bluuebunny/crossref_metadata_2025_split huggingface dataset:
Moderating Night Radiative Cooling Reduces Frost Damage to Metrosideros polymorpha Seedlings Used for Forest Restoration in Hawaii
Authors: Scowcroft Paul G. , Meinzer Frederick C. , Goldstein Guillermo , Melcher Peter J. , Jeffrey Jack 
Published: March 2003

AbstractWinter frosts caused by radiative cooling were hypothesized to limit successful reintroduction of Hawaiian plants other than Acacia koa to alien‐dominated grasslands above 1700 m elevation. We determined, in the laboratory, the temperature at which irreversible tissue damage occurred to Metrosideros polymorpha leaves. We also conducted a field study of this species to determine if (1) leaf damage was correlated with sub‐zero leaf temperatures, (2) radiative cooling could be moderated by canopies of A. koa, and (3) low soil temperatures contributed to seedling damage. The last was evaluated by thermally buffering seedlings with water‐filled bladders placed at their base to keep roots warm, or by installing a radiation shield to reduce early morning transpiration when water uptake from cold soils would be least. Leaf temperatures were monitored between midnight and 7:00 a.m. using fine‐wire thermocouples, and leaf damage was recorded monthly. In the laboratory, supercooling protected leaves from mild sub‐zero temperatures; irreversible tissue damage occurred at about −8°C. In the field, leaf damage was strongly correlated with degree‐hours below freezing. Unprotected seedlings suffered the greatest leaf damage. Those sheltered under A. koa trees rarely experienced temperatures below −3°C, and damage was minimal. Shaded and thermally buffered seedlings suffered less damage than unprotected plants, probably due to elevated leaf temperatures rather than improved water relations. Using A. koa or artificial devices to reduce radiative cooling during winter nights should enhance establishment of M. polymorpha in high‐elevation rangeland.
Modeling Nutritional Carrying Capacity for Translocated Desert Bighorn Sheep in Western Texas
Authors: DeYoung Randall W. , Hellgren Eric C. , Fulbright Tim E. , Robbins W. Frank , Humphreys Ira D. 
Published: March 2003

AbstractRestoration of desert bighorn sheep (Ovis canadensis) is proceeding in several western states. Measurement of nutritional resources (quality and quantity) is not normally conducted to assess future and present translocation sites, although it has been recommended generally for evaluation of ungulate habitat. We estimated nutritional carrying capacity (based on nitrogen in forage species) of three mountain ranges in Trans‐Pecos Texas where desert bighorn sheep have been translocated. We used an explicit nutritional constraint model to estimate carrying capacity on a seasonal basis. Although drought conditions prevailed during the study period, bighorns were not limited by quantity of vegetation. However, forage biomass of high nutritional quality (>1.5% N) was very low (<9 kg/ha in spring; <1 kg/ha in all other seasons). Consequently, there appeared to be inadequate forage of high N content for bighorns to meet reproductive requirements in some seasons. Estimates generated using the explicit nutritional constraint carrying capacity model appeared to be realistic relative to observed densities. Nutritional sampling and modeling can predict potential carrying capacity on areas scheduled for restoration or on ranges already stocked, predict effects of management on carrying capacity, and allow managers to compare among restoration sites. We recommend that desert bighorn managers focus on monitoring the abundance of high‐quality (%N) forage species, especially during periods of drought or higher nutritional requirements (e.g., lactation, post‐weanling growth).
Estimating the Effect of Beach Nourishment on Caretta caretta (Loggerhead Sea Turtle) Nesting
Authors: Rumbold D. G. , Davis P. W. , Perretta C. 
Published: March 2003

