Early Performance and Genetic Parameters for Atlantic Coastal and Piedmont Loblolly Pine and Their Hybrids in the Piedmont

Atlantic Coastal (C) and Piedmont (P) loblolly pine (Pinus taeda L.) sources and their hybrids were assessed at four years of age for height and survival in 15 test sites across five Piedmont regions (Piedmont, Upper Gulf, Blue Ridge, North East and Cold Area). Two intra-provenance (CxC and PxP) and two inter-provenance (CxP and PxC) populations were generated. Twenty polymix families represented each population. Main objectives of the study were to: (1) determine whether the inter-provenance hybrids can combine the growth of Atlantic Coastal and the cold hardiness of Piedmont sources when planted in Piedmont regions, (2) characterize the genetic architecture among and within populations across and within Piedmont regions, and (3) evaluate the stability of performance of families within populations across different environments. The performance of inter-provenance hybrids was intermediate to that of the parental populations. When compared to the Piedmont population, which is the commonly planted source in Piedmont regions because of its cold hardiness, CxP inter-provenance hybrids exhibited significantly better height growth, with superiority ranging among 0.16% to 5.81% for height. Survival differences among populations within Piedmont regions were not significant at this age, except in the Cold Area, where significantly higher survival was found for the Piedmont population. There were large family differences within populations for growth and survival. Genetic control for growth traits varied among populations, with stronger additive genetic control for CxP hybrids. Considerable variation was also detected for family performance for growth and stability across sites. The CxC and CxP populations were more responsive to site quality increase (measured by the test means), with a higher percentage of families having regression slopes larger than 1.0. This early evaluation showed some promise for using loblolly pine hybrids as planting stock in the Piedmont region. With additional testing for cold hardiness, there is a potential to combine the growth of Atlantic Coastal and the adaptation to cold of Piedmont sources for planting in Piedmont regions. The CxP hybrids may perform well in milder Piedmont environments, while PxC could be more suitable for more inland and north Piedmont regions. Long-term monitoring of population performance and survival is essential, as prolonged exposure to adverse climatic conditions will provide more confidence about the results.Papers and abstracts from the 27th Southern Forest Tree Improvement Conference held at Oklahoma State University in Stillwater, Oklahoma on June 24-27, 2003

Geographic Information Systems(GIS) and Virtual Reality Models (VRM) to Improve the Analysis of Genetic and Silvicultural Trials

GIS systems have become core tools for mapping needs in forestry. During the last decade software platforms have expanded the basic capabilities of data storage and retrieval in map formats. Complex overlay procedures, terrain analysis, 3D modeling, spatial and geostatistical tools, and remote sensing integration have increased the power of space related information. In addition, new VRM have emerged as improved tools for visualization, simulation and teaching. Research field trials in forestry are usually established to minimize spatial environmental variation, however exploring this assumption �ex ante� or �ex post� has been always tedious and uncertain and has lacked the power of visualization and analysis. Powerful spatial statistical analyses and interpolation analyses may be integrated to visualize site variability, remove environmental trends or integrate those to conventional statistical analyses. We investigated the �ex post� analysis of a research trial using ARCMAP/GIS and ARCScene VRM tools (ESRI, Inc) in order to explore their utility for trial analysis. Detailed sampling activities investigating specific physiological or ecological process may take full advantage of GIS and VRM tools capabilities to understand site variability and locate highly representative sampling points. That information may be used for modeling based on the same spatial information.Papers and abstracts from the 27th Southern Forest Tree Improvement Conference held at Oklahoma State University in Stillwater, Oklahoma on June 24-27, 2003

Dominance and Stand Structure Analyses of a GXE Interaction Trial

Papers and abstracts from the 27th Southern Forest Tree Improvement Conference held at Oklahoma State University in Stillwater, Oklahoma on June 24-27, 2003

