bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of polymorphic microsatellite loci in Castelnau's Antshrike, Thamnophilus cryptoleucus (Aves: Thamnophilidae)
Authors: ÁGREDA A. , LIECKFELDT D. , SCHMIDT A. , PITRA C.
Published: May 2006

In order to study the biogeography and population genetic structure of the obligate river‐island species Thamnophilus cryptoleucus (Thamnophilidae) we isolated four microsatellite loci. Number of alleles ranged from six to 11, heterozygosities from 60% to 89%, and individual populations were found in Hardy–Weinberg equilibrium. Cross‐species amplification of the loci was tested in eight species of the family Thamnophilidae and all loci successfully amplified in five or more related species.
Characterization of seven polymorphic microsatellite loci in the Baja California endemic black‐tailed brush lizard Urosaurus nigricaudus
Authors: RODRIGUEZ‐ESTRELLA R. , BLAZQUEZ M. C. , VEGA A. MUNGUIA
Published: May 2006

Seven microsatellite loci were developed for the Baja California endemic black‐tailed brush lizard Urosaurus nigricaudus, using an enriched genomic DNA library. All loci were polymorphic and overall presented high levels of variation. Number of alleles ranged from five to 16 (average 12.14), and observed heterozygosities from 0.535 to 0.923 (average 0.752). Cross‐species amplification was successful and polymorphism was detected for all the loci using the congeners Urosaurus lahtelai and Urosaurus ornatus. These markers will be useful to study fragmented populations of U. nigricaudus on agricultural landscape of the Baja California Peninsula.
Development and characterization of microsatellite markers in Eucommia ulmoides Oliver (Eucommiaceae)
Authors: DENG JIANYUN , LIU YIFEI , HUANG HONGWEN
Published: May 2006

Twenty‐three microsatellite markers were developed from an AC‐enriched genomic library of Eucommia ulmoides, an economically important tree species for both herbal medicine and organic chemical industry in China. Nineteen microsatellite loci were found polymorphic by testing 36 individuals from 10 populations, with two to 14 alleles per locus. The expected heterozygosity ranged from 0.054 to 0.874. This set of microsatellite markers has provided a useful tool for the ongoing efforts in studying population genetic structure of E. ulmoides.
Nitrogen uptake by ryegrass from organic wastes applied to a sandy loam soil
Authors: Cordovil C. M. D. S. , Cabral F. , Coutinho J. , Goss M. J.
Published: May 2006

Sandy‐textured Mediterranean soils are invariably depleted in organic matter and supply only small amounts of N to crops. To compensate for these deficiencies, we tested the N supply from six organic wastes applied to a Cambic Arenosol in pots growing ryegrass. The results showed that the behaviour of the wastes in supplying N to a ryegrass crop grown in this soil can be predicted by observing their performance in laboratory aerobic incubations. The N made available during these incubations fitted well to a one‐pool kinetic model.
Misorientations of garnet aggregate within a vein: an example from the Sanbagawa metamorphic belt, Japan
Authors: OKAMOTO A. , MICHIBAYASHI K.
Published: May 2006

In this study, the chemistry and microstructure of garnet aggregates within a metamorphic vein are investigated. Garnet‐bearing veins in the Sanbagawa metamorphic belt, Japan, occur subparallel to the foliation of a host mafic schist, but some cut the foliation at low angle. Backscattered electron image and compositional mapping using EPMA and crystallographic orientation maps from electron‐backscattered diffraction (EBSD) reveal that numerous small garnet (10–100 μm diameter) coalesce to form large porphyroblasts within the vein. Individual small garnet commonly exhibits xenomorphic shape at garnet/garnet grain boundaries, whereas it is idiomorphic at garnet/quartz boundaries. EBSD microstructural analysis of the garnet porphyroblasts reveals that misorientation angles of neighbour‐pair garnet grains within the vein have a random distribution. This contrasts with previous studies that found coalescence of garnet in mica schist leads to an increased frequency of low angle misorientation boundaries by misorientation‐driven rotation. As garnet nucleated with random orientation, the difference in misorientation between the two studies is due to the difference in the extent of grain rotation. A simple kinetic model that assumes grain rotation of garnet is rate‐limited by grain boundary diffusion creep of matrix quartz, shows that (i) the substantial rotation of a fine garnet grain could occur for the conditions of the Sanbagawa metamorphism, but (ii) the rotation rate drastically decreased as garnet grains formed large clusters during growth. Therefore, the random misorientation distribution of garnet porphyroblasts in the Sanbagawa vein is interpreted as follows: (i) garnet within the vein grew so fast that substantial grain rotation did not occur through porphyroblast formation, and thus (ii) random orientations at the nucleation stage were preserved. The extent of misorientation‐driven rotation indicated by deviation from random orientation distribution may be useful to constrain the growth rate of constituent grains of porphyroblast that formed by multiple nucleation and coalescence.
Stream Restoration Databases and Case Studies: A Guide to Information Resources and Their Utility in Advancing the Science and Practice of Restoration
Authors: Jenkinson Robin G. , Barnas Katie A. , Braatne Jeffrey H. , Bernhardt Emily S. , Palmer Margaret A. , Allan J. David ,   The National River Restoration Science Synthesis
Published: May 2006

