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We conducted a retrospective evaluation of alternative management strategies for stocks in the New England groundfish complex that have had recent history of target catches being set above the level that defines overfishing. In many cases the original target catches were unsustainable and would have resulted in stock collapses if the target catch had been removed. We evaluated (i) alternative harvest control rules, (ii) whether or not to do projections, (iii) whether the inputs to the projections (starting abundance and future recruitments) should be modified, and (iv) whether the target catches should be smoothed to prevent large changes from year to year. The greatest reductions in target catches resulted when no projections were done and the target catch was fixed over the period between assessments. Large reductions in target catches also occurred when a downward adjustment was made to the starting abundance in the projections based on the retrospective pattern. Neither approach alone was sufficient to prevent overfishing for most stocks, but when used in conjunction with one another or with an alternative control rule that reduced the target harvest rate as biomass fell below the target, the magnitude and frequency of overfishing was greatly reduced for most stocks. Attempts to adjust recruitment based on perceived changes over time were also effective for a few stocks, while attempts to smooth the target catches over often resulted in increases in the target catches. Nous avons realise une evaluation retrospective de differentes strategies de gestion pour des stocks dans le complexe de poissons de fond de la Nouvelle-Angleterre qui, dans le passe recent, ont ete vises par des objectifs de prises superieurs au niveau definissant une surpeche. Dans de nombreux cas, les objectifs de prises initiaux n'etaient pas durables et se seraient traduits par l'effondrement de stocks s'ils avaient ete atteints. Nous avons evalue (i) differentes regles de controle des prises, (ii) la pertinence de faire des projections, (iii) si les intrants des projections (abondance initiale et recrutements futurs) devraient etre modifies et (iv) si les objectifs de prises devraient etre lisses pour prevenir des variations importantes d'une annee a l'autre. Les plus grandes reductions des objectifs de prises se produisent quand aucune projection n'est faite et que l'objectif de prises est fixe pour toute la periode entre les evaluations. D'importantes reductions des objectifs de prises se produisent egalement quand un ajustement a la baisse est fait a l'abondance initiale dans les projections a la lumiere du motif retrospectif. Aucune de ces deux approches ne suffit a elle seule a prevenir la surpeche pour la plupart des stocks, mais quand elles sont utilisees ensemble ou avec une autre regle de controle qui reduit le taux de prises vise quand la biomasse passe sous l'objectif, la magnitude et la frequence des cas de surpeche sont considerablement reduites pour la plupart des stocks. Les tentatives d'ajustement du recrutement selon les changements percus au fil du temps sont aussi efficaces pour quelques stocks, alors que des tentatives de lisser les objectifs de prises se traduisent souvent par des augmentations des objectifs de prises. [Traduit par la Redaction], Introduction The aim of modern single-species fisheries management is to maintain the population size of the target stock close to the level that produces maximum sustainable yield (MSY; Hilborn 2010). [...]

High-resolution multibeam echosounder (MBES) and light detection and ranging (LiDAR) data, combined with regional gravity and aeromagnetic anomaly maps of the western Gulf of Maine, reveal numerous lineaments between central New England and the New England seamounts. Most of these lineaments crosscut the NE-SW-trending accreted terranes, suggesting that they may be surface expressions of deep basement-rooted faults that have fractured upward through the overlying accreted terranes or may have formed by the upward push of magmas produced by the New England hotspot. The 1755 Cape Ann earthquake may have occurred on a fault associated with one of these lineaments. The MBES data also reveal a NW-SE-oriented scarp just offshore from Biddeford Pool, Maine (Biddeford Pool scarp), a 60-km-long, 20-km-wide Isles of Shoals lineament zone just offshore from southeastern New Hampshire, a 50-km-long zone of mostly low-lying, WNW-ESE-trending, submerged ridge-like features and scarps east of Boston, Massachusetts, and a ~180-km-long, WNW-ESE-trending Olympus lineament zone that traverses the continental margin south of Georges Bank. Three submarine canyons are sinistrally offset ~1-1.2 km along the 'Ihresher canyon lineament of the Olympus lineament zone. Les donnees provenant d'un echosondeur multifaisceaux a haute resolution et des precedes de detection par telemetrie et ondes lumineuses (LIDAR), combinees aux cartes regionales d'anomalies gravimetriques et aeromagnetiques de la partie ouest du golfe du Maine, revelent la presence de nombreux lineaments entre la partie centrale de la Nouvelle-Angleterre et la chaine de monts de la Nouvelle-Angleterre. La plupart de ces lineaments traversent les terranes accretes d'orientation NE-SO, ce qui suggere qu'ils sont des modeles de failles profondes dont la base se trouve au sous-sol et qui se sont fissurees vers le haut, a travers les terranes accretes qui les surmontent, ou pourraient s'etre formes en raison du soulevement de magmas produits par le point chaud de la Nouvelle-Angleterre. Le seisme de Cape Ann, qui est survenu en 1755, pourrait s'etre produit le long d'une faille associee a Tun de ces lineaments. Les donnees de l'echosondeur multifaisceaux a haute resolution revelent un escarpement oriente NO-SE, tout juste au large de Biddeford Pool, au Maine (escarpement de Biddeford Pool), une zone de lineaments aux Isles of Shoals, d'une longueur de 60 km et d'une largeur de 20 km--cet escarpement est, a son tour, immediatement au large de la partie sud-est du New Hampshire; une zone de 50 km de longueur principalement formee d'accidents et escarpements submerges en forme de talus, de faible altitude, a tendance ONO-ESE, a Test de Boston, au Massachusetts; et la zone de lineaments d'Olympus de 180 km de longueur, a orientation ONO-ESE, qui traverse la marge continentale au sud de Georges Bank. Trois canyons sous-marins se trouvent en rejet horizontal transversal senestre sur une distance d'environ 1 a 1,2 km le long du lineament du canyon de Thresher de la zone de lineaments d'Olympus. [Traduit par la redaction], INTRODUCTION Previous investigators (e.g., Ma and Eaton 2007) have postulated that the New England hotspot may have produced a broad zone of structural weakness associated with seismicity. Our goals were [...]

