Effects of Repeated Cycles of Dehydration Rehydration on Drought Tolerance of Jack Pine and Black Spruce Seedlings

应用根系喷雾箱（ＲｏｏｔＭｉｓｔｉｎｇＣｈａｍｂｅｒ,ＲＭＣ）形成的５次干旱循环,通过ＰＶ曲线的水分参数研究了多重复干旱循环对１年生北美短叶松ＰｉｎｕｓｂａｎｋｓｉａｎａＬａｍｂ．和黑云杉Ｐｉｃｅａｍａｒｉａｎａ［Ｍｉｌ］Ｂ．Ｓ．Ｄ．苗木耐旱特性的影响．结果表明,生长在干旱沙地的深根性树种北美短叶松,其丧失膨压的相对含水量（８０７６％～８１４１％）和水势（（－１７４±０１０）ＭＰａ）都比较低,细胞弹性模量（５７３～６５２ＭＰａ）比较小,而束缚水含量（５２７２％～５４２６％）比较高,显示出它固有的强有力的忍耐脱水能力;但是在多重复干旱循环下它却不能进一步调节其渗透势和细胞弹性,而且其束缚水含量和吸水能力也有所下降．生长在湿润地区的浅根性树种黑云杉,虽然其丧失膨压的相对含水量（８３５３％～８５５０％）和水势（（－１６８±００３）ＭＰａ）比较高,细胞弹性模量（８６２～９６４ＭＰａ）比较大,束缚水含量（３６４４％～４６０５％）比较低,显示出较弱的耐旱能力,但是它在多重复干旱循环下却能提高其束缚水含量以改善原生质耐旱程度,降低细胞弹性以提高其吸水能力,调节其渗透势以保持较高的膨压．这表     

多重复干旱循环对北美短叶松和黑云杉苗木气体交换及水分利用效率的影响

本文研究了多重复干旱循环对１年生北美短叶松（ＰｉｎｕｓｂａｎｋｓｉａｎａＬａｍｂ．）和黑云杉（Ｐｉｃｅａｍａｒｉａｎａ［Ｍｉｌ］Ｂ．Ｓ．Ｄ．）苗木的气体交换速率及水分利用效率的影响。结果表面，多重干旱循环对它们的气体交换（Ｃｓ，Ｐｎ，Ｔｒ）有显著影响（Ｐ＜０．５），而对其水分利用效率（ＷＵＥ）影响不大（Ｐ＞０．１）。尽管北美短叶松的气孔对轻度干旱胁迫不如黑云杉敏感，但是它对中度及严重干旱胁迫的敏感程度却高于黑云杉。在轻度及中度干旱胁迫下，北美短叶松的光合作用主要受非气孔因素的影响，而黑云杉则主要受气孔因素的影响。解除干旱胁迫后，黑云杉的气孔敏感性、光合能力及水分利用效率的恢复都要比北美短叶松更快．我们认为，延迟脱水是北美短叶松的主要耐旱机理，而忍耐脱水则是黑云杉重要的耐旱途径。轻度的干旱胁迫锻炼可以帮助北美短叶松在更严重的干旱胁迫下保持固有而较强的耐旱能力。然而，通过多重复干旱循环锻炼后黑云杉在改善耐旱能力的强度方面则大于北美短叶松     

Establishing white spruce in the Boreal White and Black Spruce Zone

Two trials (``Wonowon' and ``Iron Creek') in the Prince George Forest Region of interiorBritish Columbia were begun in the mid 1980s toevaluate site preparation treatments for establishingwhite spruce (Picea glauca [Moench] Voss) in theBoreal White and Black Spruce biogeoclimatic zone. The14 treatments (9 or 10 per trial) were: [B.C.]Ministry, Sinkkila, and Bracke mounds; Bracke moundsmanually supplemented with 20-, 14-, or 6-cm cappingsof mineral soil; fertilized Sinkkila mounds; Brackepatches; fertilized Bracke patches; bladed strips;plowed ground; herbicide; and untreated controls,separately with both standard and nominally superior``alternate' planting stock. With minor aberrations,each trial consists of 5 randomized complete blockseach with one 80-tree plot per treatment; planting wasin spring, 1984 at Wonowon, 1987 at Iron Creek. Alltrees in mounding treatments and the inner 48 trees inother plots were monitored for performance through1998 at Wonowon, 1996 at Iron Creek. The herbicide andplowing treatments, and mounds capped thickly enoughwith mineral soil to inhibit weed regrowth, wereclearly superior to others. In the mounding treatments at Wonowon, survival rateincreased with capping thickness, but, while the 14 and 20 cmcappings were best, significant differences among them were few after 15 growing seasons.In both trials, patchscarification gave poorer results than did plantingwithout site preparation.     