The successful application of adaptive management to the science and practice of restoration ecology requires specific knowledge about the outcomes of past restoration efforts. Ideally, project results would be readily available to scientists or other project managers with similar goals or in analogous ecosystems. Recently, there has been a proliferation of Internet‐accessible databases, lists, and case studies of stream and river restoration projects. These resources include a wide range of information that could be accessed to aid natural resource and conservation professionals in restoration. In the U.S. Pacific Northwest, the National Marine Fisheries Service’s Northwest Fisheries Science Center and, on a national scale, the National River Restoration Science Synthesis are combining existing national and regional databases, along with the individual project descriptions, to create comprehensive, web‐based databases of stream restoration projects. In this process, more data sources were discovered than fit the scope of either of these projects. Ten international, 19 U.S. national, and 42 U.S. regional web‐accessible sources of restoration project databases and case studies are listed in this study. However, to easily use information that is currently scattered in multiple files and Web sites, databases would optimally use a common, standardized format. We provide a recommended list of information to be included in restoration databases. These efforts may provide a blueprint for development of compatible international databases of stream restoration projects.
Are Ericoid Mycorrhizas a Factor in the Success of Calluna vulgaris Heathland Restoration?
Authors: Diaz Anita , Green Iain , Benvenuto Marianne , Tibbett Mark
Published: May 2006

Methods used in the restoration of lowland heath vary depending on edaphic factors at a site and need for introduction of ericaceous propagules. This study investigates the effect of some methods on growth of an important ericaceous species, Heather (Calluna vulgaris). It also explores whether success of growth of C. vulgaris in restoration schemes is affected by its degree of colonization by ericoid mycorrhizal fungi (ERM). The success of Heather growth was compared at three sites, a control area of natural heathland and two restoration sites. These were a quarry where soil had been translocated but not chemically manipulated and a site on agricultural land where the top soil had been improved but then either stripped away or acidified prior to attempting heathland restoration. Propagules of C. vulgaris were applied either as turves or as clippings. Results show that clippings produced as dense a cover of C. vulgaris as turves over a period of 13 years and that plants in such swards can exhibit a degree of ERM colonization comparable to that found in mature plants growing in natural heathland. Young (<2 years of age) plants of C. vulgaris had less extensive mycorrhizal colonization of their roots, particularly when growing on restored agricultural soils. A relationship was found between lower levels of mycorrhizal colonization and smaller aboveground plant growth. Success of heathland restoration may be improved by finding means to enhance the rate and extent of mycorrhizal colonization of young C. vulgaris growing in a restoration environment.
Factors Limiting the Survival of Native Tree Seedlings Used in Conservation Efforts at the Edges of Forest Fragments in Upland Madagascar
Authors: Pareliussen Ingar , Olsson E. Gunilla A. , Armbruster W. Scott
Published: May 2006

We tested four reforestation techniques in tropical forest fragments that were damaged by fire in upland Madagascar. We conducted a full‐factorial experiment on the survival of transplanted seedlings of five native tree species in grassland plots adjacent to the forest fragments in the Ambohitantely Forest Reserve. The species studied were Dodonaea madagascariensis, Filicium decipiens, Olea lancea, Podocarpus madagascariensis, and Rhus taratana. A total of 480 seedlings were planted; 207 survived the 15 months of the experiment. The factors examined were distance of the reforestation plots from the forest, mixing of forest soil into the plots, application of chemical fertilizers, experimental shading of plots, and the cover of naturally establishing shrubs. Both increasing the distance of plots from the forest edge and adding chemical fertilizers significantly reduced the survival of all seedlings. The surprising negative effects of fertilization may be partly due to increased competition from naturally establishing shrubs that are adapted to exploit high nitrogen levels. Mixing soil from the forest areas into the plots did not change seedling survival. Shading reduced the survival of D. madagascariensis seedlings and did not increase the survival of any species. These findings suggest that the success of reforestation projects can be increased by planting seedlings close to the existing forest fragments. Reforestation of similar tropical forests is likely to be more successful if efforts are focused on expanding the size of existing fragments of tropical forest, rather than on establishing new fragments in grassland openings.
Seed Removal Rates Under Isolated Trees and Continuous Vegetation in Semiarid Thornscrub
Authors: Jurado Enrique , Flores Joel , Endress Anton G. , Flores Mercedes , Estrada Eduardo , Pando Marisela
Published: May 2006

Clearing native vegetation to increase the amount of land available for agriculture in northeastern Mexico has left remnants ranging in size from fragments of continuous vegetation to isolated individual trees. These provide valuable opportunities for restoring larger areas of native vegetation. We explored whether fragmentation of Tamaulipan thornscrub affects the removal of seeds from 12 woody species that encompass a range of sizes and dispersal mechanisms. We tested whether (1) seed removal rates under isolated trees were higher than under continuous vegetation; (2) dispersal structures, such as fleshy pericarps, made some seeds more attractive to seed removers; and (3) microenvironmental variation affected seed removal rates. Seeds were placed under canopies of Texas ebony (Ebenopsis ebano) and Mesquite trees (Prosopis laevigata). Seed removal trials were conducted three times, each trial lasting 30 days. Most seeds were removed in all trials by the end of one month. Seed removal rate was slower under isolated trees. In general, fleshy fruits were removed faster than other fruits; whole fruits and fleshy tissue were removed faster than depulped seeds. In species with fleshy pericarps, acid washing of seeds, to simulate seeds processed in the digestive tract of dispersers, reduced the seed removal rates, suggesting that it would be a good pre‐treatment for restoration efforts.
Oak Flat Restoration on Phosphate‐Mine Spoils
Authors: Andrews Ross L. , Broome Stephen W.
Published: May 2006

