Treesearch

In the western United States, restoration of forests with historically frequent, low-severity fire regimes often includes fuel reduction that reestablish open, early-seral conditions while reducing fuel continuity and loading. Between 2001 and 2016, fuel reduction (e.g., thinning, prescribed burning, etc.) was implemented on over 26 million hectares of federal lands alone in the United States, reflecting the urgency to mitigate risk from high-severity wildfire. However, between 2001 and 2012, nearly 20 million hectares in the United States were impacted by mountain pine beetle (MPB;...

Mississippi has approximately 63 crayfish species and no known invasive crayfish. Whereas Alabama has about 97 species, including at least three non-natives: the Kentucky River crayfish (Faxonius juvenilis), the gray-speckled crayfish (F. palmeri palmeri), and the virile crayfish (F. virilis). In addition, the red swamp crayfish (Procambarus clarkii) is probably native on Alabama’s Gulf Coastal Plain but introduced elsewhere in the state.

Vibrational spectroscopy is a very suitable tool for investigating the plant cell wall in situ with almost no sample preparation. The structural information of all different constituents is contained in a single spectrum. Interpretation therefore heavily relies on reference spectra and understanding of the vibrational behavior of the components under study. For the first time, we show infrared (IR) and Raman spectra of dibenzodioxocin (DBDO), an important lignin substructure. A detailed vibrational assignment of the molecule, based on quantum chemical computations, is given in the Supportin...

Outbreaks of conifer bark beetles in Europe and North America have increased in scale and severity in recent decades. In this study, we identify existing fossil records containing bark beetle remains from the end of the Last Glacial Maximum (~14,000 cal. yr BP) to present day using the online databases Neotoma and BugsCEP and literature searches, and compare these data with modern distribution data of selected tree-killing species. Modern-day observational data from the Global Biodiversity Information Facility (GBIF) database was used to map recorded distributions from AD 1750 to present...

In mountainous headwater catchments, downslope flow of subsurface water could buffer downslope forest communities from soil moisture stress during drought. Here we investigated changes in landscape-scale vegetation patterns at five forested headwater catchments in the Coweeta Hydrologic Laboratory in the southern Appalachians. We used a ca. 30-year Landsat Thematic Mapper (TM) image record of normalized difference vegetation index (NDVI), spanning a period of recorded warming since the mid-1970. We then, related spatial and temporal canopy patterns to seasonal water balance, streamflow...

Ashes (Fraxinus spp.) are important hardwood tree species in rural, suburban, and urban forests of the eastern USA. Unfortunately, emerald ash borer (EAB, Agrilus planipennis) an invasive insect pest that was accidentally imported from Asia in the late 1980s–early 1990s is destroying them at an alarming rate. All North American ashes are highly susceptible to EAB, although blue ash (F. quadrangulata) may have some inherent attributes that provide it some protection. In contrast Manchurian ash (F. mandshurica) is relatively resistant to EAB having coevolved with the insect pest in its...

Forests are considered a natural solution for mitigating climate change because they absorb and store atmospheric carbon. With Alaska boasting 129 million acres of forest, this state can play a crucial role as a carbon sink for the United States. Until recently, the volume of carbon stored in Alaska’s forests was unknown, as was their future carbon sequestration capacity.In 2007, Congress passed the Energy Independence and Security Act that directed the Department of the Interior to assess the stock and flow of carbon in all the lands and waters of the United States. In 2012, a team...

In Puerto Rico, the Green Iguana, Iguana iguana, is considered an introduced and invasive species responsible for annual losses estimated in millions of dollars to local governmental and private sectors. The purpose of this study was to use GAP analyses to generate habitat distribution models for Green Iguanas in Puerto Rico. The two models had 79.7% and 88.4% predictability, respectively. The second model, which included road corridors as a habitat widely known to be used by iguanas for dispersal, basking, and mating displays, might have overestimated the Green Iguana’s distribution. The...

As climate changes, locally adapted tree populations may become maladapted to the sites in which they presently occur. When natural adaptive processes are insufficient for populations to keep pace with changing climate, human‐assisted relocation of genotypes (assisted gene flow) may be a useful tool for maintaining forest resilience. While existing empirical evidence provides insight into the potential outcomes and consequences of assisted gene flow, its applicability to large‐scale plantings needs to be evaluated. We conducted a test of assisted gene flow in the context of operational...

Monitoring vegetation phenology is important for managers at several scales. Across decades, changes in the timing, pattern, and duration of significant life cycle events for plant groups can foreshadow shifts in species assemblages that can affect ecosystem services. In the shorter term, managers need phenological information to time activities such as grazing, ecological restoration plantings, biocontrol of pests, seed collection, and wildlife monitoring. However, tools to deliver timely seasonal development have been limited either spatially (data from a single tower or weather station,...