黑云杉、白云杉苗期生长性状研究

本试验对引进加拿大的黑云杉3个种源和白云杉4个种源及当地的红皮云杉进行了苗期生长性状的研究,通过对1年生苗期的高生长和径生长的数据整理分析,结果表明,3种云杉以苗期高生长差异显著,但径生长不显著。3种云杉以苗期高生长排序为白云杉>黑云杉>红皮云杉。同时对黑云杉、白云杉的种源进行了研究,结果表明,白云杉的7号种源和黑云杉的3号种源分别在高生长和径生长上有较好的适应性,可作为本引种试验的优良种源。     

Risk of Snow Damage in Unmanaged and Managed Stands of Scots Pine,Norway Spruce and Birch

The aim of this study was to assess the risk of snow damage to trees in unmanaged and managed stands of Scots pine (Pinus sylvestris L.), Norway spruce [Picea abies (L.) Karst.] and birch (Betula spp.) over a rotation. The risk assessment was based on the prediction of critical snow loads in interaction with the windspeed at which trees can be expected to break or be uprooted, and on the frequency of long-term extremes of precipitation and of suitable temperature conditions for the accumulation of snow on the tree crowns. The Scots pine stands were found to be more susceptible to snow damage than the others, and an unmanaged stand of Scots pine to be more susceptible to break and uproot than a managed one. Correspondingly, an unmanaged stand of Norway spruce was more susceptible to stem breakage than a managed one, but less susceptible to uprooting. Neither unmanaged nor managed birch stands were likely to suffer any kind of snow damage. The susceptibility of unmanaged stands is caused by low tapering of the trees. Based on the frequency of long-term extremes in precipitation at the temperatures needed for snow accumulation on tree crowns, critical snow loads of 10-19, 20-29 and 30-39 kg m^-2 occurred 19.3, 3.3 and 1.3 times in a decade in southern Finland. Critical snow loads of 10-19, 20-29, 30-39 and 60-69 kg m^-2 occurred in northern Finland 17.0, 6.3, 1.7 and 0.3 times in a decade.     

Comparative Performance of Containerised and Bare-root Sitka Spruce and Lodgepole Pine Seedlings in Upland Britain

Seedlings of Sitka spruce and Lodgepole pine were grown in fivedifferent container types; Ontario tubes, Kopparfors multipots,Finn peat pots, Japanese paperpots and Spencer-Lemaire root-trainers.They were planted in forest experiments in 1972/3 when 8-14weeks old and their subsequent performance compared with 2 years-oldbare-rooted transplants. After 2–3 years' growth, tubed seedlings proved consistentlypoorer than all other treatments for both height and survival.Finn peat pots were marginally the best of the other containerstested. Containerised plants generally showed poorer survivaland substantially less height growth than transplants, withdifferences being greater for Sitka spruce than for Lodgepolepine. For both species well-handled transplants appear the mostappropriate plant type for use in upland Britain. Implications for the future role of containerised seedlingsin upland forestry in Britain are considered. The benefits ofcontainer systems may be greatest in the production of seedlingsof ‘sensitive’ species or of high genetic quality.     

Phosphorus Nutrition of Lodgepole Pine and Sitka Spruce Stands as indicated by a Root Bioassay

A bioassay for determining P-deficiency, based on the rate ofuptake of ³²P-labelled phosphorus by roots from a standard solutionand developed on pot grown tree seedlings, has been appliedto roots from 10–18 year old lodgepole pine and Sitkaspruce stands in field fertilizer trials on peat. Rates of ³²-phosphorusuptake by roots were negatively related to quantities of P fertilizerpreviously given and to tree heights. The P content of firstwhorl needle samples were generally high but were not significantlydifferent between fertilizer treatments nor related to treeheights. There was, however, a general relationship between rates of³²P uptake by roots and P content of needles over all sitesand tree species. The bioassy, however, rapidly detects changesin internal P status of the tree which takes time to manifestitself in a change of needle P content. Preliminary work suggests that the bioassay detects a P-statusin trees, not identifiable from needle analyses. A number offactors which might influence the results of the bioassay andtherefore the field applicability of the method are discussed.     

