Factors influencing the enlargement of trunk cankers of Phytophthoracinnamomi in red oak

1992 ◽  
Vol 22 (3) ◽  
pp. 367-374 ◽  
Author(s):  
Cécile Robin ◽  
Marie-Laure Desprez-Loustau ◽  
Claude Delatour
Keyword(s):  
Tree Growth ◽  
Cold Hardiness ◽  
Detrimental Effect ◽  
Principal Component ◽  
Tree Age ◽  
Red Oak ◽  
Logistic Curve ◽  
Root Infection ◽  
Lesion Development ◽  
Discriminant Factorial Analysis

Development of cankers on red oak (Quercusrubra L.) caused by Phytophthoracinnamomi Rands was studied with dendrochronological techniques. Factors of variation among lesions were investigated. Lesion parameters proved to vary with the particular tree to which the lesion belonged. A discriminant factorial analysis and principal component analysis showed that this tree susceptibility was made up of two components. The first accounted for root infection and wound healing. The second concerned susceptibility to vertical spread of the pathogen in bark tissues. Relationships between (i) tree susceptibility and (ii) tree age and vigor were studied. From the occurrence of the first lesion at the collar, number and severity of lesions increased with time, following an exponential and logistic curve, respectively. A comparison of ring widths in infected and healthy trees showed that the disease had no detrimental effect on tree growth. However, annual necrosis length was positively correlated with the annual radial tree growth. The observed differences among trees could not be explained by the effects of time and vigor only. Temperature and drought were analyzed to determine their effect on lesion development. No direct effect of drought on this disease could be shown. The low cold hardiness of P. cinnamomi in the trunk was determined.

Agroforestry in Eastern Otago: results from two long-term experiments

2000 ◽  
pp. 93-98
Author(s):  
G.G. Cossens ◽  
M.F. Hawke
Keyword(s):  
Soil Ph ◽  
Tree Growth ◽  
Pinus Radiata ◽  
Carrying Capacity ◽  
Livestock Grazing ◽  
Tree Age ◽  
Rapid Decline ◽  
Pasture Production ◽  
Clover Content ◽  
Pasture Yield

During the first 20 years of a Pinus radiata tree rotation, tree growth and pasture yield were assessed under a range of tree spacings at Invermay and Akatore, two coastal sites in Eastern Otago. Pasture yield in association with trees thinned to 100 stems per hectare (sph) was comparable to that from open pasture up to a tree age of 12 years. By the 19th year, however, pasture production declined to 63% of open pasture yield at Invermay and to 42% at Akatore. At 200 and 400 sph at Akatore, pasture yield was similar to that from open pasture at tree age 12 years but declined to 27% and 0% of open pasture yield respectively by year 20. At both Invermay and Akatore, the ryegrass and clover content of open pasture was relatively constant throughout the term of the trial. However, both the ryegrass and clover content of pasture beneath trees began to decline by tree age 12 years with a very rapid decline at Akatore in the number of pasture species at 200 sph by the 19th year. No pasture remained at 400 sph, after 19 years. Livestock carrying capacity with sheep on tree treatments at Invermay decreased from 100% of open pasture at year 6 to 60% by year 10. At Akatore, livestock carrying capacity averaged over the 20-year life of the trial was 4.1 stock units per hectare with a maximum of 8.1 stock units at a tree age of 8 years. Tree growth at both sites was similar, averaging between 1 and 1.1 m/year in height over 20 years, with trees at Invermay at 100 sph averaging 9% greater height and diameter growth than at Akatore. Increasing tree stocking from 100 to 200 to 400 sph at Akatore, resulted in increased tree height, but decreased diameter at breast height. A comparison of the East Otago trees with those in a similar trial at Tikitere (Rotorua) 900 km further north indicated that the southern trees were about 6 years later in their growth pattern by tree age 20 years. On both sites, soil pH tended to be lower in the presence of trees and was significantly lower than in open pasture by year 20. The results and comparisons with the Tikitere data suggest that, in an integrated agroforestry regime, there will be livestock grazing under the trees further into the tree rotation in Otago than in North Island sites. However, slower tree growth would result in a longer rotation time to harvest. Current recommendations to farmers are to plant trees on the less productive areas of the farm and adopt a tree stocking rate which fully utilises the site. Keywords: agroforestry, livestock, pasture, Pinus radiata, soil pH, tree stocking