Abstract--Recently, it has been suggested that spiny dogfish (Squalus acanthias) in the western North Atlantic Ocean have a shorter gestation period than the widely cited 2 years, have an asynchronous [...]

The Litchfield pluton is a poorly exposed 7 [km.sup.2] composite alkalic intrusive complex that cuts previously deformed and metamorphosed Silurian turbidites in south-central Maine. The pluton includes a variety of alkaline syenites, including the type locality of 'litchfieldite,' a coarse-grained cancrinite-, sodalite-, and lepidomelane-bearing nepheline syenite first recognized over 150 years ago and common in many petrologic collections. A new U-Pb zircon age of 321 ± 2 Ma from the nepheline syenite is interpreted to represent the crystallization age of the plutonic complex. A new biotite [sup.40]Ar/[sup.39]Ar age of 239 ± 1 Ma from the syenite is similar to previously published mica ages from the surrounding country rocks and dates the time of regional cooling in the area below ~ 300°C. Whole-rock chemical analyses of rocks of the Litchfield pluton reveal silica-undersaturated alkaline compositions that are consistent with formation in a within-plate tectonic setting. The age and geochemical characteristics of the alkalic igneous rocks near Litchfield are consistent with a model that invokes the generation of a small volume of alkalic magma beneath south-central Maine during a period of Carboniferous transcurrent tectonism in the northern Appalachian orogen. Le pluton de Litchfield est un complexe intrusif alcalin composite de sept kilometres carres peu affleurant qui recoupe des turbidites siluriennes precedemment deformees et metamorphisees dans le centre-sud du Maine. Le pluton inclui diverses syenites alcalines, notamment la localite type de la << litchfieldite >>, une syenite nephelinique renfermant de la cancrinite, de la sodalite et de la lepidomelane a grain grossier identifiee pour la premiere fois il y a plus de 150 ans et repandue dans maintes collections petrologiques. Une nouvelle datation U-Pb sur zircon de 321 ± 2 Ma de la syenite nephelinique est interpretee comme une representation de lage de la cristallisation du complexe de roches plutoniques. Une nouvelle datation de la syenite par biotite et [sup.40]Ar/[sup.39]Ar de 239 ± 1 Ma est similaire aux ages du mica des roches encaissantes voisines publies auparavant et situe le moment du refroidissement regional dans le secteur au-dessous d'environ 300°C. Des analyses chimiques sur roche totale des roches du pluton de Litchfield revelent des compositions alcalines sous-saturees de silice correspondant a une formation dans un milieu tectonique intraplaque. L'age et les caracteristiques geochimiques des roches ignees alcalines pres de Litchfield sont conformes a un modele evoquant la production dun volume modeste de magma alcalin sous le centre-sud du Maine durant une periode dactivite tectonique de coulissage du Carbonifere dans le nord de l'orogene appalachien. [Traduit par la redaction], INTRODUCTION Since the mid-1800s (Jackson 1845; Clarke 1886), the small village of Litchfield in south-central Maine (Fig. 1) has been known as a collecting locality for specimens of cancrinite, sodalite, [...]

