Central Nova Scotia Research Articles

Forestry Best Management Practices: Evaluation of Alternate Streamside Management Zones on Stream Water Quality in Pockwock Lake and Five Mile Lake Watersheds in Central Nova Scotia, Canada

The effects of timber harvesting on stream water quality and efficiency of alternate streamside management zones were evaluated in Pockwock Lake and Five Mile Lake watersheds in central Nova Scotia, Canada. The streamside management zone (SMZ) included a 20 m no cut, 20 m select cut and a 30 m select cut buffer strips along the stream. Water quality of eight streams, six in harvested and two in not-harvested watersheds were monitored for two years before and two years after the harvesting of timber. Nonparametric statistical tests on stream water quality showed that there was significant change in the concentration of potassium in six streams, manganese in five streams, zinc in two streams and total nitrogen in one stream after timber harvesting. There was no significant change in the quality of water in two streams used as control sites in the neighboring watersheds of similar size and hydrological characteristics. The results show that forest management practices were most favorable in streams maintained with 30 m select cut followed by 20 m no cut and 20 m select cut SMZ. The streamside zone width and treatment of select cut or no cut in the zone played an important role in filtering or retaining the minerals in surface water runoff. In buffer zones of similar width, the buffer zone with no cut or forested buffer was relatively more effective at protecting stream water quality than select cut SMZ. The vegetation in the zone may have decreased the flow velocity and increased residence time and thus increased filtration and retention of minerals in the riparian soil.

Provenance of Lower Cretaceous sandstones onshore and offshore Nova Scotia from electron microprobe geochronology and chemical variation of detrital monazite

Abstract Electron-microprobe geochronology on detrital monazite grains from fluvial sandstones of the Lower Cretaceous Chaswood Formation onshore Nova Scotia and New Brunswick and from fluvial and deltaic sandstones of the Missisauga and Logan Canyon formations of the offshore Scotian basin was determined to understand sediment dispersal patterns and paleogeography. After removing grains showing Th or U mobility and single analyses that were extreme outliers, ages from 393 analyses from 78 monazite grains were interpreted. In addition, monazites were classified into six types based on their rare-earth element abundance, determined by electron microprobe analysis, and six types of chemical zoning, interpreted from backscattered electron and wavelength dispersive spectrometer images. Detrital monazite grains from southern New Brunswick yielded Silurian ages exclusively, whereas in central Nova Scotia, Ordovician ages predominate, with a few grains of Cambrian or latest Neoproterozoic ages in eastern Nova Scotia. Monazite in the Scotian basin is predominantly of Ordovician age, with a significant number of Mesoproterozoic and Paleoproterozoic grains. Monazite grains with well-developed zoning from southern New Brunswick and eastern Nova Scotia have a high-grade metamorphic source; common grains with patchy, low contrast zoning have a source from low-to intermediate-grade metamorphic rocks; and unzoned monazite grains that predominate in central Nova Scotia, with Y-rich rims, may have a granite or migmatite source. Variations in detrital monazite age and composition suggest that several rivers transported sediment southwards from multiple bedrock sources. One supplied southern New Brunswick, one central Nova Scotia, at least one in eastern Nova Scotia, and one or more rivers draining western Newfoundland were the principal source of monazite to the main depocentre near Sable Island.

Gradual encroachment of a rocky shoreline by an invasive sea during the Mississippian at the southeastern margin of the Maritimes Basin, Nova Scotia, Canada

