Ring Width Patterns of Douglas Fir in Relation to Crown Vitality and Age

IAWA Journal ◽  
1997 ◽  
Vol 18 (1) ◽  
pp. 53-67 ◽  
Author(s):  
Ingrid de Kort ◽  
Pieter Baas
Keyword(s):  
The Netherlands ◽  
Growth Performance ◽  
Radial Growth ◽  
Forest Decline ◽  
Ring Width ◽  
Douglas Fir ◽  
Age Classes ◽  
Data Set ◽  
Needle Loss

Ring width patterns often different stands, five vitality classes and three age-classes are used to explore the effect of the decline in vitality on radial growth of Douglas fir in the Netherlands and to determine the onset of this decline. A relationship between growth performance and crown vitality is found in most stands, although the variation within and between stands is large. Severe needle loss leads to serious decline in ring width. The onset of the decline varies from c. 1959 to 1976. The present data set does not enable a choice between the various causal scenarios of forest decline that have been proposed in the literature.

Dépérissement, déficit hydrique et variations de croissance radiale chez le Picea abies

1990 ◽  
Vol 68 (7) ◽  
pp. 1536-1541 ◽  
Author(s):  
P. M. Badot ◽  
P. Perrier ◽  
M. J. Badot
Keyword(s):  
Water Content ◽  
Radial Growth ◽  
Forest Decline ◽  
Water Status ◽  
Ring Width ◽  
Growth Index ◽  
Diameter Growth ◽  
Past Century ◽  
Severe Drought ◽  
French Jura

Changes in the water status of spruce needles have been studied in relation with the present dieback disease of forests in the French Jura. A study of the variation in width of annual rings has been conducted to evaluate if radial growth was disturbed during forest decline. The water content of the needles displayed great individual variability, but at the population level, variation in water content was closely correlated to the health status of the trees: at the same age, the needles of the damaged trees showed lower water content than those of the healthy ones. A mean diameter growth index was used to take into account the effect of ageing of the trees on diameter growth. Globally, this index increased during the past century: such a result indicates that the vigour of the spruce populations had not been altered since the beginning of the century. The healthy and diseased trees displayed the same variation in the mean growth index until 1949. Then, the affected spruces had annual increments lower than those of the healthy trees during two periods, from 1949 to 1959 and from 1973 to 1987. These growth crises correspond to periods with a pronounced rainfall deficit, which often included one or several years of severe drought. Thus, poor water supply could play a role in the present decline of spruce in the French Jura. Key words: radial growth, forest decline, tree-ring width, drought, water content.

Wood production and latewood percentage of Douglas-fir from different stands and vitality classes

1993 ◽  
Vol 23 (7) ◽  
pp. 1480-1486 ◽  
Author(s):  
Ingrid de Kort
Keyword(s):  
The Netherlands ◽  
Biomass Production ◽  
Douglas Fir ◽  
Total Biomass ◽  
Radial Increment ◽  
Small Decrease ◽  
Wood Biomass ◽  
Wood Production ◽  
Volume Increment ◽  
Needle Loss

Trunk wood production and amount of latewood of 171 Douglas-firs (Pseudotsugamenziesii (Mirb.) Franco) belonging to different vitality classes are analysed. The trees originated from 10 stands in the Netherlands varying in age from 25 to 70 years. Wood production is expressed as radial and volume increment over the last 15 years before sampling. The trees of 25–35 years old showed a better average vitality (less needle loss) than the older trees, and had a higher radial increment. Percentage of needle loss at the time of sampling was significantly and negatively correlated with radial and volume increment. The average latewood percentage over the last 15 years was the lowest in non vital trees. In non vital trees the wood-biomass production over the last 15 years was only ~30% of that in more vital trees. For the Netherlands as a whole the radial and volume increment in the last 15 years are estimated to be ~20% and ~4% lower, respectively, than they hypothetically would have been if all Douglas-firs belonged to the vitality classes 0 and 1. Total biomass production by Douglas-fir stands in the Netherlands is not greatly reduced by the small decrease in density in nonvital trees and is approximately 4% lower than if all trees were vital or slightly less vital.

