bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sawgrass Seedling Responses to Transplanting and Nutrient Additions
Authors: Miao S. L. , Borer R. E. , Sklar F. H. 
Published: July 2003

AbstractUnderstanding Cladium jamaicense (sawgrass) seedling establishment is an important component of an Everglades restoration program because the degree of sawgrass recovery and concurrent Typha domingensis (cattail) decline will be used to evaluate restoration success. To understand sawgrass recovery at locations with increased soil nutrients, we tested the effects of transplanting sawgrass seedlings to pots at different densities and investigated how nutrient additions affect seedling growth. Survivorship of seedlings transplanted into moist commercial potting soil at three densities ranged from 61% to 95%. After 6 months, maximum survivorship (90%) occurred at medium densities (2–4 seedlings per pot 16 cm in diameter). Nutrient additions, totaling 6.5 N g/m2, 9.8 P g/m2, 6.5 g/m2, were applied approximately 4 months after seedlings were transplanted. The biomass of the plants receiving nutrient additions (pulsed) was significantly higher (by over 30%) than plants with no nutrient addition (control). Photosynthetic rates for nutrient‐enriched plants (measured 6‐weeks after the nutrient additions) were significantly greater (by 32–45%) than for control plants. Instantaneous leaf water use efficiency increased significantly (by more than 20%) in pulsed plants. The results suggest that preventing root damage is crucial for the success of trans planted sawgrass seedlings and that nutrient additions enhanced seedling growth.
Soil Ripping and Herbicides Enhance Tree and Shrub Restoration on Stripmines
Authors: Ashby W. Clark 
Published: July 2003

AbstractI evaluated responses by 16 native woody species to differential soil compaction and density of ground cover. The trees and shrubs studied represent sites in southern Illinois that commonly have restrictions to root growth from soil or drainage conditions. The study site was a restored surface coal mine in southern Illinois with a rooting medium compacted by grading and a dense ground cover of pasture species. Soil compaction was alleviated in half the study area before tree planting by mechanically ripping the soil to a depth of 1.2 m. Roots of half the trees and shrubs were dipped in a Terra® slurry before planting, and the ground cover around all planting spots was afterwards sprayed with herbicide. In year 2 after planting the ground cover in half of the unripped and half of the ripped area was further controlled by repeated application of herbicides. Ripping significantly increased height growth of all trees combined and all species individually in each year of the study. Second‐year control of ground cover increased height growth of all trees combined and of seven species individually. Some species were damaged by herbicides. Terra® had little evident effect on species performance. Animal damage reduced early survival and growth, especially of Acer (maple) and Cornus (dogwood) species, and later growth of Quercus rubra (red oak). Removal of ground cover with herbicides tended to increase deer browse. Soil ripping, herbicide application, and choosing tree species unattractive to deer can be recommended to increase success in planting trees for forest restoration.
Restoration of Woody Plants to Capped Landfills: Root Dynamics in an Engineered Soil
Authors: Handel Steven N. , Robinson George R. , Parsons William F. J. , Mattei Jennifer H. 
Published: July 2003

AbstractClosed or abandoned landfills represent significant land areas, often in or near urban centers, that are potential sites for ecological restoration of native woodlands. But current guidelines in many jurisdictions do not allow for the installation of trees or shrubs above landfill clay caps, although these plants have many environmental, functional, and aesthetic advantages, including a rapid start to community succession. Typical closure procedures for capped landfills include only a grass cover to control moisture infiltration and impede soil erosion. The main concern that limits the application of a woody cover to a closed landfill is that roots may penetrate and weaken the clay cap. As part of a comprehensive experimental program on woodland restoration, we installed 22 tree and shrub species on Staten Island, New York (the Fresh Kills Sanitary Landfill). We found no evidence that roots of the transplanted woody plants penetrate caps used on these landfills. Root growth requirements and dynamics stop penetration of these materials. Anoxic and acidic conditions were found in the sandy subsoil above the cap, as indicated by corrosion patterns on steel test rods. Also, the intensity of mycorrhizal infection on the experimental plants was high in the surface soil and decreased progressively with increasing soil depth. The potential vertical rooting depth during this time period was greater than that occurring over the clay cap. This was shown from data collected on a nearby control site, where seven of the species were installed on an engineered soil lacking a clay barrier layer, and roots of all seven species penetrated deeper than on the landfill. The engineered landfill soils are poor growth media for roots, and below ground constraints that limit restoration on these sites must be addressed.
Smoke Enhanced Seed Germination for Mine Rehabilitation in the Southwest of Western Australia
Authors: Roche Shauna , Koch John M. , Dixon Kingsley W. 
Published: July 2003

