Treesearch

Longleaf pine (Pinus palustris Mill.) restoration in the southeastern United States offers opportunities for carbon (C) sequestration. Ecosystem C stocks are not well understood in longleaf pine forests, which are typically of low density and maintained by prescribed fire. The objectives of this research were to develop allometric equations for above- and below-ground biomass and quantify ecosystem C stocks in five longleaf pine forests ranging in age from 5 to 87 years and in basal area from 0.4 to 22.6 m2 ha-1. Live aboveground C (woody plant + ground cover) and live root C (longleaf...

This resource update provides an overview of forest resources in North Dakota 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 North Dakota Forest Service. Estimates are based on field data collected using the FIA annualized sample design and are updated yearly. The estimates presented in this update are for the measurement year 2013 with comparisons made to data reported in 2008. The sample plot population in North Dakota consists of 7,622 plots, collected across a period of 5...

Urban ecology and its theories are increasingly poised to contribute to urban sustainability, through both basic understanding and action. We present a conceptual framework that expands the Industrial → Sanitary → Sustainable City transition to include non-sanitary cities, "new cities", and various permutations of transition options for cities encountering exogenous and endogenous "triggers of change". When investigating and modeling these urban transitions, we should consider: (1) the triggers that have induced change; (2) situations where crisis triggers change; (3) why cities transition...

Common Kingsnakes (formerly known collectively as Lampropeltis getula) are experiencing localized declines throughout the southeastern United States. Because there have been limited studies to determine how snakes regulate prey populations, and because Kingsnake declines may result in ecosystem impacts, we evaluated the hypothesis that Kingsnakes regulate the abundance of one of their prey, the venomous Copperhead (Agkistrodon contortrix). We generated a database of captures of the two species across the southeastern United States and, while controlling for large-scale habitat preferences,...

1. Snakes often occur in species-rich assemblages, and sympatry is thought to be facilitated primarily by low diet overlap, not interspecific interactions. 2. We selected, a priori, three species pairs consisting of species that are morphologically and taxonomically similar and may therefore be likely to engage in interspecific, consumptive competition. We then examined a large-scale database of snake detection/nondetection data and used occupancy modelling to determine whether these species occur together more or less frequently than expected by chance while accounting for variation in...

Ecological restoration is frequently guided by reference conditions describing a successfully restored ecosystem; however, the causes and magnitude of ecosystem degradation vary, making simple knowledge of reference conditions insufficient for prioritizing and guiding restoration. Ecological reference models provide further guidance by quantifying reference conditions, as well as conditions at degraded states that deviate from reference conditions. Many reference models remain qualitative, however, limiting their utility. We quantified and evaluated a reference model for southeastern U.S....

Anoplophora glabripennis (Motsch.) is a polyphagous member of the Cerambycidae, and is considered, worldwide, to be one of the most serious quarantine pests of deciduous trees. We isolated four chemicals from the trail of A. glabripennis virgin and mated females that were not present in trails of mature males. These compounds were identified as 2-methyldocosane and (Z)-9-tricosene (major components), as well as (Z)-9-pentacosene and (Z)-7-pentacosene (minor components); every trail wash sample contained all four chemical components, although the amounts and ratios changed with age of the...

Rainfall runoff erosivity (R) is one key climate factor that controls water erosion. Quantifying the effects of climate change-induced erosivity change is important for identifying critical regions prone to soil erosion under a changing environment. In this study we first evaluate the changes of R from 1970 to 2090 across the United States under nine climate conditions predicted by three general circulation models for three emissions scenarios (A2, A1B, and B1) from the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Then, we identify watersheds that are most...

Emissions from wildland fire are both highly variable and highly uncertain over a wide range of temporal and spatial scales. Wildland fire emissions change considerably due to fluctuations from year to year with overall fire season severity, from season to season as different regions pass in and out of wildfire and prescribed fire periods, and from day to day as weather patterns affect large wildfire growth events and prescribed fire windows. Emissions from wildland fire are highly uncertain in that every component used to calculate wildland fire emissions is uncertain - including how much...

Wildfires are an important component of the terrestrial carbon cycle and one of the main pathways for movement of carbon from the land surface to the atmosphere. Fires have received much attention in recent years as potential catalysts for shifting landscapes from carbon sinks to carbon sources. Unless structural or functional ecosystem shifts occur, net carbon balance in fire-adapted systems at steady state is zero when assessed over the entire post-fire successional sequence and at landscape scales. When evaluated at fine spatial scales and over short periods of time, however, wildfires...