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• 31. [Article] Regeneration patterns on some modified staggered-setting clearcuts on the H.J. Andrews experimental forest

  A survey of natural regeneration of Doug1as-fir and associated species was made on 15 staggered-setting cuttings four and five years after logging. These areas were on the H. J. Andrews Experimental Forest ...

  Citation × Citation Citation Abstract Copy Title: Regeneration patterns on some modified staggered-setting clearcuts on the H.J. Andrews experimental forest Author: Franklin, Jerry F. A survey of natural regeneration of Doug1as-fir and associated species was made on 15 staggered-setting cuttings four and five years after logging. These areas were on the H. J. Andrews Experimental Forest which is located in the McKenzie River area of western Oregon. Five types of cuttings were represented: (1) four north-south oriented strip clear cuts varying from 50 to 330 feet in width; (2) three east-west orientated strip clear-cut varying from 100 to 300 feet in width; (3) six patch or group clear-cuts varying from one fourth to four acres in size; (4) a shade-seed-tree cutting on which residual trees were left to provide shade and seed; and (5) a typical staggered-setting clear-cut. The modified cuttings were designed to utilize shade from the residual stand to favor regeneration by reducing high surface, soil temperatures, a major deterrent to the establishment of tree seedlings in this area. Results of the survey showed that all of the modified cutting units were better stocked than the typical staggered-setting clearcut and with two exceptions had at least 500 we11-spaced trees per acre. The east-west orientated strips regenerated best with 69 to 89 percent of milacre plots stocked. The small group clearcuts also regenerated well; stocking varied from 8 to 72 percent of milacre plots stocked. The north-south orientated strips were the most poorly stocked group of small cuttings with from 35 to 61 percent of milacre plots stocked. The shade-seed-tree cutting had 61 percent of plots stocked and the staggered-setting clearcut 28 percent of plots stocked. The statistical analysis indicated that the parameter of shade hours per plot was consistently related to regeneration of all species together and of Douglas-fir alone. The degree of this relationship varied considerably between types of units and to a lesser extent among units of a particular type. In addition there was some evidence that intermittent shading was more effective in favoring regeneration than a similar amount of shade received in a single period of time. Distance from seed source was not found to be related to stocking on the small cutting units studied. This author concludes that consideration should be given to the use of special cutting methods such as east-west orientated strip clearcuts, small patch clearcuts, and shade-seed-tree cuttings, to aid in natural regeneration of Douglas fir, especially on severe sites. These cuttings should be laid out primarily to provide shade rather than from the standpoint of seed dispersal. Title: Regeneration patterns on some modified staggered-setting clearcuts on the H.J. Andrews experimental forest Author: Franklin, Jerry F. A survey of natural regeneration of Doug1as-fir and associated species was made on 15 staggered-setting cuttings four and five years after logging. These areas were on the H. J. Andrews Experimental Forest which is located in the McKenzie River area of western Oregon. Five types of cuttings were represented: (1) four north-south oriented strip clear cuts varying from 50 to 330 feet in width; (2) three east-west orientated strip clear-cut varying from 100 to 300 feet in width; (3) six patch or group clear-cuts varying from one fourth to four acres in size; (4) a shade-seed-tree cutting on which residual trees were left to provide shade and seed; and (5) a typical staggered-setting clear-cut. The modified cuttings were designed to utilize shade from the residual stand to favor regeneration by reducing high surface, soil temperatures, a major deterrent to the establishment of tree seedlings in this area. Results of the survey showed that all of the modified cutting units were better stocked than the typical staggered-setting clearcut and with two exceptions had at least 500 we11-spaced trees per acre. The east-west orientated strips regenerated best with 69 to 89 percent of milacre plots stocked. The small group clearcuts also regenerated well; stocking varied from 8 to 72 percent of milacre plots stocked. The north-south orientated strips were the most poorly stocked group of small cuttings with from 35 to 61 percent of milacre plots stocked. The shade-seed-tree cutting had 61 percent of plots stocked and the staggered-setting clearcut 28 percent of plots stocked. The statistical analysis indicated that the parameter of shade hours per plot was consistently related to regeneration of all species together and of Douglas-fir alone. The degree of this relationship varied considerably between types of units and to a lesser extent among units of a particular type. In addition there was some evidence that intermittent shading was more effective in favoring regeneration than a similar amount of shade received in a single period of time. Distance from seed source was not found to be related to stocking on the small cutting units studied. This author concludes that consideration should be given to the use of special cutting methods such as east-west orientated strip clearcuts, small patch clearcuts, and shade-seed-tree cuttings, to aid in natural regeneration of Douglas fir, especially on severe sites. These cuttings should be laid out primarily to provide shade rather than from the standpoint of seed dispersal. Close

• 32. [Article] Growth behavior of Douglas-fir reproduction in the shade of managed forest in the interior Coast Range of Oregon

  During the past 20 years, repeated thinning of a Douglas-fir forest, now 65 years old, has allowed desired limits of basal area to be maintained. In the process, the understory environment has altered ...

