bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth of loblolly pine rooted cuttings compared with seedlings
Authors: Foster G. S. , Lambeth C. C. , Greenwood M. S.
Published: April 2008

Growth and morphology of loblolly pine (Pinustaeda L.) rooted cuttings were compared with that for seedlings after several years in the field in two experiments. Experiment 1 included rooted cuttings from 1- and 5-year-old ortets and seedlings from the same five families and experiment 2 compared rooted cuttings from 4-year-old ortets with seedlings from the same 15 families. Significant age-related effects on the growth of the rooted cuttings, even with as little as 4 years difference in ortet age, were observed. Height, DBH, and number of growth cycles, but not number of branches per unit of height or per growth cycle, differed significantly between the two cutting sources. Size and condition of the rooted cuttings and seedlings at the time of planting influenced their growth for several years afterward and could be a confounding factor in comparisons among propagule types. In experiment 1 cuttings outgrew seedlings, while in experiment 2 the reverse occurred. Considering both experiments, growth in the early years seems to be related more to condition of the propagule rather than asexual or sexual origin when unconfounded with age. The family rank correlations between propagation types for the same trait were always positive but were significant for only part of the traits, while the correlations among traits for the same propagation type were generally, but not always, lower for rooted cuttings than seedlings. This effect was pronounced in the first few years after field planting and was likely the result of plant quality (variability induced by the rooting and conditioning system) rather than propagation type; nonetheless, there is cause for concern when using early field data from rooted cutting trials to rank family performance.
Leaf area – sapwood area relationships in adjacent young Douglas-fir stands with different early growth rates
Authors: Bancalari M. A. Espinosa , Perry D. A. , Marshall John D.
Published: April 2008

The relationship between foliage area and sapwood basal area was studied in three adjacent 22-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands that differed in early growth rates. Sapwood width was fairly constant for most of the stem above the stump, but the number of annual rings in the sapwood decreased gradually with height. Sapwood area also decreased with increasing height in the tree, the stands differing significantly only at breast height. The proportion of heartwood from stump to near the base of the crown was significantly higher for the stand of fastest early growth. Ratios of leaf area to sapwood area were significantly higher for that stand and varied in every stem section, the ratio lower at breast height than at the base of the live crown. At the base of the crown, the ratio of leaf area to sapwood area was 1.33 and 1.57 times greater in the fast-growing stand than in the intermediate- and slow-growing stands, respectively. Leaf area was as closely related to dbh as to sapwood area at breast height. Sapwood area at the crown base was more accurate than sapwood area at breast height for predicting leaf area in the fast stand and was equally accurate in the other two stands. Ratios of leaf area to sapwood area correlated positively with sapwood ring width. However, because sapwood ring width also correlated closely with sapwood area, it did not improve predictive equations. The results suggest that the "pipe model" theory must be modified to account for the internal structure of the "pipe" and that caution should be exercised when using published leaf area to sapwood area ratios.
Biomass and nutrients in Great Lakes – St. Lawrence forest species: implications for whole-tree and conventional harvest
Authors: Hendrickson O. Q. , Burgess D. M. , Chatarpaul L.
Published: April 2008

Total aboveground biomass and nutrient contents were measured in a mixed conifer and hardwood stand in Ontario. Removal of woody stems > 9 cm dbh (conventional harvest) yielded 138 000 kg/ha; removal of essentially all aboveground woody material (whole-tree harvest) yielded an additional 52 000 kg/ha, a 38% increase. Whole-tree harvest increased N removal by 191 kg/ha (132%). Logging slash on the conventional harvest plot added 163 kg N/ha to the forest floor. Nutrients within various biomass components of seven tree species were compared. Pinusresinosa Ait., the dominant conifer, produced the greatest amount of biomass per unit mass of nutrient, combining low nutrient concentrations with a high proportion of biomass in stem wood. Populustremuloides Michx., the dominant hardwood, had high proportions of cation-rich bark but had a lower whole-tree N concentration than most other species. High nutrient contents in Abiesbalsamea (L.) (Mill.) and Piceaglauca (Moench) Voss were related to large amounts of fine branches and foliage. Compared with the dominants, shade-tolerant species had less differences in nutrient concentrations between small and large diameter portions of stems and branches, suggesting a limited capacity for retranslocation. Abiesbalsamea was particularly poor at conserving K. A conventional harvest often leaves small diameter stems of species (Abiesbalsamea, Acerrubrum L.) that accumulate large amounts of nutrients and that may be poorly adapted to low throughfall cation inputs and high light intensities following overstory removal. Replacement of stands of Pinus spp. by Populus spp. represents a less efficient use of site nutrient capital in that the latter species produce less biomass per unit nutrient retained in permanent aboveground tissues. Whole-tree harvesting on nutrient-poor sites in the Great Lakes – St. Lawrence forest may lead to establishment of aspen stands of low productivity.
Nitrogen mineralization in forest soil profiles from central Alberta
Authors: Fyles J. W. , McGill W. B.
Published: April 2008

