Comparison of black spruce (Picea mariana) radial growth reduction in different soil moisture regimes during a spruce budworm (Choristoneura fumiferana) outbreak

2012 ◽  
Vol 42 (7) ◽  
pp. 1410-1419 ◽  
Author(s):  
Melissa E. Lacey ◽  
Jeffery P. Dech

The objective of this study was to determine if the stand‐level soil moisture regime had a significant effect on the reduction in black spruce (Picea mariana (Mill.) B.S.P.) radial growth during the most recent spruce budworm (Choristoneura fumiferana Clem.) outbreak in the boreal forest region of northeastern Ontario. We collected a stratified random sample of co-dominant black spruce trees from three moisture regimes and compared the reduction of radial growth during a spruce budworm outbreak between dry, moist, and wet stands. We focused on the most recent outbreak from 1975–1987, which we dated by dendrochronological analysis of black spruce increment cores from the Romeo Malette Forest near Timmins, Ontario. Samples collected from dry and moist sites showed significantly greater maximum radial growth reduction than those from wet sites. Mean growth reduction over the entire outbreak was not significantly different among moisture regimes but followed the same trend. We found no evidence of spatial autocorrelation in the growth reduction response, suggesting that the moisture effect was not confounded by location.

2012 ◽  
Vol 42 (7) ◽  
pp. 1220-1227 ◽  
Author(s):  
Cornelia Krause ◽  
Boris Luszczynski ◽  
Hubert Morin ◽  
Sergio Rossi ◽  
Pierre-Y. Plourde

Spruce budworm ( Choristoneura fumiferana (Clemens)) defoliation is known to regularly produce radial growth decrease in black spruce ( Picea mariana (Mill.) Britton, Sterns & Poggenb.) in the boreal forest of Quebec. Some studies have already shown that the first year of defoliation does not induce growth losses in the stem but could occur in other tree parts. We therefore examined the timing and duration of the growth reduction caused by the last outbreak in black spruce by also considering the branches. More than 79% of branches and 65% of stems exhibited a >40% growth decrease.The reduction was first registered in the upper part of the stem before being detected lower in the stem in 87% of the trees. Probabilities of growth reduction in the upper part of the stem were highest in 1976 and 1977. In the lower stem, the probabilities were highest in 1978. An interesting finding was that in 69% of the studied stands, the probability of growth reduction started earlier (1–2 years) in the branches than in the stem at 1.3 m. Branch analysis should be considered whenever questions arise in regard to the evolution of spruce budworm defoliation as well as the timing of observed growth reduction in black spruce.


2009 ◽  
Vol 19 (2) ◽  
pp. 81-89 ◽  
Author(s):  
Federico P.O. Mollard ◽  
Pedro Insausti

AbstractThe soil moisture regime may affect dormancy of seeds and their sensitivity to signals that promote germination. We studied the effect of moisture regime on the sensitivity to light of dormantBromus catharticusseeds, and on the emergence pattern of seedlings. Seeds were incubated under continuously hydrated, continuously dehydrated, or fluctuating moisture regimes in a controlled environment (25°C, darkness) for 2 months. After moisture treatments, seeds were exposed to red or far-red light pulses, or to darkness, to determine germinability. In addition, grassland mesocosms with intact seed bank and vegetation were irrigated or subjected to a drought regime in a glasshouse at summer temperatures. After 2 months, the temperature was reduced to correspond to grassland temperatures in autumn; the canopy was removed and half of the mesocosms were covered with filters that exclude red light. Density ofB. catharticusseedlings was evaluated after 2 weeks. Dormancy decreased in continuously hydrated seeds but they still required red light for germination. In contrast, an important fraction of seeds that experienced continuously dehydrated or fluctuating moisture regimes germinated in darkness or after far-red light pulses. In the mesocosms that had experienced a soil drought, a higher density of seedlings emerged in the absence of red light than in the daily irrigated mesocosms. This indicates that a fraction ofB. catharticusseeds acquired the capability to germinate under the canopy, especially in the drought moisture regime. Results indicate that the soil moisture environment experienced during dormancy affects the sensitivity to light ofB. catharticusseeds, as well as the emergence pattern of seedlings.