In any stock assessment application, the implicit assumptions regarding spatial population structure must be carefully evaluated. Tag-integrated models offer a promising approach for incorporating spatial structure and movement patterns in stock assessments, but the complexity of the framework makes implementation challenging and the appraisal of performance difficult. A flounder-like fishery was simulated to emulate the metapopulation dynamics of the three yellowtail flounder (Limanda ferruginea) stocks off New England, and the robustness of spatially explicit tag-integrated models were compared with closed population assessments. Different movement parametrizations and data uncertainty scenarios were simulated, while the ability of the tag-integrated model to estimate reporting rate and time-varying movement were also evaluated. Results indicated that the tag-integrated framework was robust for the simulated fishery across a wide range of connectivity levels and that tag reporting rates were accurately estimated. Closed population models also demonstrated limited error. Therefore, spatially explicit approaches may not always be warranted even when regional connectivity is occurring, but tag-integrated models can provide improved parameter estimates when reliable tagging data are available. Tag-integrated models also serve as valuable tools for informing spatially explicit operating models, which can then be used to evaluate the assumptions and performance of closed population models. Dans toute application devaluation des stocks, les hypotheses implicites concernant la structure spatiale de la population doivent faire l'objet d'une evaluation soigneuse. Si les modeles integrant les donnees de marquage constituent une approche prometteuse pour incorporer la structure spatiale et les motifs de deplacement aux evaluations des stocks, la complexite de leur cadre en rend l'application compliquee et revaluation de la performance difficile. Une peche s'apparentant a la peche a la limande a ete simulee pour reproduire la dynamique de metapopulation des trois stocks de limandes a queue jaune (Limanda ferruginea) au large de la Nouvelle-Angleterre, et la robustesse de modeles spatialement explicites integrant le marquage a ete comparee avec des evaluations de population fermee. Differentes parametrisations des deplacements et differents scenarios d'incertitude des donnees ont ete simules, et la capacite du modele integrant le marquage a estimer les taux de declaration et les deplacements variables dans le temps ont aussi ete evalues. Les resultats indiquent que le cadre integrant les donnees de marquage est robuste pour la peche simulee pour une grande fourchette de niveaux de connectivite et que les taux de declaration des marques etaient estimes avec exactitude. Les modeles de population fermee presentaient egalement des erreurs restreintes. Ainsi, si les approches spatialement explicites ne sont pas toujours necessaires meme quand il y a connectivite regionale, les modeles integrant le marquage peuvent toutefois fournir de meilleures estimations des parametres quand des donnees de marquage fiables sont disponibles. Les modeles integrant les donnees de marquage constituent egalement de bons outils pour alimenter les modeles d'exploitation spatialement explicites, qui peuvent ensuite etre utilises pour evaluer les hypotheses et la performance des modeles de population fermee. [Traduit par la Redaction], Introduction Spatial population structure and movement patterns play a critical role in the regulation of abundance (Cadrin and Secor 2009). Attempting to incorporate the intricacies of fine-scale population structure into [...]

In this article the development of aquaculture, keeping and rearing fish in enclosed ponds that was prevalent in New England and the Mid Atlantic in the mid nineteenth century is discussed. American farmers were successfully able to adapt to changes in their physical environment by development of private fishing ponds in the eighteenth century.

Integrated geochronologic and paleomagnetic investigation of the arc-related Lynn and Mattapan volcanic complexes around Boston, Massachusetts, establishes a Neoproterozoic paleopole for the Southeastern New England Avalon Zone. Four new U-Pb zircon dates obtained using isotope dilution and thermal ionization mass spectrometry (IDTIMS) methods range from 597.4 [+ or -] 1.5 Ma to 595.7 [+ or -] 1.6 Ma, in agreement with published Lynn-Mattapan results of ca. 596 Ma. The mean direction calculated from the A component of magnetization at nine Lynn-Mattapan sites has a declination (D) of 319.9[degrees] and an inclination (I) of 57.0[degrees] ([alpha]95 = 7.4[degrees]); the paleopole based on this mean direction is 206[degrees]E, 60[degrees]N. These results pass both reversals and fold tests and are regionally consistent among lithologies that include basalt, andesite, rhyodacite, and rhyolite, which represent both volcanic and subvolcanic phases. Most sites also contain stable B and C magnetic components with directions that suggest Ordovician to Permian remagnetizations. A broadly comparable A component direction with D = 109.0[degrees] and I = -63.4[degrees] ([alpha]95 = 9.4[degrees], n = 11 samples) was obtained from one site in the Squantum Member of the Roxbury Conglomerate (maximum age of 593 Ma) overlying the volcanic sequence. The Lynn-Mattapan results indicate that southeastern New England occupied a mid-latitude position at ca. 595 Ma, similar to those reported from Avalonian terranes in maritime Canada. The most likely peri-Gondwanan position for Avalonia consistent with these paleomagnetic data lies off the West African margin. Using poles from the East Sahara craton (Egypt) and the Rio de la Plata craton (Brazil) has permitted reconstruction of West Gondwana without recourse to Laurentian proxies. Keywords: Avalon Zone, New England, Neoproterozoic, U-Pb geochronology, paleopole, paleogeography.

