Crown architecture, crown leaf area distribution, and individual tree growth efficiency vary across site, genetic entry, and planting density

Abstract

We examined crown architecture and within crown leaf area distribution effects on Pinus taeda L. growth in North Carolina (NC), Virginia (VA), and Brazil (BR) to better understand why P. taeda can grow much better in Brazil than in the southeastern United States. The NC, VA, and BR sites were planted in 2009, 2009, and 2011, respectively. At all sites, we planted the same two genetic entries at 618, 1236, and 1854 trees ha −1 . In 2013, when trees were still open grown, the VA and NC sites had greater branch diameter (24%), branch number (14%), live crown length (44%), foliage mass (82%), and branch mass (91%), than the BR site. However, in 2017, after crown closure and when there was no significant difference in tree size, site did not significantly affect these crown variables. In 2013, site significantly affected absolute leaf area distribution, likely due to differences in live crown length and leaf area, such that there was more foliage at a given level in the crown at the VA and NC sites than at the BR site. In 2017, site was still a significant factor explaining leaf area distribution, although at this point, with crown closure and similar sized trees, there was more foliage at the BR site at a given level in the crown compared to the VA and NC sites. In 2013 and 2017, when including site, genetic entry, stand density, and leaf area distribution parameters as independent variables, site significantly affected individual tree growth efficiency, indicating that something other than leaf area distribution was influencing the site effect. Better BR P. taeda growth is likely due to a combination of factors, including leaf area distribution, crown architecture, and other factors that have been identified as influencing the site effect (heat sum), indicating that future work should include a modeling analysis to examine all known contributing factors.

Effect of Different Spacing on the Growth and Yield of California Wonder Bell Pepper (Capsicum annuum) on Sandy Loam Soil in the Gambia

“…Finally, the maximum number of leaves per plant (116) was recorded from treatment (T1). These results are in agreement with findings by Albaugh et al [15] reporting in higher plant densities can be observed a lower number of leaves, branches [16] reported the minimum number of leaves per plant of green pepper was recorded from the closest spacing which was however statistically similar to the widest spacing. The measurements made on plant components show that more leaves were observed as plant population reduced probably in relation to lower competition for physical production resources (soil moisture and nutrients) which would enhance nutrient availability and efficient utilization of assimilates.…”

Sentinel-2 Leaf Area Index Estimation for Pine Plantations in the Southeastern United States

“…Growth efficiency (the efficiency with which an individual tree makes use of site resources to produce stem biomass) as well as LAI have been considered across sites with variability such as these before, with responses to silviculture being most apparent on nutrient-deficient, poorly drained sites like RW20-NC [40]. Albaugh et al (2019) specifically explored the growth efficiency and crown dynamics of RW20 sites, concluding that unexplored site variables are causing the large degree of variance in crown architecture, crown leaf area distribution, and individual tree growth efficiency between individual sites [41]. The ideal training dataset would cover as broad of a geographic range as possible to account for variety in loblolly pine's native range.…”

Effects of Competition on the Vertical Distribution of Foliage Biomass within the Crowns of Planted Korean Pine Trees in Northeast China

“…The spatial distribution of foliage biomass is also a crucial characteristic of canopy architecture because the amount and distribution of intercepted radiation intrinsically depend on the crown structure of the individual trees [43,44]. The importance of the vertical distribution of foliage biomass has already been emphasized for Douglas fir [45,46], jack pine [34], and loblolly pine [18].…”

“…Light interception drives tree growth and so growth is generally related to leaf area [17]. Specific tree species with a high number of branches and high branch biomass exhibit greater productivity because they are able to develop a crown with a higher leaf area [18]. The leaf area of an individual tree is therefore closely related to photosynthesis and productivity [19].…”