Treesearch

The frequency and timing of frost events and the length of the growing season are critical limiting factors in many human and natural ecosystems. This study investigates the temporal and spatial variability of the date of last spring frost (LSF), the date of first fall frost (FFF), and the length of the frost-free season (FFS) in the Great Lakes region of the United States using two gridded reanalysis datasets for the period of 1980-2010. Across most of the Great Lakes region, there has been a negative trend for the LSF and a positive trend for the FFF, leading to a lengthening of FFS. The...

Aim Anderson & Stebbins (1954, Evolution, 8, 378–388) posited that human activities promote species hybridizations by creating opportunities for hybridization and new habitats for hybrids to persist through disturbances (i.e. the ‘disturbance hypothesis’). While the first part of this hypothesis appears to be well supported, the second part has not been corroborated with empirical evidence, probably because of the lack of appropriate data. In this study, I (1) document the richness and distribution of hybrid plants in the United States; (2) examine the relationships between hybrids of...

A thorough analysis of the kraft pulping process makes it obvious why it has dominated for over a century as an industrial process with no replacement in sight. It uses low-cost raw materials; collects and regenerates over 90% of the chemicals needed in the process; and is indifferent to wood raw material and good at preserving the cellulose portion of the wood, the part that provides strong fibers. Although the process is odiferous, extremely capital intensive, and very poor at preserving hemicellulose yield, no alternatives have been able to replace it for process cost and product...

This publication provides an overview of the forest resources in Ohio based upon inventories conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program of the Northern Research Station. Information about the national and regional FIA program is available online at http://fia.fs.fed.us. Since 2001, FIA has implemented an annual inventory in Ohio. For the 2013 inventory, estimates for current variables, such as forest area, volume, and biomass, are based on 4,296 plots (both forested and nonforest) inventoried from 2009-2013. Change variables, such as net growth,...

This report provides an overview of forest resources in Rhode Island based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program of the Northern Research Station. Estimates are based on field data collected using the FIA annualized sample design. Results are for the measurement years 2009-2013 with comparisons made to 2003-2007. Forest resource measurements were taken on 123 plots with about 20 percent of the plots measured each year. Estimates will be updated and published annually. For core tables and more information, including definitions and...

This report provides an overview of forest resources in Connecticut based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program of the Northern Research Station. Estimates are based on field data collected using the FIA annualized sample design. Results are for the measurement years 2009-2013 with comparisons made to 2003-2007. Forest resource measurements were taken on 320 plots with about 20 percent of the plots measured each year. Estimates will be updated and published annually. For core tables and more information, including definitions and...

This report provides an overview of forest resources in Massachusetts based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program of the Northern Research Station. Estimates are based on field data collected using the FIA annualized sample design. Results are for the measurement years 2009-2013 with comparisons made to 2003-2007. Forest resource measurements were taken on 545 plots with about 20 percent of the plots measured each year. Estimates will be updated and published annually. For core tables and more information, including definitions...

Miconia calvescens de Candolle (Melastomataceae) is an invasive tree considered the most serious threat to natural ecosystems of Hawaii and other Pacific islands. The success of M. calvescens as an invasive species is greatly owing to its shade tolerance and the shaded habitat it creates, where many native plant species that are light-demanding cannot survive. Salbia lotanalis Druce (Lepidoptera: Crambidae), a neotropical leaf roller attacking M. calvescens, was evaluated for two mechanisms by which it reduces leaf area of its host plant: feeding (defoliation), which removes leaf tissue,...

This study investigated the possibility of a facilitative relationship between Chinese privet (Ligustrum sinense) and exotic earthworms, in the southeastern region of the USA. Earthworms and selected soil properties were sampled five years after experimental removal of privet from flood plain forests of the Georgia Piedmont region. The earthworm communities and soil properties were compared between sites with privet, privet removal sites, and reference sites where privet had never established. Results showed that introduced European earthworms (Aporrectodea caliginosa, Lumbricus rubellus,...

A principal challenge of federal forest management has been maintaining and improving habitat for sensitive species in forests adapted to frequent, low- to moderate-intensity fire regimes that have become increasingly vulnerable to uncharacteristically severe wildfires. To enhance forest resilience, a coordinated landscape fuel network was installed in the northern Sierra Nevada, which reduced the potential for hazardous fire, despite constraints for wildlife protection that limited the extent and intensity of treatments. Small mammal and songbird communities were largely unaffected by...