Through an examination of seventeenth-century English sources and later Indian folklore, this article illustrates the centrality of religion to defining masculinity among Algonquian-speaking Indians in southern New England. Manly ideals were represented in the physical and spiritual excellence of individual living men like the Penacook sachem-powwow Passaconaway and supernatural entities like Maushop. For men throughout the region, cultivating and maintaining spiritual associations was essential to success in the arenas of life defining Indian masculinity: games, hunting, warfare, governance, and marriage. As is stressed throughout the essay, masculinity was also juxtaposed with femininity in a number of important ways in Indian society.

Variability in upper ocean optical properties is often driven by changes in the particle pool. We investigated the effects of such changes by characterizing individual particles. For particles in natural assemblages, we used a combination of Mie theory and flow cytometry to determine diameter (D), complex refractive index (n + in'), and optical cross-sections at 488 nm. Particles were grouped into categories of eukaryotic pico/nanophytoplankton, Synechococcus, heterotrophic prokaryotes, detritus, and minerals to interpret variability in concurrently measured bulk inherent optical properties (IOPs) in New England continental shelf waters during two seasons. The summed contributions of individual particles to phytoplankton absorption and particle scattering were close to values for these properties measured independently using bulk methods (87% and 107%, respectively). In surface waters during both seasons, eukaryotic phytoplankton were responsible for the majority of both total particle absorption and total particle scattering. Mineral particles contributed the most to backscattering ([b.sub.b]) in the spring, whereas in the summer both mineral and detrital particles were important. Synechococcus and heterotrophic prokaryotes never contributed more than 14% to IOPs. Our findings emphasize that the measurement of nonliving particles, including detritus and minerals, is necessary for understanding variability in [b.sub.b] in the ocean, an important quantity in the interpretation of satellite ocean color.

The conditions at which monazite and allanite were produced and destroyed during prograde metamorphism of pelitic rocks were determined in a Buchan and a Barrovian regional terrain and in a contact aureole, all from northern New England, USA. Pelites from the chlorite zone of each area contain monazite that has an inclusion-free core surrounded by a highly irregular, inclusion-rich rim. Textures and [sup.208]Pb/[sup.232]Th dates of these monazites in the Buchan terrain, obtained by ion microprobe, suggest that they are composite grains with detrital cores and very low-grade metamorphic overgrowths. At exactly the biotite isograd in the regional terrains, composite monazite disappears from most rocks and is replaced by euhedral metamorphic allanite. At precisely the andalusite or kyanite isograd in all three areas, allanite, in turn, disappears from most rocks and is replaced by subhedral, chemically unzoned monazite neoblasts. Allanite failed to develop at the biotite isograd in pelites with lower than normal Ca and/ or A1 contents, and composite monazite survived at higher grades in these rocks with modified texture, chemical composition, and Th-Pb age. Pelites with elevated Ca and/or Al contents retained allanite in the andalusite or kyanite zone. The best estimate of the time of peak metamorphism at the andalusite or kyanite isograd is the mean Th-Pb age of metamorphic monazite neoblasts that have not been affected by retrograde metamorphism: 364.3 [+ or -] 3.5 Ma in the Buchan terrain, 352.9 [+ or -] 8.9 Ma in the Barrovian terrain, and 403.4 [+ or -] 5.9 Ma in the contact aureole. Some metamorphic monazites from the Buchan terrain have ages partially to completely reset during an episode of retrograde metamorphism at 343.1 [+ or -] 9.1 Ma. Interpretation of Th-Pb ages of individual composite monazite grains is complicated by the occurrence of subgrain domains of detrital material intergrown with domains of material formed or recrystallized during prograde and retrograde metamorphism.

1 As peatlands form they create a temporal archive of community development, allowing the reconstruction of vegetation dynamics through the analysis of sediments and the development of detailed chronologies of successional change. Peatland formation occurs through two mechanisms: (i) terrestrialization, when a water body fills with sediments and peat; and (ii) paludification, the conversion of dry land to peatland. In temperate regions, where high summer temperatures may limit peat accumulation, general models of peatland development suggest that allogenic factors such as climate change control peatland development and that terrestrialization is the primary mechanism of formation. 2 This study evaluates this widely accepted model by comparing the developmental histories of three peatlands within the same climate region in New England in order to: (i) describe the development and timing of successional events among peatlands; (ii) document the roles of paludification and terrestrialization as developmental mechanisms; and (iii) evaluate the importance of climate change vs. autogenic factors in peatland development in this temperate region. 3 Basin morphometry, sediment stratigraphies, and chronologies of community change determined through radiocarbon dating indicate that peatland development at each site involved terrestrialization followed by paludification, with no apparent influence of broad-scale climate change on the timing of these processes. Paludification was consistently initiated coincident with the consolidation of a shrub mat across each lake-basin, and was controlled in extent and rate by the topography of the adjoining uplands. The timing of stratigraphic changes varied among sites, suggesting that autogenic factors associated with the accumulation of peat rather than regional climate change controlled development. These results provide the foundation for a model of temperate peatland development driven by autogenic factors and caution against the use of temperate peatland development as a proxy for climatic reconstruction. Key-words: allogenic control, autogenic control, climate, paludification, terrestrialization, peatland, stratigraphy, New England

