Working time design for industrial forest plantations in East Kalimantan

The objectives of this study were to clarify physiological loads under tropical conditions and to establish a proper working time design for tropical forestry operations. The research was conducted in East Kalimantan, Indonesia, in 1995. In this research, physiological loads and thermal conditions were investigated under various conditions,i.e., in forests and nurseries, on roads and at logged-over areas. Using the standards of the American Conference of Governmental Industrial Hygienists (ACGIH), a structure of work to rest proportions could be designed properly. Results showed that felling and cutting trees and weeding in the forest could be done continuously early in the morning and with 25% rest time for the remainder of the work day. Spreading fertilizer at the nursery could be done almost continuously all day. Road maintenance could be performed continuously during early morning but 50–100% rest time was needed for the remainder of the day. At logged-over areas, path clearing using chainsaws and soil hoeing required 50% rest early in the morning and 75–100% rest after that time, while planting required 25% rest early in the morning and 50–100% rest after that time. In conclusion, work done at logged-over areas required a greater percentage of rest time than work at other locations except early in the morning. A part of this paper was orally presented at the 107th Annual Meeting of the Japanese Forestry Society (1996). Corresponding author.     

Soil and microbial respiration in a loblolly pine plantation in response to seven years of irrigation and fertilization

Because soil CO₂ efflux or soil respiration (R_S) is the major component of forest carbon fluxes, the effects of forest management on R_S and microbial biomass carbon (C), microbial respiration (R_H), microbial activity and fine root biomass were studied over two years in a loblolly pine (Pinus taeda L.) plantation located near Aiken, SC. Stands were six-years-old at the beginning of the study and were subjected to irrigation (no irrigation versus irrigation) and fertilization (no fertilization versus fertilization) treatments since planting. Soil respiration ranged from 2 to 6 μmol m⁻² s⁻¹ and was strongly and linearly related to soil temperature. Soil moisture and C inputs to the soil (coarse woody debris and litter mass) which may influence R_H were significantly but only weakly related to R_S. No interaction effects between irrigation and fertilization were observed for R_S and microbial variables. Irrigation increased R_S, fine root mass and microbial biomass C. In contrast, fertilization increased R_H, microbial biomass C and microbial activity but reduced fine root biomass and had no influence on R_S. Predicted annual soil C efflux ranged from 8.8 to 10.7 Mg C ha⁻¹ year⁻¹ and was lower than net primary productivity (NPP) in all stands except the non-fertilized treatment. The influence of forest management on R_S was small or insignificant relative to biomass accumulation suggesting that NPP controls the transition between a carbon source and sink in rapidly growing pine systems.     

Density structure and growth dynamics of a Larix principis-rupprechtii stand for water conservation in the Wutai Mountain Region of Shanxi Province, North China

To discover the site adaptability and density suitability of Larix principis-rupprechtii as a water conservation forest in Wutai Mountain, Shanxi Province, the growth process and diameter distribution characteristics of 10-year-old artificial L. principis-rupprechtii forests with density structures of 2600 trees/hm² and 3500 trees/hm² were studied using trunk analysis of a sample tree. The results showed that: 1) The tree height increment of the two kinds of forests were the same, and it was almost not affected by density. However, the growth process of the diameter and timber volume showed a great distinction. The growth status and density structure of the low density forest were superior to the high density forest. 2) The skewness (S _k) of diameter distribution had great distinction. The S _k (0.01) of the low density forest approached a normal distribution, which showed that the density structure was reasonable, while the S _k (0.45) of the high density forest was partial to a normal distribution, which showed that the density structure was on the high side. The kurtosis (K) of the two forests (one was −0.64, the other was −0.74) had little distinction and the density factor had limited function to forest polarization. 3) The increment of diameter at breast height, timber volume and trunk stock of the low density forest increased yearly without the effect of density. However, the increment of high density forests had declined from the sixth year, which was restricted by high density. 4) The reasonable density of the 10-year-old L. principis-rupprechtii artificial forest was about 2600 trees/hm², which is also the reasonable planting density if the utilization of double cutting is not considered. __________ Translated from Science of Soil and Water Conservation, 2007, 5(1): 1–6 [译自: 中国水土保持科学]     

中亚热带钱江流域天然次生林集水区溪流与降水水质比较

对浙江钱江源生态站大气降水和天然次生林生态系统的径流水质指标进行逐月取样测试和对比分析.结果表明:天然次生林集水区水体中溶解氧含量年平均值达到8.10 mg·L-1,是大气降水的1.12倍;总氮含量年平均值达7.68 mg·L-1,是大气降水的4.49倍.大气降水的生化需氧量年平均值达2.10 mg·L-1,是天然次生...     