Cone and Seed Insect Pest Research: The Role of the Southwide Studies

A reliable supply of genetically improved pine seed is critical to the success of production forestry. The most significant environmental threat to the ability to meet this demand (over 100,000 pounds per year) is insect predation. Cone and seed insect pests can easily destroy half the potential orchard crop, and there have been instances in which 90% of the harvest was lost. Effective insect control is dependent on continued availability of pesticides, both because the economic loss threshold is low, and because alternative control methods have not been successful. Because seed orchards are a minor use, there is limited support from pesticide manufacturers for either efficacy testing or continued product registration. The tree improvement community has responded to this challenge by developing a collaborative working arrangement between entomologists and seed orchard managers that has resulted in a series of southwide efficacy studies. These studies, which have now included evaluations of Guthion�, Asana�, Capture�, and Imidan�, were coordinated through the Seed Orchard Pest Management Subcommittee, a working group of the Southern Forest Tree Improvement Committee. Southwide studies are the culmination of a multi-step process in which promising pesticide formulations and rates are first identified by USDA Forest Service entomologists through small-scale testing, typically with hydraulic spray applications to single trees. This method of application, while allowing for accurate treatment evaluations, does not reflect operational conditions. It is therefore necessary to evaluate the most promising treatments under operational conditions with aerial applications on large treatment blocks. Results from both published and unpublished studies have underscored the strengths and weaknesses of these large-scale tests. Efficacy studies are difficult to implement and have substantial direct and indirect costs to the participants. Seedbug control is easy to achieve. Coneworm control, however, is much more difficult both to achieve and to accurately document. Interpretation of composite traits such as the number of good seed produced per initial flower can lead to erroneous conclusions when efficacy is primarily due to seedbug control. Despite these deficiencies, southwide studies will continue to be needed to validate cone and seed insect control under operational conditions. Studies that will be needed in the future are discussed.Papers and abstracts from the 27th Southern Forest Tree Improvement Conference held at Oklahoma State University in Stillwater, Oklahoma on June 24-27, 2003

Fourth-Year Results from a Clonal Test of Loblolly Pine

In November and December 1998, two experimental plantings were established using rooted cuttings from 450 clones of eight unrelated full-sib families of loblolly pine (Pinus taeda L.). Clones from four of the families (282 clones) were planted in South Carolina and clones from the other four families in Florida (168 clones). Both tests were laid out as randomized complete blocks with nine blocks and one ramet/clone/block. Height, survival and rust resistance were measured annually and diameter was measured at age four. Best Linear Unbiased Prediction of clone genetic values were estimated for height and volume at age four. Estimated genetic gains from various clone selection strategies, the effect of increasing or decreasing the number of ramets for testing on genetic gain, height age-age and trait-trait genetic correlations were estimated. Estimated genetic gain was highly sensitive to the intensity of clonal selection. Selecting the single best clone from each test resulted in an estimated gain of 13% (SC) and 14% (FL) in height at age four over the test average (all the clones). The single best clone from each family at each site (four in total) resulted in an estimated gain of 10% (SC) and 10% (FL). However, if six clones were selected from each family (twenty-four in total), gain was reduced to 8% (SC) and 6% (FL) in height. The genetic correlations between height at age one and height at age four were low (0.60 at SC, 0.58 at FL), but increased to 0.96 (SC) and 0.97 (FL) between heights at ages three and four. Simulations using test parameters showed that estimated gain increased with the number of ramets tested up until ten ramets per clone, but did not increase appreciably with ramet numbers above ten. Moreover, approximately 90% of the gain could be obtained using only six ramets. These data, additional details and the implications of these results will be discussed.Papers and abstracts from the 27th Southern Forest Tree Improvement Conference held at Oklahoma State University in Stillwater, Oklahoma on June 24-27, 2003

Responsiveness of Diverse Families of Loblolly Pine to Fertilization: Eight-Year Results from SETRES-2

Papers and abstracts from the 27th Southern Forest Tree Improvement Conference held at Oklahoma State University in Stillwater, Oklahoma on June 24-27, 2003