Abstract Caretta caretta (loggerhead sea turtle) nesting activity was recorded daily during three seasons prior to and two seasons immediately following a beach nourishment (replenishment) project in Palm Beach County, Florida. Surveys were done at the nourished beach (Jupiter/Carlin) and at two natural beaches (Juno and Tequesta). The size of the nourishment effect on nesting activity was estimated using Before‐After‐Control‐Impact Paired Series (BACIPS) models. Nesting declined by 4.4 to 5.4 nests km−1 day−1 on the nourished beach compared to the two natural beaches in the first season after nourishment. At the same time, false crawls (FC, non‐nesting crawls) increased by 5.0 to 5.6 FC km−1 day−1 on the nourished beach. In the second season following nourishment, nesting was reduced by 0.5 to 1.6 nests km−1 day−1 on the nourished beach compared to the two natural beaches. The increase in false crawl frequency in the second season following nourishment was 0.7 to 0.9 FC km−1 day−1.These results suggest that beach nourishment significantly decreased loggerhead sea turtle nesting during the first season following the project. However, the size of the effect, in terms of nesting frequency and false crawl frequency, was much reduced by the second season following nourishment.
Wyoming Big Sagebrush Density: Effects of Seeding Rates and Grass Competition
Authors: Williams Mary I. , Schuman Gerald E. , Hild Ann L. , Vicklund Laurel E. 
Published: March 2003

AbstractThe mining industry commonly seeds shrubs and grasses concurrently on coal‐mined lands of northeastern Wyoming, but ecological interactions between seeded shrubs and grasses are not well documented. Artemisia tridentata Nutt. ssp. wyomingensis (Beetle and Young) (Wyoming big sagebrush) is the dominant pre‐mining shrub on many Wyoming mine sites. Despite past failures to establish Wyoming big sagebrush, the Wyoming Department of Environmental Quality, Land Quality Division's rules and regulations require establishment of 1 shrub per m2 on 20% of post‐mined land in Wyoming. A study was established at the Belle Ayr Coal Mine south of Gillette, Wyoming to evaluate the effects of sagebrush seeding rates and grass competition on Wyoming big sagebrush seedling density. Three sagebrush seeding rates (1, 2, and 4 kg pure live seed [pls]/ha; 350, 700, and 1,400 pls/m2, respectively) and seven cool‐season perennial grass mixture seeding rates (0, 2, 4, 6, 8, 10, and 14 kg pls/ha; 0, 187, 374, 561, 750, 935, and 1,309 pls/m2, respectively) were applied during winter 1998–1999. Pascopyrum smithii (Rydb.) A. Love (western wheatgrass), Elymus lanceolatus (Scribner & J.G. Smith) Gould (thickspike wheatgrass), and Elymus trachycaulus (Link) Gould ex Shinners (slender wheatgrass) comprised the grass seed mix (equal seed numbers of each species). Sagebrush seedling density differed among sagebrush seeding rates but not among grass seeding rates. On all sampling dates in 1999 and 2000, sagebrush seedling density differed among sagebrush rates and was greatest at the 4 kg pls/ha sagebrush seeding rate. All sagebrush seeding rates provided densities of at least 1 shrub per m2 after two growing seasons. Grass density and production in 2000 suggest that adequate grass production (75 g/m2) was achieved by seeding at 6 to 8 kg pls/ha. Within these grass seeding rates, four or more sagebrush seedlings per m2 were attained when sagebrush was seeded at 2 to 4 kg pls/ha. Use of these seeding rate combinations in mine reclamation can achieve Wyoming big sagebrush standards and reduce reseeding costs.
Rehabilitation of Degraded Areas of Central Amazonia Using Direct Sowing of Forest Tree Seeds
Authors: Camargo José Luís Campana , Ferraz Isolde Dorothea Kossman , Imakawa Angela Maria 
Published: March 2003

