New methods for measuring root growth capacity: their value in assessing lodgepole pine stock quality

1979 ◽  
Vol 9 (1) ◽  
pp. 63-67 ◽  
Author(s):  
A. N. Burdett
Keyword(s):  
Root Growth ◽  
Constant Temperature ◽  
Lodgepole Pine ◽  
The Other ◽  
Night Temperature ◽  
Root Volume ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
New Methods ◽  
Stock Quality

The survival of lodgepole pine (Pinusconforta Dougl.) planted in the spring under a variety of conditions was found to be closely related to its root growth capacity as measured by two newly developed methods. One method employed a displacement technique to measure the root volume of test seedlings, nondestructively, both at the beginning and end of a period of growth under standard conditions. The change in root volume that occurred during the test was taken as a measure of root growth capacity. The other method for measuring root growth capacity was to record, by means of a semiquantitative scale, the number of newly elongated roots possessed by test seedlings after a 1-week period of growth under standard conditions. For comparative purposes, it was found that very similar results were obtained in root growth capacity tests of this type run at two widely differing temperatures (30 °C day – 25 °C night temperature, and a constant temperature of 15 °C).

Changes in drought resistance and root growth capacity of container seedlings in response to nursery drought, nitrogen, and potassium treatments

1992 ◽  
Vol 22 (5) ◽  
pp. 740-749 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Drought Stress ◽  
Root Growth ◽  
Drought Resistance ◽  
Lodgepole Pine ◽  
Dry Weight ◽  
White Spruce ◽  
Douglas Fir ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
N Treatment

Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), lodgepole pine (Pinuscontorta Dougl.), and white spruce (Piceaglauca (Moench) Voss) seedlings, each represented by two seed lots, were grown in Styroblock containers in a greenhouse and plastic shelter house from February 1989 to January 1990. The seedlings were exposed to two nitrogen (N) treatments and three potassium (K) treatments arranged factorially within three drought treatments. After winter storage, seedlings from a complete set of treatments were planted into hygric, mesic, and xeric sand beds during 12–14 March. Increasing nursery drought stress increased survival of Douglas-fir and lodgepole pine after planting, and high N treatment level increased survival of lodgepole pine and white spruce. Under xeric conditions, combined nursery drought and high N treatments increased survival of lodgepole pine by 33%, indicating the importance of nursery cultural regime for stock quality. Increase in nursery drought decreased seedling size relatively little, but increase in N increased seedling size one season after planting. A positive relationship between shoot/root ratio and survival in lodgepole pine and white spruce indicated that increase in N increased both shoot growth and drought resistance over the N range investigated. Only Douglas-fir showed an interaction between drought and N treatment and a small response in both survival and dry weight to K. Root growth capacity, measured at the time of planting, showed an approximate doubling in all species due to high N treatment, and was also increased in white spruce by drought stress. Survival and root growth capacity were poorly correlated, but dry-weight growth in sand beds was well correlated with root growth capacity. Shoot dry weight and percent N in shoots measured after nursery growth were correlated with root growth capacity. Manipulation of root growth capacity by changing nursery treatment was apparently possible without altering resistance to drought stress after planting.

Understanding root growth capacity: theoretical considerations in assessing planting stock quality by means of root growth tests

1987 ◽  
Vol 17 (8) ◽  
pp. 768-775 ◽  
Author(s):  
A. N. Burdett
Keyword(s):  
Root Growth ◽  
Cold Hardiness ◽  
Quantitative Relationship ◽  
Forest Tree ◽  
Tree Seedlings ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
Planting Stock Quality ◽  
Field Evidence ◽  
Stock Quality

Laboratory assays for measuring the root growth capacity (RGC) of forest tree seedlings were first developed in the belief that root extension immediately after planting is a major determinant of establishment success. An assumption underlying the development of these tests was that root growth under standardized conditions in the laboratory is indicative of root growth under the generally quite different and often highly variable conditions in the field. Evidence in support of this assumption is slight. Recently, it has been proposed that RGC affects seedling performance, not directly, but by virtue of a correlation with cold hardiness or other types of stress resistance that directly affect performance. For this hypothesis, also, the evidence is slight. There is a need for a clearer understanding of the relationship between RGC and seedling establishment to decide how best to measure and interpret RGC as a gauge of stock quality. This is illustrated by a discussion of the optimum conditions for measuring RGC and of the quantitative relationship between RGC and early performance of planted stock.

Frost hardiness, root growth capacity, and field performance relationships in interior spruce, lodgepole pine, Douglas-fir, and western hemlock seedlings

1990 ◽  
Vol 20 (5) ◽  
pp. 566-572 ◽  
Author(s):  
David G. Simpson
Keyword(s):  
Root Growth ◽  
Lodgepole Pine ◽  
Field Performance ◽  
Douglas Fir ◽  
Frost Hardiness ◽  
Western Hemlock ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
Forest Sites ◽  
Interior Spruce

Interior spruce (Piceaglaucaengelmannii complex), lodgepole pine (Pinuscontorta Dougl.), Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), and western hemlock (Tsugaheterophylla (Raf.) Sarg.) were grown from seed for 20 weeks in containers, with 18-h photoperiods. Fortnightly, over a 12-week acclimation period (September 7 – December 1) outdoors at Vernon, B.C., samples were taken for (i) foliage frost hardiness measurement, (ii) poststorage root growth capacity, and (iii) outplanting on forest sites. In all species, frost hardiness and root growth capacity increased with weeks of acclimation. Frost hardiness and root growth capacity were correlated with each other in western hemlock, lodgepole pine, and Douglas-fir, and with field performance (survival or growth) in interior spruce, lodgepole pine, and Douglas-fir.

