bluuebunny/crossref_metadata_2025_split huggingface dataset:
Yellow Bush Lupine Invasion in Northern California Coastal Dunes II. Mechanical Restoration Techniques
Authors: Pickart Andrea J. , Theiss Karen C. , Stauffer Howard B. , Olsen Garrett T. 
Published: March 2003

AbstractInvasion of coastal dunes by Lupinus arboreus (yellow bush lupine) results in soil enrichment and displacement of native plants. Restoration by means of heavy equipment was tested as an alternative to costly manual techniques in a heavily invaded area of relatively flat terrain. Two experiments were conducted in consecutive years at the Eureka Dunes Protected Area in Humboldt County, California. Each experiment consisted of three plots subjected to one of three primary treatments: removal of vegetation with a brush rake, removal of vegetation with a brush rake followed by removal of litter and duff with a plough blade or bucket, and removal of vegetation with tractor‐pulled chokers. Plots were then subdivided into smaller secondary treatment plots subjected to one of two treatments or a control. Secondary treatments consisted of weedmat placed for a 1‐ or 2‐year duration. The goal of the treatments was to remove and prevent reestablishment of nonnative vegetation, including but not limited to bush lupine; success was measured by percent cover of recolonizing vegetation 1.5 years after treatment ended. In the first experiment, primary treatment (vegetation removal) but not secondary (prevention of reestablishment) resulted in significant differences in cover by the end of the experiment. The brush rake and plough blade treatment was most successful at preventing reestablishment of nonnative vegetation. In the second experiment, secondary treatment (prevention of reestablishment) but not primary (removal of vegetation) resulted in significant differences at the end of the experiment. Re‐invasion increased with the amount of time subplots were left uncovered. The difference in the results of the first and second experiments was attributed to variation in rainfall and, to a lesser extent, to localized variation in species composition. Results suggest that mechanical restoration by means of combination of the brush rake and plough blade primary treatment with the 2‐year weedmat secondary treatment would be most successful in meeting the dual goals of removal of nonnative vegetation and prevention of its reestablishment.
Some Suggested Guidelines for Geomorphic Aspects of Anadromous Salmonid Habitat Restoration Proposals
Authors: Kondolf G. Mathias 
Published: March 2003

AbstractProposals to improve fish habitat for anadromous salmonids by modifying channel form or substrate must be justified based on geomorphology as well as biology, because geomorphic factors often cause such projects to fail. Proposals should address the geomorphic setting at the watershed scale, by specifying changes in flow regime or sediment yield through tools such as a sediment budget. Proposals should also address geomorphic setting and process at the reach scale, indicating the basis for design channel form and dimensions, calculating the frequency of bed mobilization, and assessing existing gravel quality for spawning habitat enhancement projects. Proposals should include explicit provisions for post‐project performance evaluation, including adequate baseline data to permit project‐induced changes to be quantified. Restoration projects also require clear objectives and adequate funding for long‐term monitoring, and generally would benefit from an adaptive management approach to implementation and evaluation.
Effect of Nutrient Enrichment on Native Tropical Trees Planted on Singrauli Coalfields, India
Authors: Singh Arvind , Jha A. K. , Singh J. S. 
Published: March 2003

AbstractGrowth performance of nine native tropical tree species planted on mine spoil under two levels of NPK treatment was studied by measuring height and diameter. Of the nine species, four were leguminous. All the tree species responded positively to NPK fertilization; however, the impact on leguminous species was little compared to non‐leguminous species. In general, the height/diameter ratio decreased from control to full‐dose NPK treatment, suggesting that nutrient enrichment influenced the resource allocation pattern such that the diameter growth was favored. The log‐transformed height‐diameter relationships were significant for the three treatments in all the tree species. The slopes (β) obtained were compared with three different models of tree growth (i.e., elastic similarity, geometric similarity, and constant stress). Acacia catechu, Dalbergia sissoo, Gmelina arborea, and Azadirachta indica fitted the elastic similarity model, whereas Pongamia pinnata and Phyllanthus emblica followed the constant stress model. Tectona grandis was the only species that followed the geometric similarity model. In Albizia lebbeck and Terminalia bellirica, the β values were considerably lower (i.e., below 0.5) and these two species did not fit any of the three models of tree growth. In several cases the β values were considerably influenced by nutrient enrichment.Key words: chemical fertilization, coal mine spoil, growth response, tree structure, tree volume, tropical tree species, height/diameter ratio.
Ecology of Mangrove Growth and Recovery in the Lesser Antilles: State of Knowledge and Basis for Restoration Projects
Authors: Imbert Daniel , Rousteau Alain , Scherrer Pierre 
Published: March 2003