  Citation × Citation Citation Abstract Copy Title: Growth behavior of Douglas-fir reproduction in the shade of managed forest in the interior Coast Range of Oregon Author: Del Rio, Ernest During the past 20 years, repeated thinning of a Douglas-fir forest, now 65 years old, has allowed desired limits of basal area to be maintained. In the process, the understory environment has altered sufficiently to allow Douglas-fir reproduction to establish in abundance. The forest is located on the east side of the Coast Range, north of Corvallis, Oregon. A study was undertaken to examine growth patterns of understory trees in relation to microenvironment, physical attributes of the tree and time. This information would help determine how long a tree can be maintained at a given level of shade and still function properly. This information also would add to the understanding of modification of growth strategies for survival. To characterize the understory environments of the three thinning intensities (23 to 30, 30 to 37 and 37 to 44 m2/ha basal area), measurements were made of plant moisture stress, evaporative demand, air and soil temperature, light and vegetative cover. Light measured at seedling crown best separated the environments; light was found to increase with a decrease in stand basal area, averaging 5, 8 and 12 percent of daily sun for the three thinning levels. Trees, randomly selected, ranged in height from 10 cm to 1.5 m and in age from 4 to 15 years. Parameters measured included leader growth for the past two seasons, diameter growth, above-ground biomass, height and age. Bud phenology and beginning of cambial activity were also observed. Development of buds in the spring was inversely related to light while renewed cambial activity was directly related to tree size and light. Increments of height and diameter growth were found to increase with light and tree height. Linear differences in average leader and diameter growth and above-ground biomass production were found between the three intensities of thinning, with trees under the heaviest thinning growing most. Average growth is predictable for at least two years. However, rates of leader growth and biomass production, in relation to growth of the previous year and leaf biomass, were not different for individual trees from the three understory environments. A balance of foliar to stem bioniass was maintained by understory trees. Physical characteristics of the tree accounted for most of the variation in growth. As thinning of young Douglas-fir becomes a widespread management practice, it can be expected that, in similar vegetation types, Douglas-fir seedlings will establish naturally in the understory. If the new forest is established at final harvest several years in lag time may be saved; regeneration problems often associated with clear-cutting will be alleviated, planting costs reduced or eliminated, and the forest gene pool maintained. Title: Growth behavior of Douglas-fir reproduction in the shade of managed forest in the interior Coast Range of Oregon Author: Del Rio, Ernest During the past 20 years, repeated thinning of a Douglas-fir forest, now 65 years old, has allowed desired limits of basal area to be maintained. In the process, the understory environment has altered sufficiently to allow Douglas-fir reproduction to establish in abundance. The forest is located on the east side of the Coast Range, north of Corvallis, Oregon. A study was undertaken to examine growth patterns of understory trees in relation to microenvironment, physical attributes of the tree and time. This information would help determine how long a tree can be maintained at a given level of shade and still function properly. This information also would add to the understanding of modification of growth strategies for survival. To characterize the understory environments of the three thinning intensities (23 to 30, 30 to 37 and 37 to 44 m2/ha basal area), measurements were made of plant moisture stress, evaporative demand, air and soil temperature, light and vegetative cover. Light measured at seedling crown best separated the environments; light was found to increase with a decrease in stand basal area, averaging 5, 8 and 12 percent of daily sun for the three thinning levels. Trees, randomly selected, ranged in height from 10 cm to 1.5 m and in age from 4 to 15 years. Parameters measured included leader growth for the past two seasons, diameter growth, above-ground biomass, height and age. Bud phenology and beginning of cambial activity were also observed. Development of buds in the spring was inversely related to light while renewed cambial activity was directly related to tree size and light. Increments of height and diameter growth were found to increase with light and tree height. Linear differences in average leader and diameter growth and above-ground biomass production were found between the three intensities of thinning, with trees under the heaviest thinning growing most. Average growth is predictable for at least two years. However, rates of leader growth and biomass production, in relation to growth of the previous year and leaf biomass, were not different for individual trees from the three understory environments. A balance of foliar to stem bioniass was maintained by understory trees. Physical characteristics of the tree accounted for most of the variation in growth. As thinning of young Douglas-fir becomes a widespread management practice, it can be expected that, in similar vegetation types, Douglas-fir seedlings will establish naturally in the understory. If the new forest is established at final harvest several years in lag time may be saved; regeneration problems often associated with clear-cutting will be alleviated, planting costs reduced or eliminated, and the forest gene pool maintained. Close