The nitrogen mineralization characteristics of soils from stands dominated by jack pine (Pinusbanksiana Lamb.) and white spruce (Piceaglauca (Moench) Voss) were examined using a 37-week incubation with periodic leaching to allow measurement of mineralized N. Soils were compared on the basis of total N, N mineralized during the incubation, potentially mineralizable N, mineralization rate constant, and nitrification potential. Nitrogen characteristics of LFH horizons primarily reflected the age and species composition of the existing vegetation while those of A horizons appeared to relate to conditions in previous as well as present stands. Characteristics of B horizons were independent of vegetation implying control by long-term accumulation and transformation of N within the soil. The N fertility of a forest site therefore represents the integration of processes acting within different time frames and an understanding of the relative contributions of short- and long-term processes in the control of N availability is required for efficient fertility management.
Dormancy in Pinusmonticola seed related to stratification time, seed coat, and genetics
Authors: Hoff R. J.
Published: April 2008

The inner layer of the seed coat, a papery membrane, and physiological conditions of the gametophyte–embryo were shown to be major sites of dormancy in seed of western white pine. The hard seed coat layer was a minor site. With no stratification, 7% of the seeds were not dormant, 9% were dormant because of the hard seed coat, 34% were dormant because of the inner seed coat, and 50% were dormant because of physiological conditions of the gametophyte–embryo. These values varied with stratification times and seed lots (families).
Seasonal patterns of soil respiration and CO2 evolution following harvesting in the white spruce forests of interior Alaska
Authors: Gordon Andrew M. , Schlentner Robert E. , Cleve Keith Van
Published: April 2008

The effect of timber harvesting on soil respiration was investigated in a white spruce (Piceaglauca (Moench.) Voss) forest in interior Alaska. Clear-cutting increased respiration levels, especially in midsummer. Respiration estimates from an uncut, 133-year-old stand of white spruce averaged about 0.45 g•m−2•h−1 over two field seasons. In two adjacent cleared areas, the evolution of CO2 from the soil occasionally exceeded 0.6 g•m−2•h−1. Soil temperature and moisture regimes were increased after harvesting, presumably owing to increased insolation and reduced evapotranspiration. It was possible to relate the changes in these environmental parameters, by soil horizon, to respiration through previously developed nonlinear models and linear regression.
Aboveground biomass, surface area, and production relations of red fir (Abiesmagnified) and white fir (A. concolor)
Authors: Westman Walter E.
Published: April 2008

Aboveground live biomass, surface area, and net production have been estimated in two 0.36-ha stands each of white fir (Abiesconcolor), red fir (Abiesmagnifica), and mixed red and white fir in Sequoia National Park in the southern Sierra Nevada of California. Estimates are based on regressions developed from dimension analysis of 12 individuals of each fir species harvested in the adjacent Sequoia National Forest. The white fir forests are the largest and most productive of the several fir forests measured. The net production values of 1630–2200 g•m−2•year−1 are 1.3–2.7 times higher than for red or mixed fir forests and are at the high end of values reported from other highly productive coniferous forests of the western United States. The high productivity of these forests is attributable in part to the high proportion of aboveground biomass in leaves (4%), which remain on branches for up to 24 years or more, coupled with a high tolerance to shading. Production per unit leaf area is comparable to productive coast redwood and ponderosa pine stands. The biomass of white fir forests (59–97 kg•m−2) is in the range of other coniferous forests of the Pacific Northwest. The red fir forests are lower in height, smaller in biomass (40–67 kg•m−2), and lower in production (810–1030 g•m−2•year−1), consistent with the higher elevation and greater climatic stresses of their typical habitats. In growth form, the two species are similar, with red fir showing a more rapid increase in leaf biomass with stem or sapwood diameter increase than white fir and greater bark production. All-sided leaf area indices of 15–21 m2•m−2 for white fir and 17–25 m2•m−2for red fir are similar to values reported for mixed fir forests of comparable rainfall in Oregon.
Methods for using an integro-differential equation as a model of tree height growth
Authors: Hamlin David , Leary Rolfe
Published: April 2008

An integro-differential equation model of tree height growth is developed, together with a biological interpretation of its coefficients. The integro-differential equation is reduced to a second order linear differential equation with constraints on its initial conditions. Because of the constraints, fitting of the differential equation is best accomplished using a multipoint boundary value approach. An example using stem analysis data is presented. The model fit the data well and was montonically increasing with an upper asymptote, although several other curve forms are possible.
Changes in osmotic potential, cell elasticity, and turgor relationships of 2nd-year black spruce container seedlings
Authors: Colombo S. J.
Published: April 2008

Components of tissue water potential and shoot apical activity of black spruce (Piceamariana (Mill.) B.S.P.) container seedlings were evaluated during the 2nd-year cycle of shoot elongation. Water potential components estimated using the pressure–volume technique included osmotic potentials at full turgor (ψπ100) and the turgor loss point (ψπTLP) and their difference (Δψπ), relative water content at the turgor loss point (RWCTLP), total turgor pressure (ψPTOTAL), maximum bulk modulus of elasticity (Σmax), and elasticity near full turgor (ΣFT). All parameters changed in concert with the morphology of shoot elongation; ψπ100, ψπTLP, RWCTLP, and Σ were at minimum values prior to bud swelling, increasing to a maximum during rapid shoot elongation and decreasing slowly following bud initiation and needle primordia development. Δψπ and ψPTOTAL in contrast were at minimums during shoot elongation. The relationship between Σ and ψP varied with shoot phenology. Total turgor pressure over the range of naturally occurring relative water contents is proposed as an indicator of the survival and growth potential of out planted tree seedlings.
The effect of simulated acid rain on the nutrient status of subarctic woodland soils in eastern Canada
Authors: Moore T. R.
Published: April 2008