Shading Reduces both Visible and Invisible Frost Damage to Norway Spruce Seedlings in the Field

Two-year-old cuttings of Norway spruce were subjected to nightfrosts in spring on an exposed site in southern Sweden. Shadingwas used to assess the influence of sunlight on the extent ofdamage resulting from night frost. Chlorophyll fluorescencewas measured in needles in flushing shoots, and in shoots atthe stage of bud burst. The F_v:F_m ratio was significantly lowerfor plants exposed to light, compared with shaded plants onthe days following the night frost (minimum temperature –6°C).The effect was similar both in 1-year-old and current year needles.The low F_v:F_m ratios indicate damage to photosystem H, causedby an interaction between sub freezing temperatures and highlight intensity. Shading also increased the survival of flushingshoots. It is suggested that regeneration of Norway spruce onsites exposed to frost should be carried out in partial shade,for example under a shelterwood.     

台风“天鸽”对湿加松无性系种子园的影响*

2017年第13号台风“天鸽”正面袭击台山,给台山红岭种子园内的湿加松(Pinus ellittii × P. caribaea)无性系种子园造成巨大损失,一半的球果和三分之一的单株遭到严重破坏。经过调查发现,单株的受害类型可以分为两类,一种类型主要表现为枝干受损,其中主干破裂占受害株的55%,侧枝受损占36.4%,而主干破裂的类型以基部破裂为主;另一种类型表现为根系受损,只占8.7%,包括倾斜、倒伏和连根拔起。不同湿加松无性系的受灾情况存在明显差异,参与分析的53个无性系中,8个无性系（EHA10-1,EHA11-1,G3-1,G3-3,G5-1,G7-1,S95-20-1 和 S95-20-3）没有遭受风害, 7个无性系（G11-4,G3-4,A05H06-1,B16H02-1,G1-1,G5-4,S95-54-1）受灾率超过80%,说明湿加松的抗风性在基因型间存在差异。跟踪调查2016-2019年湿加松种子园的种子品质,发现台风当年（2017年）的出种率和千粒重不受影响,但发芽率明显降低;台风次年出种率下降,但千粒重和发芽率不变。说明台风影响了球果的发育,但仍可对球果进行采摘利用。     

Effect of Peat-based Container Media on Establishment of Scots Pine,Norway Spruce and Silver Birch Seedlings after Transplanting in Contrasting Water Conditions

Abstract

Urban woodlands are the subject of complex decision-making that requires a strategic overview of the resource. This article contributes a national study of municipal woodland in Denmark. Data were collected among all Danish municipalities through a postal survey (with a response rate of 52%). As much as 83% of the woodland units were located within urban settlements or at their fringe, emphasising that municipalities are important urban woodland providers. Municipal woodland resources were typically divided into many separate units of varying size. On average, the responding municipalities owned 12.6 woodland units with an allocated area of 265 ha, resulting in a mean size of 21.5 ha. A general lack of management plans, and a significant drop in recreational facilities provided with decreasing woodland size indicate that the recreational use potential of small woodland units was largely overlooked. Municipal woodland units frequently bordered other woodland or nature areas of different ownership. Thus even small municipal woodlands can play a key role in the development of multifunctional green infrastructures in the urban landscape. Only municipalities with extensive woodland property had issued a woodland policy, and/or certified woodland management. This indicates a need for development of governance and strategic management instruments attractive to municipalities with limited woodland property.     

东折棱河椴树红松林和云冷杉红松林生物多样性比较

对小兴安岭东折棱河林场2种不同类型的红松林——椴树红松林和云冷杉红松林进行调查,应用重要值、辛普森多样性指数(Simpson’s diversity index)和香农-威纳指数(Shannon-Weiner index)对2种不同红松林乔灌草三层的生物多样性进行了分析和比较。结果认为,云冷杉红松林总体物种丰富度、信息量、生物多样性指数均高于椴树红松林。     

