bluuebunny/crossref_metadata_2025 huggingface dataset:
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

Growth 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

Whereas 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

Erosion 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

We 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

Land‐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

A 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

This 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

Because 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

Dike 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

An 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

To 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.
Epineurial application of TNF elicits an acute mechanical hyperalgesia in the awake rat
Authors: Sorkin Linda S. , Doom Carmen M.
Published: March 2003

Abstract  Tumor necrosis factor alpha (TNF) injected into the sciatic nerve and neutralizing antibodies to its receptor injected around the nerve are respectively associated with inducing and blocking pain behavior beginning 1 to 3 days post‐injection. This study examined the acute effects of TNF applied around the nerve trunk on the mechanical threshold (determined with von Frey hairs) and withdrawal latency to radiant heat. TNF (0.9 and 7.7 ng in 90 μL) injected onto the nerve via an indwelling catheter elicited a decrease in mechanical threshold. Following the low dose of TNF, no change in thermal latency was observed; after the 7.7 ng dose, thermal thresholds decreased and returned to baseline multiple times within the 3‐hour observation period. Identical doses of TNF injected near, but not on the nerve, 90 ng of TNF injected on the nerve, and vehicle were without effect on either modality. These data indicate that effects of acutely administered TNF to the nerve trunk are capable of producing modality specific pain behavior. These changes may represent a first step in TNF‐induced neuropathic pain.
Endoneurial remodeling by TNFα and TNFα‐releasing proteases. A spatial and temporal co‐localization study in painful neuropathy
Authors: Shubayev Veronica I. , Myers Robert R.
Published: March 2003

Abstract  Peripheral nerve injury causing Wallerian degeneration results in endoneurial remodeling initiated by an increase in tumor necrosis factor‐α (TNF), which is activated from its precursor by extracellular proteases of the matrix metalloproteinase (MMP) family. We used immunohistochemistry to analyze the distribution of TNF, TNF‐releasing MMPs, including gelatinases (MMP‐2 and MMP‐9), and TNF‐α converting enzyme (TACE) in painful neuropathy caused by chronic constriction injury of rat sciatic nerve. Tissue was analyzed at the injury site and in the corresponding L4 and L5 dorsal root ganglia (DRG) throughout the time‐course of the neuropathy. Using confocal laser scanning microscopy, we co‐localized TNF with each MMP, and observed spatial and temporal distinction in their distribution. TNF co‐localized in vessel endothelium with MMP‐2 and in macrophages with MMP‐9 and TACE at the period of active immune cell migration. TNF co‐localized with myelin degrading MMP‐9 within Schwann cells during demyelination, and intraaxonally during remyelination. These studies were performed to explore the role of basal‐lamina degrading gelatinases and other TNF‐releasing MMPs in TNF‐mediated Wallerian degeneration. The data provided in this study may be useful in designing selective therapy for painful neuropathy using synthetic hydroxamate MMP inhibitors.
Assessment of the “common” 4.8‐kb mitochondrial DNA deletion and identification of several closely related deletions in the dorsal root ganglion of aging and streptozotocin rats
Authors: Nickander Kim K. , Schmelzer James D. , Low Phillip A.
Published: March 2003