Assessment of enrichment planting of teak (Tectona grandis) in degraded dry deciduous dipterocarp forest in the Central Highlands,Vietnam

After years of unsustainable logging, dry deciduous dipterocarp forest (DDDF) has become poor in timber stocks and has been converted to industrial crops such as rubber. The objectives of this study were to assess teak (Tectona grandis L.f.) tree establishment under degraded DDDF conditions and to determine factors that influence the suitability of teak as a forest enrichment tree species. A set of 64 experimental plots of 4 900 m² each was set up and observed for 4–5 years for testing enrichment planting with teak under various combinations of two groups of factors: ecological conditions and forest status. Weighted, non-linear, multivariate regression models were used to detect key factors that influenced the suitability of teak. The results showed that at the age of 4 years the average dominant tree height (defined as 20% of the tallest trees in the experimental plot) reached 11.2, 7.8, 5.3 and 3.8 m for very good, good, average and poor suitability levels, respectively. Survival rates of planted teak from average to very good suitability levels were over 90%. Six key factors that affected the suitability of teak were waterlogging during the rainy season, altitude, stand volume of the degraded DDDF, soil type, percentage of sand and concentration of P₂O₅ in the soil. Under the extreme ecological and environmental conditions of the DDDF, enrichment planting with teak gave promising results.     

Studies on compression wood—part VII: Distribution of lignin in normal and compression wood of tamarack [Larix laricina (Du Roi) K. Koch]

Summary The distribution of lignin has been studied in tracheids and ray cells of normal and compression wood of tamarack [Larix laricina (Du Roi) K. Koch]. The three layers in the secondary wall of normal wood tracheids are lignified to approximately the same extent, and previous evidence that the S ₃ layer should contain a higher proportion of lignin than the other regions has not been confirmed. The lignin follows closely the orientation of the cellulose microfibrils in all three layers. Compared to the tracheids, the ray cells contain a denser network of lignin in their secondary wall.Only a small proportion of the total lignin in compression wood tracheids is present in the compound middle lamella. The thick S ₁ layer is only slightly lignified; the orientation of the lignin in this region is that of the transversely oriented, lamellated microfibrils. The outer portion of S ₂ consists largely of lignin but also contains lamellae of cellulose microfibrils which probably have the same helical orientation as the microfibrils in the inner part of S ₂. The latter region, which contains the helical cavities, consists of lamellae of cellulose microfibrils which are uniformly encrusted with lignin. The ray cells in compression wood appear to be lignified to the same extent as in normal wood. Transverse sections of the cells reveal a lateral orientation of the lignin. The orientation of the cellulose microfibrils in the S ₂ layer of the first-formed springwood tracheids of compression wood is the same as in the cells which are formed later. It is suggested that for ease of reference, the outer, lignin-rich layer in compression wood tracheids be referred to as the S ₂(L) layer.

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Zusammenfassung Im Druckholz und im normalen Holz von Tamarack (Larix laricina (Du Roi) K. Koch) wurde die Verteilung des Lignins in Tracheiden und Markstrahlzellen untersucht. Die drei Schichten der Sekundärwand in den Tracheiden normalen Holzes werden in nahezu demselben Umfange lignifiziert. Frühere Feststellungen, daß die S ₃-Schicht einen höheren Ligningehalt erreicht als andere Zellwandbereiche, konnten also nicht bestätigt werden. Das Lignin folgt sehr genau der Orientierung der Cellulose-Mikrofibrillen aller drei Schichten. Im Vergleich zu den Tracheiden erfahren die Sekundärwände der Markstrahlzellen eine stärkere Ligninauskleidung.Nur ein geringer Prozentsatz des gesamten Lignins der Druckholztracheiden befindet sich in der Mittellamelle. Die dicke S ₁-Schicht ist nur wenig lignifiziert. Die Orientierung des Lignins in diesem Bereich entspricht den transversal orientierten, lamellierten Mikrofibrillen. Der äußere Teil der S ₂-Schicht enthält sehr viel Lignin, daneben aber auch Lamellen von Cellulose-Mikrofibrillen, die wahrscheinlich dieselbe spiralige Orientierung besitzen wie die Mikrofibrillen des inneren Teiles der S ₂-Schicht. Der letzterwähnte Bereich, der spiralige Kavitäten enthält, weist Lamellen von Cellulose-Mikrofibrillen auf, in welche gleichmäßig Lignin eingelagert ist. Die Markstrahlzellen des Druckholzes erscheinen ebenso stark lignifiziert wie die Markstrahlzellen des Normalholzes. Querschnitte durch diese Zellen lassen die laterale Orientierung des Lignins erkennen. Die Orientierung der Cellulose-Mikrofibrillen in der S ₂-Schicht der zuerst gebildeten Frühholztracheiden des Druckholzes ist dieselbe wie in jenen Zellen, die später ausgeformt werden. Es wird vorgeschlagen, daß zur eindeutigeren Kennzeichnung die äußere ligninreiche Schicht der Druckholztracheiden als S ₂(L)-Schicht bezeichnet wird.