AbstractCool smoke treatments were applied to unmined Eucalyptus marginata (jarrah) forest soils, rehabilitated bauxite mine soils, and broadcast seed to determine if enhancement in germination could be effected with a view toward maximizng the establishment of species in bauxite mines in Western Australia.Forest sites showed a 48‐fold increase in total germinants from the soil seed bank when treated with aerosol smoke. Newly returned bauxite mine soils showed a greater than threefold increase in total germinants after the same treatment. There were also significant increases in the number of species germinating in response to the aerosol smoke treatment in both the forest and the mined soils. Similarly, application of smoked water to the soil seed bank in previously mined sites elicited a significant positive germination response, increasing total germinants and species numbers by 56 and 33%, respectively.Treatment of mixed seed lots with aerosol smoke before broadcast resulted in highly significant improvement in germination when compared to untreated seed. Both total number of germinants, and number of species emerging from mined sites were positively influenced (85% and 34% increases, respectively).Ten target species were used to determine the relative effectiveness of different methods of smoke treatment on the germination of broadcast seed. Nine of the species involved displayed a promotive effect with at least two of the treatments. Generally, however, aerosol smoking of seed before broadcast proved to be the more effective approach. As a result of these findings, all broadcast seed for use in Alcoa's bauxite mined areas in the southwest of Western Australia is now routinely smoke treated before application.
Response of Endangered Desert Fish Populations to a Constructed Refuge
Authors: Winemiller Kirk O. , Anderson Allison A. 
Published: July 2003

AbstractThe U.S. Bureau of Reclamation created a shallow, 110‐m channel to provide habitat for two endangered fishes, Cyprinodon elegans (Comanche Springs pupfish) and Gambusia nobilis (Pecos gambusia), at the site of the fishes' former natural habitat. The ciénega (marsh) associated with Phantom Lake Spring in Jeff Davis County, Texas, was destroyed by the creation of an irrigation canal system. In 1993, the endangered fishes were stocked into the refuge with individuals from the irrigation canals, and in the case of C. elegans, hatchery stocks. The condition of habitat, status of fish populations, and fish ecology within the refuge were then monitored for two years. The abundance and density of both species increased in accordance with aquatic plant development. Cyprinodon elegans abundance peaked after one year and stabilized at an average density of 14.7/m2 by the end of our study. Juvenile C. elegans were always rare, which may indicate that the population reached the refuge's carrying capacity and that recruitment is low. Gambusia nobilis was the most abundant fish in the refuge (average density 96/m2), used the entire refuge, and outcom‐peted nonindigenous G. geiseri. The two Gambusia species used similar habitats but showed almost no dietary overlap. High densities of aquatic plants reduced the amount of open water areas necessary for C. elegans. The refuge will sustain the two endangered fishes at this historic site of endemism while maintaining flow to the irrigation system; however, the refuge is not equivalent to a restored ciénega.
Restoring Native Perennial Grasses to Rural Roadsides in the Sacramento Valley of California: Establishment and Evaluation
Authors: Buss Robert L. , Brown Cynthia S. , Anderson John H. 
Published: July 2003