1995 ◽  
Vol 71 (2) ◽  
pp. 219-227 ◽  
Author(s):  
R. L. Fleming ◽  
D. S. Mossa

Temporal changes in black spruce (Picea mariana [Mill.] B.S.P.) seedbed coverage and seedbed receptivity were investigated on coarse-textured upland sites near Thunder Bay (48°25′N 89° 15′W), in northwestern Ontario. Sowing was completed in May for three consecutive years following summer scarification at each of 12 sites. Infilling by organic debris reduced the proportion of receptive soil strata three to five years after scarification by 50–95%. Receptive seedbed coverage declined more quickly on fresh Soil Moisture Regimes with a variety of deciduous trees and shrubs than on moist Soil Moisture Regimes dominated by eracaceous shrubs. Pioneer mosses, which are also good seedbeds, invaded moist sites more readily than fresh sites, and mitigated losses in seedbed coverage. Compact Sphagnum seedbeds in lowland depressions maintained good areal coverage much longer than did receptive upland soil strata. Seedling establishment ratios varied greatly among seeding years, seedbeds and sites, but there was an underlying trend of decreasing seedbed receptivity with time since scarification. Seedlings originating from the first seeding year were taller at age 7–10 than those originating from the second or third seeding years. Key words: direct seeding, seedbed coverage, seedbed receptivity, scarification, black spruce, Picea mariana


1957 ◽  
Vol 33 (4) ◽  
pp. 364-372 ◽  
Author(s):  
J. R. Blais

Spruce budworm larvae feeding on black spruce had a lower rate of development and a higher rate of mortality than those feeding on white spruce or balsam fir. This was attributable to the lateness in opening of the black spruce buds rather than to the inferior nutritional quality of the foliage. When staminate flowers were present in abundance on black spruce trees, development and survival of the insect was fairly similar to that on the other two species of trees; the flowers provided adequate food at the time of the third and fourth instars thus permitting the larvae to survive until the opening of the shoot buds. The late opening of the black spruce buds explains the relative immunity of this species to severe spruce budworm damage.


1999 ◽  
Vol 29 (10) ◽  
pp. 1583-1591 ◽  
Author(s):  
Cornelia Krause ◽  
Hubert Morin

Radial growth along the stems and root systems of black spruce trees (Picea mariana (Mill.) BSP) was examined to determine the effects of spruce budworm defoliation. A mixed conifer and pure black spruce stand located in the boreal zone of Quebec, Canada were sampled. Following defoliation, dendrochronological analyses revealed the percent growth reduction in the ring width at different stem heights and throughout the root system. Ring widths of black spruce were found to be reduced during the last three spruce budworm outbreaks. The reduction of the tree-ring width after spruce budworm outbreaks started first in the crown region and was followed by reduction at the stem base. For the whole root system, the ring-width index exhibited a decrease. The root system showed a high sensitivity to defoliation by spruce budworm. Inside the root system, the growth reduction after a spruce budworm outbreak was variable in each root branch. The growth decrease of the pure black spruce stand was less intensive than in the mixed stand.


1992 ◽  
Vol 72 (1) ◽  
pp. 147-162 ◽  
Author(s):  
Hélène V. Petit ◽  
A. R. Pesant ◽  
G. M. Barnett ◽  
W. N. Mason ◽  
J. L. Dionne