Phosphate mining in Beaufort County, North Carolina, impacts a rare plant community type, oak flats (nonriverine wet hardwood forests [NRWHF]). Reclamation of land after mining utilizes three by‐products of mining and manufacturing: clay tailings containing dolomite, low‐pH phosphogypsum, and bucket‐wheel spoil from the surface 10 m. The open mine is backfilled with a blend of phosphogypsum and clay tailings, which may be left as the surface or capped with bucket‐wheel spoil. The objective of this study was to determine the feasibility of using these by‐products as substrates for restoring NRWHF. A field study measured survival of 11 tree and four shrub species planted in replicated plots of blend or bucket‐wheel spoil. Survival at the end of the second growing season was 59% on the blend and 52% on the bucket‐wheel spoil. A greenhouse experiment compared growth of four species of NRWHF oaks on bucket‐wheel spoil, blend, local topsoil (sterilized and unsterilized), and a commercial potting mix. Germination rates of acorns of all four species planted in topsoil were almost double those in bucket‐wheel spoil and 1.5 times greater than those in the blend. Height and stem volume of trees were significantly greater when grown in topsoil than in bucket‐wheel spoil and blend. There was no difference in tree growth on bucket‐wheel spoil and blend. In field and greenhouse soil tests, the blend had cadmium levels over 100 times that of local topsoil and the bucket‐wheel spoil had levels 40 times greater. Leaf chemical analysis in the field and greenhouse found higher cadmium levels in plants grown on the blend than on the bucket‐wheel spoil. These results indicate that the use of topsoil from the advancing mine front may lead to successful restoration of NRWHF.
Mechanical Land Clearing to Promote Establishment of Coastal Sandplain Grassland and Shrubland Communities
Authors: Lezberg Ann L. , Buresch Kendra , Neill Christopher , Chase Tom
Published: May 2006

The decline in grasslands and other species‐rich early successional habitats on the coastal sandplains of the northeastern United States has spurred management to increase the area of these declining plant communities. We mechanically removed overstory oak and applied seed from a nearby sandplain grassland on the island of Martha’s Vineyard, Massachusetts, to evaluate this technique for creating an open oak community able to support sandplain herbaceous species. We compared vegetation structure and composition before and after clearing in an area of total tree removal (clearcutting), an area where 85% of tree basal area was removed (savanna cutting), and in adjacent coastal oak forest. Plant responses to clearcutting and savanna cutting were similar. Sandplain herbs colonized at high frequencies after seeding and increased herbaceous cover from less than 7% before clearing to 22–38% three growing seasons later. Pennsylvania sedge (Carex pensylvanica) increased in cover approximately 6‐fold, accounting for 84–90% of the increased herbaceous cover. Other native ruderals and exotic herbs reached 2 and less than or equal to 1%, cover, respectively, after three years. Species richness across cleared treatments increased from 30 to 79 species. All forest species were retained. Forest shrubs and trees initially declined from their dominant cover but rebounded after three years. Tree clearing plus seeding appeared to be a viable management practice for increasing cover of herbaceous sandplain species while causing minimal increases in exotic herbaceous cover. The long‐term persistence of sandplain herbs may require periodic disturbances that limit woody regrowth.
Effects of Mulch on Seedlings and Soil on a Closed Landfill
Authors: Athy Erin R. , Keiffer Carolyn H. , Stevens M. Henry
Published: May 2006

Landfills are ideal locations for short‐rotation forestry, tree‐based bioremediation, and wildlife habitat reconstruction. However, tree survival is reduced by harsh growing conditions and poor soil quality. This study was designed to determine survival of tree seedlings and test effects of different mulch types and depths on edaphic properties and herb emergence on a closed Ohio landfill. In spring 2002, five species of hardwood tree seedlings (Fraxinus pennsylvanica, Robinia pseudoacacia, Prunus serotina, Quercus macrocarpa, and Populus sp.) were planted in a clustered fashion on 35 plots. Each plot received a mulch treatment consisting of one type of mulch (hardwood, leaf, or mixed) at a specific depth (5 or 15 cm) or was designated as a nonmulched control. The status of each seedling and edaphic qualities (soil moisture, temperature, and nutrients) were recorded for two growing seasons. Aboveground herbaceous biomass was sampled at the end of each growing season. We found that survival and growth were species dependent. At the conclusion of the experiment, Fraxinus had the highest survival rate (70%) and Prunus the lowest (7%). The use of leaf mulch (15 cm deep) increased organic matter and various edaphic properties (cation exchange capacity, P, Mg) after the second growing season. Mulch treatments did not significantly affect aboveground herbaceous biomass when compared to nonmulched controls. These results suggest Fraxinus as a good candidate for landfill plantings. Additionally, leaves and yard waste are plentiful and could quickly enrich poor soils on a landfill if left to decompose aboveground.
Activated Carbon as a Restoration Tool: Potential for Control of Invasive Plants in Abandoned Agricultural Fields
Authors: Kulmatiski Andrew , Beard Karen H.
Published: May 2006

