Deterioration of trembling aspen clones in the Great Lakes region

1981 ◽  
Vol 11 (3) ◽  
pp. 530-537 ◽  
Author(s):  
W. J. Shields Jr. ◽  
J. G. Bockheim
Keyword(s):  
Soil Properties ◽  
Basal Area ◽  
Mean Annual Temperature ◽  
Genotypic Differences ◽  
Trembling Aspen ◽  
Temperature Regimes ◽  
Exchangeable Ca ◽  
Similar Temperature ◽  
The Difference ◽  
Early Breakup

In order to test the hypothesis that the deterioration of trembling aspen (Populustremuloides Michx.) is related to variations in climate, soil properties, and genotype, 59 trembling aspen clones were sampled in Michigan, Wisconsin, Minnesota, and Ontario. A longevity index (LI) was calculated by taking the difference between predicted basal area from normal yield tables and measured basal area for each clone. Correlations of environmental variables with LI indicate that aspen longevity decreases with increasing mean annual temperature. Under similar temperature regimes, aspen growing on xeric sites and on sites low in exchangeable Ca are most susceptible to early breakup. Since there were negligible differences in soil properties between nine pairs of adjacent deteriorating and relatively well stocked clones, we hypothesize that, under similar environmental conditions, variation in the timing of deterioration may be due to genotypic differences between clones.

Spatial and temporal variability in chemical properties of a podzolic B horizon of an old-growth maple forest

1995 ◽  
Vol 75 (3) ◽  
pp. 343-348 ◽  
Author(s):  
Christian Godbout ◽  
Jean-Louis Brown
Keyword(s):  
Soil Properties ◽  
Chemical Properties ◽  
Spatial And Temporal Variability ◽  
Eastern Canada ◽  
Old Growth ◽  
Total N ◽  
Organic C ◽  
Exchangeable Ca ◽  
The Difference ◽  
Soil Changes

A Podzolic soil from an old-growth maple hardwood forest in eastern Canada was systematically sampled from a 16.5-m-long trench in 1975. In 1986, the upper 10 cm of the B horizon was resampled from two sampling lines located on each side and parallel to the 1975 trench, one at a distance of 1 m downhill and the other at a distance of 4 m uphill. Total N, organic C, pH, and exchangeable Ca, Mg and K were measured. The objectives were to evaluate the change in the chemical status of the B horizon from 1975 to 1986 and to characterize the spatial variability of the horizon. No significant change was found in the soil chemical properties tested during this 11-yr period. No significant autocorrelation was observed between soil samples 60 cm apart, except for the downhill sampling line, which was located 1 m from the trench. For most properties, the magnitude of the difference between two soil sampling units was not proportional to the distance separating them over the range of 0.6–4.2 m. Except for pH, a difference in soil properties of more than 30% was observed in 37–56% of sample pairs 60 cm apart. Resampling near (1 m) an old soil pit may not be valid because of possible local modifications of soil properties created by the pit, even when it is filled in. Key words: Podzol, soil variability, acidic deposition, soil changes

Egg hatch of forest tent caterpillar (Lepidoptera: Lasiocampidae) on two preferred host species

2012 ◽  
Vol 144 (6) ◽  
pp. 756-763 ◽  
Author(s):  
David R. Gray ◽  
Don P. Ostaff
Keyword(s):  
Populus Tremuloides ◽  
Forest Tent Caterpillar ◽  
Trembling Aspen ◽  
Egg Hatch ◽  
Egg Masses ◽  
Temperature Regimes ◽  
Host Phenology ◽  
The Difference ◽  
And Performance ◽  
Tent Caterpillar

AbstractSynchrony between herbivore and host phenology can be an important factor in herbivore fitness. The survival of first-instar forest tent caterpillar (FTC) (Malacosoma disstria Hübner; Lepidoptera: Lasiocampidae) larvae and performance of surviving larvae are reduced when egg hatch and host budbreak are asynchronous. Budbreak in trembling aspen (Populus tremuloides Michaux; Salicaceae) and largetooth aspen (Populus grandidentata Michaux; Salicaceae), two preferred hosts of FTC, differ by ∼14 days. We examined the phenological requirements of FTC egg hatch to see if an inherent difference exists between FTC egg masses on the two hosts, and if the difference would promote synchrony with each host. Egg masses from a haphazard selection of clones of each host were collected in a mixed stand of trembling and largetooth aspen in New Brunswick, Canada. Egg masses were subjected to controlled temperature regimes in the laboratory, and hatch was monitored daily. Despite the differences in host phenologies and the obvious benefits of being synchronised with host phenology, egg masses collected from trembling aspen began hatching only 3 days earlier, and completed hatching only 2 days earlier, than egg masses collected from largetooth aspen. Bet hedging is discussed as a possible strategy to explain the absence of host-specific synchrony between egg hatch of FTC and the hosts it selects for oviposition.