松树截根菌根化育苗和造林的研究*

根据苗木根系分泌物能促进菌根真菌萌发和生长的原理，结合我国林业育苗的特点，提出了松树幼苗截根与人工接种菌根真菌结合的育苗方式。结果表明，截根菌根化育苗在促进根系发育和菌根形成，加速苗木生长，提高苗木生物量、苗木质量和产苗量等方面都有显著优势，苗木的侧根数、侧根总长、苗木菌根化率、吸收根菌根化率、苗高、地径、鲜重、干重分别提高２０．０％～９６０．０％、５６．２％～３８９．５％、０．０％～４００．０％、５６．２％～１７９２．０％、２２．３％～１７９．３％、３１．２％～２５３．８％、３３．３％～９１８．２％和２１．８％～７４０．０％，苗木成活率和Ⅰ级苗分别提高９．０％～２２．１％和４９．３％～１５０．０％，Ⅱ、Ⅲ级苗和等外苗分别降低４０．６％～７７．３％、６１．６％～８８．５％和８２．５％～１００．０％。利用截根菌根化苗木造林，提高成活保存率５．５％～４６．０％，并促进幼树生长，树高、地径和材积指数分别增加１３．０％～５６．４％、２５．５％～６１．７％和８７．８％～４５０．０％。效益分析证明，截根菌根化育苗具有明显的经济效益和社会效益，仅苗期可定量计算的增收（节支）总额可达４４６６２元／ｈｍ２。     

Influence of Stem Diameter on the Survival and Growth of Containerized Norway Spruce Seedlings Attacked by Pine Weevils (Hylobius spp.)

Pine weevils (Hylobius spp.) feeding on stem bark of young conifer seedlings pose a serious threat to forest regeneration-planting programmes in Nordic countries. This study was designed to determine the threshold diameter for planted, untreated containerized seedlings, above which pine weevils cause little or no damage. The effects of sublethal weevil damage on seedling growth were also assessed. In total, 5320 containerized spruce seedlings were planted on scarified and unscarified plots on three sites in southern Sweden. Seedlings in six size classes, which differed with regard to age (1.5-3.5 yrs) and cultivation density (28-446 seedlings m 2) were grown using the Combicell system. None of the seedlings was treated with insecticides, except for those in the smallest class, where both untreated and treated seedlings were used. Inspections were made periodically during the first 3 yrs and after both 5 and 7 yrs. A statistically significant relationship was found between seedling losses due to pine weevil attack and seedling stem-base diameter at the time of planting out, on both scarified and unscarified plots. For seedlings with a stem-base diameter of around 10 mm, mortality due to pine weevil attack on scarified plots was low enough to be considered negligible. This threshold diameter was several millimetres greater for seedlings planted on unscarified plots. An analysis of the relationship between the extent of weevil damage and seedling growth rate showed that among surviving seedlings, those that grew fast tended to show low levels of damage. On unscarified plots, the mortality rate amongst seedlings treated once with a permethrin insecticide was only one-third that of untreated seedlings. On scarified plots, the corresponding difference was somewhat smaller. Repeated insecticide treatment resulted in a pronounced reduction in seedling mortality on the unscarified plots, whereas the effect was weaker on scarified plots.     

Pine Weevil Population Density and Damage to Coniferous Seedlings in a Regeneration Area With and Without Shelterwood

Damage to planted conifer seedlings by the pine weevil, Hylobius abietis (L.), is considered to be less severe in shelterwoods than in clear-cuttings. To evaluate possible reasons for this reduction, this study investigated the relationship between seedling damage and pine weevil population density in the presence and absence of shelter trees. Assessments of seedling damage throughout a full growth season and absolute population density estimates were made at a fresh clear-cutting and an adjacent shelterwood (1 ha each). A grid of 100 pitfall traps was placed over each area, and population estimates were made using the mark–recapture technique. Pine weevil damage to seedlings was about twice as high in the clear-cutting, whereas pine weevil density was estimated to be higher in the shelterwood or about the same in the two treatments (～14?000 weevils ha^?1). Existing differences in microclimate between the shelterwood and clear-cutting did not seem to be the cause of the differences in damage levels. Thus, the hypothesis that seedling damage is reduced in shelterwoods because of increased availability of alternative food remains a candidate for further testing.     

Toxicity of Five Granular Herbicides to Sitka Spruce and Lodgepole Pine

Experimental plots in young plantations of Sitka spruce andlodgepole pine were over-dosed with five granular herbicidesto ascertain the margin of crop safety involved in the use ofpropyzamide, chlorthiamid, dichlobenil, dichlobenil/dalaponmix and atrazine. It is concluded that if the five herbicidesare applied according to the standard rates and dates used inthe experiments, tree damage will be kept to an acceptable minimum.Better shoot growth resulted from herbicide treatment than fromhand weeding particularly where atrazine was used.     