Exotic plants have been found to use allelochemicals, positive plant–soil feedbacks, and high concentrations of soil nutrients to exercise a competitive advantage over native plants. Under laboratory conditions, activated carbon (AC) has shown the potential to reduce these advantages by sequestering organic compounds. It is not known, however, if AC can effectively sequester organics or reduce exotic plant growth under field conditions. On soils dominated by exotic plants, we found that AC additions (1% AC by mass in the top 10 cm of soil) reduced concentrations of extractable organic C and N and induced consistent changes in plant community composition. The cover of two dominant exotics,Bromus tectorumandCentaurea diffusa, decreased on AC plots compared to that on control plots (14–8% and 4–0.1%, respectively), and the cover of native perennial grasses increased on AC plots compared to that on control plots (1.4–3% cover). Despite promising responses to AC by these species, some exotic species responded positively to AC and some native species responded negatively to AC. Consequently, AC addition did not result in native plant communities similar to uninvaded sites, but AC did demonstrate potential as a soil‐based exotic plant control tool, especially forB. tectorumandC. diffusa.
Are Ecosystem Composition, Structure, and Functional Status Related to Restoration Success? A Test from Semiarid Mediterranean Steppes
Authors: Maestre Fernando T. , Cortina Jordi , Vallejo Ramón
Published: May 2006

Theoretical models emphasize the importance of considering the composition, structure, and functioning of an ecosystem when restoring it. However, there is a lack of empirical studies evaluating how these ecosystem attributes are linked, if any, to the success of restoration actions. We conducted experimental plantings of the native late‐successional shrubPistacia lentiscusin 10 semiarid steppes located in southeast Spain and related seedling survival rates to measures of ecosystem structure and composition and to surrogates of ecosystem functioning. Seedling survival widely differed among the studied steppes and 17 months after planting ranged from 0 to 89%. Mortality occurred mostly during the first summer in the field, coinciding with a strong drought lasting 3 months. Survival was lower in the steppes located at the highest altitudes and with the highest values of total plant cover, species richness, shrub cover, and functionality. Seedling survival was mainly controlled by abiotic conditions and showed a negative relationship with some of the surrogates of ecosystem functioning evaluated. Our results suggest, but cannot confirm, that the functional status of the ecosystem may not limit the early stages of establishment ofP. lentiscusin semiarid steppes and that abiotic conditions play an overriding role in this process. If true, its introduction in these areas would not necessarily need a previous phase of recovery of ecosystem functions like nutrient cycling and infiltration.
Influence of Polymer Seed Coatings, Soil Raking, and Time of Sowing on Seedling Performance in Post‐Mining Restoration
Authors: Turner Shane R. , Pearce Brett , Rokich Deanna P. , Dunn Robert R. , Merritt David J. , Majer Jonathan D. , Dixon Kingsley W.
Published: May 2006

This study represents part of a broader investigation into novel seed broadcasting methodologies as a means to optimize rehabilitation techniques following sand mining. Specifically, the study investigated the use of polymer seed coatings, time of sowing application, and in situ raking of the topsoil to optimize seedling recruitment to site. For polymer seed coatings, an ex situ trial was undertaken to evaluate seed coating effects on seedling emergence. Results demonstrated that seed coatings did not significantly inhibit maximum emergence percentage of 10 Banksia woodland species (out of 11 evaluated), but coated seeds from four species were on average 2–6 days slower to emerge than noncoated seeds. Seed coatings were found to have a greater effect in situ, with more coated seeds emerging than noncoated seeds. Topsoil raking (following seed sowing) and time of sowing were found to have the greatest impact on seedling emergence, with higher emergence following topsoil raking (5‐ to 90‐fold increase) and sowing in May (late autumn) (1.4‐ to 12‐fold increase) rather than in July (mid‐winter). The implications for mining rehabilitation are discussed, and areas for further research are considered.
Vegetation Succession After Bauxite Mining in Western Australia
Authors: Norman Melanie A. , Koch John M. , Grant Carl D. , Morald Tim K. , Ward Samuel C.
Published: May 2006

Alcoa World Alumina Australia has been rehabilitating bauxite mines in the jarrah forest of Western Australia for more than 35 years. An experiment was established in 1988 using three different seed treatments (legume and small understorey mix, small understorey mix only, and no seed) and two fertilizer treatments (N and P, and P only). The objectives of this study were to (1) document vegetation changes in the first 14 years after bauxite mining; (2) assess whether the vegetation is becoming more similar to the unmined forest; and (3) gain a better understanding of successional processes. Seed treatments significantly affected 13 of the 14 measured vegetation characteristics. Native species richness was higher in seeded than in unseeded sites at 1, 2, and 5 years of age, whereas diversity and evenness were generally higher at all assessment ages. Exotic species density was higher in unseeded than in seeded sites from 5 years onward, whereas richness was higher from 8 years onward. Nitrogen fertilizer significantly increased exotic species richness, density, and cover. Ephemerals dominated plant density in all rehabilitation treatments over time, whereas seeder species dominated cover. In contrast, resprouting species dominated density and cover in the unmined forest. Orchids were the only species that were not present in the first year in rehabilitated sites but increased in abundance over time. Vegetation composition in rehabilitated areas did not become more similar to the unmined forest during the 14 years since seeding, instead strongly reflected the initial species mix. Rehabilitated bauxite mines appear to follow the initial floristic composition model of succession.
A Spatial Modeling Approach to Identify Potential Butternut Restoration Sites in Mammoth Cave National Park
Authors: Thompson Laura M. , Van Manen Frank T. , Schlarbaum Scott E. , DePoy Mark
Published: May 2006