AbstractWhereas the increasing knowledge on tropical coastal wetlands highlights the ecological and economical importance of such ecosystems, anthropogenic activities within the coastal zone have caused substantial, irreversible losses of mangrove areas in the Lesser Antilles during the last decades. Such a paradox gives strength to compensatory policy efforts toward mangrove restoration. We review the available knowledge on the ecology of mangrove growth and recovery in the Lesser Antilles as a contribution to possible restoration projects in such islands. Distribution of species follows a general pattern of seaward/landward zonation according to their respective tolerance to flooding and to pore‐water salinity. An experimental study of seedling growth following simulated oil spill has documented the tolerance of Rhizophora mangle and Avicennia germinans seedlings to oil concentration in soils and the effects of natural biotic and abiotic factors on seedlings growth and survival. Monitoring mangrove recovery following hurricane Hugo has given information on growth patterns, from seedling to sapling stages, according to species and site conditions. Forest recovery was mostly due to pre‐established seedlings. For the large Rhizophora propagules, buoyancy appears to be a quite inefficient way of dispersal far inland from the sea shore or riversides. Causes of recovery failure are discussed. From these results we attempt to answer the questions when, where, how to plant mangroves, and what species to use.
Mitigation Strategies in Some Motorway Embankments (Catalonia, Spain)
Authors: Andrés Pilar , Jorba Montserrat 
Published: March 2003

AbstractErosion is one of the most dramatic problems arising after land restoration in semi‐arid Mediterranean areas. Topsoiling and subsequent hydroseeding are the main practices designed to reclaim motorway embankments, but there is a lack of information about the relationship between the ground cover furnished by the conventional seed mixtures and the erosion rate in the new created slopes. Ground cover and erosion rate were monitored simultaneously on some embankments of the Maresme motorway (Barcelona, Spain) during the first year after reclamation. Under similar geologic, topographic, and climatic conditions, the erosion rate was dependent on the percentage of herbaceous ground cover. Grasses accounted for most of the ground cover. Most of the seeded species did not contribute to the soil protection, and Lolium rigidum was the only grass growing satisfactorily on all the embankments. Legumes were important in autumn with Trifolium repens and Trifolium alexandrinum growing on the northwest‐ and southeast‐facing embankments, respectively. The erosion rate was intolerable where ground cover was <25%, and tolerable where ground cover was> 50%.
Micro‐Scale Restoration: A 25‐Year History of a Southern Illinois Barrens
Authors: Anderson Roger C. , Schwegman John E. , Anderson M. Rebecca 
Published: March 2003

AbstractWe studied vegetation change of a remnant barrens in southern Illinois over twenty‐five years. The study area was periodically burned between 1969 and 1993, but fire was excluded for a 16‐year period (1974–1989). During the study, the barrens supported a mixture of species whose preferred habitats ranged from prairie and open woodlands to closed forest communities. The herbaceous vegetation may be on a trajectory characterized by increasing dominance of woodland species and declining prairie species. Fire management temporarily reversed this trend, but it continued once fire was excluded. Reintroduction of prescribed burning in 1990–1993 altered the vegetation trajectory but not back toward a species composition comparable to that present on the site before cessation of fire management after 1973. Following interruption of prescribed burning, tree basal area more than doubled, and density showed a 67% increase between premanagement conditions in 1968 and 1988. Salix humilis (prairie willow) density had significant negative correlations with tree density and basal area. However, there was no consistency in response of shrub species on the site to the varied site conditions over time. Fire management on the site may not recover the historic barrens that occurred on the site. Nevertheless, consistent fire management will drive vegetation changes toward increasing abundance of prairie and open woodland species that would otherwise be lost without burning.
Land‐Use History in Ecosystem Restoration: A 40‐Year Study in the Prairie‐Forest Ecotone
Authors: Kettle W. Dean , Rich Paul M. , Kindscher Kelly , Pittman Galen L. , Fu Pinde 
Published: March 2003