Abstract  The identification of several mitochondrial DNA (mtDNA) deletions and the accumulation of the “common” 4.8‐kb mitochondrial DNA deletion (mtDNA4834) with aging and experimental streptozotocin‐induced diabetes (STZ) were studied in the rat dorsal root ganglion (DRG). Twenty‐one mtDNA deletions, including mtDNA4834, were identified in rat L4‐L6 DRG mtDNA of 15‐month‐old Spraque‐Dawley rats with 13 months of STZ and age‐matched controls. These deletions were flanked by breakpoints that ranged from 16‐bp direct repeats to no direct repeats. The sciatic nerve contained undetectable levels of mtDNA deletions. Levels of mtDNA4834 in rat DRG mtDNA significantly accumulated with age at a rate much higher than those reported in the brain, yet were not statistically different in STZ. Southern blot analysis demonstrated no significant accumulation of the total amount of mtDNA deletions in STZ over age‐matched controls. The accumulation of mtDNA4834 has not been studied in rat peripheral nerve tissue. Our identification of several mtDNA deletions with and without direct repeats at their breakpoint support the hypothesis that deletions can occur by both the slip‐replication model and random recombination. Although there is a significant increase in accumulation of mtDNA4834 associated with aging, the lack of significant accumulations of mtDNA deletions in STZ over age‐matched controls indicates that this type of mtDNA damage is likely not a major alteration in STZ, although the changes could be confined to a small population of neurons that undergo apoptosis between 8 and 15 months.
Neuropeptide expression following constriction or section of the inferior alveolar nerve in the ferret
Authors: Bird Emma V. , Long Adele , Boissonade Fiona M. , Fried Kaj , Robinson Peter P.
Published: March 2003

Abstract  Some of the sensory abnormalities that follow peripheral nerve injury may result from the development of ectopic discharge from the damaged axons. Previous studies in our laboratory have shown that, following tight ligation of the inferior alveolar nerve (IAN), there is a close association between the time‐course of this neural activity and the accumulation of neuropeptides at the injury site. In this study we investigated whether the type of injury has any effect on the time‐course or level of neuropeptide expression. In 36 adult ferrets, the IAN was either loosely constricted or sectioned, and the animals left to recover for 3 days, 3 weeks, or 3 months. The tissue was processed using indirect immunofluorescence and image analysis was used to quantify levels of substance P, calcitonin gene‐related peptide, vasoactive intestinal polypeptide, enkephalin, galanin, and neuropeptide Y. Immunoreactivity to all of the neuropeptides was present within the injured nerve 3 days after both types of injury, and decreased to lower levels by 3 weeks and 3 months. Comparisons between the levels of neuropeptide immunoreactivity in each group revealed that the pattern of accumulation was similar following loose constriction or section, and also similar to that found in our previous study on tight ligation. For each injury the time‐course of neuropeptide expression was similar to that of the spontaneous activity we had previously recorded. These data support the suggestion that neuropeptide accumulation may be linked to the development of ectopic neural activity but indicate that the type of injury has little effect on the extent of expression.
EFFECTS OF LISINOPRIL ON STREPTOZOTOCIN‐INDUCED DIABETIC NEUROPATHY IN RATS
Authors: Aggarwal M , Singh J , Sood S , Arora B.
Published: March 2003

Streptozotocin (STZ)‐induced diabetic neuropathy in rats was monitored by measuring the motor nerve conduction velocity (MNCV) and histopathology of the tibial nerve. Pretreatment with lisinopril (2 mg/kg p.o., 5 days prior to STZ and continued for 10 weeks) significantly (p < 0.01) prevented deterioration of MNCV ms compared to STZ‐diabetic animals. Nerve sections from the lisinopril pretreated group revealed less structural damage as compared to STZ‐diabetic rats. However lisinopril had no effect on blood sugar i.e., it did not alter the diabetic state. It is concluded that lisinopril prevents the development of experimental diabetic neuropathy in STZ‐induced diabetic rats.
DERMAL NEUROVASCULAR DYSFUNCTION IN TYPE 2 DIABETES
Authors: Vinik AI , Erbas T , Park TS , Stansberry KB , Scanelli JA , Pittenger GL.
Published: March 2003