Tree growth as affected by stem and crown structure

Trees ◽  
2021 ◽  
Author(s):  
Hans Pretzsch
Keyword(s):  
Tree Growth ◽  
Scaling Theory ◽  
Tree Age ◽  
Stem Volume ◽  
Projection Area ◽  
Metabolic Scaling ◽  
Crown Structure ◽  
The Future ◽  
Metabolic Scaling Theory ◽  
Crown Characteristics

Abstract Key message Prediction of tree growth based on size or mass as proposed by the Metabolic Scaling Theory is an over-simplification and can be significantly improved by consideration of stem and crown morphology. Tree growth and metabolic scaling theory, as well as corresponding growth equations, use tree volume or mass as predictors for growth. However, this may be an over-simplification, as the future growth of a tree may, in addition to volume or mass, also depend on its past development and aspects of the current inner structure and outer morphology. The objective of this evaluation was to analyse the effect of selected structural and morphological tree characteristics on the growth of common tree species in Europe. Here, we used eight long-term experiments with a total of 24 plots and extensive individual measurements of 1596 trees in monospecific stands of European beech (Fagus sylvatica L.), Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and sessile oak (Quercus petraea (Matt.) Liebl.). Some of the experiments have been systematically surveyed since 1870. The selected plots represent a broad range of stand density, from fully to thinly stocked stands. We applied linear mixed models with random effects for analysing and modelling how tree growth and productivity are affected by stem and crown structure. We used the species-overarching relationship $$\mathrm{iv}={{a}_{0}\times v}$$ iv = a 0 × v between stem volume growth, $$\mathrm{iv}$$ iv and stem volume, $$v,$$ v , as the baseline model. In this model $${a}_{0}$$ a 0 represents the allometric factor and α the allometric exponent. Then we included tree age, mean stem volume of the stand and structural and morphological tree variables in the model. This significantly reduced the AIC; RMSE was reduced by up to 43%. Interestingly, the full model estimating $$\mathrm{iv}$$ iv as a function of $$v$$ v and mean tree volume, crown projection area, crown ratio and mean tree ring width, revealed a $$\alpha \cong 3/4$$ α ≅ 3 / 4 scaling for the relationship between $$\mathrm{iv}\propto {v}^{\alpha }$$ iv ∝ v α . This scaling corresponded with Kleiber’s rule and the West-Brown-Enquist model of the metabolic scaling theory. Simplified approaches based on stem diameter or tree mass as predictors may be useful for a rough estimation of stem growth in uniform stands and in cases where more detailed predictors are not available. However, they neglect other stem and crown characteristics that can have a strong additional effect on the growth behaviour. This becomes of considerable importance in the heterogeneous mixed-species stands that in many countries of the world are designed for forest restoration. Heterogeneous stand structures increase the structural variability of the individual trees and thereby cause a stronger variation of growth compared with monocultures. Stem and crown characteristics, which may improve the analysis and projection of tree and stand dynamics in the future forest, are becoming more easily accessible by Terrestrial laser scanning.