Onlap of a rocky shoreline by marine beds of the Mississippian Windsor Group occurred at the southeastern margin of the composite upper Paleozoic Maritimes Basin in central Nova Scotia. The sedimentology of thin basal rudaceous deposits suggests that, although the transgression was rapid, there were times of prolonged shoreline stability. Boulder beach deposits indicate a high-energy coastline and a large marine basin. Clastic delta deposits were proximal to thick biohermal banks in shallow areas near the southeast margin of the sea while sulphate deposition was occurring basinward. According to their contained biota and stratigraphic relationships, the marginal banks evolved in a less saline environment than banks forming away from river inputs, on paleotopographic highs located farther offshore. Because diversity of the biota decreases with an increase in both water depth and distance from the paleoshore and because bank development in shallow or marginal areas was apparently synchronous with evaporitic deposition in deeper or less marginal areas, we conclude that both a vertical and a lateral gradient of salinity existed due to the thrusting of fluvial fresh water above salt water and its infiltration along the paleoshoreline. As salinity increased with time, bank building eventually aborted and sulphate deposition gave way to salt deposition in the deepest parts of the basin. Lastly, the onlap of evaporites above marginal clastic deposits indicates that evaporite deposition occurred in a transgressive context, although a gradual thinning of the water column may have simultaneously occurred due to basin infilling.

Crustal structure of the central Nova Scotia margin off Eastern Canada

SUMMARY The central Nova Scotia margin off Eastern Canada is located at a transition from a volcanic margin in the south to a non-volcanic margin in the north. In order to study this transition, a wide-angle refraction seismic line with dense airgun shots was acquired across the central Nova Scotia margin. The 500-km-long transect is coincident with previous deep reflection profiles across the Lahave Platform and extending into the Sohm Abyssal Plain. A P-wave velocity model was developed from forward and inverse modelling of the wide-angle data from 21 ocean bottom seismometers and coincident normal-incidence reflection profiles. The velocity model shows that the continental crust is divided into three layers with velocities of 5.5‐6.9 km s −1 . The maximum thickness is 36 km. A minor amount (∼5 km) of thinning occurs beneath the outer shelf, while the major thinning to a thickness of 8 km occurs over the slope region. The seaward limit of the continental crust consists of 5-km-thick highly faulted basement. There is no evidence for magmatic underplating beneath the continental crust. On the contrary, a 4-km-thick layer of partially serpentinized mantle (7.6‐7.95 km s −1 ) begins beneath the highly faulted continental crust, and extends ∼200 km seawards, forming the lower part of the oceancontinent transition zone. The upper part of the transition zone consists of the highly faulted continental crust and 4- to 5-km-thick initial oceanic crust. The continent‐ocean boundary is moved ∼50 km farther seawards compared to an earlier interpretation based only on reflection seismic data. The oceanic crust in the transition zone consists of layer 2 and a high-velocity lower crustal layer. Layer 2 is 1‐3 km thick with velocities of 5.6‐6.0 km s −1 . The high-velocity lower crustal layer is 1‐2 km thick with velocities of 7.25‐7.4 km s −1 , suggesting a composite layer of serpentinized peridotite and gabbroic layer 3. Oceanic crust with normal thickness of 5‐7 km and more typical layer 3 with velocities of 6.95‐7.3 km s −1 is observed at the seaward end of the profile.

The West Indian Road pit, central Nova Scotia: key to the Early Cretaceous Chaswood Formation

The West Indian Road pit is the only large outcrop in Nova Scotia of the Chaswood Formation, the terrestrial equivalent of the offshore Missisauga and Logan Canyon formations. It provides outcrop information on sedimentology, gravel petrology, and structures for a formation that is otherwise known from a few small overgrown pits and from boreholes. The Chaswood Formation in the pit is > 60 m thick and consists principally of sorted sand and gravel with three thinner clay units. Successions of sedimentary structures indicate deposition from a coarse-bedload river flowing to the east-southeast. Gravel consists principally of vein quartz, quartz arenite, and subarkose, together with minor igneous lithologies that can be matched to sources in the Cobequid Highlands to the north. Quartz arenite and subarkose appear derived from Carboniferous Horton Group. Single-crystal 40Ar/39Ar dates of detrital muscovite are a little older than the muscovite ages for the South Mountain batholith, interpreted to mean that the muscovite is second cycle from the Horton Group, which records the earliest unroofing of the batholith. The Chaswood Formation accumulated during progressive tectonic deformation along NNE-trending strike-slip faults in basement rocks, resulting in syn-sedimentary faulting and local unconformities. Sedimentation kept pace with the creation of accommodation. Unrelated younger deformation folded the Chaswood Formation at the pit into an east–west-trending syncline. The Early Cretaceous paleogeography of the Maritime Provinces is interpreted to have consisted of fault-bound horsts shedding coarse detritus surrounded by an interconnected series of basins that accumulated fluvial sands and gravels and overbank muds with well-developed paleosols.