Treatment of small plots in a spruce–lichen woodland near Schefferville over two summers with simulated acid rain at pH 3, 4, and 5.5 and comparison with plots exposed to natural rainfall revealed increased leaching of nutrient cations, especially Mg2+, but only with the pH 3 treatment. Most changes in composition occurred as the solutions passed through the lichen mat with its associated litter and vascular plants. Experiments with laboratory soil columns showed that the subsoil horizons neutralize much of the acidity of the pH 3 treatments, presumably because of sulphate-fixation in the Fe-rich horizons. Based on measurements of field litter decomposition and laboratory carbon dioxide flux, the simulated acid treatments have little effect on organic matter decomposition. The treatments did not affect cation leaching from burnt plant tissues, but in the most acid treatment a larger proportion of the released nutrient cations were lost from the soil column. Laboratory experiments did not detect significant changes in mineralization rates, but there were increased leaching losses of NH4+-N with the pH 3 treatment. Because of the acid nature of the soils (soil pH 4.0), there appear to be few significant changes in soil nutrient status associated with acid rain, but this conclusion must be interpreted with caution because of the relatively short duration of the experiments and the harsh climatic and edaphic environment in which subarctic plants grow.
Fifty years of compositional change in deciduous and coniferous forest types in New Hampshire
Authors: Leak William B.
Published: April 2008

Fifty-year records (52–53 years) from 29 cruise plots on the Bartlett Experimental Forest, New Hampshire, indicated that composition is moving toward a predominance of one or two tolerant species in response to soils (habitat) and, to a lesser extent, elevation. Plots on fine till are moving toward American beech (Fagusgrandifolia Ehrh.) and sugar maple (Acersaccharum Marsh.), with some indication that perpetuation of sugar maple in this region of granitic soils depends upon canopy disturbance. Stands on coarse washed (sandy) till are moving toward beech, with some representation of tolerant conifers. Plots with shallow basal till (well drained to poorly drained), shallow bedrock, or ice-contact gravel are moving toward eastern hemlock (Tsugacanadensis (L.) Carr.) and (or) red spruce (Picearubens Sarg.). Eastern hemlock is successful below elevations of 500–550 m, while red spruce is successful at higher elevations.
Patterns of allozyme variation within and among Douglas-fir breeding zones in southwest Oregon
Authors: Merkle S. A. , Adams W. T.
Published: April 2008

Gametophytes from wind-pollinated seeds of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) parent trees (mean 56) in each of 22 breeding zones in southwest Oregon were analyzed electrophoretically for gene frequency patterns at 27 loci. Allozyme variability levels were high, as shown by breeding-zone averages for the percentage of polymorphic loci (71.7%, 0.99 criterion), mean number of alleles per locus (2.46), and expected heterozygosity (0.178). Differences among zones in allele frequency were significant (p < 0.05) for only 2 of the 27 loci surveyed, and analysis of hierarchical population structure showed that less than 1% of genetic diversity was attributable to differences among breeding zones. Genetic distance between zones was small [Formula: see text] and, in general, bore no relation to geographical or environmental distance. The limited allozyme differentiation among zones contrasts strikingly with the environment-related variation in seedling quantitative traits previously reported for southwest Oregon Douglas-fir. Allozymes do not appear to be useful for mapping patterns of adaptive variation or for certifying Douglas-fir seed in this region.
Vegetative propagation of wavy grain sycamore maple
Authors: Rohr René , Hanus Dominique
Published: April 2008

Cuttings of sycamore maple stump sprouts were rooted in soil or cultured invitro on synthetic media under aseptic conditions. Rooting of invitro shoots was accomplished. The trials concerned a "standard wood" tree and two trees with wavy grains. Regeneration of invitro plantlets occurred within 3 weeks of culture with all three trees. Contamination was a severe problem. Growth regulators were not required to induce root formation. Invitro regenerated plantlets developed as well as seedlings when transferred to soil.
Selection of Piceamariana for growing space efficiency
Authors: Damme Laird Van , Parker William H.
Published: April 2008

In an attempt to select black spruce (Piceamariana (Mill.) B.S.P.) based on growing space efficiency, 398 candidate black spruce trees from a 60-year-old upland stand were measured for various growth and crown parameters. The best 10 trees were selected by two base lines: basal area increment vs. crown area and stem volume vs. crown radius. For comparison 10 trees were also selected by a height vs. age base line and 10 were randomly chosen to serve as a control. Only one tree was selected by all three base lines, but four other trees were selected by two of the three methods. Although discriminant analysis correctly classified 85% of the trees into the four selection and control groups, the high levels of variation associated with the growing-space efficiency base line trees made it impossible to identify a generalized form (crop ideotype) that was associated with either method. Short-term and long-term progeny tests were established to determine the relative gains associated with the different base-line selection methods. A greenhouse test was conducted over one growing season and included light intensity as a treatment; the long-term test was planted in 1984 and included spacing as a treatment. Results of the short-term test demonstrated strong family differences and strong family × light interaction, but no selection method differences or selection method × light interaction. While the long-term test was not yet mature enough to test the effect of spacing, the 2-year height growth results demonstrated strong family differences and no selection method differences. Correlation between the results of the two tests was significant (r = 0.61, P < 0.01), indicating a fairly high level of reproducibility in the juvenile progeny results. A weak, but consistent, trend of slower growth by the progeny of selected parents relative to randomly selected controls was observed. These early results suggest that if black spruce trees selected for superior growing space efficiency have inherent advantages in lower light intensities or more densely spaced situations in mature stands, their open-pollinated progeny do not express these qualities after one or two season's growth.
Vulnerability of white spruce with slowly expanding lower boles on dry, cold sites to early seasonal attack by spruce beetles in south central Alaska
Authors: Hard John S.
Published: April 2008