OBJECTIVE: To review evidence for a relationship between dermal neurovascular dysfunction and other components of the metabolic syndrome of type 2 diabetes. RESEARCH DESIGN AND METHODS: We review and present data supporting concepts relating dermal neurovascular function to prediabetes and the metabolic syndrome. Skin blood flow can be easily measured by laser Doppler techniques. RESULTS: Heat and gravity have been shown to have specific neural, nitrergic, and independent mediators to regulate skin blood flow. We describe data showing that this new tool identifies dermal neurovascular dysfunction in the majority of type 2 diabetic patients. The defect in skin vasodilation is detectable before the development of diabetes and is partially correctable with insulin sensitizers. This defect is associated with C‐fiber dysfunction (i.e., the dermal neurovascular unit) and coexists with variables of the insulin resistance syndrome. The defect most likely results from an imbalance among the endogenous vasodilator compound nitric oxide, the vasodilator neuropeptides substance P and calcitonin gene‐related peptide, and the vasoconstrictors angiotensin 11 and endothelin. Hypertension per se increases skin vasodilation and does not impair the responses to gravity, which is opposite to that of diabetes, suggesting that the effects of diabetes override and counteract those of hypertension. CONCLUSIONS: These observations suggest that dermal neurovascular function is largely regulated by peripheral C‐fiber neurons and that dysregulation may be a component of the metabolic syndrome associated with type 2 diabetes.
HYPERMETHYLATION AT CPG‐MOTIFS IN THE DINOFLAGELLATES AMPHIDINIUM CARTERAE (DINOPHYCEAE) AND SYMBIODINIUM MICROADRIATICUM (DINOPHYCEAE): EVIDENCE FROM RESTRICTION ANALYSES, 5‐AZACYTIDINE AND ETHIONINE TREATMENT
Authors: Lohuis Michael R. , Miller David J.
Published: March 2003

Because of their peculiar chromatin features and phylogenetic position, dinoflagellates are potentially uniquely informative with respect to possible roles and evolution of DNA methylation systems. Here we report that DNA from Amphidinium carterae Hulburt and Symbiodinium microadriaticum Freudenthal was not significantly digested by a range of CpG methylation‐sensitive endonucleases. Corresponding methylation‐insensitive isoschizomers cleaved all DNA preparations. Treatment with the methylation inhibitors 5‐azacytidine and ethionine resulted in major increases in digestibility of dinoflagellate DNA by CpG methylation‐sensitive enzymes. The 5‐azacytidine effect was not confined to heterochromatin. Our studies indicate that at least in some dinoflagellates, a high proportion of CpG motifs and a significant number of CpNpG motifs are normally methylated, implying methyltransferase substrate specificities similar to those of higher plants.
CYANOBACTERIAL ASSEMBLAGES IN PERMANENT ICE COVERS ON ANTARCTIC LAKES: DISTRIBUTION, GROWTH RATE, AND TEMPERATURE RESPONSE OF PHOTOSYNTHESIS
Authors: Fritsen Christian H. , Priscu John C.
Published: March 2003

The proliferation of microalgae in the McMurdo Dry Valleys of Antarctica is intricately linked to the seasonal cycle involving the freezing and melting of water. Anecdotal observations and preliminary sampling have found cyanobacterial cells in ice covers on lakes in the McMurdo Dry Valleys, and several of these ice covers are known to undergo seasonal freeze–thaw cycles. Therefore, we sought to determine the distribution and abundance of cyanobacterial assemblages in several permanent ice covers throughout the McMurdo Dry Valleys and to determine their rates of growth and their photosynthetic physiologies upon encountering liquid water. We found that the majority of the permanent ice covers contained cyanobacterial assemblages in close association with sedimentary material. Cyanobacterial biomass was conspicuously absent in sediment‐free ice covers, suggesting that the seasonal interaction between the sediments, ice, and solar radiation present the necessary liquid water environment for cyanobacterial growth. All assemblages exhibited extremely low rates of photosynthesis when first exposed to liquid water. Despite the low rates of photosynthesis, a large proportion (41%) of the photosynthate was incorporated into protein, indicating that the cells were undergoing efficient net cellular growth. The short‐term response (24 h) of photosynthesis to a range of temperatures showed optimum rates occurring at temperatures >15° C, which is similar to those of psychrotrophic cyanobacteria isolates from soil and stream habitats, which we believe provides the inoculum for the in‐ ice habitats.
DEVELOPMENT OF PROTOPLASTS FROM HOLDFASTS AND VEGETATIVE THALLI OF MONOSTROMA LATISSIMUM (CHLOROPHYTA, MONOSTROMATACAE) FOR ALGAL SEED STOCK
Authors: Chen Yean‐Chang
Published: March 2003

