Treesearch

This is the third in a series of studies to quantify yields of hybrid sweetgum (Liquidambar formosana x styraciflua) biomass at an afforested site in north Louisiana. Pooling across herbicide and varietal treatments to produce a single model system to estimate weight was determined to be statistically appropriate on the 2-year-old (1-0) seedling stock. An equation constructed from that study, where moisture content on the oven-dry basis averaged 107.5 percent (51.8 percent wet-basis), estimated the weight of standing trees. Field measurements of stem diameter occurred at 1-foot increments...

Stand-level basal area mixed-effects models are commonly being developed for species around the World. We wanted to determine if a stand-level basal area mixed-effects model fit using one species (for example, loblolly pine (Pinus taeda L.) plantations where biological and economical rotation ages can range from 20 to 40 years) could produce accurate estimates following calibration using data from another species. This approach would be useful in those situations where there is limited data available for a species (for example, naturally regenerated black spruce (Picea mariana (Mill.)...

Hardwoods significantly contribute to Louisiana’s forest economy. Unfortunately, the emerald ash borer (Agrilus planipennis), or EAB, will have untold impacts on those contributions. Here, we estimated one scenario’s effects on Louisiana’s hardwood timber product value. Ash (Fraxinus spp.) mortality due to EAB was assumed to follow a Beta distribution to eliminate essentially all ash within 25 years. Mortality rates were relatively slow in the near future, peaked after the middle stage of infestation, and tapered precipitously near the end of the projection period. Annual growth of ash was...

Point-sampling selects sample trees by projecting horizontal angles. In many inventories, angles are to be projected to where diameter at breast height (d.b.h.) is measured (4.5 feet above the ground), but due to user error, angles are often projected to diameters at other heights. Thus, errors are made as to which trees should be sampled, probabilities of sampling individual trees are incorrect, and the basal area estimate does not truly correspond to d.b.h. The objective of this paper is to determine the potential economic impacts of projecting angles at heights other than d.b.h. when...

Pine (Pinus spp.) plantations in the Southeastern United States are managed intensively following even-aged silviculture. Trees are harvested at young ages resulting in inferior wood quality. We modeled two fast-growing southern pines using the Forest Vegetation Simulator to determine the price premium that forest landowners need to grow higher quality pines on longer rotation ages. Different management regimes were optimized using a land expectation value maximization approach. Results suggested that delaying final harvest by 10 years is financially obtainable, while a 20-year rotation...

A mixed-effects height-diameter model is presented for longleaf pine (Pinus palustris P. Mill.) plantations in northern Florida and Georgia. After obtaining height-diameter measurements from a plot/stand of interest, this mixed-effects model can be calibrated to produce localized individual tree height estimates. Based on model calibration of independent data from South Carolina, the use of three or four longleaf pine trees from a plot to calibrate the model provides a reasonable compromise between predictive ability and field sampling time. If calibrated at the stand-level, three trees...

Data from permanent remeasurement plots established in loblolly pine (Pinus taeda L.) plantations growing in the Misiones/Paraná region of South America were used to develop and test a system of equations for predicting and projecting volume yields for thinned and unthinned stands in that region. Component equations parameterized with the data included dominant height/site index, basal area prediction and projection, survival, and total volume yield prediction. Improved estimates of yield were achieved when geographic coordinates were included in the basal area and total volume yield...

As part of many forest inventories, sample sizes needed to meet some desired level of precision are estimated. In many timber inventories, based on estimates of the inherent variability (e.g., coefficient of variation, CV), sample sizes are estimated for average total merchantable volume or for the most valuable product class such as average sawlog volume. However, often foresters are equally interested in producing accurate and precise stand tables. Stand tables contain number of trees by diameter and/or height classes while stock tables contain amount of volume by diameter and/or height...

Aspects of governance of non-wood forest products (NWFPs) include institutional rules, stakeholder arrangements, and decision-making processes that govern production systems from access to resources, their use, and to markets. Compared with other forest products, few studies have investigated the governance of NWFPs in European post-socialistic countries transitioning from a planned to a market economy. This study compares institutional frameworks and stakeholder arrangements related to NWFPs in Russia and Ukraine using a case study approach. Both countries have a legacy of top-down forest...

In the present study, we examined the relationships between (1) N, P, total organic carbon (TOC), and total suspended sediment (TSS) each and stream flow and water table elevation, individually (2) N, P, and TOC, each and TSS, and (3) stream water C/N ratios and stream flow in managed pine forests with various switchgrass treatments implemented on four watersheds in coastal North Carolina plain. The treatments included a young pine forest–natural understorey (27.5 ha), a young pine forest with switchgrass intercropped between pine rows replacing natural understorey (IC) (26.3 ha), a mature...