Two stands of white spruce (Piceaglauca (Moench) Voss), one on a south aspect and one on a north aspect on the Kenai Peninsula of Alaska, were sampled intensively to determine site and host variables associated with high attack densities by spruce beetle, Dendroctonusrufipennis (Kirby). Attacks peaked during the early phase of tree radial growth on both aspects as the rate of tree expansion slowed. Generally, the first trees attacked, also the most heavily attacked, expanded more slowly before and after beetle attack than did trees attacked later or not at all. High attack densities were concentrated in trees on dry, cold soils. Mean percent basal-area growth of plots was inversely related to stocking of live spruce and to percentage of sample trees attacked and killed.
On the error of continuous forest inventory estimates
Authors: Cunia Tiberius
Published: April 2008

Although not explicitly recognized, the error of the volume estimates in Continuous Forest Inventory Systems has two main error components, one due to sample plots and another due to volume tables. The common procedure by which the volume estimates are calculated takes into account only the first component; the second component is simply ignored. An approach is shown that introduces the error of the volume tables into the total error of the CFI estimates of average volume per tree, average volume per acre, and growth components such as net change from one to the next occasion, mortality or ingrowth volume.
Long-term changes of needle litter in coniferous forests of Finland
Authors: Raunemaa T. , Hari P. , Kukkonen J. , Anttila P. , Katainen H.-S.
Published: April 2008

Long-term effects of air pollutants in Finland have been studied by analyzing needle litter of pine (Pinussilvestris L.) and spruce (Piceaabies L. Karst) in 13 stands from the years 1958 to 1982. A considerable annual increase in elemental concentrations was observed in the southern stands where acid deposition is high. No apparent increase was seen in the north, where deposition is low. During recent years the concentration of mobile nutrients, especially potassium in the needle litter has started to decrease. The decline seems to be very steep, probably due to acidic processes in soil.
Tree growth and nutrient cycling in dense plantings of hybrid poplar and black alder
Authors: Côté B. , Camiré C.
Published: April 2008

The cycling of N, P, K, Ca, and Mg was quantified during the third growing season in plantings (33 × 33 cm) of black alder (Alnusglutinosa (L.) Gaertn.) and hybrid poplar cv. Roxbury (Populusnigra L. × Populustrichocarpa Torr and Gray). First-year nutrient uptake, tree growth, and nutrient status of poplar were also assessed. During the 1st year, height and above-ground biomass growth of poplar were positively correlated with the proportion of alder in a plot. Poplar was twice as tall as alder in a mixed treatment and produced three times the aboveground biomass of alder in mixed plantings. On an individual tree basis, 1st year soil N uptake of alder averaged 46% of poplar N uptake. First-year winter dieback of poplar in this study prevented alder from being completely shaded by the poplars. Biomass growth and N status of poplar in the 2nd year were improved in mixed culture. After 3 years, accumulation of N and P in trees increased with the proportion of alder in a plot (maxima of 219 and 21 kg ha−1, respectively), but the greatest accumulations of N derived from the soil and K, Ca, and Mg were in mixed plantings (140, 88, 69, and 22.4 kg ha−1). Except for P, soil nutrient uptake during the third growing season was highest in plots with one alder for two poplars (maxima of 108, 9.1, 50, 60, and 19 kg ha−1 for N, P, K, Ca, and Mg). Throughfall nutrient content was not affected by species mixture. Except for Ca, nutrient content of total leaf litter increased with the proportion of alder (maxima of 80, 3.1, 13, 35, and 6.9 kg ha−1 for N, P, K, Ca, and Mg). After 3 years, no accretion of total N was detected in the soil, but exchangeable K increased 93% in the top 5 cm. Because stimulatory effect of interplanted alder on poplar growth decreased with time, reduced competition for soil N and light from the smaller alder during the first growing season were considered the most important factors in increasing individual poplar growth in our plantation.
Classification of decayed Abiesamabilis logs
Authors: Hope S. M.
Published: April 2008