The use of an indirect Ostertagia ostertagi ELISA to predict milk production response after anthelmintic treatment in confined and semi-confined dairy herds

An indirect Ostertagia ostertagi ELISA was used in late lactation milk samples from cows in confined and semi-confined dairy herds to determine if it could predict milk production response after endectocide treatment at calving. Holstein cows from 9 dairy farms from Prince Edward Island (PEI), 5 from central Nova Scotia and 16 from southern Ontario that were participating in a clinical trial of endectocide treatment around calving were used in this study. The cows were randomly treated with either eprinomectin pour-on endectocide or a placebo solution. Milk samples were obtained from cows late in the lactation before treatment was applied. These samples were tested for antibodies to gastrointestinal nematodes (GIN) using the indirect ELISA with the results expressed as optical density ratios (ODR). Production records were obtained from a computerized database of dairy herd improvement data. Pre-calving ODR showed a seasonal pattern. They were higher in the summer and fall and lower during the winter months. Older animals had higher pre-calving ODR values compared with younger cows. Similarly, cows from semi-confined herds had higher parasite antibody levels compared with cows from confined herds. The endectocide treatment did not affect the milk production response in the overall study population. However, the interaction effect between treatment and pre-calving ODR on milk production response after endectocide treatment was significant ( P = 0.02), with some evidence of positive treatment response in cows with an ODR > 0.4. The relationship between pre-calving ODR and production response appeared to be quadratic rather than linear.

Early Carboniferous deformation and mineralization in the Cobequid shear zone, Nova Scotia: an 40Ar/39Ar geochronology study

Latest Devonian to Early Carboniferous igneous rocks along the Cobequid shear zone of central Nova Scotia record a complex history of intrusion, volcanism, deformation, and hydrothermal alteration. Twenty new 40Ar/39Ar age determinations have been made on biotite and hornblende separates from rocks that constrain these events. The mafic plutons of the Cobequid shear zone are synchronous with the previously dated granitoid plutons (363–355 ± 4 Ma), with the exception of the younger Folly Lake gabbro (355–350 ± 4 Ma). High temperature shear deformation continued along the Cobequid shear zone during this entire period of pluton emplacement. Several samples from mylonitic and hydrothermally altered rocks with dates ca. 340 Ma indicate renewed movement along the Cobequid shear zone at this time, accompanied by minor magmatism. Younger ∼330–320 Ma ages reflect final movement along the Rockland Brook fault resulting in mid-Namurian uplift of the Cobequid Highlands. Following this regional Alleghenian event, there was no significant motion on the northern faults of the Cobequid shear zone and deformation moved southward to the Cobequid fault and its continuation in the Hollow and Chedabucto fault zones. Hydrothermal alteration, probably driven by a mid-crustal gabbro heat source, was widespread along the Cobequid and Rockland Brook faults in the early Carboniferous, resulting in albitization, potassic alteration, and iron mineralization.