In most communities, a considerable number of the constituent species will only occupy a small percentage of sites or habitat patches. However, the factors that limit the distribution and abundance of rare species are seldom examined and are poorly understood. I tested several explanations of landscape-scale rarity in the New England cobble beach plant community, an assemblage of halophytic forbs associated with fringing beds of the marine intertidal grass Spartina alterniflora. Spartina reduces flow velocity and stabilizes the cobble substrate, thereby reducing the burial of seeds and seedlings of other species. Frequencies of the presence of forb species behind 387 sampled Spartina beds distributed along 120 km of shoreline in Narragansett Bay, Rhode Island, USA, ranged from 0.005 to 0.382. Both the whole forb assemblage and individual species were strongly nested with respect to patch size and species richness. Species that were rare on a landscape scale were generally only found behind the longest beds, and bed length was positively related to species diversity. Experimental seed additions to 40 beds ranging in length from 8 to 688 m indicated that intermediate-sized beds often occupied by common species are not habitable by three rare forbs. When present behind the longest beds, these rare species are always associated with a microhabitat characterized by a relatively fine-grained and highly stable substrate. A series of substrate manipulations combined with experimental seed additions indicated that the rare annuals Spergularia marina, Salicornia biglovii, and Atriplex arenaria are restricted to the longest Spartina beds because smaller beds lack suitable substrate. These experiments also suggest that seed supply, competitors, and herbivores are not the proximate causes of the absence of these species from smaller beds, although dispersal limitation may prevent the colonization of many larger habitable patches. The microhabitat required by the rare forbs appears to be generated by the deposition of fine-grained particles behind the center of the longest Spartina beds. Consequently, bed length is causally related to the distribution of populations at a landscape scale and to species richness and composition at the scale of a whole habitat patch. Key words: cobble beach: diversity; facilitation; halophytic forbs; nestedness; rarity: species richness.

Research is presented on the history of rifting events in the Narragansett basin, including pyroclastic rocks, rhyolite flows, basalt flows and non-marine, sedimentary rock. Formation is attributed to partial melting superceded by limited fractional cyrstallization.

1 The New England cobble beach plant community is an intertidal assemblage of halophytic forbs found exclusively behind fringing beds of the grass Spartina alterniflora. The purpose of this study was to determine the life stage and factors that limit the upper (landward) distribution of cobble beach plants in Narragansett Bay, Rhode Island, USA. 2 Seed traps and soil samples above the community border contained large numbers of seeds and buried seedlings of three cobble beach species, indicating that seed supply and germination do not limit vertical plant distribution. Experimentally added seeds of four species germinated above the community border, but seedlings did not emerge suggesting that seedling emergence is the proximate life stage limiting population and community distribution. 3 Measures of wave disturbance (cobble movement and change in cobble depth) indicated that substrate instability is substantially greater above than within the community, probably due to the lack of buffering by the S. alterniflora bed at higher tidal heights. 4 A second seed addition experiment demonstrated that seedlings of Suaeda linearis, a common cobble beach forb, are only able to emerge and grow into reproductive adults above the community border when the substrate there is artificially stabilized. Seedling transplants and glasshouse manipulations demonstrated that neither herbivores nor soil quality limited seedling emergence. 5 Overall, the vertical restriction of habitat modification by S. alterniflora appears to result in substrate instability at higher tidal elevations sufficient to prevent seedling emergence and limit the vertical distribution of cobble beach plants. Keywords: facilitation, seed availability, Spartina alterniflora, vertical distribution, zonation

Examination of 36 Devonian to Pennsylvanian plutons within and bordering the Central Maine terrane of north-central New England shows that the plutons display regional variations in mineral and bulk-rock compositions and in oxygen and sulfur isotopic values. These variations principally correspond to the regional structural trends of the Central Maine terrane. Plutons located on that terrane's southeast flank adjacent to the Massabesic Gneiss complex, on the terrane's northwest flank adjacent to the Bronson Hill anticlinorium, and in the northeastern part of the Northeast Kingdom batholith of Vermont have biotites with relatively low Al concentrations (11%), low (delta)(super 34)S values (-25%), Al-rich biotites (>3.3 cations p.f.u.), and An-poor plagioclases ( Keywords: Avalon, granites, Grenville, New England.

Across the Appalachian orogen of New England, the splitting of core-refracted shear waves from a wide range of arrival directions indicates the presence of two nearly uniform horizontal layers of anisotropic upper mantle. The anisotropy in the lower layer has a fast axis nearly parallel to the absolute motion of the North American plate and thus is attributed to basal shear as the plate plows through asthenospheric mantle. The anisotropy of the upper layer is inferred to be a fossil fabric, residing in lithospheric mantle. The finite extension direction of the upper fabric is subhorizontal and oriented normal to the local trend of the Appalachian orogen. The upper fabric is consistent over a broad region beneath and west of the New England Appalachians, which indicates that it formed after Devonian closure of the lapetus ocean, probably during or after the Paleozoic Acadian and Alleghany orogenies. Tectonic scenarios for synconvergent or postconvergent extension, developed for Tibet, predict rapid surface uplift and increased heat flow due to lithospheric thinning, consistent with coeval late orogenic mantlederived magmatism in both the northern Appalachians and Morocco.