AbstractAlong rural roadsides of the Sacramento Valley of California, we seeded native and non‐native perennial grasses to gauge their potential value in roadside vegetation management programs. In trial I (polycultures), three seeded complexes and a control (resident vegetation only) were tested. Each seeded plant complex included a different mix of perennial grasses seeded into each of several roadside topographic zones. The seeded levels of plant complex were: native perennial grasses 1 (8 species); native perennial grasses 2 (13 species); and non‐native perennial grasses (3 species). In trial II, plots were seeded to monocultural plots of 15 accessions of native Californian and three cultivars of non‐native perennial grasses. Plots in both trials were seeded during January 1992 and evaluated for three successive years.
Response of Understory Species to Gap Formation and Soil Disturbance m Lonicera maackii Thickets
Authors: Luken J. O. , Kuddes L. M. , Tholemeier T. C. 
Published: July 2003

AbstractWe studied the utility of gap formation and soil disturbance as methods to enhance establishment of plant species in the understory of a northern Kentucky forest where Lonicera maackii (Amur honeysuckle) produced dense thickets. In May 1994, gaps (5 m diameter) were cut in the shrub thicket. In adjacent areas, the shrub canopy remained intact. Subplots were established where soil was either turned with a spade to a depth of 15 cm or not disturbed. We monitored plant establishment for three growing seasons (1994, 1995, and 1996). Shrub removal increased light availability to about 10% of full sun. Gap formation had a significant (p < 0.05) and positive influence on total plant density (exclusive of L. maackii), and soil disturbance did not (p > 0.05). After three growing seasons, the most important species were L. maackii, Alliaria petiolata, Parthenocissus quinquefolia, Vitis vulpina, and Acer negundo. Of these species, only V. vulpina showed significantly (p < 0.05) higher densities in gaps. Other less important species such as Phytolacca americana, Campsis radicans, and Eupatorium rugosum occurred almost exclusively in gaps. Of the 44 taxa observed in this study, most were generalist species that also occur in early successional habitats. Long‐term dominance of the understory by L. maackii has likely modified system attributes with corresponding effects on community development. Shrub removal provides a window of establishment for various plant species, but successful restoration may require further management species availability and to control new invaders.
Genetic Variation and the Reproduction of Cordylanthus maritimus ssp. maritimus to Sweetwater Marsh, California
Authors: Helenurm Kaius , Parsons Lorraine S. 
Published: July 2003

AbstractThis study evaluated the genetic consequences of a reintroduction of the endangered annual plant Cordylanthus maritimus ssp. maritimus to Sweetwater Marsh (San Diego County, California). A survey of 21 enzyme loci in natural populations revealed that genetic diversity is very low and is primarily found as rare alleles at a few loci, making this species especially susceptible to the loss of alleles and heterozygosity through genetic drift. The reintroduction was performed in 1991 and 1992 by sowing seeds (collected from Tijuana Estuary) in numerous small patches of suitable habitat. For this study, leaf tissue was collected from all plants in all patches during flowering in 1995 and surveyed for genotype at the three enzyme loci that are polymorphic at Tijuana Estuary. Rare alleles were absent in 27 out of 30 patches for Pgm‐1, in 17 out of 30 patches for Pgm‐2, and in 10 out of 11 patches for Mdh‐1. In all, half of the patches lacked any rare allele. Rare alleles tended to occur in patches with few individuals. Overall rare allele frequency was lower than in the colonies from which seeds were collected at two of the three loci, and heterozygosity was reduced. The Sweetwater Marsh population is at risk of losing most of its genetic variation at enzyme loci through the extinction of patches with few individuals. Future reintroduction attempts should attempt to create contiguous sets of patches or to periodically reseed existing patches to reduce the loss of genetic variation.
Exotic Grass Competition in Suppressing Native Shrubland Re‐establishment
Authors: Eliason Scott A. , Allen Edith B. 
Published: July 2003

