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1.
《Scandinavian Journal of Forest Research》2012,27(1-4):540-549
In this study an attempt was made to gather information on the relationships of morphological attributes of bareroot Pinus sylvestris seedlings in order to determine the possible use of these attributes for grading purposes. The covariance structure of different morphological variables was studied in commercially produced crops. From each selected batch of Scots pine seedlings, 300 seedlings were sampled, three successive living seedlings from each of the 100 systematically selected sampling points ("clusters"). Variance in the seedlings crop was described using a linear model: total covariance was divided into variance between batches, between clusters and between individual seedlings (error). Most of the correlations between different plant parts were large and positive. Only needle length and root length seemed to vary independently of other “length”; variables. Within one batch, at the end of the growing season, height‐diameter was more clearly size‐independent than shoot‐root ratio. Needle biomass increased exponentially with seedling height but the smallest seedlings had relatively less needle biomass than the biggest seedlings. It is not necessary to include dry mass in the requirements for seedling quality since it correlates well and can be described with other variables that can be measured more easily. Of the principal components for morphological characteristics, the “stem”; component explained 69% of the height variation and 77% of the diameter variation, the “needle”; component explaining 79% of the variation in current needle length, and the “root”; component 58% of the variation in root length. Together the three components explain 76% of the total variance in the original crops. 相似文献
2.
The height variation of Scots pine (Pinus sylvestris L.) seedling stock was studied using data from annual inventories of seedling crops. The heights of 240 batches of 2-year-old and 3-year-old transplanted seedling from the years 1973–1986 grown at three nurseries in southern Finland were examined. From each batch, 100 clusters of three successive seedlings were systematically located and measured. The mean heights of the seedling batches ranged from 7.8 to 27.0 cm, with a mean of 14.1 cm. Within batch standard deviations ranged from 1.7 to 7.8 cm, with a mean standard deviation of 3.7 cm. There was considerable variation in the mean heights of seedling batches both within a given year and between years. However, estimated variance components of seedling height showed that year, batch and cluster effect each accounted for about 20 percent of the total variance, while seedling effect explained the remaining 40 percent. The implications of results for single tree and batch grading are discussed. 相似文献
3.
Applications of growth retardants, daminozide and CCC (chlormequatchloride), were studied in order to determine their effects on morphology and post-planting growth of silver birch (Betula pendula Roth) container seedlings. Daminozide was sprayed once (on 28 June at concentrations of 1.0 – 6.0 g l–1) and CCC was sprayed twice (on 29 June and 27 July at concentrations of 0.5–3.0 gl–1). Height growth, morphology of seedlings at the end of the growing season, the shoot and root growth potential the following spring and field performance during the following seasons were measured. During the first summer in the nursery, both daminozide and CCC retarded height growth,but daminozide was more effective. The effects of compounds on stem diameter during the summer of application were small. Neither of the compounds affected the field performance of seedlings. The most suitable applications for retardation of height growth, without negative effects on other morphological variables, were 4 g l–1 (32 mg per seedling) for daminozide and 2 g l–1 (16 mg per seedling), sprayed in two applications, for CCC. 相似文献
4.
J. Heiskanen 《New Forests》1995,9(3):181-195
Containerized Scots pine seedlings growing in light Sphagnum peat growth medium in a greenhouse were subjected to three irrigation treatments. The seedlings were irrigated by saturating the growth medium with a nutrient solution (i) daily or when (ii) –5 or (iii) –10 kPa medium matric potential was achieved. In general, the nutrient concentrations in the foliage of the seedlings were rather similar for all irrigation treatments. In the wet (daily) irrigation treatment, however, the foliar concentration of N was lower and the foliar concentrations of P, Ca, S, Mn and Na were higher than in the other two treatments. In the wet irrigation treatment, height growth was lower than that in the other treatments. In this treatment the shoot to root ratio and several other morphological characteristics were also reduced, while the number of root lenticels and seedling mortality were increased compared to the other treatments. Rapid growth was obtained by irrigating at –5 to –10 kPa matric potential. In the wet irrigation treatment, the median matric potential and air-filled porosity of the peat medium were –0.4 kPa and 11%, respectively, which indicated waterlogging and very suboptimal aeration to the seedlings. The respective values for the irrigations at –5 and –10 kPa were –2.7 to –3.3 kPa and 39 to 43%, which were considered to cover the range from optimum to slightly suboptimum for average water availability and aeration. 相似文献
5.