Deglaciation of Nova Scotia: Stratigraphy and chronology of lake sediment cores and buried organic sections

The deglaciation of Nova Scotia is reconstructed using the AMS-dated chronology of lake sediments and buried organic sections exposed in the basins of former glacial lakes. Ice cleared out of the Bay of Fundy around 13.5 ka, punctuated by a brief read- vance ca. 13-12.5 ka (Ice Flow Phase 4). Glacial Lake Shubenacadie (1) formed in central Nova Scotia, impounded by a lobe of ice covering the northern Bay of Fundy outlet. Drainage was re-routed to the Atlantic Ocean until the Fundy outlet became ice free after 12 ka. When this lake drained, bogs and fens formed on the lake plain during climatic warming. Organic sediment (gyttja) began to accumulate in lake basins throughout Nova Scotia. Glacierization during the Younger Dryas period (ca. 10.8 ka) resulted in the inundation of lakes and lake plains with mineral sediment. The nature and intensity of this mineral sediment flux or "oscillation" varies from south to northern regions. Southern lakes simply record changes in total organic content whereas northern lakes, where most buried peat sections are found, feature a thick inorganic sediment layer. Glacial ice or permanent snow cover and seasonal melting are essential in the formation of this mineral sediment layer; both to provide the water source for erosion, and to prevent plant re- colonization and landscape stabilization. Some northern lakes do not appear to record the Younger Dryas event, with organic accumulation starting around 10 ka. During the Younger Dryas, fine and coarse-grained deposits were deposited in Glacial Lake Shubenacadie (2) and other lowland areas at elevations similar to former (12 ka) lake levels, impounded by re-invigorated residual ice caps and permanent snow/aufeis.

Multiproxy evidence of an early Holocene (8.2 kyr) climate oscillation in central Nova Scotia, Canada

AbstractAn early Holocene lake sediment record from central Nova Scotia contains a minerogenic oscillation that is closely correlative with the 8.2 kyr event (ca. 8200 cal. yr BP), an event that has not been reported elsewhere in Atlantic Canada. A variety of biological and sedimentological indicators have been examined to characterise autochthonous and allochthonous changes that occurred during this time. The minerogenic upper oscillation (UO, ca. 8400 cal. yr BP) is marked by an increase in the chrysophyte:diatom ratio. Following the oscillation, the diatom community reflects a shift to more productive, less acidic conditions. The pollen record shows no major response to this short‐lived event. Lithostratigraphic analyses indicates that the UO is characterised by an increase in clastic content, magnetic susceptibility and mean sediment grain size, all indicators of changing environmental conditions, most likely the result of regional cooling. The Taylor Lake record adds to a growing body of evidence for a widespread, hemispheric climate oscillation at 8.2 kyr. Copyright © 2002 John Wiley & Sons, Ltd.

RADARSAT‐1 Imagery and GIS Modeling for Mineral Exploration in Nova Scotia, Canada

Radarsat's Application Development and Research Opportunity (ADRO) Project 656, with the Canadian Space Agency, has provided a wealth of Radarsat imagery for the Centre of Geographic Sciences. The focus has been on the validation of Radarsat data pertaining to geological investigations and base metal minerals exploration modeling. Two adjacent, descending Radarsat orbital tracks, comprising four Standard Beam Mode (S2) scenes, were ortho‐rectified, histogram matched, filtered and mosaicked. The imagery encompasses a substantial portion of central Nova Scotia, Canada. The S2 mode Radarsat imagery has been integrated with digital geological, geophysical and stream sediment mineral data layers utilising GIS and image analysis software packages. Within the broader framework of ADRO Project 656, mineral potential models have been constructed for a selected sub‐area in north‐central Nova Scotia. These models, which consist of value‐added Radarsat S2, geological, geophysical and stream sediment mineral concentration data layers, have contributed to a better understanding of the geological nature of central Nova Scotia and facilitated potential identification of mineral emplacement targets.

