Treesearch

Changes in species composition of overstory trees (percent of basal area) and size class were monitored over 60 years on 441 cruise plots located on the Bartlett Experimental Forest, a 1052 ha experimental forest in the White Mountains of New Hampshire. The plots were analyzed by elevation class, landtype (deciduous and coniferous), and year (1931-32, 1939-40, and 1991-92) within managed and unmanaged stands. The primary changes in species composition over the 60-year period were due to natural succession, which resulted in marked increases (doubling) of the eastern hemlock (Tsuga canadensi...

Computer optimization of gang-rip-first processing is a difficult problem when working with specific cutting bills. Interactions among board grade and size, arbor setup, and part sizes and quantities greatly complicate the decision making process. Cutting the wrong parts at any moment will mean that more board footage will be required to meet the bill. Using the ROugh MIll RIP First Simulator (ROMI-RIP), different part prioritizing methods were examined. The "best" method of prioritizing part sizes appears to be both cutting bill and lumber grade dependent. Dynamic prioritization strategies...

This paper describes the design, conversion, and deployment of a reliable, compact, automatic multiple-exposure photographic system that was used to photograph nest predation events. This system may be the most versatile yet described in the literature because of its simplicity, portability, and dependability. The system was very reliable because it was designed around a high quality, all-electronic camera. It was an inexpensive alternative (about US $110) to the few other commercially available photographic systems that offered similar features, and was the first system to provide these...

The diameter distributions of 10 previously unmanaged northern hardwood stands on the Bartlett Experimental Forest in New Hampshire were analyzed to determine changes over a 35 yr period since a single cutting by the diameter-limit or single-tree selection methods. The diameter distribution of an uncut old-growth stand (the Bowl) provided a comparison. The cuttings left residual basal areas of 25 to 96 ft2 of basal area per acre (5.7 to 22.0 m2/ha), as well as a wide range in diameter distribution. Basal area of the old-growth stand was 123 ft2/ac (28.2 m2/ha), and the diameter distribution...

By synthesizing more than twenty years of research at the Fernow Experimental Forest, we have documented 7 symptoms of nitrogen saturation in two adjacent watersheds. The symptoms include: 1) high relative rates of net nitrification, 2) long-term increases in streamwater concentrations of nitrate and base cations, 3) relatively high nitrate concentrations in solution losses, 4) little seasonal variability in stream-water nitrate concentrations, 5) a high discharge of nitrate from a young aggrading forest, 6) a rapid increase in nitrate loss following fertilization of a young aggrading...

Although extensive research on acidic deposition has been directed toward spruce-fir forests, less research has been done on the impacts of air pollution on eastern montane hardwood forests. The purpose of this study was to describe precipitation chemistry for several Appalachian hardwood forest sites at or near the Fernow Experimental Forest (FEF) to assess the potential for problems associated with acidic deposition. Emphasis was placed on seasonal patterns of ionic concentrations (H+, Ca++, NH4+, NO3-, and S04=) and spatial variability of ionic concentrations and deposition among sites....

Among the current environmental concerns for forests of the eastern United States is nitrogen (N) saturation, a result of excessive inputs of N associated with acidic deposition. We studied nutrient responses on N-treated and untreated watersheds of the Fernow Experimental Forest, West Virginia, to test for evidence of N saturation on the treated watershed. The watersheds were WS7 (23-year-old even-aged control), WS4 (mature mixed-aged control), and WS3 (23-year-old even-aged treatment). WS3 has received aerial applications of (NH4)2S04 from 1989 to the present (a total of 4 years for the...

Depletion of Ca in forests and its effects on forest health are poorly quantified. Depletion has been difficult to document due to limitations in determining rates at which Ca becomes available for ecosystem processes through weathering, and difficulty in determining changes in ecosystem storage. We coupled a detailed analysis of Sr isotopic composition with a mass balance at Cone Pond Watershed, New Hampshire, in order to further constrain estimates of these processes Strontium acted as an analog for Ca in most processes except translocation of nutrients within forest vegetation. Variabili...

In 1992 and 1993, we surveyed the foraging and feeding activity of bat species with broadband bat detectors at 2 foliage heights in 4 age classes of northern hardwood and spruce/fir forest stands in White Mountain National Forest, New Hampshire and Maine. The association of bat activity with trails and water bodies and the effect of elevation were measured. Mist nets, a harp trap, and ultrasonic detectors were used to establish species presence. Bat activity was concentrated at trail and water body edges and was uniform within a forest stand at the same sampling height. Within the forest,...

Invasive pests, or 'biological pollutants' are among the most serious threats to biological diversity in the forest ecosystems of the USA. Additionally, they can disrupt forest management practices and cause enormous financial losses. In the USA, as elsewhere, the receiving country inherits the problem and, along with its citizenry, bears the permanent economic costs. The incidence ol the introduction of invasive pests, the pathways utilized, and their economic and ecological impacts are presented using Dutch elm disease (Ophiostoma ulmi), chestnut blight (Cryphonectria par asitica), gypsy...