Research was conducted to examine the ages of arc magmatism, metamorphism and collisional tectonics in the Taconian orogen of western New England. Geochronologic ages of intrusive and volcanic rocks indicate that the Bronson Hill and Shelburne Falls arcs are not spatially or temporally discrete. Results provide evidence of a long-lived volcanic arc terrane that prograded oceanward and a collision with this time-composite art terrane that produced the Taconian orogeny.

This paper analyses the 20-21 October 1996 rainstorm along the coastal zone of New England in terms of its synoptic setting and its temporal and spatial patterns, and assesses its recurrence interval. The event was primarily generated by an intense cutoff low aloft, with an associated frontal boundary at the surface, both of which slowly drifted across New England. Storm rainfall totals ranged as high as 488 mm, which fell just short of the all-time greatest storm event ever recorded in New England, but statewide 1-day precipitation records were set in Maine and New Hampshire. Recurrence interval analysis revealed that this event was in gross excess of a 100-yr rainfall event and may be greater than a 400-yr event in this region.

1 We examined the effects of nutrient availability on the competitive interactions of the New England salt marsh perennials that occupy discrete vegetational zones parallel to the shoreline. 2 Fertilized and unfertilized plots of pair-wise mixtures and monocultures of Spartina alterniflora, S. patens and Juncus gerardi were compared in order to assess the effects of nutrient addition on the competitive dynamics of these species in the field. In addition, we examined competition between some of these species and Distichlis spicata, a species common to disturbed marsh habitats. 3 After two growing seasons, changes in above-ground biomass of the species indicated that in fertilized plots, S. alterniflora outcompeted S. patens, S. patens outcompeted J. gerardi, and D. spicata outcompeted both J. gerardi and S. patens. This was the reverse of the interactions seen under ambient marsh conditions, and suggested that, under conditions of nutrient limitation, competitive dominance may result from efficient competition for nutrients. 4 Using a conceptual model of salt marsh zonation as a function of competition, physical stress and nutrient limitation, we hypothesize that a nutrient-induced reversal in the competitive dynamics among salt marsh perennials may result in modification of the pattern of plant zonation in this and similar marshes. Keywords: competitive reversal, Distichlis, Juncus, nutrients, Spartina, stress gradient

Tip-up mounds, pits, and other microsites created by hurricanes may promote diversity in many forests by providing opportunities for different species to regenerate. To see if we could detect differences in microsite preference among closely related species, we studied the regeneration of three sympatric Betula species on five types of microsites on experimental mound-pit complexes. Microsites were created by pulling down canopy trees to simulate damage from past hurricanes in southern New England. Seeds were collected in litter traps and experimentally released over mounds and pits to determine effects of microtopography on fine-scale dispersal patterns. The fate of naturally germinating seedlings was monitored on the disturbed site, and seedlings were also transplanted onto microsites to examine growth patterns, causes of mortality, and leaf-level physiology. Seed rain onto the disturbed site was abundant and spatially heterogeneous because of scattered residual canopy trees and surviving uprooted trees. Seeds tended to disperse away from vertically oriented surfaces of mounds and to accumulate in pits. Most seedlings germinated on scarified level areas rather than on mounds or in pits, but mounds became more favorable for germination the second year following disturbance. Two fundamentally different types of mortality were observed in transplanted seedlings. Extrinsic factors such as frost heaving, burial by soil and litter, and browsing were dominant on some microsites. Mortality due to these factors occurred primarily during the winter and was unrelated to seedling size. On other microsites, resource limitation (low light levels and lack of water or nutrients) was the major cause of death. Small seedlings were most susceptible to mortality on these microsites, and most deaths occurred during the growing season. White birch (Betula papyrifera Marsh.) exhibited the fastest growth and most flexible photosynthetic response to changing light levels but suffered greatest mortality on shaded microsites. Black birch (B. lenta L.) showed increased leaf area ratio in shaded conditions. Yellow birch (B. alleghaniensis Britt.) was least flexible and grew more slowly than the other species but was best able to survive on shaded microsites. All species attained maximum growth on tip-up mounds. After three growing seasons, the tallest seedlings reached nearly 3 m above the forest floor, enabling us to predict which individuals would ultimately reach the canopy to complete the regeneration process. Key words: Betula; coexistence; disturbance; germination; growth; Massachusetts; microsites; mortality; mound - pit complex; regeneration; seed dispersal; windthrow., INTRODUCTION Plant communities persist through the process of regeneration, a broad and rather imprecise term widely used in the ecological literature. Regeneration may refer to the recruitment of a particular [...]

