SECONDARY SUCCESSION OF NATURAL KOREAN PINE FORESTS

ThereisatractofsecondaryforestsinnatUfKoreanghn(Pinuskorniensis)forestndon-FenlinNatUrReserveswithanareaofl8l65.4hIn,locatedinthesouthslopeofXiaOking'anlingMountain.ThisresearchwascAnedoutonthesuccessionofhosstandNATURAL0unS0FwiSTANDSInl93l,therewasawildfireinthevir-ginKoreanPineforests,whichstretchedfromShanggedingalongTangwangffivertonorth-eastuntilstandNo.32OfFenglinNatureRe-serves.Thefiredareawasabout2,44Ohm2.TOdate,thestandsisbroadleavedmixedfOr-estsdOndnatedbywhitebirch(…     

Vegetation structure,composition and effect of pine plantation harvesting on riparian buffers in New Zealand

The composition and structure of vegetation within riparian buffers prior to, and immediately post-harvesting in a managed radiata pine (Pinus radiata D.Don) forest is described and compared with riparian buffers in residual adjoining native forest on the Coromandel Peninsula, New Zealand. One hundred and twenty-one species (71% native) representing life forms from grasses to trees were recorded. The highest species richness, including both native and adventive (non-native) species, was found in riparian buffers in the post-harvest and native reference sites which had 18–25 species per site. Riparian buffers in mature pine plantations contained a mix of native species that was generally similar to, and not significantly reduced in species richness, from the reference native forest. Native species comprised 82–92% of the total cover in mature pre-harvest sites (irrespective of riparian width), and 99.8% in native reference sites. Compared with native forest the principal difference was a reduction of total cover in the upper tiers (5–12 m), and some increase in cover in the lower tiers. Adventive species in post-harvest sites comprised 16–67% of the total cover and were most frequently found in riparian areas highly disturbed by recent harvesting of the pines, particularly where riparian buffers were narrow or absent. Invasion by light-demanding adventives is expected to be temporary and most species are likely to be shaded out as the new rotation of pine trees develops. Radiata pine plantations in Whangapoua Forest can provide suitable conditions for the development of riparian buffer zones that will become dominated by native species, similar in richness and structure to neighbouring native forest.     

A succession and silviculture model for the broad-leaved Korean pine forests of Changbai Mountain Area

IntroductionGaPSinforestSwereoftenfomledduetobigtreesfalldown.Regenerationandgrowtl1inthegapsincreasebe-causeofIheAnprovementoflightcondition-Thegapwillbefilledwithnewregeneratedtrees.Wattnamedtl1isforesIdynamicsastheforestgrowtllcycle.SinceD.Bot-kindevelopedthefirstGapmo`Iel(JANOWAnlodel)basedontheforestgrowthcycletheory,dleresearchongapmodelbecameoneofthemostactivedirectio11slilecologybecauseofJANoWAnlodeI'ssuccess.H.Sl1ug-artandhisstUdentSmadegreatc()ntributio11stogapmodeI'sdeve…     

联营林场红松天然母树林的经营

本文对联营林场红松天然母树林的经营谈了一套实践经验 ;红松优良林分的选择标准 ;促进红松母树结实的疏伐 ;如何加强经营管理及组织好林木种子的生产。     

Canopy gap characteristics and its influence on the regeneration of broad-leaved Korean pine forests in Changbai Mountain

lntroductionBroad-leavedKoreanpineforestisacldriaxforestli1tCm-peratezoneofNortheaster11Cl1ina.ltscharacteristichasIligllstabilityandproductivity.Therewerenlanyresearcl1worksfocusedontl1estructure,dynandcsanditsmain-tainingmechanisn1.Researchontheforestregeneratio11wasamali1approaclltoundersta11dtlleforestdynanlicsI;j.ThereweremanyresearcI1eso11tl1erege11erationofh1iskindofforestsincel95ol5~ll].Butfewoftl1emweredoneundertheconsiderationofcanopygapdistUrbance.Sincel99O's,moreandmoreresearch…     

Vulnerability of planted forests to biotic and abiotic disturbances

Losses through reduced growth or mortality attributable to pests, diseases, and abiotic disturbances are generally less in intensively managed, planted forests than in natural forests. Among plantation forests, the most healthy forests are those of exotic species growing a long way from their native range (e.g., Pinus radiata D. Don in New Zealand) and the least healthy ones are those of indigenous species (e.g., Eucalyptus nitens (Deane & Maiden) Maiden in Tasmania). The better health of plantations is a reflection of the generally good growing conditions, the proper matching of site to species that is possible in artificial culture and in the case of exotic species, the freedom from the many pests and diseases present in the native habitat of exotics.     