Tracheid Length in Vital and Non Vital Douglas Fir (Pseudotsuga Menziesii) in the Netherlands

IAWA Journal ◽  
1990 ◽  
Vol 11 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Ingrid de Kort
Keyword(s):  
The Netherlands ◽  
Pseudotsuga Menziesii ◽  
Growth Ring ◽  
Ring Width ◽  
Douglas Fir ◽  
Growth Reduction ◽  
Tracheid Length ◽  
Growth Ring Width ◽  
Temporary Growth

Tracheid length in relation to growth ring width is recorded for five Douglas firs from different sites in the Netherlands. The investigated trees differed in vitality assessed by crown appearance. Non vital trees showed a growth reduction which coincides with a decrease in tracheid length. Temporary growth reductions in vital trees did not result in a decrease of tracheid length. The relations hip between tracheid length and ring width is discussed.

PATTERNS IN GROWTH OF EARLYWOOD, LATEWOOD, AND PERCENTAGE LATEWOOD DETERMINED BY COMPLETE ANALYSIS OF 18 DOUGLAS-FIR TREES

1966 ◽  
Vol 44 (4) ◽  
pp. 453-466 ◽  
Author(s):  
J. H. G. Smith ◽  
L. Heger ◽  
J. Hejjas
Keyword(s):  
Pseudotsuga Menziesii ◽  
Radial Growth ◽  
Annual Ring ◽  
Ring Width ◽  
Height Growth ◽  
Douglas Fir ◽  
Growth Patterns ◽  
Complete Analysis ◽  
Annual Rings ◽  
Breast Height

Widths of earlywood and latewood in each annual ring, measured on an average radius on a disk taken halfway between each branch whorl, were analyzed to define their variation in 18 Douglas-fir trees (Pseudotsuga menziesii (Mirb.) Franco). Distribution of ring width and percentage latewood also was investigated in these trees which had from 20 to 50 whorls above stump height. Multiple regression and correlation analyses showed that number of rings from pith, and its reciprocal, square, or logarithm accounted for most of the variation in radial growth. Number of rings from pith influenced thickness of both earlywood and latewood much more than the climatic differences reflected by variations in annual height growth and in widths of earlywood and latewood formed at breast height in the same calendar year. Since earlywood and latewood are distributed differently and controlled by different factors, they should be studied separately within annual rings. The statistical methods used in this study provide a simple, efficient, and comprehensive basis for thoroughly describing growth patterns, and for objectively analyzing factors that govern growth.

Differential effects of Douglas-fir tussock moth and western spruce budworm defoliation on radial growth of grand fir and Douglas-fir

1979 ◽  
Vol 9 (1) ◽  
pp. 95-105 ◽  
Author(s):  
Linda B. Brubaker ◽  
Shannon K. Greene
Keyword(s):  
Host Species ◽  
Radial Growth ◽  
Ring Width ◽  
Spruce Budworm ◽  
Douglas Fir ◽  
Western Spruce Budworm ◽  
Tussock Moth ◽  
Rate Of Growth ◽  
Growth Loss ◽  
The Impact

This study compares the effects of separate Douglas-fir tussock moth (Orgiapseudotsugata McDunnough) and western spruce budworm (Choristoneuraoccidentalis Freeman) infestations on the radial growth of two host species, grand fir (Abiesgrandis (Doug.) Lindl.) and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco). Growth records from nonhost species were also examined to substantiate that growth reduction in the hosts resulted from feeding by the respective defoliators. Ring-width data, standardized to remove trends of decreasing width from pith to bark, were tested statistically to identify significant differences in the effects of each defoliator on each host species. Four measures of radial growth were examined: maximum rate of growth decline, average rate of growth recovery, 1-year growth loss, and 5-year growth loss. The effects of tussock moth did not differ statistically between host species, but the impact of budworm defoliation on grand fir was significantly greater than on Douglas-fir. Differences occurred between the overall effects of tussock moth and budworm on the host species, with tussock moth causing significantly more rapid growth reductions and greater growth losses than budworm. It is concluded that (1) grand fir and Douglas-fir ring patterns, individually or in combination, can provide good evidence of severe defoliation by Douglas-fir tussock moth, (2) grand fir ring patterns can be used to identify severe defoliation by western spruce budworm, and (3) Douglas-fir ring patterns can provide evidence of budworm infestation only if corroborative evidence of a budworm infestation is present in the ring patterns of grand fir trees in the same stand.

scholarly journals Radial growth trends of loblolly pine in the Virginia Coastal Plain

1996 ◽  
Vol 26 (9) ◽  
pp. 1660-1669 ◽  
Author(s):  
Gregory A. Reams
Keyword(s):  
Loblolly Pine ◽  
Coastal Plain ◽  
Radial Growth ◽  
Ring Width ◽  
Growth Patterns ◽  
Age Classes ◽  
Individual Tree ◽  
Forest Inventory And Analysis ◽  
Growth Trends ◽  
Individual Tree Growth

