Treesearch

The Madrean Sky Island region is an ecologically important area harboring exceptional biodiversity, including a unique avifauna that supports a thriving ecotourism industry in southeastern Arizona. This area has been impacted by several large wildfires in recent decades. These wildfires have altered vegetation composition and structure in forests and woodlands, and the effects of these changes on bird populations and distribution are not well understood. We studied occupancy and habitat associations of forest and woodland birds within five mountain ranges in southeastern Arizona from 1991...

This resource update provides an overview of forest resources in Indiana based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Northern Research Station in cooperation with the Indiana Department of Natural Resources. Estimates are based on field data collected using the FIA annualized strategic sample design and are updated yearly. The current 2011-2016 sample set consists of 5,381 plots with 1,372 of them being forested or partially forested. In 2014, NRS-FIA changed to a 7-year inventory cycle, wherein 1/7th (14.3 percent) of the...

The 606 is the world's first multiuse elevated trail, extending for 2.7 mi (4.35 km) through diverse neighborhoods whose per capita of open space is one of the lowest in Chicago. The trail connects six ground-level parks and is managed for recreation, but it also serves as a cross-town transportation connector and was funded partially with transportation dollars. Managers sought information about trail use to maintain a safe and harmonious experience for users, to plan operations and maintenance, and to document the benefits of trail development. The use of The 606 was examined during the...

Black ash (Fraxinus nigra) is an endangered hardwood tree species under threat of extirpation by the emerald ash borer (EAB), an aggressive exotic phloemfeeding beetle. We have developed an efficient regeneration system through adventitious shoot organogenesis in F. nigra using in vitro-derived leaf explants. Two types of leaf explants were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of plant growth regulators to induce callus and adventitious shoot bud formation. Significant effects of explant, and plant growth regulator interactions were found....

Ailanthus altissima ((Mill.) Swingle, tree-of-heaven), an exotic invasive tree that is common throughout much of the eastern United States, can invade and expand dramatically when forests are disturbed. Anecdotal evidence suggests that fire facilitates its spread, but the relationship between fire and this prolific invasive tree is poorly understood. To better understand the impacts of fire on Ailanthus, we conducted studies at Tar Hollow State Forest in southeastern Ohio, where Ailanthus is widely distributed and where, since 2001, prescribed fire has been applied to 25% of the 3885-ha...

Epiphytic lichens are bioindicators of climate, air quality, and other forest conditions and may reveal how forests will respond to global changes in the U.S. Pacific States of Alaska, Washington, Oregon, and California. We explored climate indication with lichen communities surveyed by using both the USDA Forest Service Forest Inventory and Analysis (FIA) and Alaska Region (R10) methods. Across the Pacific States, lichen indicator species and ordination “climate scores” reflected associations between lichen community composition and climate. Indicator species are appealing targets for...

We measured vegetation growth 5, 10, and 20 years following plantation establishment at 12 Long-term Soil Productivity installations in California’s Sierra Nevada and Southern Cascades. The combined effects of soil compaction (none, moderate, severe), organic matter removal (tree bole only, whole tree, whole tree plus forest floor), and competing vegetation control (complete: VC, none: NVC) on aboveground biomass were tested. Soils ranged from sandy loams to clay loams and were compacted (10-25% bulk density increase) prior to planting of mixed-conifer seedlings. Soil compaction resulted...

Global food security concerns emphasize the need for sustainable agriculture and local food production. In Puerto Rico, over 80 percent of food is imported, and local production levels have reached historical lows. Efforts to increase local food production are driven by government agencies, non-government organizations, farmers, and consumers. Integration of geographic information helps plan and balance the reinvention and invigoration of the agriculture sector while maintaining ecological services. We used simple criteria that included currently protected lands and the importance of slope...

• Climate change is increasing drought frequency, which may affect symbiotic N2 fixation (SNF), a process that facilitates ecosystem recovery from disturbance. Here, we assessed the effect of drought frequency on the ecophysiology and SNF rate of a common N2-fixing tree in eastern US forests.•We grew Robinia pseudoacacia seedlings under the same mean soil moisture, but with different drought frequency caused by wet–dry cycles of varying periodicity.•We found no effect of drought frequency on final biomass or mean SNF rate. However, seedlings responded differently to wet and dry phases...

Fire and smoke models are numerical tools for simulating fire behavior, smoke dynamics, and air quality impacts of wildland fires. Fire models are developed based on the fundamental chemistry and physics of combustion and fire spread or statistical analysis of experimental data (Sullivan 2009). They provide information on fire spread and fuel consumption for safe and efficient prescribed (Rx) burning and wildfire suppression. They also provide inputs of heat release and emissions for smoke modeling. A large number of fire models such as BehavePlus, FIRETEC, NEXUS, FARSITE, and WFDS have...