Fifty Years of Landscape Transformation in Managed Forests of Southern Finland

Intensive forest management has changed both local and regional characteristics of Fennoscandian forest. However, quantitative documentation of landscape transformations is rare. In this study, five forest landscapes were examined in order to define and quantify forest landscape transformation in southern Finland from the 1940s to the 1970s and 1990s. These areas of 140-200 km² contained both private and state-owned forests. Digital aerial photographs of each area were classified into no-canopy forest (clear-cut and seedling stands, open mires) and closed-canopy forest (young and mature stands). Patch density, mean patch size, largest patch index and edge density calculated for closed-canopy patches indicated fragmentation from the 1940s to the 1970s and recovery from the 1970s to the 1990s. Trends were very similar in both ownership groups. Thus, fragmentation of closed-canopy forests has not progressed continuously in southern Finland, but shows different patterns depending on the period. However, the recovery observed between the 1970s and 1990s does not necessarily mean an increased abundance of the natural old-growth areas that are needed to host many of the currently threatened species.     

不同穗条类型、长度的欧洲云杉扦插苗质量评价

[目的]为欧洲云杉扦插穗条选择和扦插苗培育提供依据。[方法]采用完全随机区组试验设计,研究了2种穗条类型(嫩枝基部带1.5年生硬枝、嫩枝)、3种穗条长度(5 10、10 15、15 20 cm)的嫩枝扦插苗从移植当年到第3年的成活率、保存率和生长情况。[结果]2种穗条类型扦插苗间的移植成活率和保存率差异不显著,但移植后嫩枝基部带1.5年生硬枝扦插苗的苗高、新梢生长量、地径、侧枝数、冠幅、鲜质量、干质量差异显著,都是嫩枝基部带1.5年生硬枝扦插苗大于嫩枝扦插苗。3种长度扦插苗的移植成活率、保存率的差异均显著;其中,15 20 cm长度穗条扦插苗移植成活率和保存率最高,分别是98.00%和86.00%,不同长度穗条扦插苗移植成苗率逐年下降,而且与穗条长度有关,弱小穗条获得的扦插苗成苗率低;5 10 cm的扦插苗移植成活率为46.00%,到第3年时保存率仅为23.33%,且移植后苗高、新梢生长量、地径、侧枝数、冠幅、鲜质量、干质量的差异也显著,且都以15 20cm穗条的扦插苗值最高,10 15 cm穗条的扦插苗次之,5 10 cm的扦插苗最小。嫩枝带硬枝扦插苗的苗木质量指数(QI)是嫩枝的7.74倍,15 20 cm穗条的扦插苗质量指数(QI)是5 10、10 15 cm扦插苗的5.47、5.23倍。扦插苗地径初始值与移植当年地径、苗高初始值与移植当年苗高间呈极显著正相关关系。[结论]扦插苗最初的生根状况和穗条质量影响后期培育过程中的存活和生长,嫩枝基部带1.5年生硬枝扦插苗和15 20 cm穗条的扦插苗不仅移植成活率、保存率高,而且生长量、生物量、质量指数都比短而弱小穗条的扦插苗高。     

Effect of Genotype,Age and Treatment of Stock Plants on Propagation of Hybrid Aspen (Populus tremula×Populus tremuloides) by Root Cuttings

The ability of 1- and 2-yr-old stock plants of five hybrid aspen (Populus tremula L.×Populus tremuloides Michx.) clones to produce root cuttings and sprout was studied. Different stock plant treatments designed to improve root mass production and rooting vigour of cuttings were also tested. The 2-yr-old stock plants produced significantly more cuttings than the 1-yr-olds, but the age of stock plants did not have a significant impact on the sprouting ability of cuttings. The stock plant treatments caused significant variation in sprouting of cuttings. The clones differed significantly in their ability to produce cuttings and to sprout, and in the time needed for sprouting. Variations in the studied characteristics indicate that genotype selection will be efficient and economically worthwhile in root cutting method. The root cutting method clearly results in more cuttings and sprouted aspen plants per stock plant than the stem cutting method.     