AbstractLand‐use history, recent management, and landscape position influence vegetation at the Rockefeller Experimental Tract (RET), a 40‐year‐old restoration experiment in northeast Kansas. RET is representative of the prairie‐forest ecotone, containing native tallgrass prairie and oak‐hickory forest, but unique in having tracts of replanted prairie, seeded in 1957, that have undergone long‐term restoration treatments: burned, grazed, mowed, or untreated. A land‐use history database for RET was compiled using a geographic information system to integrate historic and contemporary sources of information. Restoration management on the reseeded prairie has had a profound effect on forest development: mowing or burning precluded forest establishment (<3% forest cover), whereas portions of untreated or grazed areas became heavily forested (>97% forest cover). Forest colonization depends upon biotic and edaphic conditions at the time restoration was initiated: for areas replanted to prairie and managed by grazing, forestation was 6% on land in cultivation prior to replanting, 20% on former pastureland, and 98% on land deforested just before replanting. Patterns of forest colonization were also significantly associated with three landscape positions: near existing forest, along water courses, and along ridge tops. Additionally, land‐use history analyses showed that the presence of various prairie and forest species resulted from persistence and not from colonization following restoration. Because of the lasting imprint of historic land use on the landscape, our results indicate that it is essential that restoration studies be evaluated within a site‐specific historical context.
Restoration of Wetlands from Abandoned Rice Fields for Nutrient Removal, and Biological Community and Landscape Diversity
Authors: Comín Francisco A. , Romero José A. , Hernández Oliver , Menéndez Margarita 
Published: March 2003

AbstractA number of experimental freshwater wetlands (150 m long × 75 m wide) with different ages since they were abandoned as rice fields, were used to analyze the prospects of multipurpose wetland restoration for such degraded areas. Nitrogen and phosphorus removal rate of the wetlands were determined monthly during the flooding season to estimate their efficiency as filters to remove nutrients from agricultural sewage. The number of wetland birds was recorded regularly to identify their habitat preferences. Both the temporal dynamics and changes in the spatial pattern of land use cover during the last 20 years were determined from aerial photographs and field analysis. All the wetlands appeared to be very efficient in the removal of nitrogen and phosphorus exported from rice fields. Usually 50–98% of the nitrogen and less than 50% of the soluble phosphorus were removed by the wetlands at any stage of restoration. Wetland birds preferred wetlands with intermediate plant cover for resting and sleeping activities better than rice fields and either very open wetlands or very dense ones with tall vegetation. Apart from the improvement in water quality and the restoration of natural habitats, restoration of wetland belts around lagoons will increase spatial heterogeneity and diversity of the landscape.
Spiders and Other Arthropods as Indicators in Old‐Growth Versus Logged Redwood Stands
Authors: Willett Terrence R. 
Published: March 2003

AbstractThis study, conducted in the Santa Cruz Mountains of California, provides data on the abundance and diversity of litter spiders and other arthropods in three redwood forest conditions: old growth, second growth, and tree farm. Litter spiders are linked to and reflect habitat structure and prey abundance and can act as indicators for redwood forest restoration and monitoring. There were significant declines in spider and other arthropod diversity and abundance with increased logging and decreased herb cover. The absolute and relative increase in nocturnal spiders and detritivores in unlogged sites suggests that guild structures of spiders and other arthropods can indicate forest recovery from logging disturbance. Furthermore, selectively harvested stands do not retain old‐growth levels of litter arthropod diversity or abundance. This study identifies potential indicator redwood litter spiders that show higher abundances in old‐growth areas, Zelotes sp. (Gnaphosidae), Xysticus sp. (Thomisidae), and Ceratinops inflata (Linyphiidae) and a possible old‐growth specialist, Phrurotimpus sp. (Liocranidae). These findings strengthen the case for including soil arthropods in redwood forest monitoring and assessment and for the preservation of undisturbed forest areas.
Restoration of the Sieperda Tidal Marsh in the Scheldt Estuary, The Netherlands
Authors: Eertman Richard H. M. , Kornman Bart A. , Stikvoort Ed , Verbeek Harm 
Published: March 2003