The aim of this study was to isolate and cultivate the protoplasts of the green alga Monostroma latissimum Wittrock and subsequently induce them to form algal filaments to act as an algal “seed” stock. Protoplasts of the alga were isolated enzymatically with 4% cellulase Onozuka R‐10 and 2% Macerozyme R‐10. The highest number of protoplasts was obtained on a 50‐rpm shaker with 1.2 M of sorbitol after 6 h of incubation, with a yield of 9 × 106 protoplasts·g−1 of fresh thallus (including holdfast). Protoplasts from both holdfasts and erect thalli usually began to form new cell walls within 5 h after isolation and began to divide from day 6 to day 9 in PES medium; cell clusters, filaments, and/or tubular thalli were formed from day 14 to day 18. For algae collected in March, about 60% of protoplasts isolated from vegetative thalli regenerated to form tubular thalli, and about 45% of protoplasts isolated from holdfasts regenerated to form filaments. However, for algae collected in May, about 1% of protoplasts isolated from vegetative thalli developed directly to form tubular thalli, and 59% of protoplasts regenerated to form cell clusters without the ability to differentiate, whereas protoplasts isolated from holdfasts failed to develop. Regenerated filaments were kept in an incubator for more than 3 years at 24° C under the low irradiance of 66μmol photons·m−2·s−1. After this time, they retained the ability to develop to form tubular thalli under irradiance of 166 and 300 μmol photons·m−2·s−1 at 18°–30° C. Subsequently, these tubular thalli can develop to form leafy thalli after being cultivated at high irradiance of 300 μmol photons·m−2·s−1 and at 18°–22° C. Therefore, the filaments could serve as“seed” stock for algal mass culture.
PHYLOGENY OF THE BANGIOPHYCIDAE (RHODOPHYTA) AND THE SECONDARY ENDOSYMBIOTIC ORIGIN OF ALGAL PLASTIDS
Authors: Oliveira M. C. , Bhattacharya D.
Published: March 2003

The Rhodophyta are composed of the subclasses Bangiophycidae and Florideophycidae. Two evolutionarily interesting features of the Bangiophycidae are: (1) they are the ancestral pool from which the more morphologically complex taxa in the Florideophycidae have arisen and (2) they are the sources of the plastids, through secondary endosymbioses, for the Cryptophyta, Haptophyta, and the Heterokonta. To understand Bangiophycidae phylogeny and to gain further insights into red algal secondary endosymbioses, we sequenced the plastid‐encoded small subunit ribosomal DNA coding region (ssu rDNA) from nine members of this subclass and from two members of the Florideophycidae. Phylogenetic analyses were performed with other red algal plus chlorophyll a+c algal plastid ssu rDNA coding regions. Our results are consistent with a monophyletic origin of the Florideophycidae forming a sister group of the Bangiales. The Bangiophycidae is of a paraphyletic origin, and orders such as the Porphyridiales polyphyletic and distributed over three independent red algal lineages. The plastids of the heterokonts are most closely related to members of the Cyanidium ‐ Galdieria group of Porphyridiales and are not directly related to cryptophyte and haptophyte plastids. The phylogenies provide strong evidence for the independent origins of these “complex” algal plastids from different members of the Bangiophycidae.
IN SITU GROWTH AND REPRODUCTION OF PORPHYRA PERFORATA IN THE PACIFIC COAST OF BAJA CALIFORNIA
Authors: Zertuche‐Gonzalez A. J. , Pacheco‐Ruiz I. , Cabello‐Pasini A. , Chee‐Barragan A. , Guzman J.M. , Galvez A. , Arroyo E. , Yarish C.
Published: March 2003