Pacific silver fir (Abiesamabilis (Dougl.) Forbes) fallen logs near Snoqualmie Pass, Washington, U.S.A., were classified according to visual, chemical, and physical characteristics. The purpose of the study was (i) to test differences in log classification according to three- and five-unit decay classes, and (ii) to determine which variables appeared to be successful descriptors of decay for Pacific silver fir. Discriminant analysis was used to select variables to describe decay levels. According to analyses, wood density and lignin and cellulose percentages were acceptable criteria for describing decay levels using either a three- or five-unit classification system. Using a three-unit system defined by field characteristics and laboratory measures, cellulose discriminated among the classes 67% of the time. The variable wood density could be successfully classified 60% of the time. With a five-unit decay class system, individual variables placed logs within classes with less than 50% accuracy. Combinations of variables such as cellulose, wood density, and wood failure level improved class discrimination. Combined field measures were less successful in discriminating decay classes than variables measured under laboratory conditions. Results showed that (i) selection of structural characteristics can change the allocation of logs to particular classes, and (ii) three decay classes could be defined more clearly than five decay classes.
Seasonal variation in root hardiness of container-grown Scots pine, Norway spruce, and lodgepole pine seedlings
Authors: Lindström Anders , Nyström Christer
Published: April 2008

Roots of containerized seedlings of Scots pine (PinussylvestrisL.), Norway spruce (Piceaabies (L.) Karst.), and lodgepole pine (Pinuscontorta Dougl.) grown for one season were experimentally frozen during autumn, winter, and spring. After freezing, root growth capacity and seedling survival were determined by growing the seedlings for 3 weeks in a growth chamber. Root vitality was also tested with the triphenyl tetrazolium chloride method. The seedlings showed a progressive increase in root hardiness towards midwinter and a dehardening as spring approached. Scots pine and lodgepole pine roots were more sensitive to low temperatures than Norway spruce roots. Northern provenances of Scots pine and Norway spruce had the hardiest roots during the autumn. During winter and spring, provenance differences became less clear. Northern Scots pine and lodgepole pine seedlings sown in July tended to be more sensitive to low root temperatures than older seedlings sown in May. No age effects were found in southern Scots pine and Norway spruce seedlings. Although the root systems survived temperatures as low as −15 °C to −25 °C during late fall and midwinter, the capacity to grow roots tended to be stunted at considerably higher temperatures. This indicates the sensitivity of roots and emphasizes the importance of protection against low root temperatures.
Root growth capacity and field performance of jack pine and black spruce in boreal stand establishment in Ontario
Authors: Sutton R. F.
Published: April 2008

Data from tests of root growth capacity (RGC) of jack pine (Pinusbanksiana Lamb.) and black spruce (Piceamariana (Mill.) B.S.P.) on subsamples of planting stock outplanted on variously prepared sites appropriate to the species in boreal Ontario are examined in relation to field performance. These data were collected from six outplantings per species (two per annum for 3 years) and from further subsamples of the planting stock planted in low-stress nursery plantings. Five kinds of microsite were outplanted: untreated, Bräcke patch bottom, and two kinds of mound. On each site, 600 bare-root trees, either2 + 0 pine or 1.5 + 1.5 spruce, were slit planted during the spring planting season. The RGC data are designated RGC-a (no. of roots < 1 cm), RGC-b(no. of roots > 1 cm), RGC-c (mean aggregate length of roots > 1 cm), and RGC-d (mean mean length of roots > 1 cm). Against these, all available quantifications of performance were examined by correlation analysis. In general, correlation of RGC-d with 3rd-year field performance was much stronger than that of RGC-a, RGC-b, and RGC-c. In particular, the correlation between RGC-d and 3rd-year survival was highly significant (P < 0.01) in both species.
The effects of plant moisture stress on red pine (Pinusresinosa) seedling growth and establishment
Authors: Becker C. A. , Mroz G. D. , Fuller L. G.
Published: April 2008

Red pine (Pinusresinosa Ait.) 2-0 and 3-0 bare-root and 1-0 containerized seedlings were subjected to five different watering regimes (drying cycles). Overall, moisture stress as measured with a pressure bomb was highly correlated with seedling growth and survival. While shoot elongation during the drought period was unaffected, stressed seedlings showed pronounced decreases in cambial activity, secondary needle elongation, subsequent bud formation, root length, and number of active mycorrhizal root tips per centimetre compared with control treatments. This resulted in reduced top and root dry-matter production. Watering treatments with average seasonal internal moisture stress values in the range of −8 to −11 bar (1 bar = 100 kPa) showed no measurable reductions in seedling growth. Consistently, less internal moisture stress in the containerized seedlings indicate they are better able to avoid drought. Overall, performance of the 2-0 bare-root seedlings was superior to that of the 3-0 and containerized stock.
Influence of flooding and soil temperature on the water relations and morphological development of cold-stored black spruce and white spruce seedlings
Authors: Grossnickle Steven C.
Published: April 2008