One-year-old interior spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry) spring-stock and summer-stock were grown under two phosphorus (P) fertility regimes, with (+P) or without (–P), followed by a simulated winter, and a second growing period under an adequate fertility regime in a controlled environment room. The two stock-types differed in their response to low P availability. For spring-stock, morphological development, phosphorus-use efficiency (PUE) and P specific absorption rate (SAR) were similar between –P and +P seedlings. For summer-stock, –P seedlings compared to +P seedlings had lower (p 0.05) morphological development, but greater PUE and SAR. For both stock-types, P content increased in +P seedlings, remained low in –P seedlings, and P concentration decreased in nursery-needles (i.e., formed in the nursery) of –P seedlings. The difference in stock-type response to low phosphorus availability (–P) was attributed to internal supply of P and it's retranslocation. Assimilation (A) of CO2 in nursery-needles was similar between –P and +P seedlings for both stock-types. For spring-stock, +P seedlings had greater A in new-needles (i.e., needles formed during the trial) than –P seedlings. It was recommended that the spring-stock be selected over summer-stock for sites low in P availability. 相似文献
6.
When spring frosts occur on recently planted forest sites, severe damage may occur to the seedlings. The aim of the present study was to test how different low levels of nutrient concentrations in Norway spruce (Picea abies (L.) Karst.) seedlings affected spring frost hardiness and time of bud break. Seedlings were grown in a greenhouse for one season and supplied with fertiliser containing 22, 43 and 72 mg N l–1, respectively. The treatments resulted in needle nitrogen concentrations ranging from 0.9 to 1.8% in autumn. After winter storage at 0 °C, bud break was recorded on seedlings growing in the greenhouse, outdoors and in growth chambers at 12 °C and at 17 °C. Freezing tests were performed on seedlings directly removed from winter storage and following one week growth in the greenhouse. Seedlings receiving fertiliser with 43 mg N l–1 had less freezing injury than the two other fertilisation treatments in the present study. The earliest bud break occurred in seedlings receiving 72 mg N l–1. 相似文献
7.
Differences in sensitivity to soil conditions across tree species and developmental stage are important to predicting forest response to environmental change. This study was conducted to compare elemental concentrations in leaves, stems, and roots of (1) sugar maple (Acer saccharum Marsh.) seedlings vs. mature trees and (2) mature sugar maple vs. mature American beech (Fagus grandifolia Ehrh.) in two sites that differ in soil base saturation and pH. Both sites are located in Huntington Forest, NY, USA; one site (hereafter ‘H’) has higher soil pH and Ca, Mg, and Mn concentrations than the other site (hereafter ‘L’). Sugar maple growth at H (14.8 cm2 year−1 per tree) was much greater than at L (8.6 cm2 year−1 per tree), but the growth of beech was not different between the two sites. Leaves, roots, and stem wood of mature beech trees and sugar maple seedlings and mature trees were sampled for nutrient analysis. Foliar Ca, K, and Al concentrations were positively correlated with soil elements, but Mn concentrations were negatively correlated. Sugar maple differed more than beech between sites in foliar K and Mn concentrations. Root Mg and P concentrations reflected soil chemistry differences, in contrast to foliar concentrations of Mg and P, which were indistinguishable between the sites. In sugar maple, seedlings differed more than in mature trees in nutrient concentrations in roots, especially for Mg and Mn. Although beech was not as responsive to nutrient availability as sugar maple in foliar and root nutrient concentrations, Ca and Mg concentrations in beech wood were higher in H (52% higher for Ca and 68% higher for Mg), while sugar maple did not differ between sites. Sugar maple regeneration failure on acidic soils in the same region is consistent with our finding that sugar maple seedlings were very sensitive to nutrient availability. This sensitivity could ultimately contribute to the replacement of sugar maple by American beech in regions of low pH and base cations if base cation leaching by anthropogenic deposition and tree harvesting continues. 相似文献
8.