AbstractDeforestation in the Amazon Basin is still increasing, and the rehabilitation of these lands continues to be a challenge. Autoecological studies of most Amazonian species are rare, and efficient techniques for restoration of forested habitats have yet to be developed. The aim of this study was to test direct sowing as a rehabilitation technique for sites with different degrees of disturbance: bare soil, pasture, and secondary and mature forests in Central Amazonia, Brazil. At each site, we sowed seeds of 11 native tree species. Throughout the following year we evaluated germination and seedling survival. The germination differed according to the study site and species. Seedling survival in degraded sites was higher than in other areas. After 1 year in the bare soil site, 33% of the sown seeds of eight species developed seedlings; in the pasture the establishment was 23%, in secondary forest 15%, and in mature forest 12% of only four species. The only widespread survivor with more than 45% emergence in all perturbed sites was Caryocar villosum. No pioneer seedlings remained after 1 year. There was a positive correlation between seed size and survival. Large‐seeded non‐pioneer species seem to be more suitable for direct sowing than small‐seeded species. We recommend a combination of direct sowing and planting of seedlings as an appropriate means to accelerate the rehabilitation of degraded areas in Central Amazonia.
A Monitoring Protocol to Assess Tidal Restoration of Salt Marshes on Local and Regional Scales
Authors: Neckles Hilary A. , Dionne Michele , Burdick David M. , Roman Charles T. , Buchsbaum Robert , Hutchins Eric 
Published: March 2003

AbstractAssessing the response of salt marshes to tidal restoration relies on comparisons of ecosystem attributes between restored and reference marshes. Although this approach provides an objective basis for judging project success, inferences can be constrained if the high variability of natural marshes masks differences in sampled attributes between restored and reference sites. Furthermore, such assessments are usually focused on a small number of restoration projects in a local area, limiting the ability to address questions regarding the effectiveness of restoration within a broad region. We developed a hierarchical approach to evaluate the performance of tidal restorations at local and regional scales throughout the Gulf of Maine. The cornerstone of the approach is a standard protocol for monitoring restored and reference salt marshes throughout the region. The monitoring protocol was developed by consensus among nearly 50 restoration scientists and practitioners. The protocol is based on a suite of core structural measures that can be applied to any tidal restoration project. The protocol also includes additional functional measures for application to specific projects. Consistent use of the standard protocol to monitor local projects will enable pooling information for regional assessments. Ultimately, it will be possible to establish a range of reference conditions characterizing natural tidal wetlands in the region and to compare performance curves between populations of restored and reference marshes for assessing regional restoration effectiveness.
Constraints of Seed Bank Species Composition and Water Depth for Restoring Vegetation in the Florida Everglades, U.S.A.
Authors: Smith Stephen M. , McCormick Paul V. , Leeds Jennifer A. , Garrett Patrick B. 
Published: March 2003

AbstractThe Rotenberger Wildlife Management Area (RWMA) is a northern Everglades marsh, in Florida, U.S.A., that will undergo hydrologic restoration to remedy an artificially shortened hydroperiod. In an effort to predict vegetation responses to the impending changes in hydrology, plant community development from the resident seed bank was observed in response to three different moisture regimes in March and September 1998. Percent cover, species densities, total seedling densities, and percentages of facultative, facultative‐upland, and upland indicator species were significantly higher in moist than in saturated soils. Flooding inhibited the germination of all species except Typha domingensis (cattail), which emerged in the highest numbers from saturated soils in both assays. Lythrum alatum (purple loosestrife) was abundant in both saturated and moist conditions. The season of assay affected species densities and the communities. Percent facultative‐wetland species increased in saturated soils in the March assay but not in September. In contrast, percent obligate hydrophytes were higher in saturated conditions only in the September assay. In general the assay communities bore little resemblance to vegetation in currently undisturbed or historic wetlands of the northern Everglades. Consequently the RWMA seed bank will contribute little to the development of a restored community. Moreover, rehydration may encourage the spread of undesirable hydrophytes such as T. domingensis. This study supports the contention that hydrologic restoration must be accompanied by some level of active vegetation management and that the reference condition cannot be attained passively.
Are ‘Green TIDES’ Harmful Algal Blooms? Allelopathic Properties of Extracts from Ulva Fenestrata and Ulvaria Obscura
Authors: Nelson T. A. , Lee D. , Smith B. C. , Prins R. 
Published: March 2003