AbstractDisturbance of coastal sage scrub in southern California has led to extensive displacement of native shrubs by exotic annual grasses. The initial conversion from shrubland to exotic grassland is typically associated with disturbance caused by intense grazing, high fire frequency, or mechanical vegetation removal. While native shrubs have been shown to recolonize annual grasslands under some conditions, other annual grasslands are persistent and show no evidence of shrub recolonization. This study examined the mechanisms by which annual grasses may exclude native shrubs and persist after release from disturbance. Grass density was manipulated in experimental plots to achieve a series of prescribed densities.Artemisia californica, a dominant native shrub, was seeded or planted into the plots and responses to the grass density treatments were measured over two growing seasons.A. californicagermination, first season growth, and survival were all negatively related to the density of neighboring annual grasses. The most probable mechanism underlying the reduction of first season growth and survival was depletion of soil water by the grasses. The effects of the grasses onA. californicawere no longer significant in the second season. The results of this study indicate that Mediterranean annual grasses reduce recruitment and can persist by inhibiting post‐disturbance establishment ofA. californicafrom seed. Although succession alone may not return disturbed annual grasslands to their former shrubland composition, the results suggest that restoration can be achieved by using container plantings or grass removal followed by seeding.
Role of Soils in Determining Sites for Lowland Heathland Reconstruction in England
Authors: Clarke Christopher T. 
Published: July 2003

AbstractNo guidelines are currently available that advise which soil properties of arable land can be used to suggest suitable locations for heathland reconstruction. This paper reviews studies comparing soil properties of heathland or semi‐natural grassland with those of adjacent arable fields, investigations in the autecology of the dominant heathland plant, Calluna vulgaris (common heather), and long‐term experiments of fertilizer inputs on arable soils. Three properties must be assessed before the suitability of a field can be determined: extractable phosphorus, exchangeable calcium, and pH. A number of other nutrients may also be important, but evidence is currently insufficient to substantiate this. Natural changes in levels of extractable phosphorus, exchangeable calcium, and pH appear to be very slow, so nutrient stripping and acidification will be necessary where recommended levels are exceeded to successfully restore heathland vegetation.
Effectiveness of Road Ripping in Restoring Infiltration Capacity of Forest Roads
Authors: Luce Charles H. 
Published: July 2003

AbstractMany forest roads are being closed as a step in watershed restoration. Ripping roads with subsoilers or rock rippers is a common practice to increase the infiltration capacity of roads before closure. When considering the effectiveness of ripping for reducing runoff and erosion and the potential reduction in slope stability by saturating road fills, it is important to know how ripping changes the infiltration capacity of forest roads. Hydrographs from simulated rainfall on 1 × 1 m plots were analyzed to find the saturated hydraulic conductivity, an indicator of infiltration capacity. I examined saturated hydraulic conductivity for three treatments on two different soils. One road was built in a soil derived from the metamorphic belt series geology of northern Idaho, a soil noted for its high rock fragment content. The second road was built in a sandy soil derived from decomposed granitics of the Idaho batholith. On each soil, five plots were installed on a road before ripping, and nine plots were installed on the same road segment following ripping, four covered with a heavy straw mulch and five without. Three half‐hour rainfall events with intensities near 90 mm/hr were simulated on each plot. Results show that ripping increases hydraulic conductivities enough to reduce risk of runoff but does not restore the natural hydraulic conductivity of a forested slope. The unripped road surfaces had hydraulic conductivities in the range of 0–4 mm/hr, whereas ripped roads were in the range of 20–40 mm/hr after the second event. Surface sealing and tilled soil subsidence processes are important in reducing the hydraulic conductivity of the soils with repeated wetting. Subsidence appears to be important on the granitic soil, whereas surface sealing was more important on the belt series soil.
Beyond Pharmacotherapy: Surgical Management
Authors: Ryvlin Philippe 
Published: July 2003

