Treesearch

To test the effects of altered hydrology on organic soil decomposition, we investigated CO2 and CH4 production potential of rich-fen peat (mean surface pH = 6.3) collected from a field water table manipulation experiment including control, raised and lowered water table treatments. Mean anaerobic CO2 production potential at 10 cm depth (14.1 ± 0.9 µmol C g-1 d-1) was as high as aerobic CO2 production potential (10.6 ± 1.5 µmol C g-1 d-1), while CH4 production was low (mean of 7.8 ± 1.5 nmol C g-1 d-1). Denitrification enzyme activity indicated a very high denitrification potential (197 ±...

Biomass residue produced by timber harvest operations is estimated for the Olympic and Kitsap Peninsulas, Washington. Scattered residues were sampled in 53 harvest units and piled residues were completely enumerated in 55 harvest units. Production is based on 2008 and 2009 data and is stratified by forest location, ownership type, harvest intensity, and harvest method. An additional sampling was taken to ascertain the mass of wood present in a pile of biomass: 20 piles of biomass were measured for gross volume, processed into hog fuel, and remeasured for volume; five samples were drawn...

Carnivores are important elements of biodiversity, not only because of their role in transferring energy and nutrients, but also because they influence the structure of the communities where they occur. The fisher Martes pennanti is amammalian carnivore that is associated with late-successional mixed forests in the Sierra Nevada in California, and is vulnerable to the effects of forest management. As a candidate for endangered species status, it is important to monitor its population to determine whether actions to conserve it are successful. We implemented a monitoring program to estimate...

This science update provides an overview of forest resources in Mississippi based on an inventory conducted by the U.S. Department of Agriculture Forest Service, Forest Inventory and Analysis (FIA) program at the Southern Research Station in cooperation with the Mississippi Forestry Commission. Data 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 2011 with comparisons made to data reported in 2010. The sample plot population in Mississippi consists of 3,667 plots,...

We compared the growth of eastern cottonwood (Populus deltoides Bartr. ex Marsh.) trees planted at 40- by 40-foot spacing and subjected to four pruning treatments from the 2nd through the 8th year of growth. Treatments were (1) no pruning, (2) prune to one-third of total height annually, (3) prune to one-half of total height annually, and (4) prune to 17 feet when diameter at breast height (d.b.h.) exceeded 8.5 inches, which occurred in the 4th year. Diameter and height measurements were taken annually for 15 years. By age 15, average diameters differed significantly among all four...

It is important to understand the fate of carbon in boreal peatland soils in response to climate change because a substantial change in release of this carbon as CO2 and CH4 could influence the climate system. The goal of this research was to synthesize the results of a field water table manipulation experiment conducted in a boreal rich fen into a process-based model to understand how soil organic carbon (SOC) of the rich fen might respond to projected climate change. This model, the peatland version of the dynamic organic soil Terrestrial Ecosystem Model (peatland DOSTEM), was calibrated...

This guidebook describes Fox Hollow Research Natural Area (RNA), a 66-ha (163-ac) area that supports dry-site Douglas-fir (Pseudotsuga menziesii)–ponderosa pine (Pinus ponderosa) forest within the Oregon Coast Range ecoregion. Major forest plant associations represented at Fox Hollow RNA include Douglas-fir/salal/western swordfern (Pseudotsuga menziesii/Gaultheria shallon/Polystichum munitum) forest and Douglas-fir/Oregongrape (Pseudotsuga menziesii/Berberis nervosa) forest. Other forested communities are represented within the RNA in minor amounts including: Douglas-fir/poison oak...

Since current standard laboratory methods are time-consuming macro-assays that rely on subjective visual ratings of mould growth, rapid and quantitative laboratory methods are needed to screen potential mould inhibitors for use in and on cellulose-based products. A colorimetric micro-assay has been developed that uses XTT tetrazolium salt to enzymatically assess metabolic activity in mould spores, saving significant time and resources (i.e. wood specimens). Minimal inhibitory concentration (MIC90) of isothiazolinone, a known mould inhibitor, in the XTT assay was the same or within a...

Nonstructural carbohydrate reserves support tree metabolism and growth when current photosynthates are insufficient, offering resilience in times of stress. We monitored stemwood nonstructural carbohydrate (starch and sugars) concentrations of the dominant tree species at three sites in the northeastern United States. We estimated the mean age of the starch and sugars in a subset of trees using the radiocarbon (14C) bomb spike. With these data, we then tested different carbon (C) allocation schemes in a process-based model of forest C cycling. We found that the nonstructural carbohydrates...

Due to projected increases in winter air temperatures in the northeastern USA over the next 100 years, the snowpack is expected to decrease in depth and duration, thereby increasing soil exposure to freezing air temperatures. To evaluate the potential physiological responses of sugar maple (Acer saccharum Marsh.) to a reduced snowpack, we measured root injury, foliar cation and carbohydrate concentrations, woody shoot carbohydrate levels, and terminal woody shoot lengths of trees in a snow manipulation experiment in New Hampshire, USA. Snow was removed from treatment plots for the first 6...