• 33. [Article] The effects of supercritical CO₂ on the bending properties and treatment defects of four refractory wood species

  It is difficult to treat the heartwood of many wood species with liquid preservatives using conventional liquid processes. Supercritical fluids (SCF) used as carriers of preservatives to impregnate refractory ...

  Citation × Citation Citation Abstract Copy Title: The effects of supercritical CO₂ on the bending properties and treatment defects of four refractory wood species Author: Anderson, Matthew E. It is difficult to treat the heartwood of many wood species with liquid preservatives using conventional liquid processes. Supercritical fluids (SCF) used as carriers of preservatives to impregnate refractory wood species may be an attractive alternative to conventional liquid carriers. While SCF impregnation has many potential advantages, some wood species exposed to elevated pressures can be subjected to excessive pressure gradients during treatment. These gradients can lead to treatment defects, such as collapse and splitting, and may also result in significant losses in bending properties. This study examined the effects of three treatment parameters on the bending properties and the development of treatment defects in Douglas-fir (Pseudotsuga menziesii), yellow poplar (Liriodendron tuhpifera), western redcedar (Thuja phcata), and Engelmann spruce (Picea engelmannii). Two rates of pressurization (0.34, 3.44 MPa/min.), two treatment pressures (10.34, 20.69 MPa) and two rates of venting (0.34, 3.44 MPa/min.) were examined on small clear specimens of each species using one treatment temperature (60 °C) and one treatment time (30 min.). SCF treatment of yellow poplar produced no significant reduction in bending properties, while bending properties increased in Douglas-fir. The latter increase appears to have resulted from differences in mean specific gravities between treatments since pressurization rate, treatment pressure, or venting rate did not significantly affect bending properties. Bending properties in western redcedar and Engelmann spruce were significantly reduced when exposed to SCF treatment conditions. Comparisons between treatment and control in western redcedar specimens showed 21.7 to 23.1% reductions in MOR and 26.0 to 31.0% reductions in WML. Properties of Engelmann spruce declined 10.8 to 21.6% in MOR, 16.0 to 21.4% in MOE, and 7.2 to 29.0% in WML following SCF treatment. Rapid venting, at a rate of 3.44 MPa/min., produced the most significant reductions on bending properties for western redcedar, while Engelmann spruce was affected by both the 0.34 and 3.44 MPa/min. pressurization and venting rates. Examination of transverse sections for all species revealed that collapse can occur externally as well as internally within SCF treated samples of Douglas-fir, western redcedar and Engelmann spruce, while the anatomical characteristics of yellow poplar were observed to be unaffected by SCF treatments. The results indicate that SCF treatments, while effective for treating refractory woods, must be used with some caution to avoid inducing negative effects on wood properties. Title: The effects of supercritical CO₂ on the bending properties and treatment defects of four refractory wood species Author: Anderson, Matthew E. It is difficult to treat the heartwood of many wood species with liquid preservatives using conventional liquid processes. Supercritical fluids (SCF) used as carriers of preservatives to impregnate refractory wood species may be an attractive alternative to conventional liquid carriers. While SCF impregnation has many potential advantages, some wood species exposed to elevated pressures can be subjected to excessive pressure gradients during treatment. These gradients can lead to treatment defects, such as collapse and splitting, and may also result in significant losses in bending properties. This study examined the effects of three treatment parameters on the bending properties and the development of treatment defects in Douglas-fir (Pseudotsuga menziesii), yellow poplar (Liriodendron tuhpifera), western redcedar (Thuja phcata), and Engelmann spruce (Picea engelmannii). Two rates of pressurization (0.34, 3.44 MPa/min.), two treatment pressures (10.34, 20.69 MPa) and two rates of venting (0.34, 3.44 MPa/min.) were examined on small clear specimens of each species using one treatment temperature (60 °C) and one treatment time (30 min.). SCF treatment of yellow poplar produced no significant reduction in bending properties, while bending properties increased in Douglas-fir. The latter increase appears to have resulted from differences in mean specific gravities between treatments since pressurization rate, treatment pressure, or venting rate did not significantly affect bending properties. Bending properties in western redcedar and Engelmann spruce were significantly reduced when exposed to SCF treatment conditions. Comparisons between treatment and control in western redcedar specimens showed 21.7 to 23.1% reductions in MOR and 26.0 to 31.0% reductions in WML. Properties of Engelmann spruce declined 10.8 to 21.6% in MOR, 16.0 to 21.4% in MOE, and 7.2 to 29.0% in WML following SCF treatment. Rapid venting, at a rate of 3.44 MPa/min., produced the most significant reductions on bending properties for western redcedar, while Engelmann spruce was affected by both the 0.34 and 3.44 MPa/min. pressurization and venting rates. Examination of transverse sections for all species revealed that collapse can occur externally as well as internally within SCF treated samples of Douglas-fir, western redcedar and Engelmann spruce, while the anatomical characteristics of yellow poplar were observed to be unaffected by SCF treatments. The results indicate that SCF treatments, while effective for treating refractory woods, must be used with some caution to avoid inducing negative effects on wood properties. Close