A number of recent studies have shown reduced individual-tree growth throughout the 1970s and early 1980s in natural loblolly pine (Pinustaeda L.) stands in the southeastern United States. This study updates radial growth trends of loblolly pine in the Virginia Coastal Plain through 1989. Ring-width series were initially grouped into two age-classes (<50 or ≥50 years) and a clustering procedure was used to identify common radial growth patterns. These data suggest that radial growth trends of loblolly pine are cyclic and support previous findings of reduced growth in the 1970s. A reversal in trend has occurred since the early 1980s with radial growth increasing since then for both old and young trees. This change to increased growth corroborates the finding of increased growth of loblolly pine identified in the most current Forest Inventory and Analysis (FIA) survey cycle for the Virginia Coastal Plain.

Relationship of the production of the toxin, cerato-ulmin, to synnemata formation, pathogenicity, mycelial habit, and growth of Ceratocystis ulmi isolates

1980 ◽  
Vol 58 (6) ◽  
pp. 658-662 ◽  
Author(s):  
Shozo Takai
Keyword(s):  
United States ◽  
United Kingdom ◽  
The Netherlands ◽  
Radial Growth ◽  
The United States ◽  
Measurable Quantity ◽  
The United Kingdom ◽  
Relationship Of ◽  
The Relationship

Forty-seven isolates of Ceratocystis ulmi collected from Canada, the United States, the United Kingdom, France, the Netherlands, and Iran were classified with respect to their ability to produce cerato-ulmin (CU) and synnemata, their radial growth, mycelial habit, and pathogenicity.Twenty-nine isolates clearly produced CU in a measurable quantity while 18 isolates produced it only in trace quantities. In general, the former produced fluffy mycelium and were active in synnemata formation. They were aggressive in pathogenicity with one exception. The latter group of isolates generally produced waxy, yeastlike mycelium and formed very few synnemata. They were all nonaggressive in pathogenicity. Radial growth was generally higher among the isolates that produced CU in larger quantities than among those producing CU in trace quantities. The relationship between CU production and pathogenicity affords a method for estimating isolate pathogenicity without the need for host inoculation.

Nowcasting heavy precipitation over the Netherlands using a 13-year radar archive: a machine learning approach

2021 ◽  
Author(s):  
Eva van der Kooij ◽  
Marc Schleiss ◽  
Riccardo Taormina ◽  
Francesco Fioranelli ◽  
Dorien Lugt ◽  
...  
Keyword(s):  
Machine Learning ◽  
The Netherlands ◽  
Heavy Rainfall ◽  
Predictive Performance ◽  
Heavy Precipitation ◽  
Early Warning Systems ◽  
Training Data ◽  
Short Term ◽  
Data Set ◽  
Radar Images

&lt;p&gt;Accurate short-term forecasts, also known as nowcasts, of heavy precipitation are desirable for creating early warning systems for extreme weather and its consequences, e.g. urban flooding. In this research, we explore the use of machine learning for short-term prediction of heavy rainfall showers in the Netherlands.&lt;/p&gt;&lt;p&gt;We assess the performance of a recurrent, convolutional neural network (TrajGRU) with lead times of 0 to 2 hours. The network is trained on a 13-year archive of radar images with 5-min temporal and 1-km spatial resolution from the precipitation radars of the Royal Netherlands Meteorological Institute (KNMI). We aim to train the model to predict the formation and dissipation of dynamic, heavy, localized rain events, a task for which traditional Lagrangian nowcasting methods still come up short.&lt;/p&gt;&lt;p&gt;We report on different ways to optimize predictive performance for heavy rainfall intensities through several experiments. The large dataset available provides many possible configurations for training. To focus on heavy rainfall intensities, we use different subsets of this dataset through using different conditions for event selection and varying the ratio of light and heavy precipitation events present in the training data set and change the loss function used to train the model.&lt;/p&gt;&lt;p&gt;To assess the performance of the model, we compare our method to current state-of-the-art Lagrangian nowcasting system from the pySTEPS library, like S-PROG, a deterministic approximation of an ensemble mean forecast. The results of the experiments are used to discuss the pros and cons of machine-learning based methods for precipitation nowcasting and possible ways to further increase performance.&lt;/p&gt;

scholarly journals Forward modelling of tree-ring width and comparison with a global network of tree-ring chronologies