Demonstration of radon removal from SF6 using molecular sieves

The gas SF6 has become of interest as a negative ion drift gas for use in directional dark matter searches. However, as for other targets in such searches, it is important that radon contamination can be removed as this provides a source of unwanted background events. In this work we demonstrate for the first time filtration of radon from SF6 gas by using a molecular sieve. Four types of sieves from Sigma-Aldrich were investigated, namely 3Å, 4Å, 5Å and 13X. A manufactured radon source was used for the tests. This was attached to a closed loop system in which gas was flowed through the filters and a specially adapted Durridge RAD7 radon detector. In these measurements, it was found that only the 5Å type was able to significantly reduce the radon concentration without absorbing the SF6 gas. The sieve was able to reduce the initial radon concentration of 3875 ± 13 Bqm−3 in SF6 gas by 87% when cooled with dry ice. The ability of the cooled 5Å molecular sieve filter to significantly reduce radon concentration from SF6 provides a promising foundation for the construction of a radon filtration setup for future ultra-sensitive SF6 gas rare-event physics experiments

Pulping and bleaching of partially CAD-deficient wood

"May 2002."Submitted to Journal of Wood Chemistry and Technology

Modelling the limits on the response of net carbon exchange to fertilization in a south-eastern pine forest

Using a combination of model simulations and detailed measurements at a hierarchy of scales conducted at a sandhills forest site, the effect of fertilization on net ecosystem exchange ( NEE ) and its components in 6-year-old Pinus taeda stands was quantified. The detailed measurements, collected over a 20-d period in September and October, included gas exchange and eddy covariance fluxes, sampled for a 10-d period each at the fertilized stand and at the control stand. Respiration from the forest floor and above-ground biomass was measured using chambers during the experiment. Fertilization doubled leaf area index (LAI) and increased leaf carboxylation capacity by 20%. However, this increase in total LAI translated into an increase of only 25% in modelled sunlit LAI and in canopy photosynthesis. It is shown that the same climatic and environmental conditions that enhance photosynthesis in the September and October periods also cause an increase in respiration The increases in respiration counterbalanced photosynthesis and resulted in negligible NEE differences between fertilized and control stands. The fact that total biomass of the fertilized stand exceeded 2·5 times that of the control, suggests that the counteracting effects cannot persist throughout the year. In fact, modelled annual carbon balance showed that gross primary productivity ( GPP ) increased by about 50% and that the largest enhancement in NEE occurred in the spring and autumn, during which cooler temperatures reduced respiration more than photosynthesis. The modelled difference in annual NEE between fertilized  and  control  stands  (approximately  200 1;g 2;C 3;m −2 y −1 )  suggest that the effect of fertilization was sufficiently large to transform the stand from a net terrestrial carbon source to a net sink.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73712/1/j.1365-3040.2002.00896.x.pd

Elongation, rooting and acclimatization of micropropagated shoots from mature material of hybrid larch

Factors were defined for elongation, rooting and acclimatization of micropropagated shoots of Larix x eurolepis Henry initiated from short shoot buds of plagiotropic stecklings serially propagated for 9 years from an 8-year-old tree. Initiation and multiplication were on Schenk and Hildebrandt (SH) medium supplemented with 5 μM 6-benzyladenine (BA) and 1 μM indole-butyric acid (IBA). Stem elongation was obtained in 36% of the shoots on SH medium containing 0.5 μM BA and 63% of the remaining non-elongated shoots initiated stem elongation after transfer on SH medium devoid of growth regulators. Rooting involved 2 steps: root induction on Campbell and Durzan mineral salts and Murashige and Skoog organic elements, both half-strength (CD-MS/2), supplemented with 1 μM of both naphthaleneacetic acid (NAA) and IBA, and root elongation following transfer to CD-MS/2 medium devoid of growth regulators. Repeating this 2-step sequence yielded up to 67% rooted shoots. Acclimatization of plantlets ranged from 83% to 100%. Over 300 plants were transferred to the greenhouse; some showed plagiotropic growth