Gary A. Ritchie 《New Forests》1986,1(1):29-42
An experiment was conducted to ascertain what relationships might exist among dormancy status, cold hardiness and stress resistance in 2+0 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), seedlings. Seedlings were lifted from a western Washington nursery on six dates spanning the 1980–81 lifting season. On each date samples of seedlings were subjected to the following treatment: (1) tumbling for 5 minutes, (2) desiccation of roots for 30 minutes at 30°C and 2.1 kPa vapor pressure deficit, (3) exposure of shoots to temperatures of –10°C, –15°C or –20°C for two hours and (4) unstressed control. On two lift dates sub-samples of seedlings were placed into –1°C storage and held for two months before the above stress treatments were administered. Bud dormancy status was determined, using a bud break test, on seedlings from each lift date before and after storage.After one growing season in the field percent survival, vigor, height growth and shoot and root weight were determined on stressed and unstressed seedlings. Survival and vigor were less affected by the stress treatments than were height and weight. Severity of stress was in the order –20°C > –15°C > desiccation > handling > –10°C. Degree of cold injury was directly related to seedling dormancy status whether dormancy status had been attained in the nursery from natural chilling or in frozen storage. Seedlings in a mid-range of dormancy release (between deep rest and quiescence) were most resistant to all imposed stresses. 相似文献
9.
The capacity of Aleppo pine (Pinus halpensis Mill.) seedlings to overcome the planting shock in dry conditions was assessed by firstly studying the survival and water status during the first year after planting in relation to soil water content. In spite of receiving only 177 mm rainfall during the year studied, survival of planted Aleppo pine was very high (88.5%). Soil water during summer months (after receiving 67 mm rainfall in winter and spring) was only available at 30–60 cm depth, with tension values of –1.1 and –1.3 MPa in July and August respectively; in these conditions, July predawn xylem water potential measured was –2.5 MPa, and midday potential was –3.6 MPa. According to different authors, these values don't jeopardize the survival of Aleppo pine. In addition, acclimation of outplanted seedlings to environmental conditions was followed by comparing their water relations with those of naturally regenerated seedlings on the site. Predawn and midday xylem water potential showed differences in favour of outplanted seedlings since June, indicating an adjustment to this dry site. Compared to naturally regenerated trees, nursery grown stock of the same age before field planting had much more biomass and higher N and P concentrations and contents; although shoot:root balance and Dickson quality index were not significantly different. Finally, planted seedlings acclimation level during first year was also evaluated by Transplant Stress Index, which value (–0.1278) indicated a slight planting impact. 相似文献
10.
Alan E. Harvey Deborah S. Page-Dumroese Martin F. Jurgensen Russell T. Graham Jonalea R. Tonn 《New Forests》1996,11(3):255-270
This report documents impacts from manipulations of native forest soils and competing vegetation on development and ectomycorrhizal formation of outplanted western white pine and Douglas-fir in the Inland Northwest. Treatments were: 1) mounding surface horizons with competition left in place, 2) mounding surface horizons with subsequent physical or chemical control of competing vegetation, 3) scalping for control of competing vegetation, and 4) a control, or no postharvest disturbance. Treatments were applied on a low-altitude, relatively harsh site and on a higher altitude, more moderate site. Wich established seedlings, mounding with no competition control generally produced small seedlings (5–15g; both species) with low numbers of ectomycorrhizal short roots (21). Mounding with competition control produced large seedlings (20–48g) with moderate numbers of short roots (25). Scalping produced small seedlings (8–16g) with high numbers of short roots (41). The control also produced small seedlings (8–13g) but with a moderate number of short roots (27). Douglas-fir produced more short roots on the harsh than the moderate site. Western white pine produced high root to shoot ratios (above 0.60) in the mound with competition on the harsh site. Douglas-fir produced very high root to shoot ratios (above 1.0) in both the mound with no competition of the harsh site and in the mound with competition of the moderate site. Throughout, western white pine produced more ectomycorrhizae more rapidly than Douglas-fir. Ectomycorrhizal development and root and shoot weight of both conifers were adversely affected by competing vegetation. 相似文献
11.
