Response of sugar maple (Acer saccharum, Marsh.) tree crown structure to competition in pure versus mixed stands

2016 ◽  
Vol 374 ◽  
pp. 20-32 ◽  
Author(s):  
Martin-Ducup Olivier ◽  
Schneider Robert ◽  
Richard A. Fournier
2011 ◽  
Vol 162 (6) ◽  
pp. 186-194 ◽  
Author(s):  
Hans Pretzsch ◽  
Stefan Seifert ◽  
Peng Huang

This paper addresses the potential of terrestrial laser scanning (TLS) for describing and modelling of tree crown structure and dynamics. We first present a general approach for the metabolic and structural scaling of tree crowns. Out of this approach we emphasize those normalization and scaling parameters which become accessible by TLS. For example we show how the individual tree leaf area index, convex hull, and its space-filling by leaves can be extracted out of laser scan data. This contributes to a theoretical and empirical substantiation of crown structure models which were missing so far for e.g. quantification of structural and species diversity in forest stands, inventory of crown biomass, species detection by remote sensing, and understanding of self- and alien-thinning in pure and mixed stands. Up to now works on this topic delivered a rather scattered empirical knowledge mainly by single inventories of trees and stands. In contrast, we recommend to start with a model approach, and to complete existing data with repeated TLS inventories in order to come to a consistent and theoretically based model of tree crowns.


2002 ◽  
Vol 32 (3) ◽  
pp. 379-389 ◽  
Author(s):  
Michel Fortin ◽  
Yves Mauffette

Variations of leaf suitability within forest canopies may have important consequences for the biology of phytophagous insects. In this study we examined over 4 consecutive years (1994–1997), the influence of vertical stratification of leaves within a sugar maple (Acer saccharum Marsh.) stand on biological performance and feeding preference of Malacosoma disstria Hbn. Each year, 10 healthy sugar maple trees and about 15 understory sugar maple seedlings were selected. Leaves were collected from the lower (3–6 m above ground) and the upper crown (20–25 m above ground) sections of the trees and from seedlings. Sampled leaves were set in Petri dishes for insect rearings in controlled environment. The performance of the insect, especially pupal masses and the number of eggs of adult females, was higher when larvae were fed with leaves from the upper crown section of trees. Results for the feeding preference tests showed that larvae of fourth instars consumed more surface area from leaves collected in the upper crown section of the trees. More total nitrogen found in leaves from the upper tree crown could explain the higher performance of this insect. Our results confirm the importance of the heterogeneity in leaf suitability along a vertical stratification in forests by its influence on biological performance and feeding preference of M. disstria.


Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 673 ◽  
Author(s):  
Olivier Martin-Ducup ◽  
Robert Schneider ◽  
Richard Fournier

The material distribution inside tree crowns is difficult to quantify even though it is an important variable in forest management and ecology. The vertical distribution of a relative density index (i.e., vertical profile) of the total, woody, and leafy material at the crown scale were estimated from terrestrial laser scanner (TLS) data on two species, sugar maple (Acer saccharum Marsh.) and balsam fir (Abies Balsamea Mill.). An algorithm based on a geometrical approach readily available in the Computree open source platform was used. Beta distributions were then fitted to the vertical profiles and compared to each other. Total and leafy profiles had similar shapes, while woody profiles were different. Thus, the total vertical distribution could be a good proxy for the leaf distribution in the crown. Sugar maple and balsam fir had top heavy and bottom heavy distributions respectively, which can be explained by their respective architectural development. Moreover, the foliage distribution of sugar maples shifted towards the crown base when it was found in mixed stands, when compared to pure stands. The opposite behavior was observed for balsam firs, but less pronounced. According to the shape of the foliage distribution, sugar maple takes advantages from mixture contrarily to balsam fir. From a methodological point of view, we proposed an original approach to separate wood from leaf returns in TLS data while taking into account occlusion. Wood and leaf separation and occlusion problems are two challenging issues for most TLS-based studies in forest ecology.


2020 ◽  
Vol 52 (3) ◽  
pp. 292-297
Author(s):  
Tara Lee Bal ◽  
Katherine Elizabeth Schneider ◽  
Dana L. Richter

2017 ◽  
Vol 129 (2) ◽  
pp. 209-221 ◽  
Author(s):  
Amritpal S. Singh ◽  
A. Maxwell P. Jones ◽  
Mukund R. Shukla ◽  
Praveen K. Saxena

1995 ◽  
Vol 12 (3) ◽  
pp. 115-120 ◽  
Author(s):  
David B. Kittredge ◽  
P. Mark S. Ashton

Abstract Browsing preferences by white-tailed deer were evaluated for 6 tree species in northeastern Connecticut. Deer density averaged 23/mile². Deer exhibited no species-specific preferences for seedlings greater than 19 in. For seedlings less than 19 in., hemlock and black birch were preferred. Red maple, sugar maple, and white pine seedlings were avoided. Red oak seedlings were neither preferred nor avoided. A much higher proportion of seedlings greater than 19.7 in. in height was browsed, regardless of species. Browsing preferences for species in the smaller seedling class, combined with a lack of preference for species in the larger class may result in future stands with less diverse tree species composition. Deer densities in excess of 23/mile² may be incompatible with regeneration of diverse forests in southern New England. North. J. Appl. For. 12(3):115-120.


2015 ◽  
Vol 45 (6) ◽  
pp. 632-638 ◽  
Author(s):  
Kim Bannon ◽  
Sylvain Delagrange ◽  
Nicolas Bélanger ◽  
Christian Messier

Studies have reported divergent results on the effect of soil fertility and canopy opening on understory density and growth of sugar maple (AS; Acer saccharum Marsh.) and American beech (FG; Fagus grandifolia Ehrh.). The main objective of this study was to evaluate the effect of a gradient of canopy opening and soil fertility on the density and growth of AS and FG saplings in southwestern Quebec, Canada. We investigated 56 stands containing both AS and FG that were subjected to different disturbance history types (DHTs) (UF, unmanaged forest; PC, partial cut; and CC, clearcut) on various soil types. AS and FG absolute and relative sapling density varied greatly among the 56 stands; however, no significant effects of DHT, soil nutrient availability, or their interaction were found. Both species responded positively in terms of radial growth to canopy openings, with FG growth being slightly better than AS growth in PC stands compared with other canopy treatments. Contrary to our hypothesis, AS did not show significantly higher growth than FG following clear-cutting. These results do not support the idea that AS abundance and growth could be promoted by increasing the intensity of the canopy opening during harvest, at least on the generally acidic and base-poor soils that were investigated.


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