Growth of canopy red oak near its northern range limit: current trends, potential drivers, and implications for the future

2020 ◽  
Vol 50 (10) ◽  
pp. 975-988
Author(s):  
Rebecca L. Stern ◽  
Paul G. Schaberg ◽  
Shelly A. Rayback ◽  
Paula F. Murakami ◽  
Christopher F. Hansen ◽  
...  
Keyword(s):  
Acid Deposition ◽  
Basal Area ◽  
Growth Potential ◽  
Tree Age ◽  
Red Oak ◽  
Surprising Result ◽  
Range Limit ◽  
Size Groups ◽  
Northern Range Limit ◽  
Summer Temperatures

Red oak (Quercus rubra L.) is projected to expand into the northern hardwood forest over the coming century. We explored the connection between red oak basal area growth and a number of factors (tree age and size, stand dynamics, site elevation, and climate and acid deposition variables) for 213 trees in 11 plots throughout Vermont, USA. Red oak growth generally increased over the course of the chronology (1935–2014) and has been particularly high in recent decades. Growth differed among elevational groups but did not differ between age or size groups. Summer moisture metrics were consistently and positively associated with growth, whereas fall moisture was associated with reduced growth in recent decades. Higher summer temperatures were often negatively associated with growth, though there was evidence that low temperatures in the summer (higher elevations) and fall (lower elevations) constrain growth. Several pollution metrics were associated with reduced growth, a surprising result for a species not known to be sensitive to inputs of acid deposition that have predisposed other species in the region to decline. While red oak growth is currently robust, increases in summer temperatures, reductions in growing season precipitation, or increases in fall precipitation could reduce future growth potential.

scholarly journals Increased Individual Tree Growth Maintains Stand Volume Growth after B-Level Thinning and Crop-Tree Management in Mature Oak Stands

2019 ◽  
Vol 65 (6) ◽  
pp. 784-795
Author(s):  
Jeffrey S Ward ◽  
Jessica Wikle
Keyword(s):  
Tree Growth ◽  
Growth Response ◽  
Volume Growth ◽  
Diameter Growth ◽  
Red Oak ◽  
Individual Tree ◽  
Stand Volume ◽  
Tree Management ◽  
Individual Tree Growth ◽  
Partial Release

AbstractSix study areas were established in 80–125-year-old upland oak stands on average sites to compare stand and individual tree growth response following two active treatments (B-level thinning, crop tree) with an unmanaged control. Initial stocking of 104 percent was reduced to 62 percent and 60 percent on the B-level and crop-tree-management plots, respectively. Approximately 7,200 board feet per acre (International ¼) were harvested on the actively managed plots with upland oaks accounting for 81 percent of pre- and 86 percent of residual stand. Eleven-year diameter and volume growth of oak sawtimber trees was greater on actively managed plots. Growth response increased with degree of release and was maintained for the length of the study. Because of the increased individual tree growth of oaks in response to release, stand volume growth of oak sawtimber did not differ between treatments. In contrast to an 11-year decline of poletimber stocking on unmanaged plots, poletimber stocking increased on managed plots as diameter growth increased in response to partial release. This may increase difficulty of regenerating oak in the future. For those mature red oak stands where traditional regeneration prescriptions will not be implemented or will be delayed, commercial harvests can be conducted without compromising stand volume growth of oak.

scholarly journals Effect of Salinity on Biomass Yield and Physiological and Stem-Root Anatomical Characteristics of Purslane (Portulaca oleraceaL.) Accessions

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Md. Amirul Alam ◽  
Abdul Shukor Juraimi ◽  
M. Y. Rafii ◽  
Azizah Abdul Hamid
Keyword(s):  
Dry Matter ◽  
Detrimental Effect ◽  
Biomass Yield ◽  
Principal Component ◽  
Yield Reduction ◽  
Salinity Effect ◽  
3 Dimensional ◽  
Matter Production ◽  
Significant Damage ◽  
Salinity Levels