Chlorophyll fluorescence as an indicator of frost hardiness in white spruce seedlings from different latitudes 总被引：3，自引：0，他引：3
This study examined the utility of variable chlorophyll fluorescence (Fvar) to detect freezing damage in white spruce seedlings of four seedlots. Logistic regression analysis done for freezing tests in September showed that visible needle damage from freezing could be estimated by the Fvar attributes Fo/IABS(r2=0.94), Fp(r2=0.98), Fv/Fm (r2=0.99), and F1(r2=0.86). The regression curves indicated that for all four fluorescence attributes, inflection points occurred between 10 and 20% visible needle damage. The lack of a relationship between fluorescence attributes and visible seedling needle damage in October through December is because the minimum temperature (–18 and –24°C respectively) applied was insufficient to cause needle damage. Freezing-induced changes to Fvar attributes can be detected which also result in photosynthetic rate decreases when no visible needle damage, and even electrolyte conductivity changes are evident. Fvar attribute differences due to freezing can be resolved to the seedlot level. The Fvar curve feature manifested 5 seconds after dark-adapted seedlings have been exposed to light (F5s) will estimate (r2=0.76) photosynthetic rate after freezing. 相似文献
12.
Height and diameter increment and timber quality in Scots pine (Pinus sylvestris L.) planted as seedlings of different sizes were studied in two experiments. When compared 32–37 years after planting, seedlings that were smaller than neighbouring seedlings at the time of planting, had generally attained lower height and diameter, and had higher mortality compared to seedlings that were of equal size or larger than their neighbours. Tree size was strongly related to seedling size two years after planting. Trees originating from small seedlings had thinner annual rings and branches than trees originating from large seedlings. These characters are of importance for timber quality. It seems that the competitive ability of a tree is to a large extent established early in stand development. 相似文献
13.
T. S. George P. J. Gregory J. S. Robinson R. J. Buresh B. A. Jama 《Agroforestry Systems》2001,52(3):199-205
Green leaf biomass of Tithonia diversifolia is high in nutrients and recognised as a potential source of nutrients for crops. We conducted a field survey in western Kenya to determine the variation in leaf nutrient concentrations in tithonia grown in naturalised hedges and agricultural fields, and to examine whether leaf nutrient concentrations were related to soil nutrient status. Leaf P and K concentrations were higher in naturalised hedges (3.2 g P kg–1 and 35 g K kg–1) than in unfertilised fields (2.2 g P kg–1 and 23 g K kg–1). The critical level of 2.5 g P kg–1 for net P mineralisation was exceeded by > 90% of the leaves from hedges, but by only 14% from unfertilised fields. Leaf P and K concentration increased linearly with increasing natural logarithm of anion resin extractable soil P and exchangeable soil K, respectively. However, at the same levels of soil available P and K, field-grown tithonia consistently produced lower leaf P and K concentrations than that grown in hedges. This study indicates that biomass from tithonia planted on nutrient-depleted soils would be a less effective source of P and K, via biomass transfer, than tithonia from naturalised hedges.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
14.