• 34. [Article] Early stages in plant succession on Douglas fir clearcuts on the Mary's Peak watershed near Corvallis, Oregon

  This study has been concerned with the patterns of vegetative changes which occur during the first five years following logging and burning on Douglas-fir clear cuts. Knowledge of the successional sequence in ...

  Citation × Citation Citation Abstract Copy Title: Early stages in plant succession on Douglas fir clearcuts on the Mary's Peak watershed near Corvallis, Oregon Author: Brown, Eugene Allen This study has been concerned with the patterns of vegetative changes which occur during the first five years following logging and burning on Douglas-fir clear cuts. Knowledge of the successional sequence in the coastal forests of western Oregon is of primary importance to those concerned with the management of this resource. From the more theoretical point of view, there are many unique features associated with this type of vegetation of special interest to the ecologist. Published accounts of studies in Oregon and Washington have been of a generalized nature. None have approached a localized area with the degree of intensity attempted in this study. Due to its close proximity to Oregon State University and the cutting and burning history of the area, the Mary's Peak Watershed has been especially suitable for this study. Mary's Peak is the highest point of the Oregon Coast range having an elevation of 4,097 feet. The Corvallis watershed is located on the eastern slope of the peak and includes both the Rock Creek and Griffith Creek drainages. The area is about five miles long east and west by four miles north and south. The area is managed as a unit by the United States Forest Service. Due to the marine influence, the area has a humid climate averaging approximately 65 inches of precipitation annually with an annual mean temperature of approximately 52°F. Soils are basaltic in origin and are primarily clay loam in texture. In 1950, an epidemic of Douglas fir bark beetles made necessary a program of development which included cutting of dead and infected trees and establishing a road system. Cutting was restricted to small clear cuts. The vegetation in the study area is a Douglas fir-vine maple association. Gaultheria shallon and Berberis nervosa dominate the forest floor with traces of Castanopsis, Corylus, and Cornus. Study plots were located on nine clear cut and burned areas ranging in elevation from 1,300 to 2,800 feet and including north, south, and east exposures. Nineteen study plots, which were 100 x 100 feet, were established in uniform vegetative areas. Plots were also established in the undisturbed areas adjacent to the clear cuts for comparative purposes. Vegetative sampling was done using a device called an ocular point frame which provided a reliable indication of vegetative cover. Sampling was done in both the spring and fall on the second, third, fourth, and fifth years following burning. The stable undisturbed vegetation was sampled only once. Results of the five-year study showed a general increase in total number of plant species. The average total vegetative cover rose abruptly the third, fourth, and fifth years. An analysis indicated that south exposed plots had the greatest vegetative cover the first five years after burning. East plots ranked second and north plots third. By the fourth year, average cover values on clear cut areas exceeded the cover values of understory vegetation on the adjacent uncut forest. Analysis of data regarding seasonal variation indicated sharp decreases in total cover from spring to fall during the first three years. Increasing amounts of perennial vegetation during the fourth and fifth years reduced this seasonal variation markedly. In terms of mean cover trends, the annual herb, Senecio sylvaticus, dominated the second year; Lotus stipularis and Circium vulgare, the third; Lotus and Holcus lanatus , the fourth and fifth. All plant species indicated a wide range of cover values on the plots sampled. Some consistent trends in the sequence of cover