Competitive Interactions between Norway Spruce and Scots Pine at Gisburn Forest, NW England

Species mixtures, although promising for improving the growthof spruce on nitrogendeficient sites, carry a risk of competitionfrom the admixed nurse species. The mixture of Scots pine (Pinussylvestris) and Norway spruce (Picea abies) planted at GisburnForest in 1955, in which nutritional benefits have been observed,provided a unique opportunity to study competition between thesespecies. Pure plots of both species as well as the mixture werereplicated in three blocks, allowing the effects of interplantingon the survival and mean diameter of each species to be testedstatistically. Further, the grouped arrangement of the speciesin mixed plots presented a variety of competitive configurationsbetween the two species. Instead of demonstrating the nursing benefit of pine to spruce,comparisons of mean diameters in pure and mixed stands indicatedthat spruce suffered and pine benefited from their interplantingat this site. Frequency distributions of tree diameters confirmedthat spruce tended to be suppressed in mixture and pine dominant.Neighbour analysis revealed that spruce were significantly smallerwhen adjacent to pine and that this effect was mainly due tothe larger size of pines. The increased height of spruce atthis site, previously attributed to a nutritional benefit conferredby pine, was probably due to competition for light from an overtoppingnurse. Nurse varieties must be carefully selected if they areto promote rather than suppress the growth of crop trees.     

寒害天气对永州市赤桉组培苗造林的影响

2004年冬季永州市经历了严重的寒害天气。灾害过后,调查了东安县种植的赤桉组培苗受冻和冻后恢复情况,分析比较了赤桉组培苗种植后的耐寒性和冻后恢复能力。调查结果表明：2004年冬季是永州市罕见的寒害天气,所有引种的桉树幼林均受到不同程度的冻害,但赤桉组培苗幼林受冻程度较轻,冻后恢复较快,类似2004年冬季的寒害天气,对永州市赤桉组培苗造林没有影响。根据永州南桉北移造林的现状,提出了发展桉树产业的建议。     

Sitka Spruce and Douglas fir Seedlings in the Nursery and in Cold Storage: Root Growth Potential, Carbohydrate Content, Dormancy, Frost Hardiness and Mitotic Index

Seedlings (transplants) of 2+1 Sitka spruce (Picea sitchensis(Bong.) Carr.) and 1 + 1 Douglas fir (Pseudotsuga menziesii(Mirb.) Franco) were grown in a nursery at the Bush Estate,Scotland. Batches were lifted and cold stored at 0.5°C inNovember, December and January. Changes in growth, shoot apicalmitotic index, root growth potential (RGP), carbohydrate content,bud dormancy and shoot frost hardiness were monitored throughoutthe winter by taking samples at intervals from the nursery andfrom cold storage. Frost hardening occurred during the later stages of bud development(as mitotic indices decreased); autumn hardening was arrestedwhen seedlings were put in cold store, and some dehardeningoccurred in cold storage, especially in spring. Bud dormancystarted, and was greatest, just after bud growth (mitotic activity)virtually ceased; chilling in cold store was almost as effectivein releasing dormancy as natural chilling. The concentrationof total nonstructural carbohydrates stayed more or less constantat 100–150mg g^–1 from September to April in thenursery; in cold storage carbohydrates were depleted at 0.4–0.6mgg^–1 d^–1 (corresponding to respiration at 0.03–0.05mgCO₂ g^–1 h^–1) until there was only 40–50mgg^–1. Root growth potentials in the nursery increased in December,once the buds ceased growth, became dormant and had receivedsome chilling. Sitka spruce was ‘storable’ in November,before RGPs increased, but they then failed to achieve maximalfrost hardiness or ROP. Winter RGPs were high in Sitka spruceand were increased or maintained in cold storage, whereas RGPswere low in Douglas fir and decreased immediately after storage(except when stored in January). By the end of April, the RGPof cold stored Sitka spruce was much higher than that of directlifted plants. ROP changes in the nursery and in cold storagewere not consistently related to changes in seedling carbohydratecontents, shoot frost hardiness or bud dormancy. In practical terms, it was concluded that (1) the optimum dateto start lifting bare- rooted conifer transplants in the autumnis when their shoot apical mitotic indices have decreased tonear zero, and their RGPs have risen sharply; (2) high RGPsmay depend as much on the morphology of the roots (e.g. numberof undamaged root apices) as on the physiology of the shoots(e.g. carbohydrate status, dormancy and frost hardiness); and(3) in spring, transplants kept in cold storage since November,December or January are more frost hardy, slightly more dormant,and (in May) have higher RGPs than transplants lifted from thenursery.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

松苗猝倒病防治技术

根据多年育苗实践,简述了松苗猝倒病田间识别症状,发病流行规律。提出了防治松树苗木猝倒病应把握土壤处理、种子筛选与处理和苗木管理三个关键技术环节。