Production of quality seedlings is an important aspect of successful tree planting. No information is available on the effect of nutrients and water on the growth and development of the seedlings of neem (Azadirachta indica A. Juss), an important component of many tropical agroforestry systems. In an experiment in central India, the growth and nutrient-use efficiency of neem seedlings grown at various levels of light, nutrients (N and P), and water stress were determined. Seedlings were given light (diffused and complete) and nutrient (N and P) treatments comprising either high N-high P, high N-low P, low N-high P, or low N-low P. Seedlings grown in complete light (800 mol/m2/s) had four times more biomass than those grown in diffused light (200 mol/m2/s). Significant increase in seedling biomass was observed with nitrogen application, while phosphorus had no effect on biomass. Leaves contributed maximum biomass, followed by roots and stem. Nutrient use efficiency decreased with an increase in the supply of nutrients. In another experiment, containerized and bare-root seedlings were subjected to five watering treatments, viz., watering twice a week, watering weekly, watering every alternate week, watering every third week, and natural precipitation. Plant moisture stress affected both growth and survival of neem seedlings. Only 50 per cent of seedlings survived in severe drought treatment (no. 4) whereas 90 to 95 per cent seedlings showed growth in all other treatments. Plant moisture stress in severe drought treatment averaged –21 bar while in other treatments it ranged from –9 to –12 bar. Shoot-root ratio was high in bare-root seedlings as compared to containerized seedlings. Containerized seedlings had shown better endurance against drought than the bare-root seedlings. The results suggest that neem seedlings adjust their nutrient use efficiency and can be grown even under limited available resources. It is also inferred that the species can tolerate soil resource depletion caused by competitor species.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
15.
Studies on tree crop interaction under rainfed condition in Dehradun valley were conducted for 13 years during 1977 to 1990. Grewia optiva (Bhimal), Morus alba (Mulbery) and Eucalyptus hybrid were tried along with rice (CV: Akashi) — wheat (CV: RR-21) rotation. One-year-old tree seedlings of the above tree species were planted in line, 5 m apart in N-S direction, in July 1977, in the middle of the plot (size 20 m × 20 m). Eucalyptus was first harvested in 1987. Grewia optiva, Morus alba and coppice of Eucalyptus were harvested in 1990. All tree species had depressing effect on crop yields. Eucalyptus had maximum effect in depressing crop yield till the first harvest and had least effect thereafter. From 1987 onwards, Morus alba affected rice most, while wheat was mostly affected by Grewia optiva. The depressing effect on an average varied from 28 to 34% depending upon the species.Distance of tree line from the crop significantly affected the crop yield upto a distance of 5 m and there was 39% decrease in crop yield upto 1 m, 33% from 1–2 m, 25% from 2–3 m and 12% from 3–5 m distance. Annual removal of lops and tops from trees partly compensated the deficit. Grewia optiva could produce 1.08 t ha–1 yr–1 of branches and 0.26 t ha–1 yr–1 of leaves (air dry) and 1.28 t ha–1 yr–1 of branches and 0.28 t ha–1 yr–1 of leaves were obtained from Morus alba. Wood (ADT) produced by the trees was 33.6 t ha–1 from Eucalyptus, 9.5 t ha–1 from Grewia optiva and 11.6 t ha–1 from Morus alba. 相似文献
16.
Torsten W. Berger Erich Inselsbacher Franz Mutsch Michael Pfeffer 《Forest Ecology and Management》2009,258(11):2578-2592
Studies on the combined effects of beech–spruce mixtures are very rare. Hence, forest nutrition (soil, foliage) and nutrient fluxes via throughfall and soil solution were measured in adjacent stands of pure spruce, mixed spruce–beech and pure beech on three nutrient rich sites (Flysch) and three nutrient poor sites (Molasse) over a 2-year period. At low deposition rates (highest throughfall fluxes: 17 kg N ha−1 year−1 and 5 kg S ha−1 year−1) there was hardly any linkage between nutrient inputs and outputs. Element outputs were rather driven by internal N (mineralization, nitrification) and S (net mineralization of organic S compounds, desorption of historically deposited S) sources. Nitrate and sulfate seepage losses of spruce–beech mixtures were higher than expected from the corresponding single-species stands due to an unfavorable combination of spruce-similar soil solution concentrations coupled with beech-similar water fluxes on Flysch, while most processes on Molasse showed linear responses. Our data show that nutrient leaching through the soil is not simply a “wash through” but is mediated by a complex set of reactions within the plant–soil system. 相似文献
17.
