Comparing Three Water Quality Sampling Techniques for Measuring Non-Point Source Pollution in Forest Streams

Coshocton wheel samplers, ISCO pumping samplers, and single stage samplers were compared on each of three small (5-6 ha), forested watersheds in the Ouachita Mountains of central Arkansas. The objective of the comparisons was to evaluate the performance of each sampling method in providing reliable samples for measuring concentrations of total suspended solids (TSS). H-flumes and water level recorders provided stream discharge data; a network of recording and non-recording raingages provided preciptation measurements. Rainfall and storm discharges during the study period were unusually low. No samples were collected by the single stage samplers. They appear unsuited for use on small ephemeral headwater streams in the ~achita Mountains because only unusually large storms will provide the depth of flow required to fill the sample bottles. A few of the Coshocton Wheel samples provided eradic and unpredictable measurements of TSS; however, there was generally good agreement between the Coshoston and pumped samples. The ISCO pumping samplers provided data that were more consistent and predictable than that of the Coshocton wheel. The small number of storm events during the study precludes a definite conclusion as to which sampling method is best . Measurements are continuing

Forestry on the Island of Taiwan, ROC - The State of the Art

The forests of Taiwan vary from lush subtropical vegetation to subalpine coniferous associations. Topography is exceedingly rugged, and stands border on the verge of silvicultural inoperability. In the 1950s and 1960s, the wood products industry in the Republic of China was of paramount importance; the production of high-quality sawtimber from old-growth cypress (Cupressaceae) stands provided the financial capital that built one of the most prosperous national economies in the modern world. In the 1980s, forestry in Taiwan is a curious blend of old methods and new technologies, as modern silvicultural practices are used to reforest cutover cypress stands, to harvest and reproduce remaining old-growth stands, and to expand the silvicultural importance of other forest types on the island. Many applied research efforts would be promising in application to the forests of Taiwan, such as long-term studies of silvicultural practices on water quality, methodology of natural regeneration applied to cypress and Taiwania cryptomerioides (Taxodiaceae), uneven-aged regulation applied to bamboo, Phyllostachys pubescens (Bambusaceae), growth and yield in coniferous plantations, effectiveness of modern herbicides in controlling competition in young plantations, and application of contemporary economic assessments in the evaluation of silvicultural alternatives

Mercury Concentrations in Streams of East Texas

Recent studies on potential mercury (Hg) contamination of fish from East Texas lakes and waterways have caused concern about mercury levels in East Texas waters. Historical records of Hg concentrations in 33 East Texas streams showed that median concentrations for each stream segment were no different than other U.S. streams. All the means and medians for stream segments having at least 20 recorded measurements were less than Texas (2.4 µg/L) water quality standards. Water samples collected in December 1995 and March 1996 from 6 different stream sites in Nacogdoches County had concentrations similar to historical records. Due to biological magnification, fish Hg levels can be 20,000 times greater than water Hg levels and levels are greater in large fish than in small fish. Although a recent study on sediment cores in 13 East Texas reservoirs and lakes suggested possible increases in mercury concentrations across the region, all Hg concentrations in water and sediment were far below Texas acute and chronic quality standards. No significant correlations were found between fish mercury concentrations and mercury concentrations in water or sediment. Potential agricultural inputs of Hg in East Texas are very low; the most likely source of Hg is atmospheric deposition from fossil fuel combustion and other industrial practices. The following may be considered to minimize potential health risks: 1) consume smaller fish from a variety of waterbodies, 2) increase consumption interval, 3) avoid eating skin and fatty tissues, and 4) limit consumption to quantities recommended by the Texas Health Department

Runoff and Sediment Losses from Annual and Unusual Storm Events from the Alto Experimental Watersheds, Texas: 23 Years After Silvicultural Treatments