Fall-lifted, cold-stored black spruce (Piceamariana (Mill.) B.S. P.) and white spruce (Piceaglauca (Moench) Voss) seedlings [Formula: see text] were planted in a controlled environmental chamber with an air temperature of 20 °C, soil temperatures of 10 or 20 °C, and flooded or nonflooded soil treatments. Stomatal conductance (gwv) was lower in flooded seedlings compared with nonflooded seedlings for both black spruce and white spruce seedlings. Black spruce seedlings drained after 14 days of flooding showed gwv similar to nonflooded seedlings, while drained white spruce seedlings had gwv patterns greater than nonflooded seedlings. White spruce seedlings had diurnal xylem pressure potential (ψx) patterns slightly more negative in the flooded treatment compared with the nonflooded treatment. Measured predawn ψx was found to be more negative in flooded seedlings compared with nonflooded seedlings in both black spruce and white spruce. In both species, flooded seedlings 1 day out of cold storage had a greater resistance to water flow through the soil–plant–atmosphere continuum (RSPAC) compared with non-flooded seedlings. After 21 days out of cold storage, rspac decreased in nonflooded seedlings of both species, while flooded seedlings of both species had high RSPAC values. For both black spruce and white spruce seedlings, flooded soils inhibited root growth, while low soil temperatures resulted in a reduction in root growth in nonflooded seedlings. Shoot growth of white spruce seedlings was not influenced by 21 days of flooding or low soil temperature, while the combination of 21 days of flooding and low soil temperature in black spruce seedlings resulted in less shoot development compared with nonflooded seedlings.
Accelerating growth of silver fir seedlings under controlled environments
Authors: Puri Sunil , Tak M. A.
Published: April 2008

Studies on Abiespindrow seedlings were conducted to accelerate and attain maximum growth under controlled environmental conditions. Seedlings of age 7, 19, and 31 months collected from Manali, Shilaru, and Kashmir provenances were treated for 90 days with four photoperiods (natural day length and 12, 18, and 24 h light) and two nitrogen levels (1.0 and 1.5 g/seedling). A positive response to light and N application was observed. Initially, light had no effect on roots (up to 45 days) but later on a significant increase in length and weight of roots was observed. Root to shoot ratio decreased with light but increased with N applied to seedlings. The interaction among photoperiod, N, provenance, and age, calculated from analysis of variance, was significant for root length and root and shoot weight at 45 and 90 days. The maximum percent increase in growth and biomass was observed in the 1-0 age from the Kashmir provenance.
Enzyme activity and phytohormone production of a mycorrhizal fungus, Laccarialaccata
Authors: Ho Iwan
Published: April 2008

Six isolates of Laccarialaccata, S-167 from a forest nursery and S-238, S-283, S-326, S-444, and S-472 from natural forests, were analyzed for acid phosphatase, alkaline phosphatase, and nitrate reductase activity, acid phosphatase isozyme patterns, and IAA and cytokinin production. Differences in enzyme activity and phytohormone production were prominent among the isolates. The patterns of acid phosphatase isozyme could be clearly divided into three host-related groups. Two polymorphic gene loci could be identified as coding for enzymes of acid phosphatase. Two of these gene loci, Acp-b and Acp-c, are characterized by mostly constant, host-dependent frequencies. The other, Acp-d, exhibits allele frequencies related to different habitats. Five isolates share the same Acp-a habitat. Four isolates share the Acp-b habitat, two the Acp-c habitat, and only one isolate, S-238, was from a high elevation at the Acp-d habitat. The isolate from a forest nursery differed strikingly in several characteristics from the other isolates, all of which were from a natural forest. This suggests that nursery soilmanagement practices may select for particular edaphic ecotypes of mycorrhizal fungi.
The influence of pH on the competitive interactions of ectomycorrhizal mycobionts under field conditions
Authors: McAfee B.J. , Fortin J. A.
Published: April 2008

The effects of H2SO4 watering on the competitive interactions of outplanted mycobionts was studied in a jack pine plantation in Quebec. Ectomycorrhizal jack pine seedlings produced in growth pouches and inoculated with either Pisolithustinctorius (Pers.) Coker and Couch or Laccariabicolor (Maire) Orton as well as noninoculated seedlings were exposed weekly to H2SO4 solutions adjusted to pH 5.6, 4.0, 3.2, or 2.5 for 14 weeks. Soil pH was significantly reduced in those plots where the pH was adjusted to 2.5. Seedling growth parameters were not affected by acid treatment. Indigenous colonization was not affected by acid treatment but was suppressed by inoculation, prior to outplanting, with either L. bicolor or P. tinctorius. Acid treatment significantly influenced the persistence of the inoculated mycobiont, P. tinctorius being more sensitive than L. bicolor to acid treatment. A competition index, used to evaluate postplanting competitivity, was higher for P. tinctorius in those plots where the watering solution was adjusted to pH 5.6 while in all other plots L. bicolor was more competitive with the indigenous mycota.
The effect of pH and aluminum concentration on ectomycorrhizal formation in Abiesbalsamea
Authors: Entry James A. , Cromack Jr. Kermit , Stafford Susan G. , Castellano Michael A.
Published: April 2008

Balsam fir (Abiesbalsamea (L.) Mill.) seedlings inoculated with Cenococcumgeophillum Fr. isolate 145A, Hebelomacrustuliniforme (Bull, ex Saint-Amans) Quel, isolate S166, and Laccarialaccata (Scop, ex Fr.) Bk. and Br. isolate 238B were grown in a split-plot factorial design with pH as main plots and Al concentration and ectomycorrhizal fungal species as subplots. No Al, 50 mg Al/g substrate, and 100 mg Al/g substrate were added to the potting soil mixture, which was adjusted to a final pH of 3, 4, or 5. The seedlings were watered with one-fifth strength Arnon's solution having a pH of 3, 4, or 5 and containing 100, 50, or 0 mg Al/L. The experiment was conducted to determine the effect of acidity and concentration of Al on ectomycorrhizal formation. As solution acidity and concentrations of Al increased, ectomycorrhizal formation, root weight, shoot weight, total weight, root:shoot ratio, and B concentration decreased; however, concentrations of Fe, Mn, P, and Zn in the seedlings increased. N, Ca, K, and Mg concentrations did not vary significantly in any of the treatments. Results of this study suggest that pH and Al have a complex effect on ectomycorrhizal formation and nutrient uptake in A. balsamea seedlings.
Increases in mycorrhizal colonization and seedling growth in Pinusechinata and Quercusalba in an enriched CO2 atmosphere
Authors: O'Neill E. G. , Luxmoore R. J. , Norby R. J.
Published: April 2008