钟花樱扦插繁育研究

比较不同基质、不同生根促进剂及其质量体积浓度、不同季节、不同修剪方式、不同插穗类 型对钟花樱（Cerasus campanulata）扦插生根的影响,结果表明：扦插基质类型、生根激素种类及其质量 体积浓度、扦插季节、插穗留叶面积以及插穗类型均对钟花樱扦插成活率和生根率产生显著或极显著影 响,扦插基质采用黄心土最有利于生根;生根激素种类及其各浓度处理效果均显著高于清水对照,其中 采用IBA 以质量体积浓度2 500 mg · L-1 速蘸10 s 处理效果最佳;于春季扦插最好;插穗留1 片或半片叶 片成活率及生根率远高于不留叶插穗;采用嫩枝扦插和带踵扦插优于硬枝扦插。因此钟花樱扦插宜在春 季,采用修剪成1 片或半片叶片带踵或嫩枝的插穗,经质量体积浓度2 500 mg · L-1 的 IBA 药液蘸10 s 后 扦插在黄心土上,生根效果最好。     

Clonal propagation of Pterocarpus santalinoides L'Hér. ex DC.: the effect of substrate,cutting type,genotype and auxin

Pterocarpus santalinoides is a multipurpose tree species, native to Africa and South America. However, excessive pruning for fodder is jeopardising its seed production leading to poor regeneration in the Sahel region. Efficient vegetative propagation techniques may overcome this concern. To address this issue, four experiments were conducted to determine the effects of substrate (Experiment 1), cutting type (Experiments 2 and 3), genotype (Experiment 4) and auxins (Experiments 1, 2, and 4) on rooting ability in a non-mist propagating unit in Mali. Among the four tested substrates, no significant differences were found in rooting parameters, including the percentage of rooted cuttings, the number of roots and secondary roots per rooted cutting, and the length of the longest root per rooted cutting. Semi-hardwood cuttings rooted significantly better than softwood cuttings with a higher percentage of rooted cuttings (31.7?±?6.5% vs. 9.2?±?2.7%), greater number of roots (8.2?±?4.8 vs 1.5?±?0.7), greater number of secondary roots (16.7?±?4.2 vs 4.6?±?1.8) and longer root length (17.8?±?12.0?cm vs 2.3?±?1.0?cm) per rooted cutting. In addition, one-node cuttings cut below the second and third nodes, respectively, had the highest rooting success (88% and 90%, respectively) followed by cuttings cut below the fourth node (68%) and the first node (62%). Significant differences in the percentage of rooted cuttings were found among 12 randomly selected genotypes with rooting varying from 2% to 75%.The results also showed that auxin application, especially IBA, had a significant effect on rooting success, the number of roots and secondary roots per rooted cutting. Single-node cuttings, and cuttings of 10?cm length with multiple softwood and semi-hardwood nodes, can be used with or without auxin treatment for successful clonal propagation of P. santalinoides. The results of the present study indicated that P. santalinoides is amenable to clonal propagation using low-cost propagators and sand-based rooting media.     

直干大叶相思扦插育苗试验研究

采用不同类型插条、不同生根剂种类及不同浓度生根剂进行直干大叶相思扦插。结果表明,嫩枝扦插生根率高、平均根数多、根长;ABT-1生根粉对扦插作用效果明显;IBA采用600×10-6浓度处理直干大叶相思插穗的生根率高于其它浓度。     

Wood Production Potentials of Fenno-Scandinavian Forests Under Nature-Orientated Management

In Finland, Norway and Sweden forest management is presently changing towards a more nature-orientated management. In this study the European Forest Information SCENario (EFISCEN) model was applied to determine how this change might affect the potential for wood production in the three countries. Three different management regimes, traditional, traditional with nature conservation (''conservation''), and longer rotations with nature conservation (''conservation +''), were combined with two alternative felling levels. The results show that conserving 6.1-8.8% of the older forests in the southern regions had no limiting effects on production levels, as foreseen by the European Timber Trend Studies V by the UN-ECE for Finland and Sweden. Under the conservation + scenario, maximum sustainable felling levels decreased to 84, 79 and 72% of the present levels in Finland, Norway and Sweden, respectively. Increasing the rotation length put more pressure on the older age classes and thus did not increase the average age of the forest. If the consumption of wood increases as quickly as indicated by other studies, it will be hard to fulfil that demand and at the same time conserve considerable areas of forest in the southern regions of the countries.     