New 40Ar/39Ar data from The Straits Schist and interlayered formations in the southernmost Connecticut Valley zone of the northern Appalachian orogen, together with published 40Ar/30Ar and U-Pb data, are used to account for relatively rapid Devonian (post-Acadian) cooling of gneisses and schists near the Waterbury dome and slower Devonian through Permian cooling in structurally higher schists south of the dome. Metamorphic hornblende 40Ar/39Ar cooling ages range from 374 Ma 10 km south of the Waterbury dome to 324 Ma 15 to 40 km south of the dome. Muscovite 40Ar/39Ar cooling ages also decrease to the south, from 318 to 254 Ma. The ages from the southernmost Connecticut Valley zone are as much as 50 and 100 m.y. younger than hornblende and muscovite, respectively, from the Waterbury dome. The difference in cooling histories between the Waterbury dome and southern Connecticut Valley zone is interpreted to be a result of relatively slower cooling in the southern Connecticut Valley zone following Acadian metamorphism and/or a static Pennsylvanian (Alleghanian) thermal event that reset the muscovite K/Ar system, promoted growth of fine-grained monazite, and resulted in partial melting of the crust beneath the southern Connecticut Valley zone. Such a thermal event would have been contemporaneous with Alleghanian orogenesis in Appalachian terranes in southeastern New England, but the mechanism for generating a Pennsylvanian thermal pulse is still unknown.

Changes in land use and habitat management have led to the drastic decline in the population of New England cottontails. The populations that remain are fragmented and need the intervention of conservation agencies if they are not to fall further. Computer simulations show that habitat loss and environmental correlation could influence the viability of remaining cottontail metapopulations. However, it is believed that habitat management can ameliorate these effects enough to sustain local cottontail populations.

We conducted presence-absence surveys for Bicknell's Thrush (Catharus bicknelli) in Marine, Massachusetts, New Hampshire, New York, and Vermont during the 1992-1995 breeding seasons. The species was found at 234 sites, of which 225 (96%) were dominated by varying mixtures of balsam fir (Abies balsamea) and red spruce (Picea rubens). Ninety-one percent of the occupied sites were ≥915 m (3000 ft) in elevation. Size of occupied habitat patches was generally small; 73% of occupied areas delimited by the 915 m elevation contour were less than 1000 ha in extent. A logistic regression model using independent variables describing vegetation, elevation, land area ≥915 m located within 1 km of a site, and latitude successfully predicted thrush presence. There was no conclusive evidence of widespread population declines of Bicknell's Thrush in the United States; we found the species at 63 of 73 sites (86%) known to have been occupied prior to 1992. However, the restricted breeding distribution and narrow habitat requirements of Bicknell's Thrush in the United States suggest that it is vulnerable to habitat loss and degradation, and that continued efforts to document the species' status and ecology are warranted., Bicknell's Thrush (Catharus bicknelli), until recently considered a sub-species of the Gray-cheeked Thrush (Catharus minimus) (Ouellet 1993, American Ornithologists' Union 1995), breeds from southern Quebec and the Maritime Provinces south [...]

Introduction Numerous computer models of ground-water flow in low-relief terrain have been developed (Toth, 1962, 1963; Freeze, 1969a, 1969b; Freeze and Witherspoon, 1966, 1967, 1968; Gillham and Farvolden, 1974; and [...]

The extent and direction of fluid flow during Barrovian-type regional metamorphism in east-central Vermont and during Buchan-type regional metamorphism in south-central Maine are determined from the modal, whole-rock and mineral chemical data of rocks collected from these two regions. The rocks consist of 266 samples of micaceous sandstone, micaceous limestone and pelitic schist. The data indicates that metamorphosis occurred in Vermont at a pressure of 7 to 8 kilobars and at 3.5 kilobars in Maine.

Methods to estimate and generate free-surface evaporation E(sub p) and potential evapotranspiration E(sub t) monthly time series are presented. Results are applied to the Quabbin and Wachusett water-supply reservoirs, which serve the Boston metropolitan area, and the Connecticut and Ware River basin watersheds, using historic (1950-80) climate data from several NOAA stations located in New England. The E(sub p) and E(sub t) time series are perturbed using climate-change scenarios of several general circulation models (GCMs) to investigate the sensitivity of both time series to doubled atmospheric CO2; E(sub p) and E(sub t) are also perturbed by +2 degrees C and +4 degrees C monthly temperature rises. The sensitivity of E(sub t) to a potential climate-change-induced vegetation-canopy resistance is also examined.