Incorporation of disease resistance is nearly complete for several important North American hardwood species threatened by exotic fungal diseases. The next important step toward species restoration would be to develop reliable tools to delineate ideal restoration sites on a landscape scale. We integrated spatial modeling and remote sensing techniques to delineate potential restoration sites for Butternut (Juglans cinereaL.) trees, a hardwood species being decimated by an exotic fungus, in Mammoth Cave National Park (MCNP), Kentucky. We first developed a multivariate habitat model to determine optimum Butternut habitats within MCNP. Habitat characteristics of 54 known Butternut locations were used in combination with eight topographic and land use data layers to calculate an index of habitat suitability based on Mahalanobis distance (D2). We used a bootstrapping technique to test the reliability of model predictions. Based on a threshold value for theD2statistic, 75.9% of the Butternut locations were correctly classified, indicating that the habitat model performed well. Because Butternut seedlings require extensive amounts of sunlight to become established, we used canopy cover data to refine our delineation of favorable areas for Butternut restoration. Areas with the most favorable conditions to establish Butternut seedlings were limited to 291.6 ha. Our study provides a useful reference on the amount and location of favorable Butternut habitat in MCNP and can be used to identify priority areas for future Butternut restoration. Given the availability of relevant habitat layers and accurate location records, our approach can be applied to other tree species and areas.
Early Dynamics of Plant Communities on Revegetated Motorway Slopes from Southern Spain: Is Hydroseeding Always Needed?
Authors: Matesanz Silvia , Valladares Fernando , Tena David , Costa‐Tenorio Margarita , Bote Daniel
Published: May 2006

The increasing global rate of road construction is leading to a parallel increase of areas of degraded soil conditions and steep slopes that need revegetation. Hydroseeding with commercial seeds of fast‐growing grasses and legumes is a common practice in revegetation of motorway slopes. We carried out 3 years of monitoring of vegetation dynamics on hydroseeded and nonhydroseeded motorway slopes (48 slopes) in a maritime Mediterranean zone in Málaga (southern Spain). Our main objectives were to test whether hydroseeding significantly increases species richness and plant cover and whether hydroseeded species act as starters, facilitating the establishment of the vegetation and quickly disappearing once the communities are established. A hydroseeding success index (HSI, ranging from 0 to 1) was used to assess the relative abundance over time of the 14 species from the hydroseeding mixture. Species richness and cover was significantly higher on embankments (50–70 species per embankment, 80–90% cover) than on roadcuts (6–10 species per roadcut, 18–30% cover). Performance of hydroseeded species was poor from the very beginning (HSI, 0.2–0.3). On embankments, either presence or abundance of hydroseeded species did not significantly vary throughout the study. Both hydroseeded and nonhydroseeded communities exhibited a significant decrease in species richness, a significant increase in plant cover, and a highly dynamic species composition over time, with Sorensen index of 0.3–0.5 between years. There were no significant differences in plant cover, species richness, and aboveground biomass between hydroseeded and nonhydroseeded plots on embankments throughout the study. Our results demonstrate that there are situations in which the use of hydroseeding for revegetation is not needed. Further research should focus on understanding the establishment of autochthonous species and identifying environmental conditions under which the addition of commercial seeds may not be needed, or indeed situations where it may be harmful in suppressing autochthonous species.
Comparison of Leaf Litter Decomposition Rates in Restored and Mature Riparian Forests on the Sacramento River, California
Authors: Borders Brianna D. , Pushnik James C. , Wood David M.
Published: May 2006

One of the largest riparian restoration projects in the United States is currently taking place in California on the Sacramento River. Nearly 2,000 ha of land adjacent to the river channel have been revegetated with native riparian species in an effort to reestablish riparian forests. The objective of this study was to compare leaf litter decomposition rates in restored riparian forests to those in mature, naturally established riparian forests, in order to monitor the development of this ecosystem function in restored forests. Leaf litter decomposition rates were measured over 1 year in six restored riparian forests (4, 7, and 9 years old) and two mature remnant riparian forests (>50 years old), in order to test two hypotheses: (1) decomposition rates of restored and mature forests are significantly different and (2) decomposition rates in the chronosequence of restored forests are moving along a trajectory, approaching the decomposition rates characteristic of mature forests as they age. Statistical analyses revealed no significant differences in annual decay rates among the four different forest ages and no trajectory among leaf litter decomposition rates in restored forests. These results suggest that a functionally equivalent process of leaf litter decomposition occurs in both restored and naturally established forests and show promise for the efficiency of nutrient cycling processes in these restored forests.
Small Clusters of Fast‐Growing Trees Enhance Forest Structure on Restored Bottomland Sites
Authors: Twedt Daniel J.
Published: May 2006