Spatial and temporal trends in soil properties at a soil quality benchmark site in central Nova Scotia

In response to concerns over the widespread soil degradation occurring on Canada's agricultural lands, Agriculture and Agri-Food Canada established a network of benchmark sites to assess soil quality change by monitoring agronomically important soil properties. The Nova Scotia site was established in 1989 on Queens (Gleyed Brunisolic Gray Luvisols) and Debert (Gleyed Dystric Brunisols) soil series under a corn–forage rotation within the Annapolis–Minas Lowlands ecoregion. The objectives of the project were to quantify temporal changes in agronomically important soil properties and determine how the property values vary with the landscape and components of the soil map unit. A 20 × 25 m grid was used in 1990 and again in 1995 to sample soil from the Ap horizon and to locate saturated hydraulic conductivity and penetration resistance measurements. The samples were analyzed for pH, organic C, total N, and available P and K. The results indicate that over 5 yr, organic C, C:N ratio, available P, and saturated hydraulic conductivity declined by 7.9, 4.7, 12.5, and 53%, respectively. Significant differences in pH, organic C, total N, available K, penetration resistance and saturated hydraulic conductivity were associated with selected components of the soil map unit. Slope position had a minimal effect on soil properties except for available K where the highest levels were located on middle slope positions. Interactions between particle size and slope position were found, with soils with coarse-loamy sola on upper slope positions having the lowest pH. The results of this study also demonstrated the utility of the method for monitoring soil quality change and the importance of the soil map unit in interpreting the spatial and temporal differences in soil properties. Key words: Soil variability, soil monitoring, soil properties, soil map unit, spatial correlation

The chemistry of streams in southwestern and central Nova Scotia, with particular reference to catchment vegetation and the influence of dissolved organic carbon primarily from wetlands

The percentage of wetlands in a catchment accounted for about half of the variance in transformed data for concentrations of dissolved organic carbon (DOC) in 42 Nova Scotian streams draining catchments with 11 different kinds of vegetation. Color increased with DOC, as did total dissolved nitrogen (TDN). Thecolor/DOC andDOC/TDN quotients also rose with increasing DOC, indicating a change in the quality of dissolved organic matter with increasing wetland influence. Dissolved Fe, and to a much lesser extent dissolved Al, showed a strong positive correlation with DOC. Stream pH showed a strong negative correlation with DOC, largely from wetlands, and a strong positive correlation with non- marine Ca2+ weathered from mineral soils. Non-marine SO4 2− from acid deposition had no apparent influence on stream pH and decreased with increasing streamwater DOC in summer, presumably owing to reduction processes in wetlands that mitigated the effects of acid deposition. Apparently, these reduction processes also produced small amounts of dissolved, non-ionic organic sulfur. Non-marine Ca2+ was related strongly to the percentage of upland hardwood forests in the catchments. Wetlands exert a profound influence on the chemistry of streams, principally through their export of DOC but also because of reduction reactions in their anerobic peats.

“There’s No Penalty When You Hit the Fence&”: Sporting Activities in Central and Eastern Nova Scotia, 1880s to 1920s

“There’s No Penalty When You Hit the Fence&”: Sporting Activities in Central and Eastern Nova Scotia, 1880s to 1920s

The Ainslie Detachment: a regional flat-lying extensional fault in the Carboniferous evaporitic Maritimes Basin of Nova Scotia, Canada

The Ainslie Detachment occurs near the base of the Carboniferous Windsor Group, forming a regional flat-lying extensional fault distributed across 10 000 km2. New mapping has delineated the structure through southwestern Cape Breton Island and into central Nova Scotia. Shearing is concentrated at the top of the basal Macumber limestone along its contact with overlying evaporites and younger allochthonous units. The highly contrasting rheologies of the formations created an anisotropic zone of weakness which acted as an upper crustal stress guide, stratigraphically controlling the trajectory of the detachment through the basin. The detachment is characterized by an approximately 3–10 m thick calc-mylonite zone, with an intense planar fabric featuring alternating very fine grained shear planes and coarser annealed layers. Coarser layers are boudinaged into pinch and swell structures, locally producing segmented augen. Highly strained intraclasts, ooids, and peloids, recrystallized carbonate boudins, and carbonate vein segments are included in the calc-mylonite as semirigid inclusions and rotated porphyroclasts. Thick zones of fault breccia straddle portions of the detachment and overprint the mylonite, demonstrating an evolution to brittle conditions during progressive shear. Listric faults in the hanging wall of the detachment feature a ramp and flat geometry, with an upper detachment occurring along the upper contact of the Windsor Group with the overlying Namurian Mabou Group. Locally up to 2 km of the stratigraphic succession has been removed, with faults cutting downsection in a westerly direction producing rollover in the hanging wall.

