Relationships between foliar number and the cross-sectional areas of sapwood and annual rings in red oak (Quercusrubra) crowns

1993 ◽  
Vol 23 (7) ◽  
pp. 1245-1251 ◽  
Author(s):  
D. Andrew White

Correlations and functional relationships of sapwood and annual ring cross-sectional areas versus the number of leaves supported inside the live crowns of red oak (Quercusrubra L.) were found, based on analyses of six 20- to 25-year-old oaks from monocultures in southern Ontario. Differences in numbers of leaves supported across intervals inside the crowns were compared, using correlation analyses, with the corresponding differences in conductive sapwood (outer two annual rings) cross-sectional areas, and the current and previous year's annual ring's cross-sectional areas. These analyses showed that the current year's annual ring area had a lower correlation with number of current leaves supported (R = 0.918, P < 0.0001) than did the previous year's annual ring area (R = 0.953, P < 0.0001) or the conductive sapwood area (R = 0.939, P < 0.0001). Functional relationships between foliar numbers supported and sapwood and annual ring cross-sectional areas inside the live crowns were found with regression analysis. The previous year's ring area (PRA) had a more linear relationship to leaf counts (FQ) than did conductive sapwood area and current annual ring area. FQ = 815.6 leaves/cm2 × PRA1.14 − 137.9. The close relationship between current foliage and previous annual ring area may reflect a developmental link between foliar primordia, which will become the following year's foliage, and the cross-sectional area of the supporting xylem.

1983 ◽  
Vol 13 (3) ◽  
pp. 384-389 ◽  
Author(s):  
H. Brix ◽  
A. K. Mitchell

A 24-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand was treated with various levels and combinations of nitrogen fertilization and thinning. Over a period of 5–9 years after treatments, trees were sampled to determine effects on foliage quantity and sapwood characteristics at different stem heights together with their relationships. Sapwood width remained relatively constant up the stem where heartwood was present, but the number of annual rings it contained decreased with height. The sapwood width at breast height (bh) increased with stem diameter; treatments had little effect on percent sapwood at bh. The ratio of foliage mass to sapwood cross-sectional area changed for different portions of the crown and was lower when based on sapwood area at bh than at base of live crown. Significant linear relationships of foliage mass and area to sapwood area at bh were found, but relationships of foliage to basal area (bh) were just as close for all treatments; treatments significantly affected these relationships with control trees having the lowest regression slopes.


Author(s):  
J.-F. Revol ◽  
Y. Van Daele ◽  
F. Gaill

The only form of cellulose which could unequivocally be ascribed to the animal kingdom is the tunicin that occurs in the tests of the tunicates. Recently, high-resolution solid-state l3C NMR revealed that tunicin belongs to the Iβ form of cellulose as opposed to the Iα form found in Valonia and bacterial celluloses. The high perfection of the tunicin crystallites led us to study its crosssectional shape and to compare it with the shape of those in Valonia ventricosa (V.v.), the goal being to relate the cross-section of cellulose crystallites with the two allomorphs Iα and Iβ.In the present work the source of tunicin was the test of the ascidian Halocvnthia papillosa (H.p.). Diffraction contrast imaging in the bright field mode was applied on ultrathin sections of the V.v. cell wall and H.p. test with cellulose crystallites perpendicular to the plane of the sections. The electron microscope, a Philips 400T, was operated at 120 kV in a low intensity beam condition.


1960 ◽  
Vol 19 (3) ◽  
pp. 803-809
Author(s):  
D. J. Matthews ◽  
R. A. Merkel ◽  
J. D. Wheat ◽  
R. F. Cox

2020 ◽  
Author(s):  
Sylvia Niehuis

Issues in applied survey research, including minimizing respondent burden to encourage survey completion and the increasing administration of questionnaires over smartphones, have intensified efforts to create short measures. We conducted two studies to examine the psychometric properties of single-item measures of four close-relationship variables: satisfaction, love, conflict, and commitment. Study 1 was longitudinal, surveying an initial sample of 121 college-age dating couples at three monthly phases. Romantic partners completed single- and multi-item measures of the four constructs, along with other variables, to examine test-retest reliability and convergent (single-item measures with their corresponding multi-item scales), concurrent, and predictive validity. Our single-item measures of satisfaction, love, and commitment exhibited impressive psychometric qualities, but our single-item conflict measure performed somewhat less strongly. Study 2, a cross-sectional online survey (n = 280; mainly through Facebook), showed strong convergent validity of the single-item measures, including a .60 correlation between single- and multi-item conflict measures.


2018 ◽  
Author(s):  
Sang Hoon Lee ◽  
Jeff Blackwood ◽  
Stacey Stone ◽  
Michael Schmidt ◽  
Mark Williamson ◽  
...  

Abstract The cross-sectional and planar analysis of current generation 3D device structures can be analyzed using a single Focused Ion Beam (FIB) mill. This is achieved using a diagonal milling technique that exposes a multilayer planar surface as well as the cross-section. this provides image data allowing for an efficient method to monitor the fabrication process and find device design errors. This process saves tremendous sample-to-data time, decreasing it from days to hours while still providing precise defect and structure data.


Sign in / Sign up

Export Citation Format

Share Document