David L. Kulhavy

RED-COCKADED WOODPECKER NEST-CAVITY SELECTION: RELATIONSHIPS WITH CAVITY AGE AND RESIN PRODUCTION

We evaluated selection of nest sites by male Red-cockaded Woodpeckers (Pi- coides borealis) in Texas relative to the age of the cavity when only cavities excavated by the woodpeckers were available and when both naturally excavated cavities and artificial cavi- ties were available. We also evaluated nest-cavity selection relative to the ability of naturally excavated cavity trees to produce resin, which is used by the woodpeckers to maintain a barrier against predation by rat snakes (Elaphe spp.). Longleaf pines (Pinus palustris) selected by breeding males as nest trees produced significantly greater resin yields at 2, 8, and 24 h post-wounding than cavity trees used for roosting by other group members. This preference was observed in loblolly pine (I! taeda) and shortleaf pine (I? echinata) cavity trees only at the 2-h resin-sampling period. When only naturally excavated cavities were available, Red-cock- aded Woodpeckers in both longleaf pine and loblolly-shortleaf pine habitat selected thenew- est cavities available for their nest sites, possibly as a means to reduce parasite loads. When both naturally excavated and artificial cavity inserts were available, Red-cockaded Wood- peckers continued to select the newest cavity for nesting in loblolly-shor tleaf pine habitat but not in longleaf pine habitat. Resin production in existing longleaf pine nest trees re- mained sufficient for continued use, whereas resin production in loblolly pine and shortleaf pine nest trees decreased through time, probably because of woodpecker activity at resin wells. For these latter tree species, breeding males switched to newer cavities and/or cavity trees with higher resin yields. Received 7 )uly 1997, accepted 11 November 1997.

Stand conditions and tree characteristics affect quality of longleaf pine for red-cockaded woodpecker cavity trees

Abstract We measured resin flow of longleaf ( Pinus palustris Mill.) pines in red-cockaded woodpecker ( Picoides borealis Vieillot) clusters in the Angelina National Forest in Texas, and the Apalachicola National Forest in Florida. Sample trees were categorized as active cavity trees, inactive cavity trees and control trees. Sample trees were further categorized by stand position as either edge or interior trees. Longleaf cavity trees in Texas and Florida had similar resin flow characteristics. Active cavity trees on forest edges had the highest resin flow, whereas active cavity trees in forest interiors had the lowest. Trees experiencing both low and high levels of red-cockaded woodpecker activity and competition from other trees had low resin flow, whereas intermediate stress typically resulted in high resin flow. Results from this study indicate that the best active red-cockaded woodpecker cavity trees, from a resin flow perspective, are on or near forest edges. This may explain the woodpeckers observed tendency to excavate new cavities near edges even when interior basal area has been reduced and midstory has been controlled. Our results suggest that pines managed as potential cavity trees should be experiencing minimal competition, and that a mosaic of patches in red-cockaded woodpecker habitat may be preferable to more uniform conditions.

Does Red-Cockaded Woodpecker Excavation of Resin Wells Increase Risk of Bark Beetle Infestation of Cavity Trees?

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Comparing remotely sensed Pictometry® Web-based height estimates with in situ clinometer and laser range finder height estimates

Abstract Heights of 30 light poles were measured with a telescopic height pole. Clinometer and laser range finder in situ estimated light pole height was compared to Pictometry® estimated light pole height using hyperspatial 4-in. (10.2-cm) multispectral imagery within a Web-based interface. Average percent agreement between light pole height and clinometer and laser range finder estimated that light pole height ranged from 3.97% to 3.79% for clinometer and laser range finder estimated light pole height, respectively. Average percent agreement between light pole height and Pictometry® estimated light pole height at image magnification factors of 100%, 125%, 150%, 200%, and 300% magnification ranged from 1.77% to 2.39%. Root-mean-square error (RMSE) between light pole height and clinometer and laser range finder estimated that light pole height ranged from 0.22 to 0.20 m for clinometer and laser range finder estimated light pole height, respectively. RMSE between light pole height and Pictometry® estimated light pole height ranged from 0.10 to 0.14 m. An analysis of variance between absolute errors of light pole height estimate by different techniques indicated that Pictometry® was significantly more accurate than both clinometer and laser range finder light pole height estimates.