Influence of container nursery regimes on drought resistance of seedlings following planting. II. Stomatal conductance, specific leaf area, and root growth capacity

1991 ◽  
Vol 21 (5) ◽  
pp. 566-572 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Stomatal Conductance ◽  
Root Growth ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Lodgepole Pine ◽  
White Spruce ◽  
Temperature Treatment ◽  
Drought Treatment ◽  
Growth Capacity ◽  
Root Growth Capacity

Seedlings of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), lodgepole pine (Pinuscontorta Dougl.), and white spruce (Piceaglauca (Moench) Voss) were grown in a container nursery from February to July 1988 and then exposed to three temperatures and three levels of drought stress applied factorially during mid-July to October 1988. Seedlings were retained in a shelter house until January 1989, when they were cold-stored until early May. Measurements of stomatal conductance (gs), transpiration (E), and specific leaf area (SLA) were made at the end of the treatment period in September 1988 and again after growth the following year at the end of June. Root growth capacity (RGC) was tested in early May 1989. Results were considered in conjunction with performance of other samples of the same plants that had been planted in sand beds in April 1989, where irrigation was regulated to provide three levels of moisture stress. Low temperature (13 °C) generally reduced gs and E, which were adjusted for xylem pressure potential, and SLA in all species by the time nursery treatment was completed at the end of September. No effect of nursery temperature treatment on gs and E could be detected when new needles were measured in June and July (after 9 to 12 weeks of growth), but SLA of lodgepole pine increased with nursery temperature treatment, and SLA of white spruce decreased with nursery temperature treatment. RGC was higher for the 13 °C treatment than for the 16 and 20 °C treatments. Survival of outplanted seedlings was mainly inversely related to nursery temperature. Low nursery temperature reduced gs, E, and SLA and increased RGC. SLA of planted lodgepole pine increased with level of nursery drought treatment, and severe nursery drought increased gs under stress, when measured in June. No other effects of drought were detected, although drought treatment was effective in increasing survival of planted seedlings.

Early growth of planted spruce

1984 ◽  
Vol 14 (5) ◽  
pp. 644-651 ◽  
Author(s):  
A. N. Burdett ◽  
L. J. Herring ◽  
C. F. Thompson
Keyword(s):  
Root Growth ◽  
Shoot Growth ◽  
Slow Release ◽  
Unit Length ◽  
White Spruce ◽  
Early Growth ◽  
Height Growth ◽  
Needle Length ◽  
Growth Capacity ◽  
Root Growth Capacity

Observations were made on the growth of white spruce (Piceaglauca (Moench) Voss) and Engelmann spruce (P. engelmanni Parry), each planted at a single location in the interior of British Columbia. In both species bareroot stock (either 2 + 0 seedlings or 2 + 1 transplants) with a low root growth capacity made only limited height growth during the first two seasons after planting. In the first season, many short stem units were formed, whereas in the second season, stem units were much longer but many fewer. The length of needles formed after planting by the bareroot trees was, in the first season, only about half that of needles formed the previous year in the nursery. Needle length increased slightly in the 2nd year. Container-grown trees (1 + 0 seedlings from 336-mL containers), which had a high root growth capacity, made relatively good height growth in the first season when they formed long needles and stem units. Height growth by these seedlings was much less in the second season, however, as were needle length and stem unit number, but not stem unit length. Application of slow release N,P, and K fertilizer at planting improved shoot growth by bareroot trees more in the second season than the first. In contrast, the container-grown stock made a large shoot growth response to fertilization in both the first and the second seasons. The results are consistent with the hypothesis that, as root establishment proceeds, shoot growth tends to be limited by the supply, first of water, then of mineral nutrients. This implies that the early growth of planted spruce can be maximized by using stock with a high root growth capacity, or other adaptations to drought, and applying slow release fertilizer at planting. Observations on the white spruce revealed an acceleration in shoot growth by both stock types during the third season. This followed the establishment, by the end of the second season, of root systems several metres in diameter. A large difference in height: diameter ratio, observed at the time of planting, between the container-grown and bareroot white spruce disappeared entirely in the course of the first three growing seasons.

Survival and growth of four amabilis fir stock types on Vancouver Island

1991 ◽  
Vol 67 (2) ◽  
pp. 147-154 ◽  
Author(s):  
F. T. Pendl ◽  
B. N. D'Anjou
Keyword(s):  
Root Growth ◽  
Lateral Roots ◽  
Survival Rates ◽  
Field Performance ◽  
Vancouver Island ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
Stock Type ◽  
Stock Types ◽  
Initial Root

Four stock types of amabilis fir (Abies amabilis) planted on Vancouver Island were compared for root growth capacity and field performance. Initial root growth capacity ratings and field performance of the stock types after five years differed significantly. Ranking the stock types by decreasing survival, stem height and diameter: 1 + 1 PBR 211 (89.4%, 78 cm, 15.7 mm), 1 + 0 PSB 313 (79.7%, 73 cm, 13.8 mm), 1 + 0 PSB 211 (76.8%, 66 cm, 12.9 mm) and 2 + 0 BR (58.9%, 59 cm, 11.0 mm). Given current nursery and planting costs and survival rates, the 1 + 0 PSB 313 and 211 are least expensive reforestation options, the 2 + 0 BR and 1 + 1 PBR 211 the most expensive. Root form of samples of each stock type lack well developed tap and lateral roots with root spiralling evident in the styroblock stock. Key words: Amabilis fir, stock types, bareroot, styroblock plugs

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