Carbon stocks in Tasmanian soils

Soil Research ◽  
2012 ◽  
Vol 50 (2) ◽  
pp. 83 ◽  
Author(s):  
W. E. Cotching
Keyword(s):  
Management Practices ◽  
Agricultural Soils ◽  
C Sequestration ◽  
Mean Annual Temperature ◽  
Soil C ◽  
C Stocks ◽  
Initial Soil ◽  
If Current ◽  
Intensive Cropping ◽  
The Difference

Soil carbon (C) stocks were calculated for Tasmanian soil orders to 0.3 and 1.0 m depth from existing datasets. Tasmanian soils have C stocks of 49–117 Mg C/ha in the upper 0.3 m, with Ferrosols having the largest soil C stocks. Mean soil C stocks in agricultural soils were significantly lower under intensive cropping than under irrigated pasture. The range in soil C within soil orders indicates that it is critical to determine initial soil C stocks at individual sites and farms for C accounting and trading purposes, because the initial soil C content will determine if current or changed management practices are likely to result in soil C sequestration or emission. The distribution of C within the profile was significantly different between agricultural and forested land, with agricultural soils having two-thirds of their soil C in the upper 0.3 m, compared with half for forested soils. The difference in this proportion between agricultural and forested land was largest in Dermosols (0.72 v. 0.47). The total amount of soil C in a soil to 1.0 m depth may not change with a change in land use, but the distribution can and any change in soil C deeper in the profile might affect how soil C can be managed for sequestration. Tasmanian soil C stocks are significantly greater than those in mainland states of Australia, reflecting the lower mean annual temperature and higher precipitation in Tasmania, which result in less oxidation of soil organic matter.

scholarly journals Zuwachs und Klimasensitivität von Baumarten im Ökogramm der kollinen und submontanen Stufe

2015 ◽  
Vol 166 (6) ◽  
pp. 380-388 ◽  
Author(s):  
Pascale Weber ◽  
Caroline Heiri ◽  
Mathieu Lévesque ◽  
Tanja Sanders ◽  
Volodymyr Trotsiuk ◽  
...  
Keyword(s):  
Climate Change ◽  
Soil Properties ◽  
Climate Sensitivity ◽  
Tree Species ◽  
Ring Width ◽  
Basal Area ◽  
Growth Potential ◽  
Basal Area Increment ◽  
Tree Ring Data ◽  
Mean Sensitivity

Growth potential and climate sensitivity of tree species in the ecogram for the colline and submontane zone In forestry practice a large amount of empirical knowledge exists about the productivity of individual tree species in relation to site properties. However, so far, only few scientific studies have investigated the influence of soil properties on the growth potential of various tree species along gradients of soil water as well as nutrient availability. Thus, there is a research gap to estimate the productivity and climate sensitivity of tree species under climate change, especially regarding productive sites and forest ad-mixtures in the lower elevations. Using what we call a «growth ecogram», we demonstrate species- and site-specific patterns of mean annual basal area increment and mean sensitivity of ring width (strength of year-to-year variation) for Fagus sylvatica, Quercus spp., Fraxinus excelsior, Picea abies, Abies alba and Pinus sylvestris, based on tree-ring data from 508 (co-)dominant trees on 27 locations. For beech, annual basal area increment ( average 1957–2006) was significantly correlated with tree height of the dominant sampling trees and proved itself as a possible alternative for assessing site quality. The fact that dominant trees of the different tree species showed partly similar growth potential within the same ecotype indicates comparable growth limitation by site conditions. Mean sensitivity of ring width – a measure of climate sensitivity – had decreased for oak and ash, while it had increased in pine. Beech showed diverging reactions with increasing sensitivity at productive sites (as measured by the C:N ratio of the topsoil), suggesting an increasing limitation by climate at these sites. Hence, we derive an important role of soil properties in the response of forests to climate change at lower elevations, which should be taken into account when estimating future forest productivity.