松材线虫病检疫检验取样方法的研究

对24个样本分别采用木条（10g)和0.6cm钻头钻取的木屑（10g)作为分离材料进行线虫分离，利用方差分析的方法对线虫分离结果进行分析，其差异不显著，两种取样方法对线虫检验的结果没有影响，对19个样本分别采用木条（10g)和用1cm的钻头钻取的木屑（10g和5g)3种分离材料进行线虫分离，同样利用方差分析对虫分离结果进行分析，其差异也不显著，3种分离材料对线虫检验结果同样没有影响。因此，利用电钻取样是可行的，这种方法快速简便，易于推广应用。     

Improving harvester estimates of bark thickness for radiata pine (Pinus radiata D.Don)

Harvesters estimate bark thickness primarily from diameter over bark (DOB) and use it to estimate log volume and value. Harvester bark thickness estimation errors can reduce returns through poor bucking optimisation and out-of-specification logs. Radiata pine bark thickness data from harvested logs and permanent sample plots (PSP) were analysed to determine best-fit coefficients for current and potential future harvester bark thickness models. The most suitable current harvester bark thickness model for radiata pine is: double bark thickness = b ₀ + b ₁*DOB (the ‘DOB model’). This describes a straight line, whereas radiata pine bark relative to DOB is thicker near the stem base and consistent over the remainder. PSP data set coefficients for this model overestimated upper stem bark thickness and underestimated lower stem values. The harvester model for Scots pine bark fitted better than the DOB model for diameters <400 mm but performed poorly for larger logs, as it is restricted to trees with a diameter at breast height <590 mm. Two better models were identified: (1) a model using relative height to account for bark thickness changes with height, and (2) implementing separate DOB models for the bottom 10% and top 90% of the stem split by relative height. These approaches require approval by the StanForD committee to be implemented. Prior to approval, the upper 90% model coefficients could be applied to the entire stem to improve upper 90% stem volume and value predictions at the expense of the lower 10%. Further research will determine if this approach produces acceptable results when optimising bucking. Increasing variability of bark thickness estimates with increasing DOB in the PSP data set may reflect manual measurement errors with thicker bark or may show that additional explanatory variables are needed. Efforts to identify new variables would need to be weighed against additional returns and probable reductions in numbers of larger trees by as the clearfell age is reduced.     

Guidelines for Managing Wildlife Habitats in Southwestern Ponderosa Pine Forests of the United States

IntroductionEcoledcalrelahonshipsanddePendenceofwildlifesPe-ciesonsouthwesternPOnderosapine(Pineponderosa)fOrestsarecloselyrelat6dtohabitatuse.Foraginghabits,seasOndfoodPreferences,anduseoftreesforfeedingarelawtydePendentuponthestrUctureandspahalar-rangme…     

Multiple purpose forests and the national forest system

The history of the legislative basis for managing National Forests in the USA has led to forests managed for multiple uses for a wide diversity of users and interests. Evolution of emphasis on National Forests from mandates to preserve and protect and provide a continuous supply of timber to concerns about owls, ecosystem management and contemporary rural development have included changes in on-the-ground forest management. All of these phases include needs for planted forests established and maintained for multiple purposes and benefits.     