Low temperature induces two growth-arrested stages and change of secondary metabolites in Bursaphelenchus xylophilus

The third-stage dispersal juvenile (JIII) is the stage for survival and dispersal in the winter of the pine wood nematode, Bursaphelenchus xylophilus. Through investigations at different temperatures, we found two kinds of growth-arrested development, including the adult longevity extension and JIII formation induced by low temperature. They showed similar characters: densely packed lipid droplets and extended longevity. We considered that there were four stages in the formation of growth-arrested stages: induction, growth-arrested pathway, growth-arrested development and cold-tolerance duration. Moreover, at 4°C there were significant changes in secondary metabolites, which may be related to signal communication and metabolism associated with the formation of growth-arrested stages. The results suggested that low temperature was necessary for the dispersal of pine wood nematode and influenced distribution and intensity of pine wilt.

Effects of fertilization and herbicides on growth of young loblolly pine and infestations of Nantucket pine tip moth (Lepidoptera: Tortricidae)

Abstract A 2‐year‐old pine plantation was selected to receive treatments of fertilizers and herbicides to evaluate effects on Nantucket pine tip moth infestations and the tree growth parameters of height, diameter and volume increment. Nitrogen and phosphorus fertilizers, and hexazinone and sulfometuron methyl herbicides were used in creating six treatments: (i) control; (ii) phosphorus; (iii) nitrogen and phosphorus; (iv) phosphorus and herbicide; (v) nitrogen, phosphorus and herbicide; and (vi) herbicide. Treatments were applied in 1987 and 1988. In 1987, trees treated with nitrogen, phosphorus and herbicide had significantly greater height, diameter and volume growth than trees not receiving fertilizer treatments, but did not have significantly higher tip moth infestations than control trees. Treatments receiving phosphorus only had much lower tip moth infestation rates than other treatments except nitrogen and phosphorus. In 1988, tip moth infestations were uniformly low, with no differences in treatment effects observed.

Validating the geometric accuracy of high spatial resolution multispectral satellite data

Uses of high spatial resolution data obtained from satellite-based sensors include creating land cover maps, deriving large-scale quantitative assessments such as vegetation indices, and visually assessing an area for qualitative information only assessable from large-scale digital data. One of the more popular uses of high spatial resolution data is to use the image as a base map for on-screen digitizing spatially dependent vector products. Since most geographic information system (GIS) databases store a variety of current and historical data, the accuracy of any on-screen digitized product is dependent on the spatial accuracy of the reference data. Therefore, it is important to understand and validate the accuracy of data used to create spatially referenced product, even though the data come with high spatial resolution. One of the more popular and historical high spatial resolution data within most GIS labs is QuickBirds multispectral data at 2.44 × 2.44 m2. Although there are current sensors available with a higher spatial resolution, the sometimes prohibitive expense of obtaining high spatial resolution data necessitates the need to utilize and assess historic data. Since the QuickBird has been the mainstay of high spatial resolution data since 2001, understanding the geometric accuracy of the DigitalGlobes QuickBird user-defined panchromatic and multispectral image bundle product remains relevant. In this study, we assessed the positional accuracy of this product for its utility as an “off the shelf” base map for creating other spatially referenced products. The average Euclidean distance, RMSE (root mean square error), and RSME (root square mean error) between QuickBird-identified Universal Transverse Mercator (UTM) coordinates and coincident in situ GPS-collected UTM coordinates were calculated at 33 systematically selected locations throughout the city of Nacogdoches, Texas, USA. The average Euclidean distance, RMSE, and RSME between QuickBirds projected UTM coordinates and its corresponding GPS-collected UTM coordinates measured at 5.34 meters, 5.79 meters, and 4.05 meters, respectively. They were well within DigitalGlobes stated RMSE positional accuracy of 14.0 meters for a panchromatic and multispectral QuickBird image bundle.