dominance are noted. Title: Early stages in plant succession on Douglas fir clearcuts on the Mary's Peak watershed near Corvallis, Oregon Author: Brown, Eugene Allen This study has been concerned with the patterns of vegetative changes which occur during the first five years following logging and burning on Douglas-fir clear cuts. Knowledge of the successional sequence in the coastal forests of western Oregon is of primary importance to those concerned with the management of this resource. From the more theoretical point of view, there are many unique features associated with this type of vegetation of special interest to the ecologist. Published accounts of studies in Oregon and Washington have been of a generalized nature. None have approached a localized area with the degree of intensity attempted in this study. Due to its close proximity to Oregon State University and the cutting and burning history of the area, the Mary's Peak Watershed has been especially suitable for this study. Mary's Peak is the highest point of the Oregon Coast range having an elevation of 4,097 feet. The Corvallis watershed is located on the eastern slope of the peak and includes both the Rock Creek and Griffith Creek drainages. The area is about five miles long east and west by four miles north and south. The area is managed as a unit by the United States Forest Service. Due to the marine influence, the area has a humid climate averaging approximately 65 inches of precipitation annually with an annual mean temperature of approximately 52°F. Soils are basaltic in origin and are primarily clay loam in texture. In 1950, an epidemic of Douglas fir bark beetles made necessary a program of development which included cutting of dead and infected trees and establishing a road system. Cutting was restricted to small clear cuts. The vegetation in the study area is a Douglas fir-vine maple association. Gaultheria shallon and Berberis nervosa dominate the forest floor with traces of Castanopsis, Corylus, and Cornus. Study plots were located on nine clear cut and burned areas ranging in elevation from 1,300 to 2,800 feet and including north, south, and east exposures. Nineteen study plots, which were 100 x 100 feet, were established in uniform vegetative areas. Plots were also established in the undisturbed areas adjacent to the clear cuts for comparative purposes. Vegetative sampling was done using a device called an ocular point frame which provided a reliable indication of vegetative cover. Sampling was done in both the spring and fall on the second, third, fourth, and fifth years following burning. The stable undisturbed vegetation was sampled only once. Results of the five-year study showed a general increase in total number of plant species. The average total vegetative cover rose abruptly the third, fourth, and fifth years. An analysis indicated that south exposed plots had the greatest vegetative cover the first five years after burning. East plots ranked second and north plots third. By the fourth year, average cover values on clear cut areas exceeded the cover values of understory vegetation on the adjacent uncut forest. Analysis of data regarding seasonal variation indicated sharp decreases in total cover from spring to fall during the first three years. Increasing amounts of perennial vegetation during the fourth and fifth years reduced this seasonal variation markedly. In terms of mean cover trends, the annual herb, Senecio sylvaticus, dominated the second year; Lotus stipularis and Circium vulgare, the third; Lotus and Holcus lanatus , the fourth and fifth. All plant species indicated a wide range of cover values on the plots sampled. Some consistent trends in the sequence of cover dominance are noted. Close

• 35. [Article] The role of soil-water depletion and plant-moisture stress in soil classification and cambial activity of Douglas-fir

  Relationships between soil-water stress and plant-moisture stress were studied with respect to soil classification and cambial activity in Douglas-fir. The study sites were forested with Douglas-fir and ...