Evaluating the potential impacts of intensive silvicultural practices on water quality is critical for establishing the long-term sustainability of contemporary forest management practices. From 1979 to 1985, a study involving nine small (~2.5 ha) forested watersheds was conducted near Alto, Texas in the upper western Gulf-Coastal Plain to evaluate the impacts then-current silvicultural practices on water quality. In the years following the study, silvicultural Best Management Practices (BMPs) including Streamside Management Zones (SMZs) and other erosion control practices evolved and questions arose about the applicability of earlier results to current practices. In 1999, these same watersheds were reinstrumented to evaluate the water quality effects of intensive silviculture using modern BMPs. Three years of pre-treatment data were collected to calibrate the watersheds. During the calibration phase, in June 2001, Tropical Storm Allison struck southeastern Texas, dumping almost 11.8 cm of rainfall on saturated soils in about 3 hours. This single storm event resulted in over 73% of the annual flow and over 95% of the annual sediment for 2001. In a little over three hours, the watersheds clearcut and chopped in 1980 generated over 2.5 times more sediment that the entire year following harvest and site-preparation. 1Comparisons of data from the 1979 Alto Watershed study with pretreatment data from the current study suggest that these watersheds have a high potential for geologic erosion even with mature forest cover. Large natural variation in runoff and sediment makes it difficult to detect treatment effects for these forested watersheds

Runoff of Silvicultural Herbicides Applied Using Best Management Practices

Nine small (2.2 to 2.9 ha) and four large (70 to 135 ha) watersheds in East Texas, USA, were instrumented to compare herbicide runoff under different silvicultural systems with best management practices (BMPs). Two treatments were evaluated: conventional, with clearcutting, aerial herbicide site preparation, and hand-applied banded herbaceous release; and intensive, in which subsoiling, aerial fertilization, and a second-year aerial herbicide application were added. Herbicides were applied as operational tank mixes. The highest imazapyr concentration found in stream water was 39 mg L‑1 during the first storm after application (23 days after treatment, DAT) and in-stream concentrations during runoff events dropped to L‑1 in all streams by 150 DAT. The highest hexazinone concentration was 8 mg L‑1 for the banded application and 35 mg L‑1 for the broadcast application the following year and fell to L‑1 in all streams by 140 DAT. The highest sulfometuron methyl concentration found during a runoff event was 4 mg L‑1 and fell to L‑1 in all streams by 80 DAT. About 1 to 2% of applied imazapyr and less than 1% of hexazinone and sulfometuron methyl were measured in storm runoff. Herbicide was found in streams during storm events only (all herbicides wereµg/L in all true baseflow samples), and peak concentrations during runoff events persisted for relatively short times (\u3c 24 h). These results suggest that silvicultural herbicide applications implemented with contemporary BMPs are unlikely to result in chronic exposure of aquatic biota; therefore, herbicide use under these conditions is unlikely to degrade surface waters

European VLBI Network observations of fourteen GHz-Peaked-Spectrum radio sources at 5 GHz

We present the results of EVN polarization observations of fourteen GHz-Peaked-Spectrum (GPS) radio sources at 5 GHz. These sources were selected from bright GPS source samples and we aimed at finding Compact Symmetric Objects (CSOs). We have obtained full polarization 5 GHz VLBI observations of 14 sources providing information on their source structure and spectral indices. The results show that two core-jet sources 1433$-$040 and DA193, out of 14 GPS sources, exhibit integrated fractional polarizations of 3.6% and 1.0% respectively. The other 12 sources have no clear detection of pc-scale polarization. The results confirm that the GPS sources generally have very low polarization at 5 GHz. The sources 1133+432, 1824+271 and 2121$-$014 are confirmed as CSOs. Three new CSOs 0914+114, 1518+046 and 2322$-$040 (tentative) have been classified on the basis of 5 GHz images and spectral indices. The sources 1333+589, 1751+278 and 2323+790 can be classified either as compact doubles, and then they are likely CSO candidates or core-jet sources; further observations are needed for an appropriate classification; 0554$-$026, 1433$-$040 and 1509+054 are core-jet sources. In addition, we estimate that a component in the jet of quasar DA193 has superluminal motion of $3.3\pm0.6 h^{-1}c$ in 5.5 years.Comment: 15 pages, 23 figures, accepted for publication in A&