AbstractBecause of land reclamation, reinforcement of dikes, and the deepening of shipping channels, large areas of tidal marshes have been removed or eroded from the Scheldt estuary during the last two centuries. Tidal wetland restoration contributes toward compensating this loss of habitat. Not all restoration projects are meticulously planned, however; some are forced by nature. During a severe storm in 1990, a dike was breached in the brackish part of the Scheldt estuary and returned tidal influence to the Sieperda polder. In the 10 years since the dike breach, the former polder has changed into a brackish tidal marsh. Here we report on the geomorphologic and ecological developments that have taken place in the marsh. Tidal intrusion into the former polder turned crop fields into mudflats and changed pastures into salty marsh vegetation. The digging of a new creek improved marsh hydrology and enhanced tidal intrusion further into the marsh. Macrofauna typical of estuarine mudflats established rapidly in the developing marsh. Vegetation succession took place rapidly. Within 5 years, large areas of mudflats became covered with marsh vegetation. Birds characteristic of salt marshes were observed breeding or seen foraging in the marsh. The number of wading birds declined as areas of mudflat became overgrown. It is demonstrated that tidal flow is the engine to tidal marsh restoration. Tidal influence caused geomorphologic changes, which directed ecological developments in the former polder.
Physical and Functional Responses to Experimental Marsh Surface Elevation Manipulation in Coos Bay's South Slough
Authors: Cornu Craig E. , Sadro Steven 
Published: March 2003

AbstractDike material was used as fill to construct high, mid, and low intertidal elevations in a subsided marsh located in the South Slough National Estuarine Research Reserve, Oregon. Marsh surface elevation change (including fill consolidation and compression of the original marsh soils), vertical accretion, tidal channel development, emergent vegetation colonization, and fish use were monitored over 3 years. Significant marsh surface elevation loss was detected at all elevations, with fill consolidation accounting for 70% of the loss at the highest elevation. Vertical accretion averaged 0.19 cm/yr in the sparsely vegetated Kunz Marsh compared with 0.70 cm/yr at the densely vegetated reference sites. Tidal channel development was influenced as much by marsh surface gradient as by marsh surface elevation. Vegetation colonization was directly correlated with elevation, whereas density and species richness of fish was inversely correlated with elevation. Manipulating the marsh surface to mid‐marsh elevations favors rapid vegetation colonization and facilitates vertical accretion‐dominated tidal channel development. Low marsh elevations result in initially slower developing vegetation colonization and channel development but are more beneficial to fish during the early stages of marsh recovery. High marsh elevations appear to sacrifice tidal channel development and associated fish access for rapid vegetation colonization.
Riparian Plant Restoration in Summer‐Dry Riverbeds of Southeastern Spain
Authors: Salinas M. Jacoba , Guirado José 
Published: March 2003

