Treesearch

Exotic earthworms are invading forests in North America where native earthworms have been absent since the last glaciation. These earthworms bioturbate soils and may enhance physical interactions between minerals and organic matter (OM), thus affecting mineral sorption of carbon (C) which may affect C cycling. We quantitatively show how OM-mineral sorption and soil C inventories respond to exotic earthworms along an earthworm invasion chronosequence in a sugar maple forest in northern Minnesota. We hypothesized that mineral surface area in A horizons would increase as burrowing earthworms...

Season affects many characteristics of populations and, as a result, the interpretations of surveys conducted at different seasons. We explored seasonal variation in occupancy using data from four studies on the Pacific marten Martes caurina. Detection surveys were conducted during winter and summer using either cameras or track stations. We conducted a 'multiple location, paired season' analysis using data from all four study areas and a 'multiple season' analysis using seasonally replicated occupancy data collected at one of the areas. In the former analysis, summer occupancy estimates...

This resource update provides an overview of forest resources in South Carolina. Information for this factsheet was updated by means of the Forest Inventory and Analysis (FIA) annualized sample design. Each year 20 percent of the sample plots (one panel) in South Carolina are measured by field crews, the data compiled, and new estimates produced. After 5 years of measurements, the full sample (a cycle) is complete and a new survey cycle begins. The most reliable trend information (especially that concerning magnitude of change) comes from comparing two full cycles of data. Estimates...

This resource bulletin consolidates data from the sixth complete survey of Kentucky’s forest resources, which was conducted during the period 2005–09 by the U.S. Department of Agriculture Forest Service, Forest Inventory and Analysis (FIA) Program in coordination with the Kentucky Department for Natural Resources Division of Forestry. Data on the extent, condition, and classification of forest land and associated timber volumes, as well as growth, removals, and mortality rates are described and interpreted. Data on forest health and forest landowner characteristics are also evaluated....

During a survey of termites in Wisconsin, one colony was found from a different habitat than the remaining populations. This observation led to further genetic testing which resulted in a determination of Reticulitermes tibialis Banks. This is the first record of a termite species other than Reticulitermes flavipes (Kollar) to be established in the state.

The moisture transfer effectiveness (or latent effectiveness) of a cross-flow, membrane based energy recovery ventilator is measured and modeled. Analysis of in situ measurements for a full year shows that energy recovery ventilator latent effectiveness increases with increasing average relative humidity and surprisingly increases with decreasing average temperature. A simple finite difference heat and moisture transfer model is developed, which can explain these results and predict energy recovery ventilator latent effectiveness based on simplified physics and material properties. The...

Seed zones and seed transfer guidelines describe where plants are most likely to thrive. Scientists with the Forest Service and Agricultural Research Service undertook a 9-year project to build empirical seed zones for bluebunch wheatgrass, a foundational native grass throughout the West. The research will help the Forest Service and Bureau of Land Management accelerate restoration of native grasses and combat invasive species such as cheatgrass. Scientists documented variation in bluebunch populations, looking particularly at traits important for adaptation to drought and cold. Forest...

The joint effects of poplar biomass productivity and land costs on poplar production economics were compared for 12 Minnesota counties and two genetic groups, using a process-based model (3-PG) to estimate productivity. The counties represent three levels of productivity and a range of land costs (annual rental rates) from $128/ha to $534/ha. An optimal rotation age (ORA) was calculated that minimizes the annualized, discounted per-dry Mg biomass cost for each county, genetic group and land cover, and for two discount rates (5 and 10%). The ORA for the lowest-cost county (Todd) with...

Anthropogenic changes to nutrient supply, numbers and behavior of grazers and interactions of these factors are known to change epilithon composition and biomass. In brackish waters, these changes occur across wide-ranging abiotic conditions (e.g. nutrient concentrations and salinity), which may alter their relative impacts on microphytobenthic communities. Such mediating processes are poorly understood, particularly in tropical brackish ecosystems. We examined the separate and interactive effects of nutrient additions and grazer exclusion on epilithon composition and biomass in eutrophic...

The potential hazard and geomorphic significance of shallow landslides depend on their location and size. Commonly applied one-dimensional stability models do not include lateral resistances and cannot predict landslide size. Multi-dimensional models must be applied to specific geometries, which are not known a priori, and testing all possible geometries is computationally prohibitive. We present an efficient deterministic search algorithm based on spectral graph theory and couple it with a multidimensional stability model to predict discrete landslides in applications at scales broader...