Summary:  Purpose: To review the recent advances in the field of temporal lobe epilepsy (TLE) surgery. Results: TLE surgery has recently demonstrated a highly significant superiority over optimal medical therapy in a randomized trial. Accordingly, a median rate of 70% of class I outcome (patients free of disabling seizures postoperatively) has emerged from the pooling of all data published since the early 1990s. In addition, successful TLE surgery appears likely to reduce the risk of seizure‐related death. However, it remains largely underused and overly delayed, partly because of the legitimate fears of possible surgical complications, such as verbal memory deficits or failure to control seizures. Reasons for surgical failures are not completely understood, and include bitemporal, pseudotemporal, and temporal‐plus epilepsies, as well as insufficient resection of the mesial temporal structures. Developing techniques such as intraoperative MRI, gamma‐knife radiosurgery, and various types of cranial nerves or intracerebral chronic stimulation have the potential to alleviate part of the limitations of TLE surgery. Conclusions: The overall benefit of surgical treatment in patients with drug‐resistant TLE should encourage a more frequent and earlier referral of such patients to epilepsy surgery centers. Important progress toward higher rates of seizure‐free outcome and lower morbidity remains to be made and may be obtained by taking advantage of the new available technologies.
Karzinogenese: Gestörte Kontrollsysteme und Optionen für die molekulare Therapie
Authors: Pfützner Wolfgang 
Published: July 2003

ZusammenfassungDie Entwicklung eines malignen Tumors beruht auf DNS‐Mutationen, die zu multiplen Störungen unterschiedlicher Kontrollsysteme führen, welche für die koordinierte Regulation von Zellwachstum, Zelltod und Zellausbreitung zuständig sind. Dabei kann der Verlust einzelner dieser Kontrollsysteme durch die anderen Systeme noch kompensiert werden, erst das Zusammenbrechen des gesamten Kontrollnetzwerkes auf molekularer Ebene führt zum malignen Tumorwachstum. Das Wissen über diese Regelkreise und ihre Defekte im Rahmen der Karzinogenese ermöglicht die Entwicklung neuer Therapiestrategien. Die Gentherapie als molekulare Therapie offeriert hierbei vielversprechende Behandlungsansätze.
American canine hepatozoonosis
Authors: Panciera R. J. , Ewing S. A. 
Published: July 2003

AbstractAmerican canine hepatozoonosis is an emerging, tick-transmitted infection of domestic dogs caused by a recently recognized species of apicomplexan parasite,Hepatozoon americanum. The known definitive host of the protozoan is the Gulf Coast tick,Amblyomma maculatum. Presently recognized intermediate hosts include the domestic dog and the coyote,Canis latrans. Laboratory-reared larval or nymphalA. maculatumcan be infected readily by feeding to repletion on a parasitemic intermediate host; sporogony requires 35–40 days. Transmission of infection to the dog has been produced experimentally by oral administration of mature oocysts or oocyst-containing ticks. Canine disease follows experimental exposure in 4–6 weeks and is characterized by systemic illness, extreme neutrophilic leukocytosis, muscle and bone pain, and proliferation of periosteal bone. Histopathological findings include multifocal skeletal and cardiac myositis associated with escape of mature merozoites from within the host-cell environment. There is also rapid onset of periosteal activation and osteogenesis and, less frequently, glomerulopathy and amyloidosis. Sequential stages of development ofH. americanumin both the dog and the tick have been elucidated. Gamonts potentially infectious to ticks have been observed in peripheral blood leukocytes of the dog in as few as 28 days after exposure to oocysts. Young coyotes experimentally exposed to a canine strain ofH. americanumacquired disease indistinguishable from that of similarly exposed young dogs.
Non-infectious and iatrogenic diseases of salmon in commercial aquaculture
Authors: Speare David J. 
Published: July 2003

AbstractBased on current commercial aquaculture production practices, the production cycle for Atlantic salmon (Salmo salar) extends over a 36-month period during which time the fish are first exposed to intensive freshwater rearing conditions followed by transportation to marine netpen sites for ongrowing. It is predictable that, because of the duration of the production cycle and the variety of water conditions, deleterious environmental conditions have many opportunities to affect salmon health directly and indirectly. Furthermore, diseases which are iatrogenic arise from current methods used to prevent or treat infectious diseases. Specific, more frequently encountered examples are explored, with reference to the possible roles which these diseases may have in favouring the onset of infectious diseases.