Mill.) tested in two field trials in Denmark. The variation in height was especially observed in the field trial that was well protected against late frost in the spring and early frost in the fall by a shelter wood of larch. Provenances from the region of Serra San Bruno (Calabria) and two provenances from the region of Gariglione (Calabria) showed superior height growth at this site compared with the remaining provenances. Height was below average for two provenances from the region of Aspromonte (Calabria). The variation in height correlated significantly with biomasses of the same provenances obtained in early tests. Bud burst was earlier among provenances from the regions of Serra San Bruno and Aspromonte. These were also characterised by poor winter-frost resistance in early tests. The Romanian provenance was not represented in the shelter wood trial. The variation in height between provenances in the other field trial was mainly due to the Romanian and the Danish provenance with superior and poorer growth respectively. Otherwise, differences between the remaining provenances were not significant at this site probably due to the influence of frost. Provenances with poor winter-frost resistance had higher mortality at this site.     

Autumn Frost Damage on Young Picea sitchensis 2. Shoot Frost Hardening, and the Probability of Frost Damage in Scotland

The natural increase in frost hardiness of detached shoots ofPicea sltchensis during August to November was measured usinga programmable freezing chamber. Oregon, Queen Charlotte Islandsand Alaskan provenances were compared, and the effects on hardeningof long days, warm temperatures and frosts were determined.A computer model was constructed to mimic the observed patternsof autumn frost hardening, as functions of air minimum temperatures,daylengths and the occurrence of frosts. The model was used(a) to describe the pattern of autumn frost hardening at differentsites in northern Britain, using past meteorological records,and hence (b) to determine when frosts occurred that might havedamaged young trees. The model accurately predicted known instancesof autumn frost damage at Kirroughtree and Carnwath. The predicted probability of autumn frost damage on young treesof P. sitchensis in upland areas of Scotland was much lowerthan that previously predicted for spring frost damage. Theestimated return time for autumn frost damage to an Oregon provenanceat Eskdalemuir was 8.3 years, and the return time for a Q.C.I.provenance was longer than 10 years. Most damaging frosts occurredin October, but frosts like those on 13–15 October 1971,which followed warm weather and caused wide spread damage inScotland, have been quite rare. Alaskan provenances would rarelybe damaged by autumn frosts, nor would trees of Q.C.I. provenancegrowing in lowland areas of Scotland, or at Masset on the QueenCharlotte Islands.     

Geographic variation and genetic performance of Picea koraiensis in growth and wood characteristics

Eight provenances of 19-year-oldPicea koraiensis Nakai from the provenance trials of Maoershan (45°20′N, 127°30′E), Liangshui (47°10′N, 128°53′E) and Jiagedaqi (50°24′N, 124°07′E) in Northeast China were investigated to analyze the genetic variation in growth characteristics (tree height and diameter) and wood characteristics (tracheid length, tracheid diameter, tracheid wall thickness, annual ring width as well as wood density). Great variation in height growth and breast height diameter growth was observed among the provenances, and along with the increase of tree age, these provenances presented different geographic adaptability. The growth characteristics ofPicea koraiensis stand at age of 10 in Maoershan and Liangshui provenance trials had a positive correlation with longitude, and with increase of tree age to 15 and 19, the tree growth of the provenances displayed a significant positive correlation with latitude as well as altitude. For wood characteristics, great variation was also found among the provenances. There exists a close relation between growth characteristics and wood properties of the provenance. The height and breast height diameter growth of the provenance had a positive correlation with tracheid diameter and annual ring width, and a negative correlation with tracheid wall thickness and wood density. Genetic performance of the provenance in all above characteristics was also investigated in order to provide more useful information for comprehensive selection of this species for pulpwood and plywood production. Foundation item: The paper was supported by National Key Project of The State Forestry Administration. (96-011-01-06) Biography: WANG Qiu-yu (1957-), female, professor in College of Life Sciences, Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Song Funan