Forest Vegetation Monitoring and Foliar Chemistry of Red Spruce and Red Maple at Acadia National Park in Maine

The USDA Forest Service Forest Health Monitoring (FHM) program indicators, including forest mensuration, crown condition classification, and damage and mortality indicators were used in the Cadillac Brook and Hadlock Brook watershed forests at Acadia National Park (ANP) along coastal Maine. Cadillac Brook watershed burned in a wildfire in 1947. Hadlock Brook watershed, undisturbed for several centuries, serves as the reference site. These two small watersheds have been gauged and monitored at ANP since 1998 as part of the Park Research and Intensive Monitoring of Ecosystems Network (PRIMENet). Forest vegetation at Hadlock Brook was dominated by late successional species such as Acer saccharum, Fagus grandifolia, Betula alleghaniensis, Acer rubrum and Picea rubens. Forest vegetation at Cadillac Brook, on the other hand, was younger and more diverse and included those species found in Hadlock as well as early successional species such as Betula papyrifera and Populus grandidentata. Differences in forest species composition and stand structure were attributed to the severe wildfire that affected the Cadillac Brook watershed. Overall, the forests at these ANP watersheds were healthy with a low percentage (相似文献   

Growing hot pepper for cabbage looper, Trichopulsia ni (Hübner) and spider mite, Tetranychus urticae (Koch) control

With the public perception that synthetic pesticides leave harmful residues in crop produce for human consumption, there has been increased interest in using natural products for pest control. The potential of using fruit extracts of hot pepper for controlling the cabbage looper, Trichopulsia ni (Hübner) and spider mite, Tetranychus urticae Koch is explored in this investigation. Crude extracts from fruits of Capsicum chinense, C. frutescens, C. baccatum, and C. annuum, were prepared and tested under laboratory conditions for their insecticidal and acaricidal performance. Mortality was greatest (94%) when fruit extract of accession PI-593566 (C. annuum) was sprayed on larvae of the cabbage looper, while crude extracts of accessions PI-241675 (C. frutescens) and PI-310488 (C. annuum) were repellent to the spider mite. We investigated differences in chemical composition of the crude fruit extracts that may explain the observed differences in mortality and repellency between accessions. Gas Chromatography-Mass Spectrometry spectrometric analysis revealed that capsaicin and dihydrocapsaicin, the pungent components of pepper fruit, were not correlated with toxicity or repellency, indicating that the two capsaicinoids are not likely related to the efficacy of pepper fruit extracts. Major compounds in hot pepper fruit extracts were detected and identified as pentadecanoic acid methyl ester, hexadecanoic acid methyl ester, and octadecanoic acid methyl ester. Spectrometric analysis and toxicity to cabbage looper larvae revealed that pentadecanoic acid methyl ester is likely related to cabbage looper mortality. However, the concentration of pentadecanoic acid methyl ester in some accessions was insufficient to explain the observed mortality of cabbage looper and repellency of spider mite. Fruit extracts of accessions PI-593566 (C. annuum) and PI-241675 (C. frutescens) could be useful for managing populations of cabbage loopers and spider mites, which could reduce reliance on synthetic pesticides. Further study is needed to investigate performance of hot pepper extracts under ultra-violet light and field conditions.     

The Ecological Condition of Gulf of Mexico Resources from Perdido Key to Port St. Joe, Florida, USA: Part I. Coastal Beach Resources

Using the approach established by EPA's Environmental Monitoring and Assessment Program (EMAP), a shoreline monitoring survey was conducted in August and September 1999, encompassing the Florida Panhandle from Perdido Key, Florida to Port St. Joe, Florida. The objective of this survey was to demonstrate the use of a probabilistic survey for monitoring and estimating the condition of swimmable beach areas. Thirty stations were sampled using a probabilistic sampling design. Hydrographic data were collected in addition to samples for water chemistry. Bacterial indicators, enterococci and fecal coliforms, were enumerated from the water according to the EPA Beaches Environmental Assessment Closure and Health (BEACH) Program and Florida state guidelines. Additional criteria for site condition included the presence or absence of primary and secondary dunes, anthropogenic debris and vegetation. Based on EMAP evaluation guidelines and Florida state criteria, a baseline assessment of the condition of the Gulf of Mexico beach resources surveyed is presented.     

At-sea activity patterns of breeding and nonbreeding white-chinned petrels <Emphasis Type="Italic">Procellaria aequinoctialis</Emphasis> from South Georgia

Despite the recent burgeoning in predator tracking studies, few report on seabird activity patterns, despite the potential to provide important insights into foraging ecology and distribution. In the first year-round study for any small petrel, we examined the activity patterns of the white-chinned petrel Procellaria aequinoctialis based on data from combination geolocator-immersion loggers deployed on adults at South Georgia. The petrels were highly nocturnal, flying for greater proportions of darkness than any large procellarid studied so far, except the light-mantled albatross Phoebetria palpebrata. Flight bout durations were short compared with other species, suggesting a dominant foraging mode of small-scale searching within large prey patches. When migrating, birds reduced the proportion of time on the water and increased flight bout duration. Activity patterns changed seasonally: birds flew least during the nonbreeding period, and most frequently during chick-rearing in order to meet higher energy demands associated with provisioning offspring. The degree of their response to moonlight was also stage dependent (greatest in nonbreeding, and weakest in incubating birds), a trait potentially shared by other nocturnal petrels which will have repercussions for feeding success and prey selection. For the white-chinned petrel, which is commonly caught in longline fisheries, these results can be used to identify periods when birds are most susceptible to bycatch, and therefore when use of mitigation and checking for compliance is critical.     