Annual differences in quality of leaf litter of aspen (Populus tremuloides) affecting rates of decomposition

1988 ◽  
Vol 66 (10) ◽  
pp. 1940-1947 ◽  
Author(s):  
Barry R. Taylor ◽  
Dennis Parkinson
Keyword(s):  
Water Absorption ◽  
Leaf Litter ◽  
Populus Tremuloides ◽  
Decomposition Rate ◽  
Rocky Mountains ◽  
Absorption Rate ◽  
Trembling Aspen ◽  
Leaching Loss ◽  
The Difference

Freshly fallen leaf litter was collected from a stand of trembling aspen (Populus tremuloides Michx.) in the Rocky Mountains of Alberta each autumn from 1981 through 1984. Leaves from 1981 and 1982 were yellow, waxy, and strong. Leaves from 1983 were pale brown and very brittle, and almost 1% of them suffered symmetrical deformities. Leaves from 1984 were composed of 80% yellow leaves and 20% green leaves, which apparently abscissed before senescence. Green and yellow 1984 leaves were distinctly different with respect to total (3 days) leaching loss, leachate conductivity, and proportions of ash, cellulose, and labile material. Green 1984 leaves contained twice as much nitrogen as yellow ones (13.1 vs. 6.5 mg∙g−1) and significantly more phosphorus (1.6 vs. 1.3 mg∙g−1). Leaves of different years varied widely with respect to leaf mass, water absorption rate, mass and conductivity of leachate, and proportions of cellulose, labiles, lignin, and ash, but there was no consistent ordering among years; leaves of different colouration (especially 1981 and 1983) were often physicochemically similar, while leaves identical in appearance were often chemically different. Small but significant differences in N and P concentrations among years were removed by 2 h leaching. Leaves of 1981 decomposing in laboratory microcosms at 26 °C lost less mass than either 1982 or 1983 leaves after 1 month, but not after 2 months. Ability of the cuticle to resist water absorption was probably responsible for the difference in initial decomposition rate.

scholarly journals Bayesian Evaluation of Smartphone Applications for Forest Inventories in Small Forest Holdings

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1148
Author(s):  
Andrej Ficko
Keyword(s):  
Mobile Applications ◽  
Mobile Application ◽  
Basal Area ◽  
Small Enterprises ◽  
Private Forest ◽  
P Values ◽  
Forest Inventories ◽  
The Difference ◽  
Number Of Stems ◽  
Small Forest

There are increasingly advanced mobile applications for forest inventories on the market. Small enterprises and nonprofessionals may find it difficult to opt for a more sophisticated application without comparing it to an established standard. In a small private forest holding (19 ha, 4 stands, 61 standing points), we compared TRESTIMA, a computer vision-based mobile application for stand inventories, to MOTI, a smartphone-based relascope, in measuring the number of stems (N) and stand basal area (G). Using a Bayesian approach, we (1) weighted evidence for the hypothesis of no difference in N and G between TRESTIMA and MOTI relative to the hypothesis of difference, and (2) weighted evidence for the hypothesis of overestimating versus underestimating N and G when using TRESTIMA compared to MOTI. The results of the Bayesian tests were then compared to the results of frequentist tests after the p-values of paired sample t-tests were calibrated to make both approaches comparable. TRESTIMA consistently returned higher N and G, with a mean difference of +305.8 stems/ha and +5.8 m2/ha. However, Bayes factors (BF10) suggest there is only moderate evidence for the difference in N (BF10 = 4.061) and anecdotal evidence for the difference in G (BF10 = 1.372). The frequentist tests returned inconclusive results, with p-values ranging from 0.03 to 0.13. After calibration of the p-values, the frequentist tests suggested rather small odds for the differences between the applications. Conversely, the odds of overestimating versus underestimating N and G were extremely high for TRESTIMA compared to MOTI. In a small forest holding, Bayesian evaluation of differences in stand parameters can be more helpful than frequentist analysis, as Bayesian statistics do not rely on asymptotics and can answer more specific hypotheses.

scholarly journals Loblolly Pine Outperforms Slash Pine in Southeastern Georgia and Northern Florida

2000 ◽  
Vol 24 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Barry D. Shiver ◽  
John W. Rheney ◽  
Kenneth L. Hitch
Keyword(s):  
Loblolly Pine ◽  
Species Interactions ◽  
Basal Area ◽  
Pinus Elliottii ◽  
Slash Pine ◽  
Stand Volume ◽  
Growing Seasons ◽  
The Difference ◽  
Stand Basal Area ◽  
Better Than

Abstract A total of 141 paired plot installations remain of the 160 that were planted with slash (Pinus elliottii Engelm.) and loblolly (P. taedaL.) pine across southeastern Georgia and northern Florida, after 14 growing seasons. Installations were evenly distributed across eight soil types. Analyses indicate that loblolly performed equal to or better than slash pine. There were no soil X species interactions. After 14 yr, loblolly pine had significantly higher survival (71% vs. 66%), stand basal area (98 vs. 81 ft2/ac), total stand volume (1857 vs. 1721 ft3/ac), merchantable stand volume (1497 vs. 1310 ft3/ac), total green weight (53 tons vs. 47 tons), and merchantable green weight (45 vs. 35 tons/ac) than slash pine. Growth over the period from age 11 to age 14 was also higher for loblolly than for slash indicating that the difference in the two species is diverging over time. South. J. Appl. For. 24(1): 31-36.