Despite the diversity of trees in bottomland forests, restoration on bottomland sites is often initiated by planting only a few species of slow‐growing, hard mast–producing trees. Although successful at establishing trees, these young forests are slow to develop vertical structure, which is a key predictor of forest bird colonization. Furthermore, when natural seed sources are few, restored sites may be depauperate in woody species. To increase richness of woody species, maximum tree height, and total stem density, I supplemented traditional plantings on each of 40 bottomland restoration sites by planting 96 Eastern cottonwood (Populus deltoides) and American sycamore (Platanus occidentalis) in eight clusters of 12 trees. First‐year survival of cottonwood stem cuttings (25%) and sycamore seedlings (47%) was poor, but survival increased when afforded protection from competition with weeds. After five growing seasons, 165 of these 320 supplemental tree clusters had at least one surviving tree. Vegetation surrounding surviving clusters of supplemental trees harbored a greater number of woody species, increased stem density, and greater maximum tree height than was found on paired restoration sites without supplemental trees. These increases were primarily accounted for by the supplemental trees.
Ecological Restoration and Global Climate Change
Authors: Harris James A. , Hobbs Richard J. , Higgs Eric , Aronson James
Published: May 2006

There is an increasing consensus that global climate change occurs and that potential changes in climate are likely to have important regional consequences for biota and ecosystems. Ecological restoration, including (re)afforestation and rehabilitation of degraded land, is included in the array of potential human responses to climate change. However, the implications of climate change for the broader practice of ecological restoration must be considered. In particular, the usefulness of historical ecosystem conditions as targets and references must be set against the likelihood that restoring these historic ecosystems is unlikely to be easy, or even possible, in the changed biophysical conditions of the future. We suggest that more consideration and debate needs to be directed at the implications of climate change for restoration practice.
Maternal melatonin stimulates growth and prevents maturation of the capuchin monkey fetal adrenal gland
Authors: Torres‐Farfan Claudia , Valenzuela Francisco J. , Germain Alfredo M. , Viale María Lorena , Campino Carmen , Torrealba Fernando , Valenzuela Guillermo J. , Richter Hans G. , Serón‐Ferré María
Published: May 2006

Abstract.  The primate fetal adrenal reaches a large size relative to body weight followed by a rapid decrease in size in the postnatal period. We tested the hypothesis that maternal melatonin stimulates growth and prevents maturation of the primate fetal adrenal gland. We suppressed maternal melatonin by exposing eight pregnant capuchin monkeys to constant light (LL) from 63% to 90% gestation (term 155 days). Three of these received daily oral melatonin replacement (LL + Mel). Five mothers remaining in light:dark cycle were used as controls. Fetuses were delivered at 90% gestation. The absence of maternal melatonin selectively decreased fetal adrenal weight (Control: 488.8 ± 51.5; LL: 363.2 ± 27.7 and LL + Mel 519 ± 46 mg; P < 0.05 ANOVA) without effecting fetal weight, placental weight or the weight of other fetal tissues. Changes in fetal adrenal size were accompanied by an increase in the levels of Δ5‐3β‐hydroxysteroid dehydrogenase (3β‐HSD) mRNA (Control: 0.8 ± 0.2; LL: 5.2 ± 0.6 and LL + Mel 0.8 ± 0.1; 3β‐HSD/18S‐rRNA; P < 0.05 ANOVA). In vitro we found that maternal melatonin suppression increased basal progesterone production to levels similar to those of the adult adrenal gland (Control: 0.36 ± 0.09; LL 0.99 ± 0.13; LL + Mel 0.18 ± 0.06 and adult: 0.88 ± 0.10 ng/mg of tissue; P < 0.05 ANOVA) but no change in cortisol production. We found an increased production of cortisone (Control: 1.65 ± 0.60; LL: 5.44 ± 0.63; LL + Mel: 2.90 ± 0.38 and adult: 1.70 ± 0.45 ng/mg of tissue; P < 0.05 ANOVA). Collectively, the effects of maternal melatonin suppression and their reversion by maternal melatonin replacement suggest that maternal melatonin stimulates growth and prevents maturation of the capuchin monkey fetal adrenal gland.
Blue blocker glasses impede the capacity of bright light to suppress melatonin production
Authors: Sasseville Alexandre , Paquet Nathalie , Sévigny Jean , Hébert Marc
Published: May 2006

Abstract:  Blocking morning light exposure with dark goggles can contribute to the adjustment to night work but these glasses are incompatible with driving. Recently, it was discovered that the biological clock is most sensitive to short wavelengths (blue light). Therefore, we tested the hypothesis that cutting the blue portion of the light spectrum with orange lens glasses (blue blockers) would prevent the light‐induced melatonin suppression, a test broadly used as an indirect assessment of the circadian clock sensitivity. Fourteen normal subjects were exposed at night to a 60 min bright light pulse (1300 lx behind filters) between 01:00 and 02:00 hr while wearing orange lens glasses (experimental condition) or grey lens glasses (control condition). The amount of salivary melatonin change observed during the light pulse was compared with a melatonin baseline obtained the night before. Although both glasses transmitted the same illuminance (1300 lx) but at an irradiance 25% higher for the orange lens (408 μW/cm2) compared with the grey lens (327 μW/cm2), a non‐significant increase of 6% (95% CI, −20% to 9%) was observed with the orange lens whereas a significant (P < 0.05) reduction of 46% (95% CI, 35–57%) was observed with the grey lens. Blue blockers represent an elegant means to prevent the light‐induced melatonin suppression. Further studies are needed to show that these glasses, which are suitable for driving, could facilitate adaptation to night work.
Melatonin stimulates glucose transport via insulin receptor substrate‐1/phosphatidylinositol 3‐kinase pathway in C2C12 murine skeletal muscle cells
Authors: Ha Eunyoung , Yim Sung‐Vin , Chung Joo‐Ho , Yoon Kyung‐Sik , Kang Insug , Cho Yong Ho , Baik Hyung Hwan
Published: May 2006