Porphyra perforata is a common species off the Pacific coast of Baja California peninsula. In situ growth, phenology and reproductive characteristic of this plant are being determined in order to evaluate the feasibility of its culture in open water conditions. Contrary to previous studies that describe this species as ephymeral, P. perforata is present all year around off the north coast of the Baja California peninsula. Its vertical distribution is limited to a band, +50 to +150 cm above sea level. However, subtidal growth transplant experiments showed that the plants are capable of growing down to a depth of 5 m. Highest growth rates were observed from February to July, then tissue was lost as a consequence of sexual reproduction. Biomass continues to decreases for the rest of the year. About 50% of the plants were reproductive by May and more than 90% by August. Oysters shells were introduced and collected every month to evaluate the presence of chonchocelis phase and P. perforata recruitment. Chonchocelis was observed all year and new recruits were present from September to February. These results suggest that the foliar phase P. perforata could be cultured in the ocean for about six months of the year and could be culture subtidally.
MORPHOLOGY, LIFE HISTORY, AND MOLECULAR PHYLOGENY OF CHORDA RIGIDA, SP. NOV. (LAMINARIALES, PHAEOPHYCEAE) FROM THE SEA OF JAPAN AND THE GENETIC DIVERSITY OF CHORDA FILUM
Authors: Kawai Hiroshi , Sasaki Hideaki , Maeda Yoshiki , Arai Shogo
Published: March 2003

Chorda rigida Kawai et Arai, sp. nov. (Chordaceae, Laminariales) is described from the Sea of Japan, NW Pacific. This species resembles Chorda filum (Linnaeus) Stackhouse but is distinguished by the following characteristics: 1) the sporophytes grow on more or less exposed rocks at 2–7 m depth and do not form dense tufts; 2) compared with C. filum, sporophytes of C. rigida are much more rigid and are composed of denser cortical layers (6–18 cells thick); 3) C. filum becomes fertile and disappears in late spring to summer, whereas C. rigida appears in early summer, oversummers, and becomes fertile only in late autumn at the same localities; 4) in culture, C. rigida sporophytes tolerate higher temperature conditions (20 and 25° C) than C. filum; and 5) C. rigida has considerably longer sequences of the rDNA ITS region than does C. filum. The independence of the species is further supported by molecular phylogenetic analyses using sequence of the ITS + 5.8S ribosomal DNA. Interestingly, C. filum is shown to be genetically diverse and possibly paraphyletic, and it may require subdivision into several species or subspecies. The rbcL and associated spacer sequence data established monophyly of the genus Chorda among Laminariales, but the resolution was limited for discussing the phylogenetic relationships within the genus.
PHLOROTANNIN ALLOCATION AMONG TISSUES OF NORTHEASTERN PACIFIC KELPS AND ROCKWEEDS
Authors: Van Alstyne Kathryn L. , McCarthy James J. , Hustead Cynthia L. , Kearns Laura J.
Published: March 2003

Optimal defense theory (ODT) predicts antiherbivore defensive compounds will be allocated so that the most valuable or most susceptible tissues will be best defended. The growth–differentiation balance hypothesis (GDBH) predicts that defense allocation will be a result of trade‐offs between growth and defense. Thus, these two theories predict opposite allocation patterns with respect to “valuable,” actively growing meristematic and reproductive tissues. ODT predicts that meristems and reproductive tissues should have higher defense levels than nonmeristematic vegetative tissues; the GDBH predicts the defense levels of meristems and reproductive tissues will be lower than vegetative tissues. We examined allocation patterns of phlorotannins in 21 species of kelps (Order Laminariales) and rockweeds (Order Fucales) from nine sites on the west coast of the United States to determine if allocation patterns better matched the predictions of ODT or the GDBH and to look for differences in allocation patterns among sites. Within‐species differences in phlorotannin levels occurred in 10 of the 21 species examined. Meristems of both kelps and rockweeds had higher phlorotannin levels than nonmeristematic vegetative tissues, consistent with ODT. Phlorotannin levels in reproductive tissues of kelps were higher than vegetative tissues, but levels in reproductive tissues of rockweeds were lower than vegetative tissues, indicating that allocation strategies may follow taxonomic lines. Allocation patterns differed among sites in four of the 16 species collected from more than one site. Differences in allocation patterns among sites were usually changes in the ratios of phlorotannins in well‐defended compared to poorly defended tissues, rather than changes in which tissues were well defended or poorly defended. We concluded that environmental variability can have large effects on the concentration of phlorotannins in algae but has limited effects on allocation patterns among tissues.
SYNTHESIS OF MYCOSPORINE‐LIKE AMINO ACIDS IN CHONDRUS CRISPUS (FLORIDEOPHYCEAE) AND THE CONSEQUENCES FOR SENSITIVITY TO ULTRAVIOLET B RADIATION
Authors: Franklin Linda A. , Yakovleva Irina , Karsten Ulf , Lüning Klaus
Published: March 2003