Genetic parameters and age–age correlations in a clonally replicated test of black spruce after 10 years

Height growth at 10 years from striking was assessed for clonally replicated full-sib black spruce (Piceamariana (Mill.) B.S.P) families tested at three locations in central Nova Scotia. Variance components were interpreted according to an additive–dominance–epistasis genetic model and used to derive comparative estimates of gain from various selection and deployment strategies. Field performance at 5 and 10 years was compared with that of the original ortets and families growing in a 25-week greenhouse study, by means of phenotypic and genetic correlation, and rank-change analyses. Between age 5 and 10, the additive portion of the total genetic variance for height decreased from 66 to 38%, while the dominance portion increased from less than 3 to 13%, and the epistatic portion from 31 to almost 49%. As a consequence, narrow-sense heritability estimates were lower at age 10 and gain estimates also decreased, particularly for those strategies that capture gain primarily from additive effects. Although correlations between field performance and early growth measurements were generally poor, the strongest were found at the half-sib level; full-sib correlations were somewhat weaker and those between clone means and early ortet performance were small and not statistically significant. The strongest age–age correlations were those that involved family mean seedling weight in the greenhouse. Family rankings based on early oven-dry biomass production also showed the most consistent agreement with ranking after 5 and 10 years of field testing, although the analyses suggest that effective early selection is probably limited to culling the worst 25% of the families based on biomass. Genotype–environment interactions were statistically significant, although these were limited to only 2% of the phenotypic variance in height growth; furthermore, strong genetic correlations between environments suggested that these interactions have little impact on selection efficiency.

Formation of Carboniferous Pb-Zn and barite mineralization from basin-derived fluids, Nova Scotia, Canada

Lead-zinc and barite deposits in central Nova Scotia generally occur at the Tournaisian-Visean (Mississippian) clastic carbonate-evaporite disconformity overlying Cambrian to Devonian metasedimentary and granitic rocks. The deposits are located at the southern margin of the > 10-km-deep Carboniferous Maritimes (Fundy-Magdalen) basin.Fluid inclusion homogenization temperatures of ore-stage to postore minerals range from 230 degrees to 130 degrees C and fluid salinity is > or = 24 equiv wt percent NaCl. A mineralization age of ca. 300 to 330 Ma is suggested by: (1) fission-track dates on zircon from clastic host rock at Gays River, (2) K-Ar dates on clays from altered clastic rock in close proximity to mineralization, and (3) Rb-Sr data on illite from samples collected over a 10-m section of Tournaisian sandstone (far away from mineralization). Lead and strontium isotope data indicate that Tournaisian rock of the Horton Group could have been a source (at ca. 300 Ma) of lead and radiogenic strontium in the ore-stage minerals at the larger deposits. Visean carbonate carbon and sulfate were the dominant sources of carbon and sulfur, respectively. Hydrogen and oxygen isotope data suggest that the mineralizing fluids were basinal brines. Nonbiogenic sulfate reduction at the deposits is the likely sulfide precipitation mechanism.The ore-forming fluids may have originated at a >5-km depth under Visean evaporites in the Magdalen basin and migrated rapidly through Tournaisian clastic rocks and the immediately overlying Pembroke breccia to the basin margins. A pulse of regional tectonism may have set off at least one massive, hydrofracturing, compaction-driven, fluid expulsion event by about 300 Ma.