AbstractAn evaluation was made of the development of two experimental plots where restoration of dominant riparian plant species was conducted in December 1991 along two semiarid Mediterranean summer‐dry watercourses. An overall comparison was made of the vegetation structure, species cover, floral composition, and species richness of the plots restored using vegetation from nearby undisturbed plots along the same watercourse. The monitoring was performed in October 1993, October 1995, September 1997, and October 1999. In the restored zones previously rooted cuttings of the species most representative of these communities were planted, using the undisturbed zones as vegetation models. Climatological conditions (particularly the rainfall regime during the planting period) substantially favored the success of the planting establishment. The results show that a simple planting technique accompanied by monitoring during the first year is adequate to achieve success in establishment of planting species. It is necessary to take precautions against herbivory of small plants of Chamaerops humilis, Ficus carica, and Retama sphaerocarpa. The planting itself causes some disturbance in the soil that may alter the species composition, giving an advantage to ruderal species over others. More time is needed to attain coverage, frequency, and species composition comparable with that of undisturbed zones.
In Vitro Selection of Boreal Ectomycorrhizal Fungi for Use in Reclamation of Saline‐Alkaline Habitats
Authors: Kernaghan G. , Hambling B. , Fung M. , Khasa D. 
Published: March 2003

AbstractTo identify appropriate species of ectomycorrhizal fungi for use in the reclamation of saline‐alkaline sites, such as the composite tailings (alkaline, with high sodium, sulfate, and calcium) produced by the Canadian tar sands industry, pure cultures of nine fungal species indigenous to the Canadian boreal forest were grown on media containing different levels of CaCl2, CaSO4, NaCl, or Na2SO4, as well as on medium containing composite tailings (CT) release water, and on media at four different pH levels. Members of the Boletales (Suillus brevipes, Rhizopogon rubescens, and Paxillus involutus) and Amphinema byssoides (Aphyllophorales) were sensitive to alkalinity, and their growth was completely inhibited by CT release water. Laccaria and Hebeloma spp. (Agaricales) as well as Wilcoxina mikolae (Pezizales) were tolerant to alkalinity and survived on the medium containing CT release water. Calcium chloride proved to be the most toxic of the salts tested. Growth of seven isolates of Laccaria bicolor and three isolates of Hebeloma crustuliniforme on media containing CaCl2 and release water showed low intraspecific variation. A combination of fungal species, each with its own beneficial characteristics, is recommended for the inoculation of seedlings to be outplanted onto composite tailings.
Lipid Biomarker Analysis of the Toxic Dinoflagellate Pfiesteria Piscicida: Distribution of Sterols and Fatty Acids Within the Class Dinophyceae
Authors: Leblond J. D. , Chapman P. J. 
Published: March 2003

AbstractWithin US waters, regular blooms of harmful dinoflagellates occur in the Gulf of Mexico and Chesapeake Bay regions. Although the causes of blooms are not fully understood, events in Gulf of Mexico waters have been recorded for over 30 years, and are almost exclusively caused by the photosynthetic dinoflagellate, Karenia brevis. Conversely, blooms in the Chesapeake Bay region, caused by the heterotrophic dinoflagellate Pfiesteria piscicida, appear to be a relatively new phenomenon, and are hypothesized to be linked to an increase in nutrient‐rich runoff from chemical plants and livestock farms along tributaries leading into the Chesapeake. Despite the environmental, economic, and human health relevance of P. piscicida, there appears to be no published work on the characterization of its lipid composition. The objective of this study was, therefore to examine the sterol and fatty acid composition of cultured P. piscicida isolates as a precursor to eventual field studies of blooms of this organism. GC–MS analysis of trimethylsilyl ether derivatives of sterols in free sterol and sterol ester fractions revealed that the overwhelming majority of sterols was found as free sterols. Furthermore, free sterols were found to resemble those of other dinoflagellates, with the dominant compound being the common dinoflagellate sterol, dinosterol; a number of other 4‐methyl sterols common to other dinoflagellates were also identified. The fatty acids of P. piscicida were found to be primarily associated with a fraction containing cellular membrane phospholipids; small amounts of the recently described highly unsaturated fatty acids, octacosaoctaenoic acid [28 : 8(n‐3)] and octacosaheptaenoic acid [28 : 7(n‐6)], were observed in this fraction. The dominant fatty acid (approximately 40–60% of the phospholipid fatty acids) was docosahexaenoic acid [22 : 6(n‐3)]. Unlike K. brevis (see accompanying poster), P. piscicida does not appear to possess significant amounts of unusual sterols or fatty acids which may serve as potential biomarkers for this organism.