2014 ◽  
Vol 10 (2) ◽  
pp. 437-449 ◽  
Author(s):  
P. Breitenmoser ◽  
S. Brönnimann ◽  
D. Frank
Keyword(s):  
Data Assimilation ◽  
Tree Ring ◽  
Ring Width ◽  
Global Network ◽  
Threshold Temperature ◽  
Tree Ring Width ◽  
Data Set ◽  
Observation Operator ◽  
Tree Ring Data ◽  
Wide Range

Abstract. We investigate relationships between climate and tree-ring data on a global scale using the process-based Vaganov–Shashkin Lite (VSL) forward model of tree-ring width formation. The VSL model requires as inputs only latitude, monthly mean temperature, and monthly accumulated precipitation. Hence, this simple, process-based model enables ring-width simulation at any location where monthly climate records exist. In this study, we analyse the growth response of simulated tree rings to monthly climate conditions obtained from the CRU TS3.1 data set back to 1901. Our key aims are (a) to assess the VSL model performance by examining the relations between simulated and observed growth at 2287 globally distributed sites, (b) indentify optimal growth parameters found during the model calibration, and (c) to evaluate the potential of the VSL model as an observation operator for data-assimilation-based reconstructions of climate from tree-ring width. The assessment of the growth-onset threshold temperature of approximately 4–6 °C for most sites and species using a Bayesian estimation approach complements other studies on the lower temperature limits where plant growth may be sustained. Our results suggest that the VSL model skilfully simulates site level tree-ring series in response to climate forcing for a wide range of environmental conditions and species. Spatial aggregation of the tree-ring chronologies to reduce non-climatic noise at the site level yielded notable improvements in the coherence between modelled and actual growth. The resulting distinct and coherent patterns of significant relationships between the aggregated and simulated series further demonstrate the VSL model's ability to skilfully capture the climatic signal contained in tree-ring series. Finally, we propose that the VSL model can be used as an observation operator in data assimilation approaches to reconstruct past climate.

scholarly journals EAGLE 2006 – Multi-purpose, multi-angle and multi-sensor in-situ and airborne campaigns over grassland and forest

2009 ◽  
Vol 13 (6) ◽  
pp. 833-845 ◽  
Author(s):  
Z. Su ◽  
W. J. Timmermans ◽  
C. van der Tol ◽  
R. Dost ◽  
R. Bianchi ◽  
...  
Keyword(s):  
The Netherlands ◽  
Land Surface ◽  
Information Science ◽  
Microwave Radiometer ◽  
European Space Agency ◽  
International Institute ◽  
Data Set ◽  
Field Campaign ◽  
Land Surface Parameter ◽  
Satellite Missions

Abstract. EAGLE2006 – an intensive field campaign for the advances in land surface hydrometeorological processes – was carried out in the Netherlands from 8th to 18th June 2006, involving 16 institutions with in total 67 people from 16 different countries. In addition to the acquisition of multi-angle and multi-sensor satellite data, several airborne instruments – an optical imaging sensor, an imaging microwave radiometer, and a flux airplane – were deployed and extensive ground measurements were conducted over one grassland site at Cabauw and two forest sites at Loobos and Speulderbos in the central part of the Netherlands. The generated data set is both unique and urgently needed for the development and validation of models and inversion algorithms for quantitative land surface parameter estimation and land surface hydrometeorological process studies. EAGLE2006 was led by the Department of Water Resources of the International Institute for Geo-Information Science and Earth Observation (ITC) and originated from the combination of a number of initiatives supported by different funding agencies. The objectives of the EAGLE2006 campaign were closely related to the objectives of other European Space Agency (ESA) campaign activities (SPARC2004, SEN2FLEX2005 and especially AGRISAR2006). However, one important objective of the EAGLE2006 campaign is to build up a data base for the investigation and validation of the retrieval of bio-geophysical parameters, obtained at different radar frequencies (X-, C- and L-Band) and at hyperspectral optical and thermal bands acquired simultaneously over contrasting vegetated fields (forest and grassland). As such, all activities were related to algorithm development for future satellite missions such as the Sentinels and for validation of retrievals of land surface parameters with optical and thermal and microwave sensors onboard current and future satellite missions. This contribution describes the campaign objectives and provides an overview of the airborne and field campaign dataset. This dataset is available for scientific investigations and can be accessed on the ESA Principal Investigator Portal http://eopi.esa.int/.

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