13 selected purslane accessions were subjected to five salinity levels 0, 8, 16, 24, and 32 dS m−1. Salinity effect was evaluated on the basis of biomass yield reduction, physiological attributes, and stem-root anatomical changes. Aggravated salinity stress caused significant (P<0.05) reduction in all measured parameters and the highest salinity showed more detrimental effect compared to control as well as lower salinity levels. The fresh and dry matter production was found to increase in Ac1, Ac9, and Ac13 from lower to higher salinity levels but others were badly affected. Considering salinity effect on purslane physiology, increase in chlorophyll content was seen in Ac2, Ac4, Ac6, and Ac8 at 16 dS m−1salinity, whereas Ac4, Ac9, and Ac12 showed increased photosynthesis at the same salinity levels compared to control. Anatomically, stem cortical tissues of Ac5, Ac9, and Ac12 were unaffected at control and 8 dS m−1salinity but root cortical tissues did not show any significant damage except a bit enlargement in Ac12 and Ac13. A dendrogram was constructed by UPGMA based on biomass yield and physiological traits where all 13 accessions were grouped into 5 clusters proving greater diversity among them. The 3-dimensional principal component analysis (PCA) has also confirmed the output of grouping from cluster analysis. Overall, salinity stressed among all 13 purslane accessions considering biomass production, physiological growth, and anatomical development Ac9 was the best salt-tolerant purslane accession and Ac13 was the most affected accession.

Growth trends and stand dynamics in natural loblolly pine in the southeastern United States

1992 ◽  
Vol 22 (5) ◽  
pp. 660-666 ◽  
Author(s):  
Paul C. Van Deusen
Keyword(s):  
United States ◽  
Loblolly Pine ◽  
Tree Growth ◽  
Southeastern United States ◽  
Tree Age ◽  
Stand Age ◽  
Stand Dynamics ◽  
Individual Tree ◽  
Growth Trends ◽  
Individual Tree Growth

A number of recent studies have shown reduced stand-level and individual-tree growth in natural loblolly pine (Pinustaeda L.) stands in the southeastern United States. This study uses increment cores from dominant and codominant trees to determine if individual-tree growth has changed from 1915 to 1985. The cores are grouped for comparison by first sorting on the basis of median stand age and then further sorting these groups of cores by individual-tree age. These trees experienced increasing basal area increments from the mid-1940s into the mid-1970s, after which growth rates returned to preincrease levels. These data support recent findings of growth reductions, but also indicate previously unreported growth increases preceding the growth decreases. These and supplemental permanent plot data suggest that stand dynamics is a viable hypothesis for explaining these growth trends.

Residual-tree growth responses to partial stand harvest in the black spruce (Picea mariana) boreal forestThis article is one of a selection of papers published in the Special Forum IUFRO 1.05 Uneven-Aged Silvicultural Research Group Conference on Natural Disturbance-Based Silviculture: Managing for Complexity.

2007 ◽  
Vol 37 (9) ◽  
pp. 1563-1571 ◽  
Author(s):  
H. C. Thorpe ◽  
S. C. Thomas ◽  
J. P. Caspersen
Keyword(s):  
Boreal Forest ◽  
Tree Growth ◽  
Picea Mariana ◽  
Radial Growth ◽  
Growth Response ◽  
Black Spruce ◽  
Tree Age ◽  
Growth Responses ◽  
Partial Harvest ◽  
Partial Harvesting

Variants of partial harvesting are gaining favour as means to balance ecosystem management and timber production objectives on managed boreal forest landscapes. Understanding how residual trees respond to these alternative silvicultural treatments is a critical step towards evaluating their potential from either a conservation or a wood supply perspective. We used dendroecological techniques combined with a chronosequence approach to quantify the temporal radial growth response pattern of residual black spruce ( Picea mariana (Mill.) BSP) trees to partial harvest in northeastern Ontario. At its peak, 8–9 years after harvest, radial growth of residual trees had doubled. The growth pattern was characterized by a 2-year phase of no response, a subsequent period of increase 3–9 years after harvest, and a stage of declining rates 10–12 years after harvest. The magnitude of tree growth response depended strongly on tree age: peak postharvest growth was substantially higher for young trees, while old trees displayed only modest growth increases. Both the large magnitude and the time delay in postharvest growth responses have important implications for the development of more accurate quantitative tools to project future yields and, more generally, for determining whether partial harvesting is a viable management option for the boreal forest.