Forest tree biomass is hypothesized to increase in a CO2-enriched atmosphere if mechanisms exist to ensure acquisition of limiting nutrients in forest soils. Investment of additional photosynthate produced at elevated CO2 into mycorrhizal proliferation and root growth may provide one such mechanism. To test this hypothesis, mycorrhizal density and seedling biomass were measured in shortleaf pine (Pinusechinata Mill.) and white oak (Quercusalba L.) grown in unfertilized forest soil in controlled-environment chambers at 360 μL L−1 and 700 μL L−1 CO2. Mycorrhizal density was greater at elevated CO2 in both species after 6 weeks of exposure; in white oak, the increased density persisted for 24 weeks. Root dry weight was increased 76% in P. echinata and 91% in Q. alba at 700 μL L−1 CO2; total seedling dry weight was increased by 66 and 56%, respectively. It is hypothesized that increased photosynthesis at elevated CO2 offsets the carbon requirement for mycorrhizal establishment on shortleaf pine. Greater mycorrhizal density and enhanced 1st-year root growth in both species may facilitate future nutrient acquisition, supporting further biomass increases in an enriched CO2 atmosphere.
Estimating fine-root production and turnover from biomass and decomposition data: a compartment–flow model
Authors: Santantonio D. , Grace J. C.
Published: April 2008

Production and replacement of fine roots (diam. < 1 mm) takes 8–67% of net primary production in forests. Most of this production is lost through mortality; little appears as an increment. Traditional biomass methods underestimate fine-root production because estimating production or mortality from changes in standing crop alone does not adequately account for simultaneous and compensating processes of growth, death, and replacement which occur continuously. We propose a compartment–flow model to solve this problem and estimate fine-root production and mortality at a monthly resolution for a pine plantation in New Zealand. The main component of the model is fine-root decomposition, an exponential decay function driven by soil temperature. The model "produces" and "turns over" enough fine roots to maintain observed standing crops of live and dead fine roots given losses through decomposition each month. We have formulated the model as differential and difference equations. Monthly estimates from the model indicated smooth modal patterns. Production and mortality peaked in early spring (September) at about 600 kg•ha−1•month−1 and fell to near zero in summer (January–February). The periodicity of these two processes was out of phase with soil temperature at 10 cm. Decomposition occurred continuously; it peaked in early summer (December) and declined to low levels during winter and was in phase with soil temperature. In a validation of the decomposition portion of the model with an independent set of decomposition data, measured standing crops of dead fine root were not statistically different from predicted values.
Do nutrients retranslocate from fine roots?
Authors: Nambiar E. K. Sadanandan
Published: April 2008

The changes in nutrient and starch concentrations in live and dead roots were studied as a part of a research project concerned with the dynamics of fine root production and turnover in a Pinusradiata (D. Don) plantation. The study period of 30 months included a year of severe drought, followed by a year of more than average rainfall. Nutrient concentrations were strongly related to root diameter. Monthly variations in nutrient concentrations in fine roots were minor and showed no seasonal pattern. This was in contrast with large seasonal fluctuations in starch concentrations in roots. Prolonged drought also had only minor effects on nutrient concentrations in roots. These results and the absence of significant difference in N, P, K, and Mg concentrations between live and dead roots suggest that there is little retranslocation of nutrients from senescent roots of Pinusradiata.
Effect of thinning on production and mortality of fine roots in a Pinusradiata plantation on a fertile site in New Zealand
Authors: Santantonio D. , Santantonio E.
Published: April 2008

The effects of heavy thinning (60% reduction in basal area) on fine (< 1 mm diam.) and small roots (1–5 mm diam.) were evaluated during the 2nd year following treatment by periodic soil core sampling in a 12-year-old plantation of Pinusradiata D. Don. Data from these samples enabled us to estimate monthly standing crops of live and dead fine roots and seasonal rates of fine-root decomposition. We used a compartment-flow model to estimate production and mortality of fine roots with monthly resolution from these data. The general pattern of production and mortality was modal and out of phase with soil temperature. On an area basis, thinning reduced the overall standing crop of live fine roots from 1.38 to 0.55 Mg/ha; the standing crop of dead fine roots remained unchanged at 4.37 Mg/ha. The standing crop of live small roots declined from 1.03 to 0.54 Mg/ha. Annual production of fine roots was estimated at 2.2 and 1.9 Mg•ha−1•year−1 in the control and thinned treatment, respectively, and mortality was estimated at 2.1 and 2.0 Mg•ha−1•ear−1 in the control and thinned treatment, respectively. Thinning shortened mean fine-root longevity from 6.2 to 2.5 months. With respect to total dry matter production, fine-root production remained a minor component following a heavy thinning. It accounted for only 4.6 and 6.1% of the stand total in the control and thinned treatments, respectively. These results indicate that on a fertile site with a mild climate the opportunity to shift production from fine roots to another component, such as stem wood, is likely to be small.
Effect of different microflora on the success of ectomycorrhizal inoculation of Pinusradiata
Authors: Garbaye Jean , Bowen Glynn D.
Published: April 2008

