Treesearch

Premise of the study: Ponderosa pine ( Pinus ponderosa Douglas ex P. Lawson & C. Lawson) exhibits complicated patterns of morphological and genetic variation across its range in western North America. This study aims to clarify P. ponderosa evolutionary history and phylogeography using a highly polymorphic mitochondrial DNA marker, with results offering insights into how geographical and climatological processes drove the modern evolutionary structure of tree species in the region. Methods: We amplified the mtDNA nad1 second intron minisatellite region for 3,100 trees representing 104...

Private forest owners control most of the southern forest resource and are critical to maintaining forest health in the South. Record droughts, rising temperatures, increased frequency and intensity of wildfires, insect and plant invasions, and more intense storm events all pose threats to the health of Southern forests. Scientists project that increases in temperature and changes in rainfall patterns will cause these disturbances to become more common, occurring with greater intensity or duration. This pamphlet reviews healthy forest strategies and approaches to decrease the risks...

The relative importance of facilitation and competition between pairwise plants across abiotic stress gradients as predicted by the stress-gradient hypothesis has been confirmed in arid and temperate ecosystems, but the hypothesis has rarely been tested in tropical systems, particularly across nutrient gradients. The current research examines the interactions between a pioneer shrub Rhodomyrtus tomentosa (the nurse plant) and seedlings of a transplanted native woody Schima superba (the target species) in a tropical system in which position on a slope corresponds with a nutrient gradient;...

The way in which disturbances from human land use are patterned in space across scales can have important consequences for efforts to govern human/environment with regard to, but not only, invasive spread-dispersal processes. In this context, we explore the potential of disturbance patterns along a continuum of scales as proxies for identifying the geographical regions prone to spread of invasive plant species. To this end, we build on a previous framework of cross-scale disturbance patterns, exercising the approach for the Apulia region (South Italy). We first review procedures and...

Key Findings Climate change is affecting the southeastern USA, particularly increases in rainfall variability and air temperature, which have resulted in more frequent hydrologic extremes, such as high‐intensity storms (tropical storms and hurricanes), flooding, and drought events. Future climate warming likely will increase water loss through evapotranspiration (ET) due to increased evaporative potential and plant species shift. Greater ET can decrease total streamflow, groundwater recharge, flow rate, and regional water supplies. Water supply stress is projected to increase significantly...

Future climate and land-use changes and growing human populations may reduce the abundance of water resources relative to anthropogenic and ecological needs in the Northeast and Midwest (U.S.). We used output from WaSSI, a water accounting model, to assess potential changes between 2010 and 2060 in (1) anthropogenic water stress for watersheds throughout the Northeast and Midwest and (2) native fish species richness (i.e., number of species) for the Upper Mississippi water resource region (UMWRR). Six alternative scenarios of climate change, land-use change, and human population growth...

The aim of the special issue “Interactions of Forests, Climate, Water Resources, and Humans in a Changing Environment” is to present case studies on the influences of natural and human disturbances on forest water resources under a changing climate. Studies in this collection of six papers cover a wide range of geographic regions from Australia to Nigeria with spatial research scale spanning from a tree leaf, to a segment of forest road, and large basins with mixed land uses. These studies clearly show the strong interactions among forests, global climate change, water quantity and...

LiP (lignin peroxidase) from Trametopsis cervina has an exposed catalytic tyrosine residue (Tyr181) instead of the tryptophan conserved in other lignin-degrading peroxidases. Pristine LiP showed a lag period in VA (veratryl alcohol) oxidation. However, VA-LiP (LiP after treatment with H2O2 and VA) lacked this lag, and H2O2-LiP (H2O2-treated LiP) was inactive. MS analyses revealed that VA-LiP includes one VA molecule covalently bound to the side chain of Tyr181, whereas H2O2-LiP contains a hydroxylated Tyr181. No adduct is formed in the Y171N variant. Molecular docking showed that VA...

Long-distance introductions of alien species are often driven by socioeconomic factors, such that conventional “biological” invasion models may not be capable of estimating spread fully and reliably. In this study, we demonstrate a new technique for assessing and reconstructing human-mediated pathways of alien forest species entries to major settlements in Canada via commercial road transportation and domestic trade. We undertook our analysis in three steps. First, we used existing data on movement of commodities associated with bark- and wood-boring forest pests to build a probabilistic...

This publication provides an overview of multiflora rose (Rosa multiflora) on forest land across the 24 states of the midwestern and northeastern United States based on an extensive systematic network of plots measured by the Forest Inventory and Analysis (FIA) program of the U.S. Forest Service, Northern Research Station (NRS).