AbstractToxic properties are rarely associated with macroalgal blooms. A few studies have demonstrated inhibition of invertebrate larval development by extracts from Ulva spp. and we have observed substantial discoloration of the seawater in small bays following mass desiccation‐induced mortality of Ulvaria obscura. We examined the effects of extracts from Ulva fenestrata and U. obscura on enzyme systems, larval oyster development, Fucus gardneri zygote development, epiphytic diatom growth, and growth of Ulva and Ulvaria. Extracts from Ulvaria inhibited trypsin activity, but not pepsin or amyloglucosidase activity when tested at pH optimized for each enzyme system (pH 8, 2, and 5.5, respectively). When tested at neutral to slightly alkaline pH (7 or 8), Ulvaria extracts also inhibited amyloglucosidase activity. ‘Aged’ extract caused greater enzyme inhibition than fresh extract. Maximum inhibition occurred in 6‐h‐old‐extract. Oyster larval development was inhibited by extracts from both algae, although the visible effects were much greater when the larvae were exposed to extracts of Ulvaria. Fucus zygote development was inhibited by extracts of both species, although the effect was measurably greater in extracts from Ulvaria. Epiphytic diatom growth and growth of Ulva and Ulvaria were inhibited by extracts from both species. Thus, extracts from both Ulva fenestrata and U. obscura have allelopathic properties, although the impacts are more widespread for Ulvaria extracts. These properties could alter competitive interactions by inhibiting germination or development of algal and animal competitors. Multiple toxins are probably involved, since the two species tested cause visibly different responses.
Are Older Hazardous and Harmful Drinkers Less Likely To Participate in Health‐Related Behaviors and Practices as Compared with Nonhazardous Drinkers?
Authors: Moore Alison A. , Morgenstern Hal , Harawa Nina T. , Fielding Jonathan E. , Higa Jerilyn , Beck John C. 
Published: March 2003

OBJECTIVES: To describe the (1) prevalence of at‐risk drinking and participation in health‐related behaviors and practices and (2) associations of at‐risk drinking with other health‐related behaviors and practices among older persons completing a health‐risk appraisal for the elderly (HRA‐E).DESIGN: Cross‐sectional study using data from a self‐administered, mailed survey sample.SETTINGS: Persons from three organizations were surveyed: (1) the American Association of Retired Persons; and (2) a large medical group and (3) a community‐based senior health center in southern California.PARTICIPANTS: 1,889 persons age 55 years and older.MEASUREMENTS: The HRA‐E included items on health characteristics, drinking behaviors (including amount of alcohol use and two alcoholism screening measures: the CAGE (Cut down, Annoyed, Guilty, Eye opener) and Short Michigan Alcoholism Screening Test‐Geriatric version (SMAST‐G), and participation in selected health‐related behaviors and practices. Social drinkers were defined as those who drank fewer than 14 drinks weekly and screened negative on the CAGE (defined as two or more “no” responses) and SMAST‐G. Hazardous drinkers drank fewer than 14 drinks weekly and screened negative. Harmful drinkers drank fewer than 14 drinks weekly and screened positive. Possible at‐risk drinkers drank 14 or more drinks weekly and screened positive. Least squares regression models were used to assess the effects of hazardous, harmful, and possible at‐risk drinking on each of the health‐related practices and behaviors. We also conducted these analyses using three other definitions of social, possible at‐risk, hazardous, and harmful drinking.RESULTS: Of all respondents, 40% were social drinkers, 3% were harmful drinkers, 2% were hazardous drinkers, and 11% were possible at‐risk drinkers. Hazardous, harmful, and possible at‐risk drinkers commonly reported driving after drinking or being driven by someone who had been drinking (67%, 76%, and 64% respectively). Harmful and possible at‐risk drinkers were more likely than social drinkers to smoke and were less likely to use seatbelts regularly. These findings were observed regardless of how the drinking groups were defined.CONCLUSION: All groups of at‐risk drinkers more commonly engaged in selected adverse health‐related behaviors and practices than did social drinkers.
A Controlled Study of MRI Signal Hyperintensities in Older Depressed Patients with and without Hypertension
Authors: Greenwald Blaine S. , Kramer‐Ginsberg Elisse , Krishnan K. Ranga Rama , Hu Jian , Ashtari Manzar , Wu Houwei , Aupperle Peter , Patel Mahendra , Pollack Simcha 
Published: March 2003