Variation in drumlin orientation, form and stratigraphy relating to successive ice flows in southern and central Nova Scotia

A strong correspondence exists between striation and drumlin long-axes trends in Nova Scotia. The variation in striation trends is largely due to successive ice flow events which inscribed many outcrops with sets of superimposed striations that can be correlated over broad areas of Nova Scotia. A type of drumlin in the Nova Scotia fields is the “lobate” or “reoriented” drumlin which is a form with two principal axes parallel to ice movements established by striations and dispersal of distinctive erratics. The internal structure of Nova Scotia drumlins is generally a layer cake of till sheets. The most common situation is a grey “core” till formed by a southeastward ice flow across grey metasedimentary bedrock and a distinctly red “mantle” till formed by phases of southward to southwestward ice flow. Drumlins in the Yarmouth field of southern Nova Scotia exhibit the greatest number of stacked units capped by a coarse-textured till that represents deposition by a late stage ice mass centered inland. Nova Scotia drumlins appear to have a multi-phase origin. The first and major drumlin-forming ice flow phase was southeastward. Nucleating agents for initiation of these drumlins may have been preexisting tills or waterlain deposits. Individual and lobate drumlin axes imply a late, southward drumlin-forming ice flow phase parallel to the inferred ice flow trend for the mantle till units based on clast provenance. Some of these drumlins nucleated from preexisting southeast-trending forms.

DISTRIBUTION OF CHRYSOLINA SPP. (COLEOPTERA: CHRYSOMELIDAE) IN EASTERN ONTARIO, 18 YEARS AFTER THEIR INITIAL RELEASE

Hypericum perforatum L., St. John's - wort (Hypericaceae), is a cosmopolitan weed that, when eaten by livestock, causes photodermatitis, reduced weight gain, and, in extreme cases, death (Giese 1980). Chrysolina hyperici (Forester) and Chrysolina quadrigemina (Suffr.) (Coleoptera: Chrysomelidae) dramatically reduced populations of H. perforatum when introduced into Australia (Clark 1953) and the United States (Holloway and Huffaker 1951; Holloway 1957). These species also have served as effective biocontrol agents when introduced into central British Columbia (Smith 1958), Ontario, and Nova Scotia (Harris and Maw 1984). This paper surveys the distribution of Chrysolina spp. in eastern Ontario, 18 years after initial release of both species.

THE EUROPEAN YELLOW UNDERWING, NOCTUA PRONUBA L. (LEPIDOPTERA: NOCTUIDAE), IN THE ATLANTIC PROVINCES (CANADA) AND THE STATE OF MAINE (USA)

AbstractNoctua pronuba L. is now abundant in central Nova Scotia and has become established throughout the province, on Sable Island, Prince Edward Island, and in Newfoundland. Sporadic records indicate that this species has become established in New Brunswick and is spreading into Maine. Light-trap records illustrate the rapid population increase in Nova Scotia and the spread throughout the Atlantic Provinces.

Ambient bulk deposition, throughfall, and stemflow in a variety of forest stands in Nova Scotia

Averaged over one growing season for four conifer and four hardwood stands in central Nova Scotia, incident bulk deposition (IP) was partitioned into 28% canopy interception, 70% throughfall (TF), and 2% stemflow (SF). Hydrogen ion, ammonium, and nitrate fluxes in TF + SF were less than IP; these were presumably consumed by ion-uptake reactions in the canopy or on bark surfaces. All other measured constituents had positive net fluxes, which presumably resulted from some combination of leachage, ion exchange, or washoff of dry-deposited material. The average flux of constituent in TF + SF, expressed as a percent enhancement over IP, was as follows: K, 930; Mg, 274; PO4, 190; Ca, 170; Cl, 116; SO4, 50; Na, 50; H+, −54; NH4, −59; NO3, −69. Tree species differed greatly in concentration and flux of water and nutrient in stemflow. Conifer species generally had lower SF water fluxes, probably because of their greater leaf biomass, which resulted in relatively high rates of canopy interception of IP. Concentrations of K, PO4, and NH4 did not differ between SF of hardwoods and conifers, while NO3 concentration was higher in hardwood SF and concentrations of H+, Ca, Mg, Na, Cl, and SO4 were higher in softwood SF.