ON THE EFFECT OF CHANGES IN ELEVATION, ASPECT, SLOPE, AND DEPTH OF FREE-ROOTING MATERIAL ON THE GROWTH OF EUROPEAN LARCH, JAPANESE LARCH, SITKA SPRUCE, AND SCOTS PINE IN MYNYDD DDU FOREST

1947 ◽  
Vol 20 (1) ◽  
pp. 7-20 ◽  
Author(s):  
W. R. DAY
2020 ◽  
Vol 93 (4) ◽  
pp. 545-556 ◽  
Author(s):  
W L Mason ◽  
T Connolly

Abstract Six experiments were established between 1955 and 1962 in different parts of northern and western Britain which used replicated randomized block designs to compare the performance of two species 50:50 mixtures with pure stands of the component species. The species involved were variously lodgepole pine (Pinus contorta Dougl.), Japanese larch (Larix kaempferi Lamb. Carr.), Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth.), Sitka spruce (Picea sitchensis Bong. Carr.) and western hemlock (Tsuga heterophylla Raf. Sarg.). The first four species are light demanding, while Sitka spruce is of intermediate shade tolerance and western hemlock is very shade tolerant: only Scots pine and silver birch are native to Great Britain. In three experiments (Bickley, Ceannacroc, Hambleton), the mixtures were of two light-demanding species, while at the other three sites, the mixture tested contained species of different shade tolerance. The experiments were followed for around 50 years, similar to a full rotation of even-aged conifer stands in Britain. Five experiments showed a tendency for one species to dominate in mixture, possibly reflecting differences in the shade tolerance or other functional traits of the component species. In the three experiments, the basal area of the mixtures at the last assessment was significantly higher than predicted based on the performance of the pure stands (i.e. the mixture ‘overyielded’). In two of these cases, the mixture had had a higher basal area than found in the more productive pure stand indicating ‘transgressive overyielding’. Significant basal area differences were generally more evident at the later assessment date. The exception was in a Scots pine: western hemlock mixture where greater overyielding at the earlier date indicated a nursing (‘facilitation’) effect. In the remaining experiments, the performance of the mixture conformed to predictions from the growth of the component species in pure stands. Taken overall, the results suggest that functional traits can be used to interpret the performance of mixtures but prediction of the outcome will require better understanding of the interplay between species and site characteristics plus the influence of silvicultural interventions.


2009 ◽  
Vol 33 (-1) ◽  
pp. 49-57 ◽  
Author(s):  
Edward Feliksik ◽  
Sławomir Wilczyński

The Effect of Climate on Tree-Ring Chronologies of Native and Nonnative Tree Species Growing Under Homogenous Site ConditionsDendroclimatic studies were carried out in the experimental stands composed of many tree species situated in the Polish part of the Baltic sea-coast. Increment cores were taken from a 100-years old trees of 2 native species: Norway spruce (Picea abies (L.) Karst.), and Scots pine (Pinus sylvestrisL.) and 3 nonnative species: Douglas fir (Pseudotsuga menziesii(Mirb.) Franco), Sitka spruce (Picea sitchensis(Bong.) Carr.) and Silver fir (Abies albaMill.). Thirty trees of each species were cored. The relationships between the diameter increment and the thermal and pluvial conditions during the period from 1925 to 2005 were analyzed on the basis of standardized tree-ring chronologies and climatic data. It was found that precipitation and temperature of the growing season and months preceding that season affected the annual diameter increment of all investigated tree species. The current year winter and early spring temperatures as well as February and August precipitation had a similar effect on the variation of diameter increment of trees. On the other hand thermal and pluvial conditions of the current year June differentiated the increment rhythm of individual species. A very strong negative effect on diameter growth of trees was observed in the case of winter and early spring frosts. Norway spruce turned out to be a species most resistant to low temperatures. The investigated tree species, especially Norway spruce, was susceptible to water deficiency in the soil during spring and summer. In the case of Scots pine a high precipitation in June stimulated its growth. The diameter increments of Douglas fir, Sitka spruce, Scots pine, and Silver fir were more strongly connected with air temperature than with precipitation. So called all-species chronology of tree-ring width, constructed during this study, permitted to verify the factors having a similar effect on growth response of the investigated tree species. It reflected the mutual characteristics of diameter increments of trees of various species.


1996 ◽  
Vol 26 (3) ◽  
pp. 355-359 ◽  
Author(s):  
J.J. Philipson

Field-grown European larch (Larixdecidua Mill.) and Japanese larch (Larixkaempferi (Lamb.) Carr.) grafts were treated with main-stem girdling applied with or without injection of gibberellin A4/7 (GA4/7). The level of female coning was low in the untreated trees and was significantly increased by girdling; the mean number of seed cones per tree, on trees receiving girdling alone, was 71 for the European larch and 50 for the Japanese larch. There was considerable male flowering on the untreated trees, (701 and 1208 cones per tree on the European and Japanese larch, respectively), and on trees receiving girdling alone there were 1356 pollen cones per tree on the European larch, and 2035 on the Japanese larch, representing increases of 94 and 68%, respectively, compared with the untreated trees. The overall girdling effect on male flowering, however, was not statistically significant for either species. GA4/7 application produced no significant increases in coning, and in fact fewer pollen cones were observed on GA4/7-treated grafts than on grafts without GA4/7. Between 6 and 12% of the pollen-cone buds on untreated trees did not flush successfully, and the GA4/7 application significantly increased this proportion of unflushed buds. Girdling is an easy and effective treatment to increase female coning of European and Japanese larch and may also result in increases in pollen cones; thus, it would be a useful treatment to assist in the breeding of these species and the production of their hybrid (Larix ×eurolepis A. Henry).


2017 ◽  
Vol 40 (9) ◽  
pp. 1972-1983 ◽  
Author(s):  
Linda M. Feichtinger ◽  
Rolf T.W. Siegwolf ◽  
Arthur Gessler ◽  
Nina Buchmann ◽  
Mathieu Lévesque ◽  
...  

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