Abstract:  The prevalence of diabetes has exponentially increased in recent decades due to environmental factors such as nocturnal lifestyle and aging, both of which influence the amount of melatonin produced in the pineal gland. The present study investigated the effect of melatonin on signaling pathways of glucose transport in C2C12 mouse skeletal muscle cells. Intriguingly, treatment of C2C12 cells with melatonin (1 nm) stimulated glucose uptake twofold increase. Melatonin‐stimulated glucose transport was inhibited with co‐treatment with the melatonin receptor antagonist luzindole. Furthermore, treatment of stably over‐expressed melatonin receptor type 2B containing C2C12 myotubes with melatonin amplified glucose transport c. 13‐fold. Melatonin also increased the phosphorylation level of insulin receptor substrate‐1 (IRS‐1) and the activity of phosphoinositide 3‐kinase (PI‐3‐kinase). However, 3′,5′‐cyclic adenosine monophosphate‐activated protein kinase (AMPK), another important glucose transport stimulatory mediator via an insulin‐independent pathway, was not influenced by melatonin treatment. Activity of p38 mitogen‐activated protein kinase (MAPK), a downstream mediator of AMPK, was also not changed by melatonin. In addition, melatonin increased the expression level of forkhead box A2, which was recently discovered to regulate fatty acid oxidation and to be inhibited by insulin. In summary, melatonin stimulates glucose transport to skeletal muscle cells via IRS‐1/PI‐3‐kinase pathway, which implies, at the molecular level, its role in glucose homeostasis and possibly in diabetes. Additionally, exposure to light at night and aging, both of which lower endogenous melatonin levels may contribute to the incidence and/or development of diabetes.
Contrast‐induced nephropathy: preventive and protective effects of melatonin
Authors: Gazi Sabri , Altun Armagan , Erdogan Okan
Published: May 2006

Abstract:  Infusion of contrast agents increases osmotic load, viscosity, hypoxemia of the renal medulla and renal free radical production through post‐ischemic oxidative stress. The present experimental study sought to determine whether melatonin, because of its anti‐oxidant properties might have a preventive and protective role against the development of contrast‐induced nephropathy (CIN). Twenty‐four adult male rats were divided into four experimental groups: healthy control rats (CR), rats with CIN (CINR), rats with CIN pretreated with melatonin (CINR1M), and rats with CIN pre‐ and post‐treated with melatonin (CINR2M). In CINR, both serum creatinine (Cr) level and fractional excretion of sodium (FE‐Na) significantly increased, whereas Cr clearance decreased at post‐CIN compared with pre‐CIN period. Rats in CINR1M did not show any improvement in renal function. Cr clearance decreased, whereas both serum Cr level and FE‐Na increased in rats pretreated with melatonin. In contrast, significant improvements were observed in CINR2M. Serum Cr and Cr clearance did not change, whereas FE‐Na significantly reduced in rats pre‐ and post‐treated with melatonin. In conclusion, the present experimental study clearly demonstrated the preventive and protective role of melatonin against the development of CIN.
The Quest for the Mechanism of Melanin Transfer
Authors: Van Den Bossche Karolien , Naeyaert Jean‐Marie , Lambert Jo
Published: May 2006

Skin pigmentation is accomplished by production of melanin in specialized membrane‐bound organelles termed melanosomes and by transfer of these organelles from melanocytes to surrounding keratinocytes. The mechanism by which these cells transfer melanin is yet unknown. A central role has been established for the protease‐activated receptor‐2 of the keratinocyte which effectuates melanin transfer via phagocytosis. What exactly is being phagocytosed – naked melanin, melanosomes or melanocytic cell parts – remains to be defined. Analogy of melanocytes to neuronal cells and cells of the haemopoietic lineage suggests exocytosis of melanosomes and subsequent phagocytosis of naked melanin. Otherwise, microscopy studies demonstrate cytophagocytosis of melanocytic dendrites. Other plausible mechanisms are transfer via melanosome‐containing vesicles shed by the melanocyte or transfer via fusion of keratinocyte and melanocyte plasma membranes with formation of tunnelling nanotubes. Molecules involved in transfer are being identified. Transfer is influenced by the interactions of lectins and glycoproteins and, probably, by the action of E‐cadherin, SNAREs, Rab and Rho GTPases. Further clues as to what mechanism and molecular machinery will arise with the identification of the function of specific genes which are mutated in diseases that affect transfer.
Measles Virus Contact with T Cells Impedes Cytoskeletal Remodeling Associated with Spreading, Polarization, and CD3 Clustering
Authors: Müller Nora , Avota Elita , Schneider‐Schaulies Jürgen , Harms Harry , Krohne Georg , Schneider‐Schaulies Sibylle
Published: May 2006