Loblolly -- the pine for the twenty-first century

Loblolly pine (Pinus taeda L.) was a minor component of the vast natural forests of the southern United States before the region was settled by immigrants. Extensive planting and natural regeneration of cutover forest land and abandoned farmland between 1930 and 1990 made loblolly the leading timber species in the United States. It now predominates on 13.4 million ha (45 percent) of the commercial forest land in the southern United States (between latitudes 28° N and 39° N and longitudes 75° W and 97° W) and directly or indirectly provides 110,000 jobs and $30 billion to the economy of the region. The extreme versatility of loblolly has also provided important environmental contributions to most southern states. These include landscape beautification, erosion control, soil amelioration, excellent wildlife habitat, and outstanding recreational opportunities. Incorporating existing pest management strategies into silvicultural systems can produce substantial and long-lasting insect and disease control with little cost or physical effort. Introductions of loblolly into numerous countries around the world (especially China, Brazil, and Argentina) have proven to be very successful, environmentally sound, and commercially profitable. In some locations, loblolly grows much faster than on sites of similar quality in the southern United States.     

Growth models and site index table of natural Korean pine forests

IntroductionKoreanpine(PinuskOraiensisSieb.etZucc.)isoneofthemostimportanttimberspeciesanditisnaturaIIydistributedinHeilongjiang,JiIinandLiaon-ingprovincesinChina.ManyforestryresearchersmadeextensiveandprofoundstudiesonthisspeciesJiangYiyin(1985)studiedthegroWthandgrowthmodelsforpIantationsofKoreanpine.However,veryfewpaperswerefoundonthegroWthmodeIsofnaturalKoreanpineforest.Koreanpinehasa1onggroWthperiod.ForextensivelymanagingKoreanpineforest,itneedstheJorestrytabIeswithhighac-Curacy…     

树干注药技术预防松材线虫病的效果评价

松材线虫病是松林的毁灭性病害,过去几十年已在日本、韩国及中国等东亚国家迅速传播扩散.加强对非疫区的监测与保护是目前关注的重点,利用1％阿维菌素微囊悬浮剂对马尾松进行树干注药以预防松材线虫病,研究结果表明,树干注药处理区的枯死松树要显著少于不实施注干的对照区,且处理区内枯死松树比率不超过2％.因此,通过树干注药技术施用1％阿维菌素微囊悬浮剂对预防松材线虫病能起到显著效果.     

The effects of herbaceous and woody competition on planted white pine in a clearcut site

We investigated the effects of herbaceous and woody vegetation control on the survival and growth of planted eastern white pine (Pinus strobus L.) seedlings through six growing seasons. Herbaceous vegetation control involved the suppression of grasses, forbs, ferns, and low-shrubs, and was maintained for 0, 2, or 4 years after white pine seedlings were planted. Woody control involved the removal of all tall-shrub and deciduous trees, and was conducted at the time of planting, at the end of the second or fifth growing seasons, or not at all. Seedling height and basal diameter responded positively and proportionally to duration of herbaceous vegetation control. Gains associated with woody control were generally not significant unless some degree of herbaceous vegetation control was also conducted. Only herbaceous control increased pine crown closure and rate of crown closure. Herbaceous control and the presence of 5000–15,000 stems per ha of young overtopping aspen were associated with reduced weevil (Pissodes strobi Peck.) injury and increased pine height growth. The study suggests that white pine restoration strategies on clearcut sites should focus on the proactive, early management of understory vegetation and the gradual reduction of overtopping cover from woody vegetation to create a seedling light environment that supports acceptable growth with minimal weevil damage.     

Risk rating for mountain pine beetle infestation of lodgepole pine forests over large areas with ordinal regression modelling

The mountain pine beetle Dendroctonus ponderosae Hopkins is endemic to lodgepole pine, Pinus contorta var. latifolia Engelmann, forests in western Canada. However, the current beetle epidemic in this area highlights the challenges faced by forest managers tasked with prioritizing stands for mitigation activities such as salvage harvesting and direct control methods. In western Canada, the operational risk rating system for mountain pine beetle is based on biological knowledge gained from a rich legacy of stand-scale field studies. Due to the large spatial (millions of hectares affected) and temporal (over 10 years) extents of the current epidemic, new research into large-area mountain pine beetle processes has revealed further insights into the landscape-scale characteristics of beetle infested forests. In this paper, we evaluated the potential for this new knowledge to augment an established system for rating the short-term risk of tree mortality in a stand due to mountain pine beetle. New variables explored for utility in risk rating include direct shortwave radiation, site index, diameter at breast height, the temporal trends in local beetle populations, Biogeoclimatic Ecosystem Classification and beetle–host interaction variables. Proportional odds ordinal regression was used to develop a model for the Vanderhoof Forest District in west-central British Columbia. Prediction on independent data was assessed with the area under the receiver operator curve (AUC), indicating good discriminatory power (AUC = 0.84) for predicting levels of mountain pine beetle-caused pine mortality.     

