Treesearch

We report several contributions to the vascular flora of Puerto Rico, based on botanical collections from 2021–2023 that resulted from an interagency effort (Ecological Site Descriptions — ESDs), comprising previously unreported species, naturalizations, and new distributions. Notes including known islandwide distributions are provided for applicable cases.

Invasive forest pests can affect the composition and physical structure of forest canopies that may facilitate invasion by non-native plants. However, it remains unclear whether this process is generalizable across invasive plant species at broad spatial scales, and how other landscape characteristics may simultaneously facilitate non-native plant invasion. Here, we assembled a dataset of over 3000 repeatedly measured forest plots and quantified the impact of emerald ash borer (EAB, Agrilus planipennis) residence time, land cover, and forest structure on the accumulation and coverage of...

In response to the COVID-19 pandemic, some governments instituted mandatory stay-at-home policies. As these policies made exceptions for essential industries such as the forest sector, it is not clear a priori whether and how these policies would affect forest-based employment. This study examined the effect of mandatory stay-at-home orders on employment in the forest sector in forest dependent counties in eleven southern states in the United States. We estimated panel event study models in addition to difference-in-difference models to evaluate the policy effects with respect to initial...

The use of wood in construction requires knowledge of the mechanical properties and the particularities that wood presents in comparison with other materials used for structural purposes such as steel, concrete, brick, or stone. The introduction mentions the environmental advantages that justify the use of wood today. The orthotropy of wood is one of the differentiating characteristics that must be taken into account when studying its behaviour. The determination of the properties of wood is then addressed from a historical perspective and the differentiation is made between the properties...

Biological invasions are frequently and closely associated with armed conflict. As a key element of human history, war involves the invasion of (often distant) enemy territories, during which time species can be translocated, intentionally or unintentionally. Large-scale conflicts such as World War I and II, in which thousands of soldiers and supplies (including foodstuffs) were transported within and between continents, resulted in the spread of non-native taxa. However, smaller scale military actions may also involve rapid movements of troops between geographical areas, potentially...

Assessing the effectiveness and measuring the performance of fuel treatments and other wildfire risk mitigation efforts are challenging endeavors. Perhaps the most complicated is quantifying avoided impacts. In this study, we show how probabilistic counterfactual analysis can help with performance evaluation. We borrow insights from the disaster risk mitigation and climate event attribution literature to illustrate a counterfactual framework and provide examples using ensemble wildfire simulations. Specifically, we reanalyze previously published fire simulation data from fire-prone...

Leptographium wageneri is a native fungal pathogen in western North America that causes black stain root disease (BSRD) of conifers. Three host-specialized varieties of this pathogen were previously described: L. wageneri var. wageneri on pinyon pines (Pinus monophylla and P. edulis); L. wageneri var. ponderosum, primarily on hard pines (e.g., P. ponderosa, P. jeffreyi); and L. wageneri var. pseudotsugae on Douglas-fir (Pseudotsuga menziesii). Morphological, physiological, and ecological differences among the three pathogen varieties have been previously determined; however, DNA-based...

Soils are the largest source of atmospheric nitrous oxide (N2O), a powerful greenhouse gas. Dry soils rarely harbor anoxic conditions to favor denitrification, the predominant N2O-producing process, yet, among the largest N2O emissions have been measured after wetting summer-dry desert soils, raising the question: Can denitrifiers endure extreme drought and produce N2O immediately after rainfall? Using isotopic and molecular approaches in a California desert,we found that denitrifiers produced N2O within 15 minutes of wetting dry soils (site preference = 12.8 ± 3.92 per mil, δ15Nbulk =...

Diseases caused by invasive pathogens are an increasing threat to forest health, and early and accurate disease detection is essential for timely and precision forest management. The recent technological advancements in spectral imaging and artificial intelligence have opened up new possibilities for plant disease detection in both crops and trees. In this study, Dutch elm disease (DED; caused by Ophiostoma novo-ulmi,) and American elm (Ulmus americana) was used as example pathosystem to evaluate the accuracy of two in-house developed high-precision portable hyper- and multi-spectral leaf...

American black bears (Ursus americanus) have been successfully restored in North Carolina (NC) due to management and research efforts by the North Carolina Wildlife Resources Commission and various partners. Investigations by law enforcement in NC involving black bears typically center on a) illegal take, b) purchase, possession, and sale of bear parts, or c) human-bear interactions. Effective prosecution of illegal parties requires methods that permit individual identification of black bears. Typically, individualization is achieved using robust DNA profiling and comparison to accepted...