The induction and protective role of the UV‐absorbing compounds known as mycosporine‐like amino acids (MAAs) were examined in sublittoral Chondrus crispus Stackh. transplanted for 2 weeks in the spring and summer to shallow water under three irradiance conditions: PAR (photosynthetically active radiation; 400–700 nm), PAR + UVA (PAR + 320– 400 nm), PAR + UVA + UVB (PAR + UVA + 280– 320 nm). Sublittoral thalli collected around Helgoland, North Sea, Germany, from 6 m below the mean low water of spring tides contained less than 0.1 mg·g−1 dry weight (DW) total MAAs, whereas eulittoral samples contained over 1 mg·g−1 DW. Transplantation to shallow water led to the immediate synthesis of three MAAs in the following temporal order: shinorine (λmax 334 nm), asterina (λmax 330 nm), and palythine (λmax 320 nm), with the shinorine content peaking and then declining after 2 days (exposure to 100 mol photons·m−2). Maximum total MAA content (2 mg·g−1 DW) also occurred after 2 days of induction, exceeding the content normally found in eulittoral samples. Furthermore, the relative proportion of the different MAAs at this time was different than that in eulittoral samples. After 2 days the total content declined to the eulittoral value, with palythine as the principal MAA. Similar data were obtained for all treatments, indicating that MAA synthesis in C. crispus was induced by PAR and not especially stimulated by UV radiation. The ability of photosystem II (PSII) to resist damage by UVB was tested periodically during the acclimation period by exposing samples to a defined UVB dose in the lab. Changes in chlorophyll fluorescence (Fv/Fm and effective quantum yield, φII) indicated that PSII function was inhibited during the initial stage of acclimation but gradually improved with time. No difference among screening treatments was detected except in spring for the samples acclimating to PAR + UVA + UVB. In this treatment Fv/Fm and φII were significantly lower than in the other treatments. During the first week of each experiment, growth rates were also significantly reduced by UVB. The reductions occurred despite maximum MAA content, indicating an incomplete protection of photosynthetic and growth‐related processes.
PHYLOGENETIC RELATIONSHIPS AMONG ISOLATES OF EUDORINA SPECIES (VOLVOCALES, CHLOROPHYTA) INFERRED FROM MOLECULAR AND BIOCHEMICAL DATA
Authors: Angeler David G. , Schagerl Michael , Coleman Annette W.
Published: March 2003

Phylogenetic analyses of 19 strains representing five species of Eudorina, one strain of Pleodorina indica, and seven strains of Yamagishiella unicocca were carried out by sequencing the internal transcribed spacer region (ITS 1 and ITS 2) of the nuclear ribosomal DNA (rDNA) repeats. The sequence data resolved five phylogenetic groups, one consisting of Y. unicocca and the other four encompassing all the Eudorina species. Two isolates, Eudorina sp. (ASW 05157) and Pleodorina indica (ASW 05153), were of uncertain affiliation. Whereas one monophyletic group included strains of E. elegans only, the other strains of E. elegans appeared alongside E. cylindrica, E. illinoisensis, and E. unicocca var. unicocca in the other Eudorina clades. The distribution pattern of the carotenoid loroxanthin ([3R,3′R,6′R]‐β,ε‐carotene‐3,19,3′‐triol), a systematically useful biochemical marker within chlorophycean flagellates, was shown to match the evaluated molecular data. Whereas it was either totally absent or universally present in six of the deduced phylogenetic lines, it occurred randomly in the E. elegans clade containing only E. elegans isolates. The results substantiated the current hypothesis that the unique vegetative morphology of E. elegans has independently arisen at various times during evolution and that it is not a marker of a monophyletic group.
SECONDARY CAROTENOID ACCUMULATION IN SCENEDESMUS KOMAREKII (CHLOROPHYCEAE, CHLOROPHYTA)
Authors: Hanagata Nobutaka , Dubinsky Zvy
Published: March 2003