Data Recovery Investigations: Murvaul Creek Site (41PN175), Panola County, Texas

This report summarizes the archeological findings of the 2011 data recovery investigations at the Murvaul Creek site, 41PN175, in far northeastern Texas in Panola County. The site is located along Farm-to-Market Road (FM) 10 approximately 1 mile north of Gary, Texas (Figure 1). Geo-Marine, Inc. (GMI), performed this work under contract to the Texas Department of Transportation, Environmental Affairs Division (TxDOT ENV) under the Texas Antiquities Permit Number 5879 (Work Authorization [WA] 579 06 SA005; WA 590 08 SA005; CSJ:1222-01-014; Geo-Marine project numbers 22005.00.06 and 22005.00.09). The fieldwork for this project was conducted in advance of the planned widening of FM 10 that was to replace three bridges and a culvert over Murvaul Creek with a larger structure and shift the road approximately 26 meters (m; 85 feet [ft]) to the east. Since the planned improvements of FM 10 would result in the loss of information at the Murvaul Creek site—a site that was recommended eligible for inclusion in the National Register of Historic Places (NRHP) and for designation as a State Antiquities Landmark (SAL; formerly State Archeological Landmark)—the current data recovery investigations were initiated. The data recovery investigations were conducted between February 7, 2011, and April 3, 2011. During this period, the fieldwork was conducted in several stages: site clearing, geophysical survey, 50-x-50-centimeter (cm) excavations, block excavations, and mechanical site scraping. With the exception of the site clearing stage, the results of each of the fieldwork stages are reviewed individually in this report. The investigations resulted in the documentation of numerous features that appeared to have been the remains of a small Middle-to-Late Caddo settlement or farmstead situated on the edge of an interfluve south of the Murvaul Creek floodplain. Additionally, materials pertaining to the Archaic period were documented across the site. Although the site has been intensively studied within the TxDOT right-of-way (ROW), both the current investigations and previous work were limited to the ROW (cf. Cliff and Perttula 2002). Hence, the site is very likely larger than has been adequately documented

Ecological role of vertebrate scavengers in urban ecosystems in the UK

This is the final version of the article. Available from Wiley via the DOI in this record.Recent research has demonstrated how scavenging, the act of consuming dead animals, plays a key role in ecosystem structure, functioning, and stability. A growing number of studies suggest that vertebrate scavengers also provide key ecosystem services, the benefits humans gain from the natural world, particularly in the removal of carcasses from the environment. An increasing proportion of the human population is now residing in cities and towns, many of which, despite being highly altered environments, contain significant wildlife populations, and so animal carcasses. Indeed, non-predation fatalities may be higher within urban than natural environments. Despite this, the fate of carcasses in urban environments and the role vertebrate scavengers play in their removal have not been determined. In this study, we quantify the role of vertebrate scavengers in urban environments in three towns in the UK. Using experimentally deployed rat carcasses and rapid fire motion-triggered cameras, we determined which species were scavenging and how removal of carcass biomass was partitioned between them. Of the 63 experimental carcasses deployed, vertebrate scavenger activity was detected at 67%. There was a significantly greater depletion in carcass biomass in the presence (mean loss of 194 g) than absence (mean loss of 14 g) of scavengers. Scavenger activity was restricted to three species, Carrion crows Corvus corone, Eurasian magpies Pica pica, and European red foxes Vulpes vulpes. From behavioral analysis, we estimated that a maximum of 73% of the carcass biomass was removed by vertebrate scavengers. Despite having low species richness, the urban scavenger community in our urban study system removed a similar proportion of carcasses to those reported in more pristine environments. Vertebrate scavengers are providing a key urban ecosystem service in terms of carcass removal. This service is, however, often overlooked, and the species that provide it are among some of the most disliked and persecuted.Scientific and Technological Research Council of Turkey (Grant/Award Number: “Post-doctoral fellowship”) Natural Environment Research Council (Grant/Award Number: “NE/J015237/1”)