Treesearch

Differential habitat use and intraguild competition are both thought to be important drivers of animal population sizes and distributions. Habitat associations for individual species are well-established, and interactions between particular pairs of species have been highlighted in many focal studies. However, community-wide assessments of the relative strengths of these two factors have not been conducted. We built multi-scale habitat occupancy models for five carnivore taxa of New York’s Adirondack landscape and assessed the relative performance of these models against ones in which...

Improving management practices in industrial forest plantations may increase production efficiencies, thereby reducing pressures on native tropical forests for meeting global pulp needs. This study aims to predict stem volume (V) in plantations of fast-growing Eucalyptus hybrid clones located in southeast Brazil using field plot and airborne Light Detection andRanging (LiDAR) data. Forest inventory attributes and LiDAR-derived metrics were calculated at 108 sample plots. The best LiDAR-based predictors of V were identified based on loadings calculated from a principal component analysis...

Dung fungi, such as Sordaria fimicola, generally reproduce sexually with ascospores discharged from mammalian dung after passage through herbivores. Their life cycle is thought to be obligate to dung, and thus their ascospores in Quaternary sediments have been interpreted as evidence of past mammalian herbivore activity. Reports of dung fungi as endophytes would seem to challenge the view that they are obligate to dung. However, endophyte status is controversial because surface-sterilization protocols could fail to kill dung fungus ascospores stuck to the plant surface. Thus, we first...

A mature shortleaf pine (Pinus echinata) stand on the Cumberland Plateau in Tennessee at the Catoosa Wildlife Management Area was harvested in 2001 in response to a regional southern pine beetle outbreak and converted into a savannah through periodic prescribed burns in 2005, 2010, and 2013. Following the harvest and series of burns, the stand was occupied by shortleaf pine seedlings and saplings of different sizes (<5 feet, 6 to 10 feet, and >10 feet) at a rate of approximately 400 stems per acre. Given the re-sprouting capability of shortleaf pine, the objective of this study was to...

We used computer simulations to test the efficacy of multivariate statistical methods to detect, quantify, and map spatial variability of forest stands. Simulated stands were developed of regularly-spaced plantations of loblolly pine (Pinus taeda L.). We assumed no affects of competition or mortality, but random variability was added to individual tree characteristics. The purpose of simulating stands without these complex interactions was to provide a controlled situation to measure the efficacy of our methods. We examined redundancy analysis, partial redundancy analysis, and spatially...

Predicting the effects of silvicultural choices on tree regeneration has traditionally been difficult with the tools currently available to foresters. In an effort to improve this, we have developed a simulation framework based on hypotheses of stand dynamics for several species found in the Missouri Ozarks. This framework includes separate modules for establishment, growth, and mortality. Within the establishment module, empirical parameters are used to stochastically simulate regeneration establishment following a variety of harvest-based silvicultural manipulations. A pre-disturbance...

Site index is the most common metric of site productivity in loblolly pine plantations. Generally applied as a constant for a particular stand, it provides an overall measure of a site’s ability to grow trees. It is well known, however, that even the most uniform stands can have considerable variation in site index due to soil factors that influence microsite, variation in genetics from tree to tree, or the uneven application of silvicultural treatments. To better account for such variability, input options to the PTAEDA (version 4.1), an individual tree growth and yield model, were...

Information provided by growth and yield models is the basis for forest managers to make decisions on how to manage their forests. Among different types of growth models, whole-stand models offer predictions at stand level, whereas individual-tree models give detailed information at tree level. The well-known logistic regression is commonly used to predict tree survival probability. In addition to the maximum likelihood approach, a new approach called CDF regression was introduced here to estimate parameters of the tree survival equation. Each of the two above approaches was evaluated as...

Increasingly, fire managers are using natural ignitions in conjunction with prescribed burns to restore and maintain fire-adapted ecosystems. Increased fuel loading from fire suppression and increasing drought indices associated with climate change, however, may cause natural ignitions to burn with greater intensity and severity. Managers must weigh risk factors versus benefits before allowing a lightning ignition to burn under these conditions. During the severe drought of 2011, the Ouachita National Forest had more lightning ignitions than any year in recorded history. While most were...

An updated whole stand growth and yield system for planted longleaf pine (Pinus palustris) was developed from permanent plot data collected annually over a 13 to 16 year period. The data set consists of 15 intensively managed longleaf pine plantations that are located in Lee, Worth, Mitchell, and Baker counties in southwest Georgia. Stand survival, dominant height, basal area and cubic foot volume yield models were developed for both low and high planting densities. Model prediction error remained low for both planting density classes. Yield models are an improvement over those published...