Treesearch

This paired watershed study tested the effects of timber harvest on water quantity and quality in the North Carolina Piedmont physiographic region. Four headwater watersheds at Hill Demonstration Forest (HF1, HF2, HFW1, and HFW2) and two at Umstead Research Farm (UF1 and UF2) were continuously monitored for discharge and water quality from 2007 to 2013. The HF1 and UF1 watersheds were clearcut (treatment), leaving a 15.2-m vegetated riparian buffer around the streams to protect water quality as described in the North Carolina Neuse River Basin Riparian Buffer Rule. HF2 and UF2 were uncut...

Bioenergy crops have the potential to enhance soil carbon (C) pools from increased aggregation and the physical protection of organic matter; however, our understanding of the variation in these processes over heterogeneous landscapes is limited. In particular, little is known about the relative importance of soil properties and root characteristics for the physical protection of particulate organic matter (POM). We studied short-term (3-year) changes in aggregation and POM-C pools under three cropping systems (switchgrass, a triticale/sorghum double crop, continuous corn) replicated...

Litter decomposition is mediated by multiple variables, of which climate is expected to be a dominant factor at global scales. However, like other organisms, traits of decomposers and their communities are shaped not just by the contemporary climate but also their climate history. Whether or not this affects decomposition rates is underexplored. Here we source decomposer communities from three forest sites contrasting in climate (tropical, temperate, boreal), and, using experimental microcosms, quantify decomposition of a common litter under a factorial combination of four temperature (15,...

The College of Menominee Nation Sustainable Development Institute's theoretical model (SDI model) conceptualizes sustainable development as the process of maintaining the balance and reconciling the inherent tensions among six dimensions of sustainability: land and sovereignty; natural environment #including human beings); institutions; technology; economy; and human perception, activity, and behavior. Each dimension is understood to be dynamic, both internally and in relationship to each of the other five dimensions. Change within one dimension will impact other dimensions in a continual...

Worldwide hardwood lumber production fluctuated between 1995 and 2013 and changed considerably with respect to regional market shares. Similarly, worldwide hardwood lumber imports and exports have been constantly changing. Understanding these changes is important because collectively, they define the hardwood lumber consumption of a region or country. In 1995, North America accounted for 25% of worldwide hardwood lumber production whereas East Asia and Oceana (EAO) produced 26%. In the current century, a decline in production in the United States and increased production in China and...

We examined responses of the woodland salamander Ensatina (Ensatina eschscholtzii) to commercial thinning by helicopter in late-seral Douglas-fir forest in northwestern California, USA, using a before-after control-impact (BACI) design. We employed passive pitfall traps on eight (four each treatment and control) 100 trap grids over eight years (1996–2003), three years pre- and five years post-treatment. We conducted 3–11 weekly site visits within each of 10 trap periods depending upon weather over two spring and eight fall periods for a total of 50 visits to test for differences in surface...

Summary1. Counter-gradient growth, where growth per unit temperature increases as temperature decreases, can reduce the variation in ectothermic growth rates across environmental gradients. Understanding how ectothermic species respond to changing temperatures is essential to their conservation and management due to human-altered habitats and changing climates.2. Here, we use two contrasting populations of western pond turtles (Actinemys marmorata) to model the effect of artificial and variable temperature regimes on growth and age at reproductive maturity. The two populations occur on...

Water diversions can disrupt flows and alter thermal regimes changing seasonal patterns that signal the onset of life-history functions of native organisms and compromise the fitness of their populations. We compared size, growth, relative mass, volumetric body condition, and reproductive status of Western Pond Turtles (Actinemys marmorata) across a decade on two forks of California’s Trinity River, one regulated and the other free-flowing. Turtles on the regulated fork experienced flows designed to accommodate anthropocentric demands, whereas those on the free-flowing fork experienced...

Pyrenophora semeniperda, an important pathogen in Bromus tectorum seed banks in semi-arid western North America, exhibits >4-fold variation in mycelial growth rate. Host seeds exhibit seasonal changes in dormancy that affect the risk of pathogen-caused mortality. The hypothesis tested is that contrasting seed dormancy phenotypes select for contrasting strategies for increasing pathogen fitness, and that increased fitness on nondormant seeds involves a resource trade-off between toxin production and growth. The strategy for successfully attacking rapidly germinating nondormant seeds at high...

The recent coal ash spill on the Dan River in North Carolina, USA has caused several negative effects on the environment and the public. In this analysis, I report a monetized value for these effects after the first 6 months following the spill. The combined cost of ecological damage, recreational impacts, effects on human health and consumptive use, and esthetic value losses totals $295,485,000. Because the environmental impact and associated economic costs of riverine coal ash spills can be long-term, on the order of years or even decades, this 6-month assessment should be viewed as a...