Seedlings of Pinusradiata D. Don. were grown in containers in three autoclaved soils and inoculated with three ectomycorrhizal fungi: Rhizopogonluteolus Fr. and Nord., Paxillusinvolutus Batsh. ex Fr., or Hebelomacrustuliniforme Quélet. General soil microfloras from four soils were added and ectomycorrhizal infection was assessed at 3 and at 4 months. Infection was enhanced or impeded by the soil microfloras, depending largely on the soil on which the plants were grown and on the mycorrhizal fungus. Enhancement of infection by added microflora was more frequent than reduction. The results are discussed in the context of mycorrhizal inoculation in forest nurseries.
Effect of soil transfer on ectomycorrhiza formation and the survival and growth of conifer seedlings on old, nonreforested clear-cuts
Authors: Amaranthus M. P. , Perry D. A.
Published: April 2008

Small amounts (150 mL) of soil from established conifer plantations and mature forest were transferred to planting holes on three clear-cuts in southwest Oregon and northern California to enhance mycorrihiza formation. The clear-cuts, 8–27 years old and unsuccessfully reforested, included a range of environmental conditions. At Cedar Camp, a high-elevation (1720 m) southerly slope with sandy soil, transfer of plantation soils increased 1st-year Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedling survival by 50%. Notably, soil from a plantation on a previously burned clear-cut doubled mycorrhiza formation and tripled seedling basal area growth. Soil from mature forest did not improve survival and growth. Less dramatic effects owing to soil transfer were evident on other sites, which were lower in elevation and had clayey soils with greater water-holding capacity, and where woody shrubs had apparently preserved mycorrhizal fungi. At Crazy Peak (1005 m), seedling survival was uniformly good, and soil from a previously burned plantation increased Douglas-fir mycorrhiza formation. At Wood Creek (500 m), soil from a plantation on a previously unburned clear-cut increased mycorrhizal branching on sugar pine (Pinuslambertiana Dougl.) seedlings, but there was no other effect. Results suggest that adequate mycorrhiza formation is critical to seedling growth and survival on cold, droughty sites. Populations of mycorrhizal fungi, and perhaps other beneficial soil biota, decline if reforestation is delayed or other host plants are absent. These declines can be offset by soil transfer from the proper source; in this study, soil from vigorous young plantations.
Ectomycorrhiza formation and growth of Sitka spruce seedlings on first-rotation forest sites in northern Britain
Authors: Wilson Julia , Mason P. A. , Last F. T. , Ingleby K. , Munro R. C.
Published: April 2008

The potential benefits of inoculation of Piceasitchensis (Bong.) Carr. seedlings with ectomycorrhizal fungi are being explored in trials on two first-rotation forest sites (at Wealside and Gleedlee) in Northumberland. Trials have been initiated on two contrasting soil types at each site, using plants inoculated with isolates of fungi that occur early in the mycorrhizal succession (Hebelomacrustuliniforme (Bull, ex St. Amans) Quélet, H. subsaponaceum Karst., Laccarialaccata (Scop, ex Fr.) Cooke, L. proximo (Boud.) Pat., L. tortilis (Bolt.) S. F. Gray, Paxillusinvolutus (Batsch) Fr., and Thelephoraterrestris Ehrenb. ex Fr.), together with appropriate control treatments. Inoculation treatments produced significant differences in growth on both sites. At Wealside, and on one soil type at Gleedlee, height increment was positively correlated with the proportion of the root system that was mycorrhizal at planting, rather than to the type of inoculum perse. In contrast, on the other soil at Gleedlee, increment was positively correlated with root/shoot ratio at the time of planting, not with mycorrhizal infection. Examination of root systems at Wealside suggested that inoculant fungi could infect new roots on site for at least 4 years and that, despite proximity of established woodland, mycorrhizal formation with indigenous fungi was slow. The data suggest that further work on mycorrhizal inoculation for British forestry and elsewhere is justified.
Structure et variabilité génétique de populations d'épinette noire (Piceamariana (Mill.) B.S.P.) dans la zone hémiarctique du Nouveau-Québec
Authors: Desponts Mireille , Simon Jean-Pierre
Published: April 2008

The genetic structure of five populations of black spruce located at l'Eau Claire Lake, in the subarctic region of Nouveau-Québec, were analysed by acrylamide gel electrophoresis of seven enzyme systems. The analysis of 25 loci disclosed an average polymorphism of 0.80 and a level of heterozygosity of 0.351. Results indicate that there is no loss of genetic variability in these marginal populations that could be attributed to genetic drift. Data based on Wright's statistics indicate an excess of heterozygotes for most loci. Populations share the same alleles at most loci and are only slightly differentiated from each other (Fst = 0.06). Results suggest that gene flow between these isolated populations remains sufficiently high to override the effect of geographic isolation.