A shrubby, exotic honeysuckle, Lonicera tatarica L., has aggressively invaded woodlands throughout the northeastern United States. This paper explores its effects on herbaceous species and tree regeneration in three stands in southwestern Vermont and one in northwestern Massachusetts. In mesic stands with relatively rich soil, total herbaceous cover, herb species richness and density of tree seedlings were substantially depressed when L. tatarica cover exceeded ca. 30%, a relationship not observed at a dry poor site. Ordination indicates that evergreen herbaceous species and sprawling or vining understory species may be more tolerant of L. tatarica, suggesting that its effects on the community may be related to seasonal competition for light.

A study was conducted to analyze the development of the southern New England orogen. The structure forms part of the eastern margin of Gondwana. Fault-bounded, narrow, elongate, rapidly filled sedimentary basins provide basis that the orogen developed from a high-angle plate convergence zone in the Carboniferous period into either a transform or highly obique-convergent margin of the Early Permian period.

The orientation and spatial distribution of veins in the Lockport dolostone attest to a fluid circulation system active during the Acadian orogeny in western New York and southern Ontario. Outcrops east of the Clarendon-Linden fault zone are cut by a prominent eastnortheast systematic calcite-filled vein set, whereas these systematic veins are absent west of the fault zone, except in two quarries. Systematic veins display distinct characteristics: the mean vein orientation rotates clockwise from 067 [degrees] in the east to 086 [degrees] farther west, veins do not propagate into the basal Lockport Group, and calcite vein [[delta].sup.18] [O.sub.PDB] Values are significantly lighter to the east of the Clarendon-Linden fault zone. Maximum horizontal stress ([S.sub.H]) trend lines drawn parallel to the strike of the systematic veins are incompatible with [S.sub.H] inferred from Alleghanian plateau and other post-Paleozoic structures. However, because east-west [S.sub.H] trend lines are compatible with an Acadian tectonic event in western New England, our interpretation is that systematic veins in the Lockport Group are a cratonward signature of the Acadian orogeny., The development of the Appalachian orogen is punctuated by major pulses in tectonic activity, one of which involves the post-Silurian Acadian orogeny. The Lockport dolostone veins show evidence of an active fluid circulation system through their orientation and spatial distribution. Clockwise rotation has a mean orientation from east 067 degrees to west 086 degrees. The veins do not extend into the basal Lockport group while exhibiting lighter calcite vein delta(super)18-O(sub)PDB values east of the Clarendon-Linden fault. These systematic veins represent the Acadian orogeny's cratonward signature.

New U-Pb zircon ages of selected rocks from the Bronson Hill anticlinorium in southern New England are as follows: Microcline gneiss of the Dry Hill Gneiss in the Pelham dome, believed to be metamorphosed alkali rhyolite, is confirmed as Late Proterozoic, yielding an age of 613 [+ or -] 3 Ma. Another sample shows strong evidence of zircon inheritance with a minimum mean age of 1402 Ma. Plagioclase-rich gneisses with associated amphibolites (Swanzey, Pauchaug, Monson, and Fourmile gneisses), now believed to represent metamorphosed intrusive igneous rocks, yield ages from 454 to 442 +3/2-2 Ma, thus ranging from early Late through latest Ordovician, consistent with other absolute ages of the Oliverian plutonic series in the region. Quartz-phyric rhyolite from the upper member of the Ammonoosuc Volcanics and rhyolite tuff from the Partridge Formation are dated at 453 [+ or -] 2 Ma and 449 +3/-2 Ma, respectively, indicating that eruption of felsic lavas in the overlying volcanic section spanned an interval of approximately 4 m.y. Additional zircon ages are reported from a crosscutting but deformed tonalite dike in the Swanzey Gneiss (381 [+ or -] 3 Ma) and a coarse-grained gabbro from the Prescott Intrusive Complex (407 +3/-2 Ma) intrusive into the Partridge Formatin. Metamorphic overprinting of the region during both the Acadian and Alleghanian orogenies is indicated by U-Pb titanite ages of 357 [+ or -] 5 Ma and 292 [+ or -] 5 Ma from a tonalite gneiss on Prescott Peninsula and the Dry Hill Gneiss, respectively. The above ages and other zircon ages, as well as petrography and geochemistry, of the Fourmile, Monson, Swanzey, Pauchaug, and other plagiclase-rich gneisses of the Bronson Hill anticlinorium suggest that they represent the plutonic root of a calc-alkaline magmatic arc at least 250 km long that was produced partly or entirely on a continental margin in Late Ordovician time (ca. 454-442 Ma). The physically overlying cover sequence of chemically different tholeiitic arc-volcanic and sedimentary rocks of the Ammonoosuc Volcanics and Partridge Formation, previously thought to rest unconformably on the plagioclase-rich plutonic gneisses, is now shown to have had a magmatic history overlapping with them. The zircon ages in the plutonic gneisses and the cover sequence indicate that both are the same age or slightly younger than the Late Ordovician (Caradocian) emplacement of the Giddings Brook slice of the Taconian allochthons, and too young to have formed above an early and medial Ordovician subduction zone.