Treesearch

The ability to assess spatial patterns of ecological conditions in river networks has been confounded by difficulties of measuring and perceiving features that are essentially invisible to observers on land and to aircraft and satellites from above. The nature of flowing water, which is opaque or at best semi-transparent, makes it difficult to visualize fine-scale patterns in habitat and biota at close range, and the linear topology of river networks complicates the process of scaling up to detect coarse-scale patterns. This spatially incomplete perspective limits our understanding of...

Our vision for a future "cyber forest" at the Andrews Experimental Forest foresees high performance wireless communications enhancing connectivity among remote field research locations, station headquarters, and beyond to the university and outside world. New sensor technologies and collaboration tools foretell exponential increases in data and information flow to accommodate both research and education. We envision improving data transmission speed and bandwidth, enveloping the Andrews in a wireless cloud, installing new technologies for near real-time access to sensor networks, and...

Originally described from Japan by Sanshi Imai in 1933, the hypogeous ascomycete Terjezia gigantea was subsequently discovered in the Appalachian Mountains of the USA. Morphological, electron microscopic, and phylogenetic studies of specimens collected in both regions revealed that, despite this huge geographic disjunction, (1) the Japanese and Appalachian specimens are remarkably similar both in morphology and the sampled rDNA sequences, (2) the species unambiguously falls into the Morchellaceae and is separated from the genus Terjezia in the Pezizaceae, (3) its spores are much larger...

Rain-on-snow (ROS) melt production and its contribution to water available for runoff is poorly understood. In the Pacific Northwest (PNW) of the USA, ROS drives many runoff events with turbulent energy exchanges dominating the snow energy balance (EB). While previous experimental work in the PNW (most notably the H.J. Andrews Experimental Forest (HJA» has quantified these energy balance components for a handful of ROS events, little is known about the EB components of snowmelt at HJA on an annual basis and how the relative importance of each component changes with different time periods...

Large floods are often attributed to the melting of snow during a rain event. This study tested how climate variability, snowpack presence, and basin physiography were related to storm hydrograph shape in three small (

Crown length is a fundamental tree dimension for characterizing growth potential, wildlife habitat, and wood quality. The relative rates of height growth and crown recession detennine the progression of crown length over time. We investigated patterns in crown recession of three co-occurring species in the northern Rocky Mountains: western white pine (Pinus monticola Dougl. ex D. Don), ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.), and interior Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. glauca). Past height, diameter, and crown base on 169 forest-grown trees were...

Episodic stand-replacing wildfire is a significant disturbance in mesic and moist Douglas-frr (Pseudotsuga menziesii (Mirb.) Franco) forests of the Pacific Northwest. We studied 24 forest stands with known fire histories in the western . Cascade Range in Oregon to evaluate long-tenn impacts of stand-replacing wildfire on carbon (C) and nitrogen (N) pools and dynamics within the forest floor (FF, Oe and Oa horizons) and the mineral soil (0-10 cm). Twelve of our stands burned approximately 150 years ago ("young"), and the other 12 burned approximately 550 years ago ("old"). Forest floor mean...

We developed new equations to predict Oregon white oak (Quercus garryano Dougl. ex Hook.) development within ORGANON, a stand-development model that is widely used in the Pacific Northwest. Tree size, competitive status, crown ratio, and site productivity were statistically significant predictors of growth and mortality. Three scenarios were projected with the new equations, the previous ORGANON model, and the Forest Vegetation Simulator. Compared with the two other models, the new equations predicted greater diameter growth in oak woodland and a greater effect of conifer removal in a...

As river restoration has matured into a global-scale intervention in rivers, a broader range of technical disciplines are informing restoration goals, strategies, approaches, and methods. The ecological, geomotphological, hydrological, and engineering sciences each bring a distinct focus and set of perspectives and tools, and are themselves embedded in a larger context of social, economic, legal, and historical drivers. Restoration practices carried out in different countries and cultures reflect this context. Ecological concerns drive much of the current restoration activities in the...

Covering about 4% of the United States, the 338,000 km2 of protected areas in the National Park System contain representative landscapes of all of the nation's biomes and ecosystems. The U.S. National Park Service Organic Act established the National Park System in 1916 "to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations. Approximately 270 national park system areas contain significant natural resources....