Leaching of nitrogen (N) and phosphorus (P) through container peatmedium and N and P uptake by seedlings were determined in commercial productionof birch grown with three different types of fertilization. Half of the amountof nutrients was premixed into the peat medium and the other half was appliedasliquid (=fertigated) in the treatment (PF) commonly used in Finland. In twoother treatments all nutrients, either totally (P-VN) or partly (P-N) inslow-release form, were premixed into the peat. Independently of the treatment,the largest proportion (60 to 80%) of total N leached during May and June.During two growing seasons, the amounts of N leached from PF treatments (9 to36kg ha–1) were as large as the amounts of Nleachedfrom P-VN and P-N treatments (24 to 46 kg ha–1).Due to fertigations between container trays, however, the total N load perhectare was greatest in the PF treatments. In the soil water 0.5meter beneaththe container area, the N concentration varied from 10 to 60 mgl–1. The morphological and chemical properties of theseedlings did not differ greatly between treatments. 相似文献
18.
Seedlings grown under different N supply were examined for relationships between root system size attributes and its hydraulic properties. These relationships were also studied on seedlings of different stock types (grown in different container types). Measurements with root pressure probes were taken at various times after germination, under applied hydrostatic pressure and non-limiting soil moisture. Different N-treatments and stock types were used solely to produce seedling of different sizes, especially root system sizes. Specific root hydraulic conductivity (Lpr) typically declined with an increasing root system size and correlations between Lpr and the root system size attributes were often negative. The flow of water through the root system correlated well with root system size attributes only in young (3–4 month old) seedlings but the correlations were inconsistent among different N treatments and stock types. Neither the root system surface area nor dry weight reliably reflected its ability to absorb and conduct water. Generally, the amount of water delivered through the root system and available for transpiration per unit or leaf surface area or unit of leaf dry weight correlated poorly or negatively with the root system size. Practical and scientific implications of the findings are discussed.
*Paper presented at Forest Seedling Root Development Conference: From the Nursery to the Field, Eugene, Oregon, May 12–13, 2004. 相似文献
19.
No statistically-significant effects of size (small and large) of wind-pollinated seeds from 18 seed-orchard clones could be found in the attributes of 8-month-old seedlings of Sitka spruce (Picea sitchensis (Bong.) Carr.). Clonal variations in seedling attributes was highly significant (P < 0.01), but these variations were within regional specifications for operationally-produced nursery stock. 相似文献
20.
The effects of nutrient loading (NLOAD) on the frost hardening and dehardening of Picea abies (L.) Karst. seedlings were investigated under nursery conditions. Before NLOAD, second-year container seedlings were either
short-day (SD) treated for 3 weeks in July or left for the natural photoperiod (CO). By mid-September, after 5 weeks of NLOAD,
the fertilization of three foliar nutrient concentration levels (low = L-SD, medium = M-SD, and high = H-SD) for the SD-treated
seedlings and one (medium = M-CO) for the CO-seedlings was completed. The NLOAD resulted in foliar nitrogen concentration
10.6, 16.1, 22.3, and 17.5 g kg−1 for L-SD, M-SD, H-SD and M-CO seedlings, respectively. The NLOAD had no effects on the morphology or dry mass variables of
the seedlings, while SD-treatment reduced the dry mass of shoots, but not that of roots. The frost hardiness (FH) of different
batches of the seedlings was assessed by the visual scoring of damage in their needles, stems and buds after their controlled
exposure to freezing during frost hardening and dehardening. The low nutrient concentration in the SD-treated seedlings (L-SD
seedlings) resulted in poor FH, to an even lower extent than that of the M-CO seedlings. The NLOAD did not affect the dehardening
of the seedlings at the end of the freezer storage in the following spring. 相似文献