There is great ecological interest in carrying out a new inventory of southern Québec simuliids, including an exhaustive sampling in two lake outlet streams of the Mauricie region, because data from Québec were last reported only prior to 1980. Frequent sampling is needed to determine how species distributions change in response to climatic and environmental changes. Twenty-two of the 65 Québec species were collected in the present study. One new species for Québec was collected (Prosimulium magnum complex), and new distribution areas were found for some species. Exhaustive sampling clearly showed time- and space-related distribution variations of the univoltine and polyvoltine species. Seasonal appearance of species was synchronized at the two sites studied, but generation number was smaller at Lac du Barrage than at Lac Souris. The species-colonizing process seems to be environmentally determined stream-width and substrate-type influenced, as Simulium annulus, S. jenningsi. S. pictipes, and S. innoxium, were found in high-current-velocity falls. Artificial site colonization by S. aureum in a peri-urban environment had not been observed among simuliids prior to this study, in contrast to many mosquito species.

Invasion of New England lakes by exotic macrophytes can alter trophic interactions if the invaders host macroinvertebrate and epiphyte communities different from those of the native species they replace. Macroinvertebrate density and diversity appears to increase with macrophyte complexity and epiphytic algae colonization, which are also positively correlated. Because of this confounding effect, we investigated native and exotic macrophyte species of similar complexity in order to answer the question: Does the exotic macrophyte Myriophyllum spicatum have lower epiphyte density and richness that results in lower macroinvertebrate density and diversity than those found on a native species of similar complexity? Using independent-sample t-tests, we investigated this question in mixed macrophyte stands of three Vermont lakes. Holding complexity constant, macroinvertebrate density and diversity was positively related with epiphyte density and richness (r² = 0.17 and 0.13, respectively). Generally, M. spicatum only hosted greater macroinvertebrate densities than native macrophytes when it also hosted greater epiphyte densities, but there was never a sampling period in any of the 3 lakes when M. spicatum hosted greater macroinvertebrate diversity than the native species. Therefore, if M. spicatum replaces these native species in northeastern lakes, macroinvertebrate diversity may stay the same or decrease depending on which native species are present.

Merrymeeting Bay is a 4330-ha freshwater tidal ecosystem in mid-coast Maine that historically provided important stopover habitat for migrating waterfowl. To better understand a substantial decline in the number of ducks foraging in the ecosystem over the past fifty years, we reconstructed a history of environmental change using oral histories, aerial photography, and field experiments. Our studies revealed profound environmental change throughout the 20^th century that likely influenced the capacity of the ecosystem to support migrating waterfowl. Ironically, the unregulated discharge of industrial and municipal wastes and high rates of sedimentation associated with land use in the middle decades of the 20^th century probably enhanced the extent and productivity of intertidal, emergent plant communities including key forage plant species. However, over the past 30 years, primary wastewater treatment and regional reforestation have reduced the rates of nutrient loading and sedimentation, thereby diminishing the emergent vegetation. Reinforcing this decline in emergent vegetation, a precipitous decrease in submerged aquatic vegetation between 1956 and 1981 was likely related to extreme water turbidity. The collapse of subtidal aquatic vegetation would have reduced the variety and quantity of food items available to waterfowl. These local environmental changes coincided with regional declines in several duck species migrating along the Atlantic flyway. Therefore, both regional processes affecting the overall duck populations as well as local environmental change likely influenced the abundance of waterfowl using this site over the past 50 years.