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The authors wish to express their gratitude to Messrs. A. K. Bentum, D. C. Jones, and B. W. Simson for technical assistance. They are also thankful to Dr. D. A. I. Goring, McGill University, Montreal, Canada, for valuable discussions and for making available to them important, unpublished information. This investigation was supported by the United States Department of Agriculture, Forest Service, through Forest Service Research Grant No. 1, which is hereby gratefully acknowledged.     

Nutrient concentration dynamics in an inland Pacific Northwest watershed before and after timber harvest

The nutrient loads of water draining forested watersheds are generally lower than the loads in water draining basins with other dominant land uses. Commercial forest management activities including timber harvesting, site preparation, road construction, and maintenance can alter the chemical properties of headwater forest streams, and there are concerns this can result in cumulative effects at downstream locations. Monthly water samples were collected from 1992 to 2006 in the Mica Creek Experimental Watershed (MCEW) in northern Idaho. This period of record included a pre-treatment time interval from 1992 to 1997; post-road construction period from 1997 to 2001; and post-harvest period from 2001 to 2006. Samples were analyzed for total Kjeldahl nitrogen (TKN), total ammonia nitrogen (TAN), nitrate + nitrite (NO₃ + NO₂), total phosphorus (TP), and orthophosphate (OP). Statistically significant increases (p < 0.001) were observed in NO₃ + NO₂ concentrations following both clearcut and partial cut harvest practices. Downstream of the clearcut harvest activity, mean monthly increases of 0.29 mg-N L⁻¹ were observed. Statistically significant increases were also observed at sites further downstream, but changes were smaller than those immediately below the harvest sites and reflected dilution and possibly instream processing and/or uptake. Continued monitoring at these sites will help evaluate nutrient concentration trends during stand regrowth and hydrologic recovery.     

Rotation-end financial performance of vegetation control on Eucalyptus smithii in South Africa

Control of competing vegetation during eucalypt regeneration is important but the cost-benefit of varying levels of control is not well understood. A trial was initiated to quantify the impact of five vegetation control treatments on Eucalyptus smithii R.T.Baker. to determine the potential loss in growth and differential costs against which this growth loss could be linked. Five treatments were developed to suit the predicted vegetation load at the site and varied according to weeding intensity (high, moderate and low weeding) or area around the tree that was weeded (no vegetation control, a 2 m row weeding and complete vegetation control). The vegetation control treatments were imposed at planting and maintained until canopy closure (16.4 months). Tree growth was monitored throughout the rotation and this, together with the cost of the various establishment and weeding operations, were used to make treatment comparisons. Weed growth was rapid following planting, with competition-induced divergence in tree growth occurring from 52 d. Rotation-end volume for the Weedfree check (414 m³ ha^?1) and Row weeding treatment (394 m³ ha^?1) were significantly different from the Weedy check (319 m³ ha^?1), with the Moderate (374 m³ ha^?1) and Low (371 m³ ha^?1) weeding intensity treatments intermediate but not significantly different from each other, nor from the other treatments. The financial performance (expressed as bare land value [BLV] with 6% discounting) of the Weedfree check outperformed the other treatments and was 37% higher than the Weedy check. The BLVs of the Moderate and Low weeding intensity treatments were similar to each other, indicating that these treatments were both feasible in terms of financial performance. However, the 2 m Row weeding had c. 10% higher BLV than the Moderate and Low weeding intensity treatments, and could be considered as a viable alternative to the Weedfree check. Sensitivity analysis conducted on the data in terms of local or exogenous risks indicated that between the treatments, differences in response to either local or global market risks were minor. Thus, small changes in cost and price levels, or larger changes in applicable discount rate, would not alter the ranking of the vegetation control treatments, with the Weedfree check (High weeding intensity) being the best in terms of financial performance, and the Weedy check the worst.     