松材线虫对湖南林业和生态环境影响的风险性分析

遵循国际植物保护公约（IPPC）制定的有害生物分析准则，结合森林植物检疫对象的特点，从地理和管理标准、传入、定殖、定殖后扩散的可能性、潜在的经济和环境重要性在对松材线虫传入湖南进行了风险分析。证明松材线虫完全符合检疫性有害生物地理和管理标准，随松类植物及产品的调运从国内外疫区传入的可能性极大，在湖南完全能够定殖，定殖后能迅速扩散并暴发成灾，不仅对全省林业生产影响极大，而且严重威胁世界自然遗产武陵源风景区的安全,提出了3种降低风险的管理措施。     

湿地松松木板的脱脂

对汨罗市桃林林场湿地松材试样进行脱脂工艺的研究.选择适宜的化学试剂,并以反应浓度、温度、时间等工艺条件对脱脂的影响进行探讨,通过正交设计试验,综合考虑其它几方面因素,筛选出较好的工艺条件为:浓度1%、温度120℃、时间3h.其脱脂效果良好,木材表面无溢脂现象,达到脱脂要求.     

COMPARATIVE STUDY OF WOOD PROPERTIES BETWEENWHITE WOOD OF DAHURIAN LARCH AND MONGOLIANSCOTCH PINE

DahurianlarchandMongolianscotchpinearetwomajorconunerciaIconilbroustTeesinDaxing'anlingForesnyArea.Itisob-viousthattbcwoodproPertiesandworkability'ofthetWoplantsarecompletelydifferent.Butlnrecert'years,ltlsfoundthattherearetwodiffer':nttypesinparameterofwood'scolour.phy'sicalandmechanicalproPertiesandwork-ability'inDahurianlarch,namelyredwoodandx"hite..od.l']Andthepropertiesofwhite`voodaresligl1tlyyellow-white,medianweightandhardness,goodinworkability'andLard-ness,goodinwodability'anduneas…     

Responses of water-stressedPinus thunbergii to inoculation with avirulent pine wood nematode (Bursaphelenchus xylophilus): Water relations and xylem histology

The effect of water-stress conditioning on water relations and histological features ofPinus thunbergii Parl. inoculated with avirulent isolate ofBursaphelenchus xylophilus (Steiner and Buhrer) Nickle, pine wood nematode, were investigated. Pines were kept under 8 days cycle of severe water stress. One-half of the water-stressed pines died as a result of infection by avirulent pine wood nematode and water stress tended to induce increased susceptibility and/or decreased resistance of pines to avirulent pine wood nematode. In dead pines, the water conducting function of xylem was lost, and all of the parenchyma cells died. In surviving pines, the xylem hydraulic conductivity and the xylem water content were significantly reduced (12 to 23% and 77 to 83%, respectively) compared to controls. Safranin dye perfusion of excised axis stem segments indicated that the water conductance was limited to the very narrow peripheral area of xylem. Embolism caused by cavitation in the tracheids occurred in the central part of xylem and in that dysfunctional region of the xylem the axial parenchyma cells surrounding the epithelial cells, and ray parenchyma cells partly degenerated but the epithelial cells survived. The disruption of tracheid shape observed in surviving pines indicates that avirulent pine wood nematode temporarily disturbed cell division of the cambium. Considering the differences in responses between dead pines and surviving pines after inoculation with avirulent pine wood nematode, the death of water-stressed pines apparently resulted from death of cells, in particular the vascular cambium and the loss of xylem hydraulic function by cavitation.