Persistence Of Branches Research Articles

We Are Branches by Joyce Sidman

Reviewed by: We Are Branches by Joyce Sidman Kate Quealy-Gainer Sidman, Joyce We Are Branches; illus. by Beth Krommes. Clarion, 2023 [40p] Trade ed. ISBN 9780358538189 $19.99 Reviewed from digital galleys R Gr. 2-4 Sidman follows up her poetic exploration of spirals in nature (Swirl by Swirl, BCCB 11/11) with a similar look at the persistence of branches and branching, which she defines as a "pattern that divides into two, forming a Y." The book starts with the most obvious example in tree branches as they are "lifting toward the sun, spreading wide to catch each drop of light." From there, viewers get a look at the [End Page 304] tree's roots, also a relatively easy place to spot branching, but the book asks for a bit more observation as it moves along: what about the thin veins visible in a flower petal; the layering of a bird's feathers; the crackling bursts of lightning; the angular points of a snowflake? A river spreads into branches, as do the bones making up a bat's wings. And speaking of bones, the entire human body is made up of branching tissue, veins, and bones. With spare but imagistic text, Sidman highlights the interconnectedness of life, clearly conveying how branching is an essential part of nature as it is the "most efficient way to spread something (like water or energy) from one central spot over a large area." Krommes' defined, crisp scratchboard art is especially effective in following various lines as they branch out and out again, ensuring that borders and throughlines take center stage against softer hues. This would pair nicely with Swirl by Swirl or Chin's recent The Universe in You: A Microscopic Journey (BCCB 10/22) for a look at commonalities and connection in the natural world. Copyright © 2023 The Board of Trustees of the University of Illinois

The effect of initial planting density on branching characteristics of Eucalyptus pilularis and E. grandis

Summary Branch-related defects can significantly decrease the quality of plantation eucalypt logs grown for solid-wood products. In this study we examined the effect of initial spacing on branching characteristics of 5-y-old plantation-grown Eucalyptus grandis and E. pilularis on the North Coast of New South Wales. For each sample tree all branches on the lower stem (the butt log, 0.3–6 m) were assessed for diameter, angle and condition. Trees were sampled in plots grown at four initial planting densities: 838 (3 m x 4 m), 1111 (3 m x 3 m), 1667 (3 x 2 m) and 3333 (3 m x 1 m) trees ha-1. The butt log of both species contained 55–70 branches, regardless of the initial density. Initial density did not affect branch formation, but it did affect the subsequent growth and persistence of branches. Lower initial density increased both the mean branch diameter and the number of large branches (> 2.5 cm diameter) per tree in both species. Branch size also increased with height up the stem, but the rate of increase was not different between densities. A major difference between species was that E. pilularis had more small dead branches that had not been shed. A single spacing prescription is possible for both species because there was no difference between species in the relationship between large branches and density.

Growth Response of Pitch × Loblolly Pine Hybrids Following Crown Touching Release

Abstract The 13 yr growth response of pitch × loblolly pine hybrids following a crown touching release conducted at age 7 in the Virginia Piedmont was evaluated. Growth of crop trees was related to the degree of crown release as measured by the free-to-grow (FTG) rating that ranged from 0 (no release) to 4 (complete release on all sides). Diameter growth of the released crop trees (FTG ≥ 3) was 63% greater than diameter growth in nonreleased trees (FTG < 3), while height growth was 9% greater. At age 20, the average dbh of the crop trees was 10.3 in., while the average dbh of the nonreleased trees was 7.8 in. The live crown ratio in the crop trees was significantly greater than in the nonreleased trees (47% vs. 38%), which contributed to the growth response. However, stem quality of the crop trees was poorer than in the nonreleased trees, due to the persistence of branches on the lower bole. These results suggest that sawtimber size pitch × loblolly hybrid pines can be grown in a short rotation if adequate growing space is provided.