Über Versuche zur Fütterung der Kahlrückigen Waldameise (Formica polyctena F.; Hym., Formicidae) mit den behaarten Raupen vonOrgyia antiqua L. (Lep., Lymantriidae)

O. antiqua larvae were given as food to two laboratory populations ofF. polyctena (2000–3000 workers and 2 queens each). The ants did'nt perceive L₁–L₃ as a prey. But they killed 47% (popul. A) and 77% (popul. B) of the L₄–L₆ after pulling up the long hairs of larvae.     

Helical thickenings and helical cavities in normal and compression woods of Taxus baccata

Summary The longitudinal tracheids in compression wood of Taxus baccata contain helical thickenings but no helical cavities. The thickenings are as frequent and well developed and have the same ropelike appearance as in normal wood of this species. They are an integral part of the S₃ in normal and of the S₂ in compression wood and have the same orientation as the innermost microfibrils in these layers. Except for the absence of cavities and presence of thickenings, compression wood tracheids of Taxus baccata possess all the anatomical features typical of such cells, including a rounded outline, intercellular spaces, a thick S₁ layer, a highly lignified S₂ (L) layer, and no S₃ layer. Pronounced compression wood of Pseudotsuga menziesii contains helical cavities but no helical thickenings. Thickenings and cavities seem to be mutually exclusive in Pseudotsuga and Taxus.This investigation was carried out under the McIntire-Stennis Program, Cooperative State Research Service. I am indebted to Mr. A. Rezanowich of the Pulp and Paper Research Institute of Canada for kindly providing the scanning electron micrographs.     

Allometric relations for biomass partitioning of Nothofagus antarctica trees of different crown classes over a site quality gradient

Data on tree biomass are essential for understanding the forest carbon cycle and plant adaptations to the environment. We determined biomass accumulation and allometric relationships in the partitioning of biomass between aboveground woody biomass, leaves and roots in Nothofagus antarctica. We measured above- and belowground biomass of N. antarctica trees across different ages (5–220 years) and crown classes (dominant, codominant, intermediate and suppressed) in three site qualities. The biomass allocation patterns were studied by fitting allometric functions in biomass partitioning between leaves (M_L), stem and branches (M_S) and roots (M_R). These patterns were tested for all pooled data and according to site quality and crown classes. Biomass accumulation varied with crown class and site quality. The root component represented 26–72% of the total biomass depending on age and site. N. antarctica scaling exponents for the relationships M_Lvs. M_S, M_Avs. M_R, and M_Svs. M_R were close to those predicted by the allometric biomass partitioning model. However, when biomass allocation was analyzed by site quality the scaling exponents varied following the optimal partitioning theory which states that plants should allocate more biomass to the part of the plant that acquires the most limiting resource. In contrast, the crown class effect on biomass partitioning was almost negligible. In conclusion, to obtain accurate estimations of biomass in N. antarctica trees the allometric approach appears as an useful tool but the site quality should be taken into consideration.     

Biomass and greenhouse-gas emissions from land-use change in Brazil's Amazonian “arc of deforestation”: The states of Mato Grosso and Rondônia

We calculate greenhouse-gas emissions from land-use change in Mato Grosso and Rondônia, two states that are responsible for more than half of the deforestation in Brazilian Amazonia. In addition to deforestation (clearing of forest), we also estimate clearing rates and emissions for savannas (especially the cerrado, or central Brazilian savanna), which have not been included in Brazil's monitoring of deforestation. The rate of clearing of savannas was much more rapid in the 1980s and 1990s than in recent years. Over the 2006–2007 period (one year) 204 × 10³ ha of forest and 30 × 10³ ha of savanna were cleared in Mato Grosso, representing a gross loss of biomass carbon (above + belowground) of 66.0 and 1.8 × 10⁶ MgC, respectively. In the same year in Rondônia, 130 × 10³ ha of forest was cleared, representing gross losses of biomass of 40.4 × 10⁶ MgC. Data on clearing of savanna in Rondônia are unavailable, but the rate is believed to be small in the year in question. Net losses of carbon stock for Mato Grosso forest, Mato Grosso savanna and Rondônia forest were 29.0, 0.5 and 18.5 × 10⁶ MgC, respectively. Including soil carbon loss and the effects of trace-gas emissions (using global warming potentials for CH₄ and N₂O from the IPCC's 2007 Fourth Assessment Report), the impact of these emission sources totaled 30.9, 0.6 and 25.4 × 10⁶ Mg CO₂-equivalent C, respectively. These impacts approximate the combined effect of logging and clearing because the forest biomasses used are based on surveys conducted before many forests were exposed to logging. The total emission from Mato Grosso and Rondônia of 56.9 × 10⁶ Mg CO₂-equivalent C can be compared with Brazil's annual emission of approximately 80 × 10⁶ MgC from fossil–fuel combustion.     