落叶松扦插繁殖配套技术的研究

从3个主要途径收集了落叶松优良品系,建立了采穗圃,营造了对比试验林。对优良品系无性苗扦插技术进行了较全面研究,结果表明:(1)在扦插基质选择上,以河沙为好;(2)插穗地径与生根有较大关系,采穗时应尽量剪取地径大于1.8 mm的插穗;(3)母树年龄越小,插穗生根效果越好,据此,采穗圃以经营5 a为宜;(4)不同品系落叶松的扦插生根能力不同;(5)不同配比、不同浓度的激素至关重要,采用IBA50%+IAA20%+NAA30%的质量分数为5.0×10-5 浓度溶液和IBA60%+IAA20%+NAA20%的质量分数为1.5×10-4 浓度溶液,辅以适量烟酸及链霉素等增效剂处理落叶松插穗,其生根可稳定在80%以上。     

Long-term development of soil organic carbon and nitrogen stocks after shelterwood- and clear-cutting in a mountain forest in the Bavarian Limestone Alps

Forest soils store large stocks of soil organic matter (SOM) and are of vital importance for the ecosystem supply with nutrients and water. According to the available literature, depending on management regime and site properties, different negative and positive effects of forest management (particularly of forest thinnings and shelterwood cuttings) on soil organic carbon (SOC) and nitrogen (N) stocks are observed. To elucidate the long-term impact of different shelterwood systems and small clear-cuttings on the OC and N stocks of shallow calcareous soils in the Bavarian Alps, we conducted soil humus inventories on different plots of a mixed mountain forest management experiment started in 1976. The silvicultural multi-treatment experiment consists of a NW-exposed Main Experiment (ME) site with eight plots of different cutting intensity (two unthinned controls, two light shelterwood cuttings = 30 % of basal tree area removed, two heavy shelterwood cuttings = 50 % removed, and two clear-cuttings = 100 % removed) on Triassic dolostone. Additionally, plots were installed at a N-exposed dolostone (ND) site and two sites (FL, FH) on Flysch sandstone (each with one unthinned control and one heavy shelterwood cutting). The shelterwood cuttings from 1976 were repeated in 2003 to re-establish the overstorey basal area as produced by the first cutting in the different plots. Thirty-five years after the first treatments, forest floor SOC and N stocks were significantly decreased (up to ?70 %) at the different shelterwood and clear-cut treatments compared to the unthinned control at the ME site despite vigorous development of natural rejuvenation. Also significantly smaller topsoil (forest floor plus mineral soil 0–10 cm depth) OC stocks (between ?16 and ?20 %) were detected at the thinned compared to the control plots. Differences in topsoil N stocks were also considerable (between ?3 and ?14 %), but substantially smaller than OC stock changes. For the total soil down to 30 cm depth, OC stocks in the differently thinned plots were consistently smaller compared to the unthinned control plots. Comparable to our findings at the ME site, heavy shelterwood plots at the three other sites (ND, FL, and FH) showed significant losses of OC in the forest floor (up to 43 %), mineral soil (up to 38 %), topsoil (up to 38 %), and total soil (up to 34 %). Significant large absolute and relative SOC decreases coincided with sites characterized by large initial humus stocks. Moreover, significant effects of heavy shelterwood cuttings on SOC and N stocks (on average 23 % SOC loss and 13 % soil N loss for the forest floor plus the uppermost 10 cm mineral soil) were detected on a regional level. Our results show that different shelterwood systems are accompanied with a considerable long-term decrease in OC and N stocks in shallow calcareous forest soils of the Bavarian Alps. However, a comparison with a windthrown forest stand at a nearby similar site indicates that SOM losses after thinning operations are small compared to decreases following windthrow or other calamities with subsequent large soil erosion and increased mineralization processes.     