OBJECTIVES:To compare the frequency/severity of signal hyperintensities—likely markers of cerebrovascular disease—in the subcortical gray and deep white matter on magnetic resonance imaging (MRI) scans of brains of hypertensive and normotensive older depressed and nondepressed comparison subjects.DESIGN:Between‐groups comparison of cross‐sectional MRI data employing analyses of covariance controlling for the effects of age, gender, and height.SETTING:A comprehensive inpatient‐outpatient geriatric psychiatry service in a university hospital.PARTICIPANTS:Nondemented older depressed (n = 81) and nondepressed comparison (n = 70) subjects divided into four groups (hypertensive depressed (n = 40), hypertensive normals (n = 21), normotensive depressed (n = 41), normotensive normals (n = 49)).MEASUREMENTS:Signal hyperintensities were rated on T‐2 weighted MRI scans blind to patient diagnoses employing two standardized hyperintensity rating systems (Fazekas, Boyko).RESULTS:Hypertensive depressives had significantly more‐severe hyperintensity ratings in both subcortical gray and deep white matter than did normotensive depressives and controls (P < .05) and significantly more‐severe hyperintensity ratings only in subcortical gray matter (P < .05) than did hypertensive controls. Hypertensive controls had significantly more‐severe ratings in deep white matter than either normotensive group (P < .05).CONCLUSIONS:Findings suggest a relationship between deep white matter hyperintensities and hypertension (regardless of depressive state), and a particular role of subcortical gray matter hyperintensities (possibly interacting with more‐severe deep white matter lesions) in older depressed hypertensives, as compared with older depressed normotensives of similar ages and severity of depression. These data support possible heterogeneous pathogenic contributions in late‐life depression subgroups, one of which appears to be influenced by cerebrovascular disease. J Am Geriatr Soc 49:1218–1225, 2001.
Frequency of Alzheimer's Disease and Other Dementias in a Community Outreach Sample of Hispanics
Authors: Fitten L. Jaime , Ortiz Freddy , Pontón Marcel 
Published: March 2003

OBJECTIVES:To determine the proportion of Alzheimer's disease (AD) and other dementia types in a community sample of Hispanics.DESIGN:This is a descriptive diagnostic study of a nonrandom community outreach sample utilizing established criteria for the diagnosis of dementia type. Recruitment involved direct community outreach with diagnostic evaluations conducted at a university‐affiliated outpatient clinic.SETTING:Hispanic Neuropsychiatric and Memory Research Clinic at the Olive View‐UCLA Medical Center in Sylmar, California.PARTICIPANTS:One hundred community‐dwelling Hispanics age 55 and older without prior diagnosis or treatment of their cognitive symptoms.MEASUREMENTS:Each subject underwent a complete medical diagnostic evaluation, in Spanish, including neuropsychological tests, neurological examination, laboratory tests, and brain imaging (computed tomography or magnetic resonance imaging) to establish dementia type. Presence of dementia was established according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM‐IV) criteria. Diagnosis for probable or possible AD and vascular dementia (VascD) was established using criteria from the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association for probable AD and by research criteria from the National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l'Enseignement en Neurosciences for VascD, respectively. Frontotemporal dementia was diagnosed using recommendations set forth by the Lund and Manchester groups.RESULTS:Subjects were poor, with low acculturation levels despite long years of U.S. residence. Forty percent of subjects had had undiagnosed cognitive symptoms for 3 or more years. Of those demented,65 38.5% had AD and 38.5% met criteria for VascD. The best predictors of VascD were hypertension and cerebrovascular disease, whereas apolipoprotein E4 allele best predicted AD. Other forms of dementia were also present. Twenty percent of the sample was clinically depressed but not demented.CONCLUSIONS:In comparison with data from predominantly white populations, our proportion of AD cases was lower and that of VascD cases was considerably higher than anticipated. The percentage of clinically depressed older individuals was also high. These findings could have implications for differential cultural and genetic risk factors for dementia among diverse ethnic/racial groups. Further studies are needed to obtain accurate prevalence estimates of dementing disorders among the different U.S. Hispanic populations. J Am Geriatr Soc 49:1301–1308, 2001.