Why do large,nitrogen rich seedlings better resist stressful transplanting conditions? A physiological analysis in two functionally contrasting Mediterranean forest species

We analysed the physiological bases that explain why large and high nitrogen (N) concentration seedlings frequently have improved survival and growth relative to small seedlings in Mediterranean woodland plantations. Large seedlings of Aleppo pine (Pinus halepensis Mill.) and holm oak (Quercus ilex L.) with high N concentration (L+), and small seedlings with either high (S+) or low (S−) N concentration, were planted on two sites of different weed competition intensity that created contrasting stress conditions. Seedling survival, growth, gas exchange, N remobilization (N_R) and uptake (N_U), and water potential were assessed through the first growing season. Weeds reduced survival and growth, but seedling response to weed competition varied among phenotypes and between species. At the end of the first growing season, L+ Aleppo pine seedlings had higher survival than both small seedling types in presence of weeds but no differences were observed in absence of weeds. Mortality differences among phenotypes occurred in spring but not in summer. L+ Aleppo pines grew more than small Aleppo pines independently of weed competition. No holm oak seedling type survived in presence of weeds and no mortality differences among phenotypes where observed in absence of weeds, although L+ holm oak seedlings grew more than small seedlings. Mortality and growth differences in Aleppo pine were linked to marked physiological differences among phenotypes while physiological differences were small among holm oak phenotypes. L+ Aleppo pines had greater root growth, gas exchange, N_R, and N_U than small seedlings, irrespective of their N concentration. Seedling size in Aleppo pine had a greater role in the performance of transplanted seedlings than N concentration. The functional differences among oak phenotypes were small whereas they were large in pine seedlings, which led to smaller differences in transplanting performance in holm oak than in pine. This suggests that the nursery seedling quality improvement for planting in dry sites could depend on the species-specific phenotypic plasticity and functional strategy. Improved transplanting performance in large Aleppo pine seedlings relative to small seedlings was linked to greater gas exchange, root growth and N cycling.     

Measurement of the dynamic modulus of elasticity of wood panels

This study investigated the dynamic modulus of elasticity (DMOE) of wood panels of Fraxinus mandshurica, Pinus koraiensis, and Juglans mandshurica using the natural frequency measurement system of fast Fourier transform (FFT). The results were compared with the static modulus of elasticity (E _S) tested by a mechanical test machine. The results show a significant correlation between E _S, transverse vibration DMOE (E _F), and longitudinal vibration DMOE (E _L). For all of these species, the correlation between E _S, E _F and E _L is more significant than the individual species, which indicated that the FFT method is universal. The correlations between E _S and sample’s density (ρ) are significant, but the correlation coefficient of E _S and ρ is lower than those between E _F, E _L and E _S. The E _S of wood is more accurately tested by the analysis based on FFT measurement than by the estimation based on density. __________ Translated from Scientia Silvae Sinicae, 2005, 41(6): 126–131 [译自: 林业科学, 2005, 41(6): 126–131]     

Effects of winter selective tree harvest on soil microclimate and surface CO2 flux of a northern hardwood forest

Soil surface CO₂ flux (S_flux) is the second largest terrestrial ecosystem carbon flux, and may be affected by forest harvest. The effects of clearcutting on S_flux have been studied, but little is known about the effect of alternative harvesting methods such as selective tree harvest on S_flux. We measured S_flux before and after (i) the creation of forest canopy gaps (simulating group tree selection harvests) and (ii) mechanized winter harvest but no tree removal (simulating ground disturbance associated with logging). The experiment was carried out in a sugar maple dominated forest in the Flambeau River State Forest, Wisconsin. Pre-treatment measurements of soil moisture, temperature and S_flux were measured throughout the growing season of 2006. In January–February 2007, a harvester created the canopy gaps (200–380 m²). The mechanization treatment consisted of the harvester traveling through the plots for a similar amount of time as the gap plots, but no trees were cut. Soil moisture and temperature and S_flux were measured throughout the growing season for 1 year prior to harvest and for 2 years after harvest. Soil moisture and temperature were significantly greater in the gap than mechanized and control treatments. Instantaneous S_flux was positively correlated to soil moisture and soil temperature at 2 and 10 cm, but temperature at 10 cm was the single best predictor. Annual S_flux was not significantly different among treatments prior to winter 2007 harvest, and was not significantly different among treatments after harvest. Annual (+1 std. err.) S_flux averaged 967 + 72, 1011 + 72, and 1012 + 72 g C m⁻² year⁻¹ in the control, mechanized and gap treatments, respectively, for the 2-year post-treatment period. The results from this study suggest selective group tree harvest significantly increases soil moisture and temperature but does not significantly influence S_flux.     