Alfalfa (Medicago sativa L. ’Saranac’) was grown in a greenhouse on Ste-Rosalie clay and Danby gravelly sandy loam to determine the effects of phosphorus fertilization, air temperature, soil moisture regime and soil pH on chemical composition and plant morphology. The following treatments were applied in factorial combination: three moisture regimes (1, semi-dry, with soil moisture between field capacity or 100% of available water and wilting point or 0% of available water; 2, optimal, between field capacity and 70% of available water; 3, wet, between saturation point and field capacity), three rates of phosphorus in the form of disodium phosphate (0, 12.5 and 25.0 P kg−1 of dry soil) and three soil pH levels (natural, near 5.4, 6.5 and 7.5). Half the alfalfa was grown in a warm greenhouse section with a minimum daytime temperature of 25 °C and 19 °C at night and the other half was grown in a cool section with a daytime minimum of 15 °C and 9 °C at night. Quality of alfalfa was generally improved by water deficit as shown by decreased concentrations of acid detergent fiber (ADF) and acid detergent lignin (ADL) and increased concentrations of crude protein (CP). Cold temperatures decreased ADF content which indicates that quality of alfalfa grown under cold compared to warm temperature regimes is better. Phosphorus fertilization seemed to have more effects on plant morphology and quality under cold than warm temperature regimes. In general, concentrations of CP, ADF and ADL, stem length, leaf area and the number of stems increased in parallel with soil pH. The data indicate that low temperature and low soil moisture regimes were generally associated with higher quality alfalfa than were high temperature and wet soil moisture regimes.Key words: Alfalfa, soil moisture regime, air temperature, phosphorus fertilization, soil pH


2016 ◽  
Vol 46 (8) ◽  
pp. 1059-1066 ◽  
Author(s):  
Roberto L. Salomón ◽  
Emilie Tarroux ◽  
Annie DesRochers

Spruce budworm (Choristoneura fumiferana Clem.) outbreaks cause extensive mortality and growth reductions throughout boreal forests in eastern North America. As tree vulnerability to defoliation remains partially unexplained by tree and stand attributes, we hypothesized that root grafting might attenuate the negative impact of severe defoliation in tree growth. Two experimental sites in the Abitibi-Témiscamingue region dominated by black spruce (Picea mariana Mill.) were harvested and hydraulically excavated to study tree growth in 36 trees in relation to root grafting and the last spruce budworm outbreak using dendroecological methods. Root grafts reduced the negative effects of defoliation by maintaining stable growth in connected trees during epidemic periods. Among dominant trees, growth releases immediately after the outbreak were uniquely observed in grafted trees. Among suppressed trees, grafted trees tended to grow more than non-grafted trees when defoliation severity was the highest. Carbohydrate transfers through root grafts and enhanced efficiency to acquire resources may explain the better performance of grafted trees under scenarios of limited carbon supply. This study reinforces the growing body of literature that suggests root grafting as a cooperative strategy to withstand severe disturbances and highlights the key role of root grafting in stand dynamics to cope with periodic outbreaks.


1989 ◽  
Vol 69 (4) ◽  
pp. 1149-1163 ◽  
Author(s):  
J. L. DIONNE ◽  
A. R. PESANT ◽  
G. M. BARNETT ◽  
W. N. MASON

The objectives of this study were to determine the effects of phosphorus application, air temperature, soil moisture regime and soil pH on the yield response of, and soil phosphorus availability to, alfalfa (Medicago sativa L ’Saranac’). The following treatments were used in factorial combination: three moisture regimes: (1) semi-dry, with soil moisture between FC (100% of available water or field capacity) and WP (0% of available water or wilting point), (2) optimal, between FC and 70% of available water, (3) wet, between saturation point and FC; three rates of phosphorus in the form of disodium phosphate (0, 12.5 and 25.0 P kg−1 of dry soil; and three soil pH levels: original (5.2 or 5.7), 6.5 and 7.5. Half of the alfalfa was grown in a warm greenhouse section with a minimum daytime temperature of 25 °C and 19 °C at night and the other half in a cool section with a daytime minimum of 15 °C and 9 °C at night. Although shoot yields were higher under warm than under cool conditions, yield response to phosphorus was greater under cool than warm growing conditions. Yield increases due to phosphorus were linear under optimum and wet soil moisture regimes and nonsignificant under the semi-dry regime. Phosphorus application increased root weight by 18% under the cool regime compared to 14% in the warm greenhouse. Phosphorus uptake by alfalfa increased with increasing rates of soil-applied P, except in semi-dry soils at warm temperature, where no effect of P on P uptake was recorded. Phosphorus uptake increased significantly with soil pH and was higher under warm temperature and optimal water regime.Key words: Phosphorus fertilization, available phosphorus, alfalfa, soil moisture regime, air temperature, phosphorus uptake