采伐对天然云冷杉针阔混交林半分解层凋落物现存量、含水率及林分郁闭度空间异质性的影响

[目的]以吉林省汪清林业局金沟岭林场4块天然云冷杉针阔混交林为研究对象,探究不同采伐强度下[重度(采伐强度21. 21%),中度(采伐强度11. 22%),轻度(采伐强度6. 29%)和对照(未采伐)]凋落物半分解层现存量、含水率与林分郁闭度的空间异质性。[方法]采用地统计学方法,对各样地凋落物半分解层现存量、含水率与林分郁闭度数据进行普通克里金插值,得到3个指标的空间分布格局图。[结果]表明:在10 100 m的尺度上,采伐使得凋落物现存量由离散型分布转变为聚集型分布,而对凋落物含水率的空间格局影响不大;所有样地的郁闭度均表现为聚集型分布,采伐一定程度上影响了其在中度采伐与重度采伐样地的空间异质性;凋落物现存量与林分郁闭度之间不存在相关性,而在对照样地,凋落物现存量与含水率存在显著的负相关,但相关程度较弱(r 0. 3)。[结论]采伐对凋落物半分解层含水率空间异质性影响不大;中度采伐与重度采伐样地的郁闭度异质性可能是由于采伐不均匀所导致;采伐使凋落物现存量空间异质性程度降低。     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

母猪果不同个体间插穗生根能力的变异

为了缩短育苗周期,对药用植物母猪果不同个体间插穗生根能力的变异进行研究。研究表明:母猪果不同个体间插穗的生根率、根系效果指数和平均生根速度均存在着较大的变异性,其中成年树生根率的变异范围在0%~90%,幼年树生根率的变异范围在13.5%~100%之间。相关分析表明:成年树插穗的生根率与根系效果指数存在显著的正相关关系;与平均生根速度之间存在着显著的负相关关系。因此,建议选择生根率高、发根能力强且生根快的植株作为采穗母株。此外对不同年龄段采穗母树插穗的生根能力分析表明,母猪果幼年树母株的生根能力较成年树强。     

竹柏扦插育苗技术研究

为给竹柏优良品系的扩繁提供技术支持,对不同措施处理下竹柏插穗的生根情况进行了试验。结果表明,不同季节扦插对竹柏插穗生根性状具有显著影响,春季是进行竹柏扦插的最佳季节,在春季进行扦插,竹柏的扦插生根率可达91.33%,平均生根条数为3.85条,平均最大根长为6.52cm;竹柏插穗选取的部位对竹柏生根性状有着极显著的影响,来自母树基部的插穗生根效果最好、中部次之,上部最差;不同留叶方式可极显著地影响竹柏扦插的生根率、生根数及最大根长,进行竹柏扦插,插穗应以保留2片全叶为最佳。     

闽鄂山茶扦插繁殖技术研究

针对我国特有的珍稀濒危植物闽鄂山茶种子育苗困难的问题开展扦插繁殖研究,采取不同基质、不同扦插时间、不同年龄的母株穗条和ABT-1#不同浓度处理进行扦插对比。结果表明:不同基质、不同时间、母株年龄和生根粉浓度对闽鄂山茶扦插的成活率存在影响,其中以5月份在低年龄母树上采集的中下部穗条经300×10-6ABT-1#处理后在砻糠灰中扦插效果为最佳,42 d形成不定根,成活率达到93.5%。     

杂种落叶松连续繁殖与插穗生根关系的生理研究

观察了日×长杂种落叶松连续繁殖插穗不定根发育进程,研究了连续繁殖对插穗生根力衰退的阻滞效应,并分析了一轮采穗圃与原株采穗圃插穗不定根发育期内源激素含量的动态变化。结果表明:扦插后13 31 d是愈伤组织形成和不定根原始体分化发育的关键期,此时一轮分生株愈伤组织形成和不定根发育均优于原株。连续繁殖对插穗生根性状有显著作用,尤其是生根率很低的原株,经过一轮繁殖后,生根性状有极显著提高。连续繁殖影响插穗自身激素含量,尤其是IAA,经过一轮繁殖后,含量明显高于原株。从不定根发育过程中激素的动态变化看,一轮分生株插穗(IAA+GA3+ZR)/ABA比值在不定根发育前期明显高于原株,与生根率的变化一致,可用来衡量不同繁殖次数插穗生根性状的优劣。     

一品红扦插繁殖技术研究

以一品红品种‘安琪’为供试材料,研究了不同扦插方式、不同扦插季节、不同激素处理对扦插繁殖的影响,结果表明,于花泥中进行嫩枝扦插,插条生根率可高达92.4%;春夏季插条生根率要比秋冬季高约20%,插后生根时间缩短10 d;100 mg/L NAA 100 mg/L IAA的激素组合处理休眠枝16 h,扦插效果最佳。     