Using landscape preference models and tree-scale measurements to predict stand quality

Scenic beauty estimation (SBE) models that quantify landscape aesthetics through picture-based questionnaires are complicated to develop. Therefore, precise, simple, and widely applicable models of SBE prediction based on tree and stand measurements must be developed. To investigate the application of tree- and stand-based SBE models to Chinese fir forest management, the relationships between diameter at breast height (DBH) and tree height (H) measurements and tree- (T_SBE) and stand (S_SBE)-based SBE predictions were assessed. T_SBE and S_SBE were strongly influenced by DBH and H measurements according to either a power function or linear function, depending on the variables. When the mean stand DBH was less than 8.4?cm or H was less than 9.8 m, dense canopies resulted in negative S_SBE residuals. In stands with large trees and non-dense canopies, the residuals of S_SBE were positive. We conclude that average H and DBH measurements within a stand can be used to predict S_SBE by extrapolating the tree-based SBE model to form a stand-based SBE model. Therefore, SBE models based on individual tree measurements can provide quantitative guidance for forest landscape quality planning and evaluation.     

Carbon storage in evergreen broad-leaf forests in mid-subtropical region of China at four succession stages

To better understand the effect of forest succession on carbon sequestration, we investigated carbon stock and allocation of evergreen broadleaf forest, a major zonal forest in subtropical China. We so...     

谈适地适树科学选择树种几点看法

从近5a来南康区工程项目造林绿化,个体、民营企业营造工业原料林和用材林工作实践中,对造林中未做到适地适树来选择造林树种走了弯路,致使造林林木生长不良,甚至死亡的问题进行调查分析,谈谈适地适树在造林工作中的运用。     

Estimation ofPinus radiata D. Don clear wood properties by near-infrared spectroscopy

The use of calibrated near-infrared (NIR) spectroscopy for predicting of a range of solid wood properties is described. The methods developed are applicable to large-scale nondestructive forest resource assessment and to tree breeding and silviculture programs. A series ofPinus radiata D. Don (radiata pine) samples were characterized in terms of density, longitudinal modulus of elasticity (E _L), and microfibril angle (MFA). NIR spectra were obtained from the radial/longitudinal face of each sample and used to generate calibrations for the measured physical properties. The relations between laboratory-determined data and NIR fitted data were good in all cases, with coefficients of determination (R ²) ranging from 0.68 for 100/MFA to 0.94 for density_strip. A good relation (R ² = 0.83) was also obtained forE _L estimated using data collected by SilviScan-2. The finding suggests that an NIR instrument could be calibrated to estimate theE _L of increment cores based on SilviScan data. In view of the rapidly expanding range of applications for this technique, it is concluded that appropriately calibrated NIR spectroscopy could form the basis of a testing instrument capable of predicting a range of properties from a single spectrum obtained from the product or from the raw material.     

Heterogeneity in formation of lignin

Summary The formation of lignin in the cell wall of compression wood of Pinus thunbergii was examined by selective radio-labeling of specific structural units in the lignin and visualization of the label in the different morphological regions by microautoradiography. Deposition of lignin in the tracheid cell wall of compression wood occurred in the order: p-hydroxyphenyl, guaiacyl and syringyl lignin, which is the same order as observed in normal wood. However, the period of lignification in the compression wood was quite different from those of normal and opposite woods. The p-hydroxyphenyl units were deposited mainly in the early stage of cell wall formation in compound middle lamella in normal and opposite woods, while in compression wood, they were formed in both the compound middle lamella and the secondary wall. The most intensive lignification was observed during the formation of the S₂ layer, proceeding from the outer to inner S₂ layers for a long period in compression wood. In the normal or opposite woods, in contrast, the lignification became active after formation of S₃ had begun, then proceeded uniformly in the secondary wall and ended after a short period.A part of this report was originally presented at the 1989 International Symposium on Wood and Pulping Chemistry at Raleigh, NC, U.S.A.