  Citation × Citation Citation Abstract Copy Title: The role of soil-water depletion and plant-moisture stress in soil classification and cambial activity of Douglas-fir Author: Thomas, Byron R. Relationships between soil-water stress and plant-moisture stress were studied with respect to soil classification and cambial activity in Douglas-fir. The study sites were forested with Douglas-fir and located in McDonald Forest and near Marys Peak in the Oregon Coast Range. Soil-water depletion was followed by the use of gypsum blocks on sites representing seven soil series and one soil phase. Plant-moisture stress was determined by a pressure bomb and recorded in conjunction with the soil-water depletion throughout the growing season. Cambial activity of a Douglas-fir tree growing on each study site was also recorded throughout the growing season. Summer soil temperatures were measured at a depth of 50 cm. Moisture tensions and bulk density for each horizon of each soil were determined in the laboratory. Dixonville (shallow variant), Jory (west slope), Nekia, and Jory (north slope) soils were located in McDonald Forest and had a soil-water stress of 15 bars for at least 60 consecutive days within the soil-moisture control section. Current and past weather records show that this stress will occur in at least seven out of ten years. These soils are classified as xeric-mesic. Blachly, Kilchis, Klickitat, and Hembre soils were located in the vicinity of Marys Peak and had soil-water stresses of 15 bars ranging from 21 to 47 consecutive days within the soil-moisture control section. Current and past weather records show that these soils will not develop a 15 bar stress for 60 consecutive days in seven out of ten years. Therefore, they are not xeric. The term moist-mesic is used to define such soils. Difference in elevation within a local area is not a sufficient indicator by itself to separate the xeric and non-xeric zones. Plant-moisture stress cannot be used to indicate soil-water stress for the purpose of soil classification. Some trees evidently obtain water from spaces within the fractured bedrock. This water source is not defined in the soil classification scheme. There was a highly significant difference in plant-moisture stress between the study trees growing in the xeric-mesic zone and moist-mesic zone at the time of the springwood-summerwood transition. Trees in the two zones showed large differences in plant-moisture stress at the time of dormancy. In both cases, trees growing in the xeric-mesic zone had higher stresses than trees growing in the moist-mesic zone. There were very large differences between the xeric-mesic and moist-mesic zones in the percent of available water used from the upper one-third of the soil profile at the time the trees stopped producing springwood. Large differences in the percent of available water used from the entire profile occurred between soils in the two zones at the time the trees became dormant. At both transition and dormancy, more available water was depleted from the soils in the xeric-mesic zone than the moist-mesic zone. Trees in the xeric-mesic zone produced springwood a greater number of days than the trees growing in the moist-mesic zone without necessarily producing more springwood. Trees in the xeric-mesic zone grew an average of 27 more days than trees in the moist-mesic zone without necessarily producing more total wood. Title: The role of soil-water depletion and plant-moisture stress in soil classification and cambial activity of Douglas-fir Author: Thomas, Byron R. Relationships between soil-water stress and plant-moisture stress were studied with respect to soil classification and cambial activity in Douglas-fir. The study sites were forested with Douglas-fir and located in McDonald Forest and near Marys Peak in the Oregon Coast Range. Soil-water depletion was followed by the use of gypsum blocks on sites representing seven soil series and one soil phase. Plant-moisture stress was determined by a pressure bomb and recorded in conjunction with the soil-water depletion throughout the growing season. Cambial activity of a Douglas-fir tree growing on each study site was also recorded throughout the growing season. Summer soil temperatures were measured at a depth of 50 cm. Moisture tensions and bulk density for each horizon of each soil were determined in the laboratory. Dixonville (shallow variant), Jory (west slope), Nekia, and Jory (north slope) soils were located in McDonald Forest and had a soil-water stress of 15 bars for at least 60 consecutive days within the soil-moisture control section. Current and past weather records show that this stress will occur in at least seven out of ten years. These soils are classified as xeric-mesic. Blachly, Kilchis, Klickitat, and Hembre soils were located in the vicinity of Marys Peak and had soil-water stresses of 15 bars ranging from 21 to 47 consecutive days within the soil-moisture control section. Current and past weather records show that these soils will not develop a 15 bar stress for 60 consecutive days in seven out of ten years. Therefore, they are not xeric. The term moist-mesic is used to define such soils. Difference in elevation within a local area is not a sufficient indicator by itself to separate the xeric and non-xeric zones. Plant-moisture stress cannot be used to indicate soil-water stress for the purpose of soil classification. Some trees evidently obtain water from spaces within the fractured bedrock. This water source is not defined in the soil classification scheme. There was a highly significant difference in plant-moisture stress between the study trees growing in the xeric-mesic zone and moist-mesic zone at the time of the springwood-summerwood transition. Trees in the two zones showed large differences in plant-moisture stress at the time of dormancy. In both cases, trees growing in the xeric-mesic zone had higher stresses than trees growing in the moist-mesic zone. There were very large differences between the xeric-mesic and moist-mesic zones in the percent of available water used from the upper one-third of the soil profile at the time the trees stopped producing springwood. Large differences in the percent of available water used from the entire profile occurred between soils in the two zones at the time the trees became dormant. At both transition and dormancy, more available water was depleted from the soils in the xeric-mesic zone than the moist-mesic zone. Trees in the xeric-mesic zone produced springwood a greater number of days than the trees growing in the moist-mesic zone without necessarily producing more springwood. Trees in the xeric-mesic zone grew an average of 27 more days than trees in the moist-mesic zone without necessarily producing more total wood. Close