CD3/CD28‐induced activation of the PI3/Akt kinase pathway and proliferation is impaired in T cells after contact with the measles virus (MV) glycoprotein (gp) complex. We now show that this signal also impairs actin cytoskeletal remodeling in T cells, which loose their ability to adhere and to promote microvilli formation. MV exposure results in an almost complete collapse of membrane protrusions associated with reduced phosphorylation levels of cofilin and ezrin/radixin/moesin (ERM) proteins. Consistent with their inability to activate Cdc42 and Rac1 in response to the ligation of CD3/CD28, T cells exposed to MV fail to acquire a morphology consistent with spreading and lamellopodia formation. In spite of these impairments of cytoskeleton‐driven morphological alterations, these cells are recruited into conjugates with dendritic cells as efficiently as control T cells. The signal elicited by MV, however, prevents T cells to polarize as documented by a failure to redistribute the microtubule organizing center toward the synapse. Moreover, CD3 cannot be efficiently clustered and redistributed to the central region of the immunological synapse. Thus, by inducing microvillar collapse and interfering with cytoskeletal remodeling, MV signaling disturbs the ability of T cells to adhere, spread, and cluster receptors essential for sustained T‐cell activation.
Dynamin is Involved in Endolysosomal Cholesterol Delivery to the Endoplasmic Reticulum: Role in Cholesterol Homeostasis
Authors: Robinet Peggy , Fradagrada Alexandre , Monier Marie‐Noëlle , Marchetti Marta , Cogny Anne , Moatti Nicole , Paul Jean‐Louis , Vedie Benoit , Lamaze Christophe
Published: May 2006

Cholesterol is one of the most essential membrane components in mammalian cells and plays a critical role in several cellular functions. It is now established that intracellular cholesterol transport contributes to the regulation of cellular cholesterol homeostasis by mechanisms that are yet poorly defined. In this study, we examined the role of clathrin‐ and dynamin‐dependent trafficking on the regulatory machinery involved in cholesterol homeostasis. Thus, expression levels of three major sterol‐sensitive genes, that is sterol‐regulatory element binding protein 2 (SREBP‐2), hydroxymethylglutaryl‐coenzyme A (HMGCoA) reductase and low‐density lipoprotein (LDL) receptor, were monitored to study the cell response to the addition of LDL‐derived cholesterol. We found that inhibition of clathrin‐dependent endocytosis had no effect on the intracellular distribution of cholesterol and the regulation of sterol‐sensitive genes. In contrast, inhibition of dynamin activity resulted in the lack of regulation of SREBP‐2, HMGCoA reductase and LDL receptor genes. Immunolocalization studies along with the measure of free and esterified cholesterol indicated that dynamin inactivation led to the accumulation of free cholesterol (FC) within the late endosomal (LE)/lysosomal compartment resulting in insufficient delivery of regulatory cholesterol to the endoplasmic reticulum (ER) where the transcriptional control of sterol‐sensitive genes occurs. Our data therefore indicate that dynamin plays a critical role in the delivery of cholesterol from the LE/lysosomal network to the ER and highlight the importance of LE trafficking in cholesterol homeostasis.
Toward the Systems Biology of Vesicle Transport
Authors: Quenneville Nicole R. , Conibear Elizabeth
Published: May 2006

Systems biology aims to study complex biological processes, such as intracellular traffic, as a whole. Systematic genome‐wide assays have the potential to identify the transport machinery, delineate pathways and uncover the molecular components of physiological processes that influence trafficking. A goal of this approach is to create predictive models of intracellular trafficking pathways that reflect these relationships. In this review, we highlight current genome‐wide technologies of particular relevance to vesicle transport and describe recent applications of these technologies in the framework of systems biology. Systems approaches hold great promise for placing trafficking pathways in their cellular contexts.
Cyclodextrins but not Compactin Inhibit the Lateral Diffusion of Membrane Proteins Independent of Cholesterol
Authors: Shvartsman Dmitry E. , Gutman Orit , Tietz Aliza , Henis Yoav I.
Published: May 2006

Cholesterol and glycosphingolipid‐enriched membrane domains, termed lipid rafts, were proposed to play important roles in trafficking and signaling events. These functions are inhibited following putative disruption of rafts by cholesterol depletion, commonly induced by treatment with methyl‐β‐cyclodextrin (MβCD). However, several studies showed that the lateral diffusion of membrane proteins is inhibited by MβCD, suggesting that it may have additional effects on membrane organization unrelated to cholesterol removal. Here, we investigated this possibility by comparison of the effects of cholesterol depletion by MβCD and by metabolic inhibition (compactin), and of treatment with α‐CD, which does not bind cholesterol. The studies employed two series of proteins (Ras and influenza hemagglutinin), each containing as internal controls related mutants that differ in raft association. Mild MβCD treatment retarded the lateral diffusion of both raft and non‐raft mutants, whereas similar cholesterol reduction (30–33%) by metabolic inhibition enhanced selectively the diffusion of the raft‐associated mutants. Moreover, α‐CD also inhibited the diffusion of raft and non‐raft mutants, despite its lack of effect on cholesterol content. These findings suggest that the widely used treatment with CD to reduce cholesterol has additional, cholesterol‐independent effects on membrane protein mobility, which do not necessarily distinguish between raft and non‐raft proteins.