1999 ◽  
Vol 133 (2) ◽  
pp. 203-207 ◽  
Author(s):  
M. SINGH

Two field experiments were conducted during 1996–98 at Bangalore, India to study the effect of soil moisture regimes (0·3, 0·6 and 0·9 IW:CPE ratios) irrigation water:cumulative pan evaporation (IW:CPE) ratios and three rates of nitrogen application (0, 100 and 200 kg/ha) and in another experiment, three soil moisture regimes (0·3, 0·6 and 0·9 IW: CPE ratios), two rates of nitrogen application (100 and 200 kg/ha) and modified urea materials [prilled urea (PU) and dicyandiamide coated urea (DCDCU)] on oil content, herbage, oil yield and quality of geranium grown on altisols. Soil moisture maintained at 0·6 IW:CPE ratio significantly increased the herbage and oil yields of geranium. Application of 200 kg N/ha gave the maximum herbage and oil yield compared with those obtained from 0 and 100 kg N/ha. DCDCU produced higher yield than PU. The concentration and quality of essential oil were not influenced either by soil-moisture regime, rates or carriers of N.


2015 ◽  
Vol 4 (3) ◽  
pp. 303
Author(s):  
Hanan Siam ◽  
Saleh A.L. ◽  
Abd- El-Moez M.R. ◽  
Holah S.H ◽  
Abou Zeid S.T

<p>A pot experiment was conducted in the greenhouse of NRC, Dokki, Giza, Egypt, using clay loam soil to study the effect of different moisture regimes (M1, M2 and M3) and fertilizer treatment(F0, F1, F2, F3, and F4) on electrochemical change and concentration of some nutrients in the leachate solution during growing period of rice plant (variety Sakha 102).</p><p>The important results could be summarized in the follows: PH values showed the highest decreases under all the fertilizer treatments when the moisture regime of M1 was used followed by M2 and M3 in descending order. Furthermore, pH values showed higher decreases when the fertilizer treatment of F3 was used followed by F4, F2, F1 and F0 in decreasing order.</p><p>Under all soil moisture regimes and fertilizer treatment Eh values sharply decreased during the 12 days after starting (DAS), then they decreased to the lowest values at 24 DAS. The soil moisture regimes decreased Eh values in soil solution during the growth period of rice plants. The highest decreases were obtained under soil moisture of M1 followed by M2 and M3 in descending order. The greatest decreases of Eh values were obtained by using the fertilizer treatment of F3 followed by F4, F2, F1 and F0 in descending order.</p><p>Results showed that , P, K+, Fe++ and Mn++ concentrations in soil solution were higher in the early stages of rice plans and reached a peak at 24 days after staring (DAS), then the concentrations of all the studied nutrients gradually decreased with increasing the growth period.</p><p>Inorganic N-fertilizer treatments (F1 and F2) gave higher nutrients concentrations under all soil moisture regimes as compared with N-organic fertilizer treatment alone (F4). Combination of organic and inorganic fertilizer (F3) gave the higher nutrients concentration in the leachate solutions followed by fertilizer treatments of F2, F1, F4 and F0 in decreasing order.</p><p>The highest values of , P, K+, Fe++ and Mn++ concentrations were obtained at 24 days after starting (DAS) by using the fertilizer treatment of F3 under soil moisture regime of M1 (F3 M1¬) followed by F3M2 and F3M3 in decreasing order, while the lowest values were obtained at 72DAS under soil moisture regime of M3 and unfertilized treatment F0 (M3F0).</p>


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