scholarly journals Sensitivity in the antioxidant system of discus fish (Symphysodon spp.) to cold temperature: evidence for species-specific cold resistance

2019 ◽  
Author(s):  
Shi-Rong Jin ◽  
Bin Wen ◽  
Zai-Zhong Chen ◽  
Jian-Zhong Gao ◽  
Lei Wang ◽  
...  
Keyword(s):  
Cold Hardiness ◽  
Cold Resistance ◽  
Cold Treatment ◽  
Principal Component ◽  
Interspecific Variation ◽  
Continuous Sequence ◽  
Model Animal ◽  
Set Up ◽  
Species Specific ◽  
Subordinate Function

ABSTRACTThe discus fish (Symphysodon spp.) is an endemic species of the Amazon that is among the most popular ornamental fish around the world, and is usually used as the model animal for studying the diversification of Amazon fish. Here, a comparative analysis of two species of discus fish, i.e., S. haraldi and S. aequifasciatus, based on several antioxidant indexes was conducted, to test the hypothesis that cold resistance might correlate with the diversification of discus fish. We set up a continuous sequence of three temperature programs, namely cooling (28 °C to 14 °C; -1 °C/h), cold maintenance (14 °C for 12 h) and recovery (14 °C to 28 °C; +1 °C/h). Subordinate function (SF) combined with principal component analysis (PCA) showed that the cold hardiness of S. haraldi during cold treatment was in the order of cooling > cold maintenance ≈ recovery, but the cold hardiness of S. aequifasciatus during cold treatment was in the order of cold maintenance > cooling > recovery. Specifically, the lowest cold hardiness was observed in S. aequifasciatus during recovery, indicating that cold stress resulted in more seriously oxidative stress in S. aequifasciatus than in S. haraldi. Overall, these results show a significant interspecific variation, indicating the correlation between environmental adaptation and the diversification of discus fish.

scholarly journals Inheritance and Heritability of Resistance to Citrus Leprosis

2006 ◽  
Vol 96 (10) ◽  
pp. 1092-1096 ◽  
Author(s):  
Marinês Bastianel ◽  
Antonio Carlos de Oliveira ◽  
Mariângela Cristofani ◽  
Oliveiro Guerreiro Filho ◽  
Juliana Freitas-Astúa ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Growth Parameters ◽  
Block Design ◽  
Principal Component ◽  
Component Analysis ◽  
Factorial Analysis ◽  
Inheritance Of Resistance ◽  
Measured Variable ◽  
Citrus Leprosis ◽  
Discriminant Factorial Analysis

The genetic inheritance of resistance to leprosis, the most important viral disease of citrus in Brazil, was characterized through the phenotypic assessment of 143 hybrids resulting from crosses between tangor ‘Murcott’ (Citrus sinensis × C. reticulata) and sweet orange ‘Pêra’ (C. sinensis), considered to be resistant and susceptible to the disease, respectively. All plants were grafted onto Rangpur lime (C. limonia) and inoculated with Citrus leprosis virus, cytoplasmic type through the infestation with viruliferous mites, Brevipalpus phoenicis. The experiments were arranged in a completely randomized block design with 10 replicates. Incidence and severity of the disease in leaves and stems as well as plant growth parameters (plant height and stem diameter) were recorded for 3 years after the infestation with the viruliferous mites. The average values of all variables were analyzed using principal component analysis, discriminant factorial analysis, estimation of the clonal repeatability coefficients, and frequency of the distributions of the average values for each measured variable. The principal component analysis resulted in the identification of at least two groups with resistance and susceptibility to leprosis, respectively. About 99% of all hybrids were correctly classified according to the discriminant factorial analysis. The broad-sense heritability coefficients for characteristics associated with incidence and severity of leprosis ranged from 0.88 to 0.96. The data suggest that the inheritance of resistance to leprosis may be controlled by only a few genes.

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