DNAPL remediation with in situ chemical oxidation using potassium permanganate. Part I. Mineralogy of Mn oxide and its dissolution in organic acids

Previous studies on in situ chemical oxidation of trichloroethylene (TCE) with potassium permanganate indicated that the solid reaction product, Mn oxide, could reduce the permeability of the porous medium and impact the success of dense non-aqueous phase liquid (DNAPL) removal. In order to address the issue of permeability reduction caused by precipitation, this study investigated the mineralogy of Mn oxides and the possibilities of removing the solid precipitates by dissolution. The solid reaction product from the oxidation of TCE by permanganate is semi-amorphous potassium-rich birnessite, which has a layered mineral structure with an interlayer spacing of 7.3 A. The chemical formula is K(0.854)Mn(1.786)O(4).1.55H(2)O. It has a relatively small specific surface area at 23.6+/-0.82 m(2)/g. Its point of zero charge (pzc) was measured as 3.7+/-0.4. This birnessite is a relatively active species and could participate in various reactions with existing organic and inorganic matter. The dissolution kinetics of Mn oxide was evaluated in batch experiments using solutions of citric acid, oxalic acid, and ethylenediaminetetraacetic acid (EDTA). Initial dissolution rates were determined to be 0.126 mM/m(2)/h for citric acid, 1.35 mM/m(2)/h for oxalic acid, and 5.176 mM/m(2)/h for EDTA. These rates compare with 0.0025 mM/m(2)/h for nitric acid at pH=2. Organic acids dissolve Mn oxide quickly. Reaction rates increase with acid concentration, as tested with citric acid. The dissolution mechanism likely involves proton and ligand-promoted dissolution and reductive dissolution. Citric and oxalic acid can induce ligand-promoted dissolution, while EDTA can induce ligand-promoted and reductive dissolutions. At low pH, proton-promoted dissolution seems to occur with all the acids tested, but this process is not dominant. Reductive dissolution appears to be the most effective process in dissolving the solid, followed by ligand-promoted dissolution. These experiments indicate the significant potential in using these organic acids to remove precipitates formed during the oxidation reaction.     

Aerating grasslands: effects on runoff and phosphorus losses from applied broiler litter

Aeration has been promoted as improving infiltration of rainfall and extending grass or forage productivity, but research on the impact of this practice on P losses from grasslands has had mixed results. We designed a study to determine at the field scale, using a paired watershed approach, the impact of slit aeration on runoff volume and P losses in runoff from fescue (Festuca arundinacea Schreb.)/bermudagrass (Cynodon dactylon L.) hay fields fertilized with broiler litter. Three pairs of 0.8-ha fields, each with similar soils (Typic Kanhapludults, Aquic Hapludults, and Aquultic Hapludalfs), were fertilized with broiler litter and monitored under similar management from 1995 through 1998, then one field in each pair received aeration treatment from 2001 through 2003. In the field with mostly well-drained soils, grassland aeration reduced surface runoff volume and mass losses of dissolved reactive P (DRP) in runoff by approximately 35%. In contrast, when poorly drained soils dominated, grassland aeration increased runoff volume (4.8 mm/runoff event) and mass losses of DRP and total P (0.25 kg TP ha-1 per runoff event). This implies that aeration of well-drained soils in the top poultry-producing counties of Georgia (0.2 million ha) could decrease dissolved phosphorus losses by more than 500 Mg P each year. This is not the case if soils are poorly drained.     

Ground cover impacts on nitrogen export from manured riparian pasture

Maintaining ground cover of forages may reduce the export of nitrogen (N) from pastures. The objective of this work was to determine the effect of ground cover on N export from pastured riparian areas receiving simulated rainfall. Plots were established on two adjacent sites in the North Carolina Piedmont: one of 10% slope with Appling sandy loam soils and a second of 20% slope with Wedowee sandy loam soils. Both sites had existing mixed tall fescue (Festuca arundinacea Schreb.)-dallisgrass (Paspalum dilatatum Poir.) vegetation. Forage stands were modified to represent a range of ground cover levels: 0, 45, 70, and 95% (bare ground, low, medium, and high cover, respectively), and amended with beef steer (Bos taurus) feces and urine (approximately 200 kg N ha-1). For all rain events combined, mean nitrate N export was greatest from bare ground and was reduced by 34% at low cover, which did not differ from high cover. Mean ammonium N export was slightly elevated (approximately 1.37 kg N ha-1) in months when manures were applied and negligible (<0.02 kg N ha-1) in all other months. For all rain events combined, mean export of total N was greatest from bare ground and was reduced by at least 85% at all other cover levels. Whereas site did not impact N export, results indicated that cover and time of rainfall following manure deposition are important determinants of the impact of riparian grazing.