Treesearch

This study was conducted in the Big Sunflower River Watershed (BSRW), north-west, Mississippi. The watershed has been identified as “impaired waters” under Section 303(d) of the Federal Clean Water Act due to high levels of sediment and total phosphorus. This excess is then transported to the Gulf of Mexico via the Yazoo River, further damaging the nation’s water resources. The specific objectives of this study were to assess the impact of corn (Zea mays L.), soybean (Glycine max (L.) Merr., and rice (Oryza sativa, L.) crop-rotations (corn after soybean, soybean after rice, continuous...

Table Mountain pine (Pinus pungens Lamb.) (TMP) is a threatened species, endemic to the Southern Appalachian Mountains. This study focuses on the release of TMP stems in an overstocked and pure TMP stand on the Cherokee National Forest in eastern Tennessee. The objective of the case study was to produce a cost analysis/comparison of releasing young TMP that are in the stem exclusion stage of stand development by several silvicultural methods: strip thinning, crop-tree release, and prescribed burning. Initial cost effectiveness of release treatments was analyzed. Regardless of treatment,...

The financial performance of selected management regimes for loblolly (Pinus taeda L.) and longleaf pine (P. palustris Mill.) plantations were compared for four cases, each with low- and high-site productivity levels and each evaluated using 5 and 7 percent real discount rates. In all cases, longleaf pine was considered both with and without pine straw harvesting. The analysis also examined the financial impacts of various sawtimber proportions valued as poles. With the addition of pine straw revenues, longleaf management can yield returns that are comparable to typical loblolly pine...

Poplar plantations are widely used for timber production and ecological restoration in northern China,a region that experiences frequent droughts and water scarcity. An open-path eddy-covariance (EC)system was used to continuously measure the carbon,water,and energy fluxes in a poplar plantation during the growing season (i.e., April–October)over the period 2006–2008 in the Daxing District of Beijing,China. We examined the seasonal and inter-annual variability of gross ecosystem productivity (GEP), net ecosystem exchange (NEE), and ecosystem respiration (ER). Although annual total precipita...

The second annual inventory of North Dakota's forests reports more than 772,000 acres of forest land with an average volume of more than 921 cubic feet per acre. Forest land is dominated by the bur oak forest type, which occupies more than a third of the total forest land area. The poletimber stand-size class represents 39 percent of forest land, followed by sawtimber (32 percent) and saplings/seedlings (28 percent). The volume of growing stock currently totals more than 341 million cubic feet. The average annual net growth of growing stock on forest land from 2006 to 2010 was approximately...

Pollution of surface water with harmful chemicals and eutrophication of rivers and lakes with excess nutrients are serious environmental concerns. This study estimated surface water quality in a stream within the Yazoo River Basin (YRB), Mississippi, USA, using the duration curve and recurrence interval analysis techniques. Data from the US Geological Survey (USGS) surface water monitoring station located in Deer Creek east of Leland from the YRB were selected for the analysis. Results showed that the water quality constituents, namely water temperature, specific conductivity (SC) and...

At the Harvard Forest, Petersham, MA, the impact of 20 years of annual ammonium nitrate application to the mixed hardwood stand on soil bacterial communities was studied using 16S rRNA genes pyrosequencing. Amplification of 16S rRNA genes was done using DNA extracted from 30 soil samples (three treatments x two horizons x five subplots) collected from untreated (control), low N-amended (50 kg ha-1 year-1) and high N-amended (150 kg ha-1 year-1) plots. A total of 1.3 million sequences were processed using QIIME. Although Acidobacteria represented the most abundant phylum based on the number...

Elevated phosphorus (P) in surface waters can cause eutrophication of aquatic ecosystems and can impair water for drinking, industry, agriculture, and recreation. Currently, no effort has been devoted to estimating real-time variation and load of total P (TP) in surface waters due to the lack of suitable and/or cost-effective wireless sensors. However, when considering human health, drinking water supply, and rapidly developing events such as algal blooms, the availability of timely P information is very critical. In this study, we developed a new approach in the form of a dynamic data...

Longleaf pine (Pinus palustris) savannas of the southeastern United States contain some of the world’s most diverse plant communities, along with a unique complement of wildlife. Their traditionally open canopy structure and rich understory of grasses and herbs were critical to their vigor. However, a long history of land-use practices such as logging, farming, and fire exclusion have reduced this once-widespread ecosystem to only 3 percent of its original range. At six longleaf pine plantations in South Carolina, Tim Harrington with the Pacific Northwest Research Station and collaborators...

Soil health is fundamental to ecosystem health. Disturbances such as fire and timber harvesting can affect the abundance, activity, and composition of soil microbial communities and thus affect soil productivity. In response to forest managers, scientists with the Pacific Northwest Research Station compared health and productivity indicators between soils disturbed by logging machinery to adjacent soils that were burned but not mechanically disturbed after a wildfire in the Deschutes National Forest in central Oregon. After a wildfire, one management option is to remove fire-killed trees....