scholarly journals A Comparison of the Arithmetic and Geometric Means in Estimating Stump Diameter, Basal Area, and Volume in Appalachian Hardwoods

2007 ◽  
Vol 24 (1) ◽  
pp. 71-73 ◽  
Author(s):  
Harry V. Wiant ◽  
John R. Brooks
Keyword(s):  
Geometric Mean ◽  
Basal Area ◽  
Cross Sectional Area ◽  
Practical Significance ◽  
Sectional Area ◽  
Cross Sectional ◽  
Geometric Means ◽  
The Difference ◽  
Appalachian Hardwoods ◽  
Stump Diameter

Abstract The difference between the use of the arithmetic and geometric means for estimation of average stump diameter, stump cross-sectional area and estimated tree volume was investigated using measurements from 739 stumps from an Appalachian hardwood stand located in central West Virginia. Although average stump diameter, cross-sectional area, and tree volumes were statistically different between estimates based on the arithmetic and geometric mean diameter, these differences were of little practical significance. The difference in average stem diameter, cross-sectional area, tree cubic volume, and board foot volume were 0.05 in, 0.01 ft2, 0.45 ft3, and 2.41 bd ft, respectively.

scholarly journals A PROPOSED METHODOLOGY FOR THE CORRECTION OF THE LEAF AREA INDEX MEASURED WITH A CEPTOMETER FOR PINUS AND EUCALYPTUS FORESTS

2016 ◽  
Vol 40 (5) ◽  
pp. 845-854 ◽  
Author(s):  
Domingos Mendes Lopes ◽  
Nigel Walford ◽  
Helder Viana ◽  
Carlos Roberto Sette Junior
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Correction Factor ◽  
Basal Area ◽  
Allometric Equations ◽  
Nutrient Cycle ◽  
Area Index ◽  
Physiological Processes ◽  
The Difference ◽  
Non Destructive

ABSTRACT Leaf area index (LAI) is an important parameter controlling many biological and physiological processes associated with vegetation on the Earth's surface, such as photosynthesis, respiration, transpiration, carbon and nutrient cycle and rainfall interception. LAI can be measured indirectly by sunfleck ceptometers in an easy and non-destructive way but this practical methodology tends to underestimated when measured by these instruments. Trying to correct this underestimation, some previous studies heave proposed the multiplication of the observed LAI value by a constant correction factor. The assumption of this work is LAI obtained from the allometric equations are not so problematic and can be used as a reference LAI to develop a new methodology to correct the ceptometer one. This new methodology indicates that the bias (the difference between the ceptometer and the reference LAI) is estimated as a function of the basal area per unit ground area and that bias is summed to the measured value. This study has proved that while the measured Pinus LAI needs a correction, there is no need for that correction for the Eucalyptus LAI. However, even for this last specie the proposed methodology gives closer estimations to the real LAI values.

scholarly journals Variation in Nectar Volume and Sugar Concentration ofAllium ursinumL. ssp.ucrainicumin Three Habitats

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Ágnes Farkas ◽  
Réka Molnár ◽  
Tamás Morschhauser ◽  
István Hahn
Keyword(s):  
Soil Properties ◽  
Brown Forest Soil ◽  
Full Bloom ◽  
Floral Nectar ◽  
Nectar Production ◽  
Nectar Volume ◽  
Sessile Oak ◽  
Microclimatic Conditions ◽  
The Difference

Floral nectar volume and concentration of ramson (Allium ursinumL. ssp.ucrainicum) were investigated in three different habitats, including two types of sessile oak-hornbeam association on brown forest soil with clay illuviation and a silver lime-flowering ash rock forest association on rendzina. Daily nectar production ranged from 0.1 to 3.8 μL per flower with sugar concentrations of 25 to 50%. Mean nectar volumes and concentrations showed significant differences between freely exposed flowers and covered flowers, which had been isolated from flower visitors 24 h prior to nectar studies. Both the amount and quality of nectar were affected by microclimatic conditions and soil properties and varied between populations at different habitats. In the silver lime-flowering ash rock-forest association mean nectar volumes and concentrations were lower than in a typical sessile oak-hornbeam association on three occasions, the difference being significant in two cases. During full bloom, the date of sampling did not have a profound effect on either nectar volume or concentration.

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