Treesearch

According to UN estimates, it is expected that the world population living in cities will exceed 66% in 2050 (United Nations, 2014). The complex and intense interaction of ecological and socioeconomic systems shaping cities has highlighted the need to foster an interdisciplinary approach to urban issues integrating Natural and Social Sciences (Alberti et al., 2003). Recent research has also stressed the role of urban ecosystems in providing vital services to city dwellers, and the need to embody ecosystem services in urban planning practice (Ahern et al., 2014; Colding, 2011). Ecosystem...

The eBird database is the product of a huge citizen science project at the Cornell University Laboratory of Ornithology. Members report their birding excursions both their destinations and the numbers and types of birds they observe on each trip. Based on home address information, we calculate travel costs for each birder for trips to alternative birding hotspots. We focus on the Pacific Northwest U.S. (Washington and Oregon states). Many birders are “listers” who seek to maximize the cumulative number of species they have been able to see, and each hotspot is characterized by the number...

Spatial variation in mercury (Hg) and methylmercury (MeHg) bioaccumulation in urban coastal watersheds reflects complex interactions between Hg sources, land use, and environmental gradients. We examined MeHg concentrations in fauna from the Delaware River estuary, and related these measurements to environmental parameters and human impacts on the waterway. The sampling sites followed a north to south gradient of increasing salinity, decreasing urban influence, and increasing marsh cover. Although mean total Hg in surface sediments (top 4 cm) peaked in the urban estuarine turbidity maximum...

The scale of investigation for disturbanceinfluenced processes plays a critical role in theoretical assumptions about stability, variance, and equilibrium, as well as conservation reserve and long-term monitoring program design. Critical consideration of scale is required for robust planning designs, especially when anticipating future disturbances whose exact locations are unknown. This research quantified disturbance proportion and pattern (as contagion) at multiple scales across North America. This pattern of scale-associated variability can guide selection of study and management...

The 20th International Nondestructive Testing and Evaluation of Wood Symposium was hosted by the USDA Forest Service Forest Products Laboratory in Madison, Wisconsin, USA, on September 12–15, 2017. This Symposium was a forum for those involved in nondestructive testing and evaluation (NDT/NDE) of wood and brought together many NDT/NDE users, suppliers, international researchers, representatives from various government agencies, and other groups to share research results, products, and technology for evaluating a wide range of wood products, including standing trees, logs, lumber, and wood...

Harvesting traffic may alter soil properties and reduce forest productivity if soil disturbances are not mitigated. Logging operations were conducted during high soil moisture conditions on the South Carolina, USA coast to salvage timber and reduce wildfire potential following Hurricane Hugo in 1989. Long term study sites were established on wet pine flats to evaluate effects of primary skid trails and site preparation on soil properties and loblolly pine productivity. The experiment was analyzed as a split-plot within an unbalanced randomized complete block design having 12 blocks, two...

In the USA, forest genetics research began over 100 years ago and loblolly pine breeding programs were established in the 1950s. However, the genetics underlying complex traits of loblolly pine remains to be discovered. To address this, adaptive and growth traits were measured and analyzed in a clonally tested loblolly pine (Pinus taeda L.) population. Over 2.8 million single nucleotide polymorphism (SNP) markers detected from exome sequencing were used to test for single-locus associations, SNP-SNP interactions, and correlation of individual heterozygosity with phenotypic traits. A total...

OpCost is a harvest and fuel treatment operations cost model developed to function as both a standalone tool and an integrated component of the Bioregional Inventory Originated Simulation Under Management (BioSum) analytical framework for landscape-level analysis of forest management alternatives. OpCost is an updated implementation of the Fuel Reduction Cost Simulator (FRCS). However, neither FRCS nor OpCost have been formally validated. Validation of simulation models using data that are independent of those used for model development is important for building user confidence in model...

Short-rotation woody crops (SRWC) grown for bioenergy production are considered a more sustainable feedstock than food crops such as corn and soybean. However, to be sustainable SRWC should be deployed on land not suitable for agriculture (e.g., marginal lands). Here we quantified productivity and energy yield of four SRWC candidate species grown at different planting densities (1250, 2500, 5000, and 10,000 trees ha−1) under a low-input regime on a marginal site in the Piedmont of North Carolina and responses to reduced water availability. By the end of the first growing season, 75 to 100%...