Vegetative propagation of African Blackwood (<Emphasis Type="Italic">Dalbergia melanoxylon</Emphasis> Guill. &; Perr.): effects of age of donor plant,IBA treatment and cutting position on rooting ability of stem cuttings

A study to determine the best vegetative propagation protocol was carried out for Dalbergia melanoxylon. Natural regeneration of D. melanoxylon is limited due to poor seed viability and germination. The effects of age of donor plant, indole-3-butyric acid (IBA) treatment and cutting position on rooting of stem cuttings were investigated. The effect of age of donor plant was significant (P < 0.001) only for percent rooting, position effect was significant for all studied parameters, and IBA treatment at 300 ppm was insignificant only for percent callusing. Interactive effects of cutting position × age of donor and cutting position × IBA treatment were significant for percent rooting and root number per cuttings while interactive effect of age × IBA was significant only for percent rooting. Observed difference in rooting performance could be due to uneven distribution of root promoting and inhibiting substances with respect to age of donor plant and IBA which intensified root formation. Cuttings from juvenile donor plant performed better in all rooting parameters than mature donor plant. The highest percentages in rooting were (71.11%) and (24.42%) for cuttings from juvenile and mature donor plants, respectively. IBA treated cuttings produced higher percentage rooting, number of roots and root length than untreated cuttings which revealed a strong IBA influence on rooting ability of stem cuttings in D. melanoxylon. It was concluded that stem cuttings should be taken from juvenile donor plants and basal cutting position should be used to produce high quality planting stock material for the afforestation and conservation programme of D. melanoxylon.     

赤桉、巨尾桉扦插育苗成活率试验

试验结果表明：不同浓度的ＡＢＴ生根粉液对扦插成活牵有显著影响，以２５０×１０－６ＡＢＴ生根粉液处理效果最好；扦插条硬枝、嫩枝对扦插成活率有影响，嫩枝扦插条成活率高于硬枝扦插；巨尾桉比赤桉更易扦插成活；扦插条有或无顶芽，对扦插成活影响不大；高温、高湿天气有利于扦插条成活。     

Impacts of bucking and delimbing alternatives on pulpwood and energy wood yields in young thinning stands in Finland

The supply of energy wood from young forests could be enhanced by altering the harvesting methods in integrated pulpwood and energy wood thinnings. In this study, effects of different bucking and delimbing options on the biomass division into energy wood, pulpwood and logging residue were estimated in integrated thinnings of young stands dominated by Scots pine (Pinus sylvestris), Norway spruce (Picea abies) or birches (Betula spp.) in Finland. Thinning options were simulated in the harvestings of model stands created on the basis of forest inventory data. Increasing the minimum top diameter of pulpwood (MTDP) expectedly increased energy wood and decreased pulpwood yields. Depending on tree species, energy wood yield increased by 36–65% when the top diameter was increased from the regular level (6 or 7 cm) to 8 cm in whole-tree harvesting, and was more than doubled when the top diameter was increased to 10 cm. Delimbed energy wood yield was increased by 240–280% when the top diameter was increased to 10 cm. Total harvesting yield in whole-tree thinnings was slightly increased by increasing top diameter. These increments in harvesting yields and reallocations of tree biomass could have an impact on large-scale forest energy potentials.     

The influence of alternative plant propagation and stand establishment techniques on survival and growth of eastern cottonwood (Populus deltoides Bartr.) clones

Four eastern cottonwood clones, including standard operational clone ST66 and three advanced clonal selections were produced and included in a test utilizing five different plant propagation methods. Despite relatively large first-year growth differences among clones, all clones demonstrated similar responses to the treatments and clone × cutting treatment interactions were generally non-significant. The effects of changing cutting lengths are consistent with previous studies which indicated the potential for increased plant survival and growth with increased cutting lengths. Differences in stored carbohydrate reserves alone do not appear to completely control first-year growth and development of cuttings. First-year growth of 51 cm long cuttings planted 30.5 cm deep was greater than the same cuttings planted 48 cm deep. Stem form of plants derived from whip-tip propagation did not differ from plants derived from standard, unrooted cuttings. This propagation method offers the potential of far greater production capacity from a cutting orchard and rapid bulk-up of new or limited clones. Stand uniformity assessments suggest that surviving trees of each individual cutting treatment exhibit similar levels of growth variation. Optimization of plantation establishment techniques has the potential to increase growth of young Populus plantations.