As Scenedesmus komarekii Hegewald was cultured under high light intensity and nitrogen limitation, the color of cells progressed from green to brown, and finally through orange to brick red. The secondary carotenoids astaxanthin and canthaxanthin, as well as apolar carotenoids, were detected in the brown and orange cells. These carotenoids were contained in lipoidal globules that were first formed at the periphery of the cell and progressively propagated toward its inside, eventually filling most of it. The chloroplast was single and parietal in the green cells. As the cells turned brown, the chloroplast divided into several small lobes and was pushed toward the interior by the accumulating lipoidal globules. Sometimes the outer layer of the wall of the brown cell developed one or two diametrically opposed swellings. Once the cells became orange or red, neither lipoidal globules nor any major organelles were distinguishable. The cell wall in the orange cells became thick because of the formation of electron‐dense granules between its outer and inner layers. The mode of the secondary carotenoid accumulation in S. komarekii differs from that of Haematococcus, an alga well known for its ability to accumulate secondary carotenoids, but resembles that of “Chlorella”zofingiensis (=Mychonastes zofingiensis (Dönz) Kalina et Punčochářová).
GLYCOPROTEIN MOIETY IN THE CELL WALL OF THE RED MICROALGA PORPHYRIDIUM SP. (RHODOPHYTA) AS THE BIORECOGNITION SITE FOR THE CRYPTHECODINIUM COHNII‐LIKE DINOFLAGELLATE
Authors: Ucko Michal , Shrestha Roshan Prakash , Mesika Pnina , Bar‐Zvi Dudy , Arad Shoshana Malis
Published: March 2003

The Crypthecodinium cohnii‐like heterotrophic dinoflagellate preys on the cells of the red microalga Porphyridium sp. UTEX 637, and not on other microalgae. The dinoflagellate contains enzymes that degrade the cell wall complex of this species of alga and not that of other red microalgae. The cells of the red microalgae are encapsulated within a cell wall complex composed of about 10 sugars, sulfate, and proteins. We previously hypothesized that the dinoflagellate recognizes the cell wall of this alga. In this study, we have shown that the biorecognition site is the 66‐kDa glycoprotein in the algal cell wall complex. The methodology used in this study was based on changing the algal cell wall composition and examining the prey and chemosensory response of the dinoflagellate. The dinoflagellate was not attracted to the cell wall of other red microalgae, which are similar to that of Porphyridium sp., or to sugars composing its cell wall. However, the dinoflagellate preyed on and was attracted to Porphyridium sp. mutants (DCB resistant) having modified cell wall polysaccharide composition, probably because the 66‐kDa cell wall glycoprotein was not changed. The dinoflagellate did not respond chemotactically to enzymatically degraded cell wall complex. Treatment of the cell wall complex with antiserum to the 66‐kDa glycoprotein or with the lectin concanavalin A (con A), which binds specifically to α‐d‐mannosyl and α‐d‐glucosyl residues, did not affect the chemotactic attraction. However, prey by the dinoflagellate was prevented when the algal cells were blocked with antiserum specific to the 66‐kDa glycoprotein or with con A. These latter results provide direct proof that the 66‐kDa cell wall glycoprotein isthe recognition site and prey‐prevention results from the blocking of this site on the cell wall.