Treesearch

Climate models project warmer temperatures for the north-west USA, which will result in reduced snowpacks and decreased summer streamflow. This paper examines how groundwater, snowmelt, and regional climate patterns control discharge at multiple time scales, using historical records from two watersheds with contrasting geological properties and drainage efficiencies. In the groundwater-dominated watershed, aquifer storage and the associated slow summer recession are responsible for sustaining discharge even when the seasonal or annual water balance is negative, while in the runoff-dominated...

We evaluated the utility of the composite burn index (CBI) for estimating fire severity in Alaskan black spruce forests by comparing data from 81 plots located in 2004 and 2005 fire events. We collected data to estimate the CBI and quantify crown damage, percentage of trees standing after the fire, depth of the organic layer remaining after the fire, depth of burning in the surface organic layer (absolute and relative), and the substrate layer exposed by the fire. To estimate pre-fire organic layer depth, we collected data in 15 unburned stands to develop relationships between total...

Dead wood patterns and dynamics vary with biophysical factors, disturbance history, ownership, and management practices; the relative importance of these factors is poorly understood, especially at landscape to regional scales. This study examined current dead wood amounts in the Coastal Province of Oregon, USA, at multiple spatial scales. Objectives were to: (1) describe current regional amounts of several characteristics of dead wood; (2) compare dead wood amounts across ownerships; (3) determine the relative importance, according to spatial scale, of biophysical and ownership characteris...

Over the past 50 years, forested landscapes of the Pacific Northwest have become increasingly patchy, dominated by early-successional forests. Several amphibian species associated with forested headwater systems have emerged as management concerns, especially after dearcutting. Given that headwater streams comprise a large portion of the length of flowing waterways in western Oregon forests, there is a need to better understand how forest management affects headwater forest taxa and their habitats. Mitigation strategies include alternatives to clearcutting, such as harvests that remove...

Over the last several decades, dozens of books on truffle cultivation have been published in Italian, French, and Spanish. Much new has been learned about the topic during those decades. Now a definitive book in English has at last appeared, one that brings the science and art of cultivating truffles up to date for the English-speaking audience. As a government scientist in New Zealand, Ian Hall pioneered the establishment of truffle orchards, or truffieres; since his retirement he has devoted full time to this activity. He established the program on a carefully designed, scientific...

Global variation in forests and in human cultures means that a single method for managing forests is not possible. However, forest management everywhere shares some common principles because it is rooted in physical and biological sciences like chemistry and genetics. Ecological forest management is an approach that combines an understanding of universal processes with site-specific, local knowledge to sustain forest ecosystems and to provide what people want from them. In places as diverse as the equatorial tropics and the boreal north, people use forests in different ways. Sometimes the...

Spawning salmon deliver nutrients (salmon-derived nutrients, SDN) to natal watersheds that can be incorporated into terrestrial and aquatic food webs, potentially increasing ecosystem productivity. Peterson Creek, a coastal watershed in southeast Alaska that supports several species of anadromous fish, was sampled over the course of a storm during September 2006 to test the hypothesis that stormflows reintroduce stored SDN into the stream. We used stable isotopes and PARAFAC modeling of fluorescence excitation-emission spectroscopy to detect flushing of DOM from salmon carcasses in the...

This study focused on how climate change-induced effects on weather will translate into changes in wildland fire severity and outcomes in California, particularly on the effectiveness of initial attack at limiting the number of fires that escape initial attack. The results indicate that subtle shifts in fire behavior of the sort that might be induced by the climate changes anticipated for the next century are of sufficient magnitude to generate an appreciable increase in the number of fires that escape initial attack. Such escapes are of considerable importance in wildland fire protection...

Landscapes tell stories, if we know how to listen. When Mount St. Helens erupted on May 18, 1980, the story most people heard seemed to be almost entirely about violence, danger, and devastation. But even as rescue efforts continued for the people missing on the mountain, scientists went up to the volcano looking for other stories. They wanted to see how the landscape would respond to these enormous disturbances, and they brought along some reasonable hypotheses. But much of what they saw and learned was so radically different from what they expected that their new findings have significant...

Key ecological processes affecting interactions between rivers and terrestrial mammals are identified and explained, using flood plains of Alaska as examples of relatively pristine systems. Both coastal (southeast Alaska) and interior Alaska examples are used. Coastal Alaskan rivers tend to be relatively short, flashy, rain-driven systems, whereas interior Alaska rivers tend to be large, glacial-melt-driven systems. Seven key processes were identified: (1) flooding, (2) erosion/deposition, (3) dam building by beaver (Castor canadensis), (4) fish (especially salmon, Oncorhynchus spp.)...