Human activities have increased acid deposition throughout the Ohio River Valley due to the large number of coal-fired power-generating facilities. The long-term effects of chronic acid deposition can include a decrease in soil pH, loss of soil fertility, and a decrease in base saturation—all of which can reduce forest productivity. Dysart Woods, a remnant old-growth, mixed mesophytic forest in eastern Ohio, has experienced a decrease in soil pH from 5.0 in 1971 to 4.6 in 1997, which may be due to chronic acid deposition. The objective of this study was to utilize a long-term study to evaluate how soil quality has changed due to chronic acid deposition. To meet the study objectives, a variety of soil chemical properties (pH, base saturation, C, N, P, etc.) were measured from surface soil within two stands of opposing aspect at Dysart Woods within the unglaciated Allegheny Plateau. Because soil pH correlates strongly with other soil chemical properties, we used pH data from 1971 to estimate how soil quality has changed over time. Mean soil pH from the south-facing stand was 5.0 in 1971, 4.6 in 1997, and 4.3 in 2007. While soil pH was not measured in the north-facing stand in 1971, pH was 4.6 in 1997 and 4.7 in 2007. Using changes in pH to estimate past soil properties, our results suggest that available base cations in the south-facing stand have been reduced from ≈12 to 6 (cmol_c kg^-1), with a 50% reduction in base saturation since 1971. Considering that both stands receive the same amount of acid deposition due to their close proximity to each other, results raise an interesting question: Are unglaciated Allegheny Plateau south-facing soils more susceptible to the effects of acid deposition than north-facing soils?

Isotria medeoloides (Small Whorled Pogonia) is a globally rare woodland orchid. Observed population declines in this species may be related to decreased light availability resulting from forest maturation. In East Alton, NH, a population of Small Whorled Pogonia was partitioned into two groups, with one left as a control and the other subjected to canopy-reduction management. The removal of all shrubs and 25% of the tree basal area approximately doubled light transmission to the managed group. The number of stems and seed capsules significantly increased in this group relative to the control group. While this was not a replicated experiment, our observations suggest that canopy thinning may help promote the long-term conservation of this federally threatened species.

Establishment of many invasive species, including the Eurasian thistles Carduus nutans and C. acanthoides, is believed to be promoted by disturbance. Prior research suggests that emergence and early survival of these two weeds is far higher on bare ground than in areas with interspecific competition, but this relationship has not been well quantified. We studied the effects of microsite size and watering regime on the emergence and early survival of these invasive thistles. Microsite competition was found to significantly negatively affect successful emergence and first-month survivorship of both species, while additional water was not found to significantly increase seedling emergence. These findings suggest that adequate bare ground is an important predictor of successful thistle establishment, and thus that conservation practices aimed at reducing available microsites should help to limit the invasion of these two species.

Grasslands, and species dependent on them, have been declining throughout New England since large-scale farm abandonment began in the 19^th century. Several avian grassland obligates are now considered threatened within New England. During the summer of 2009, we inventoried breeding birds at the 10.5-ha National Guard training site in Strafford, NH using systematic surveys. Dolichonyx oryzivorus (Bobolinks), Sturnella magna (Eastern Meadowlarks), and Passerculus sandwichensis (Savannah Sparrows) were found breeding at the site. Bobolinks were the most abundant grassland obligate, and their nesting success on this site indicates that small grasslands may be just as useful in grassland bird conservation as larger habitat patches. Because large grasslands in New England are few and usually consist of hayfields and pasture, blueberry barrens, military and commercial airports, and landfills, focusing conservation efforts on smaller grasslands as well as large ones seems warranted.

Acadia National Park (ANP) is a non-continuous conglomerate of park lands interspersed with private lands, which is located mainly on Mount Desert Island, ME. Surveys of fishes in ANP have largely ignored or under-sampled most of the streams on the island. Reported here are the results of a 2009 survey that sampled freshwater fishes in 43 streams flowing through Park boundaries. Overall, 19 species were collected, and many were recorded from specific streams for the first time. Notemigonus crysoleucas (Golden Shiner) was the most widely distributed species (47% of surveyed streams), while Pimephales promelas (Fathead Minnow) was recorded from ANP for the first time as a recent bait-bucket introduction. This survey provides an updated baseline for ANP stream fishes and will be used to identify streams for restoration and measure the impacts of future environmental perturbations.

Recent establishment of invasive Alosa pseudoharengus (Alewife) in Lake Champlain and in the lake's watershed has been cause for concern. Based on three larval specimens newly discovered in the New York State Museum collections, we document Alewife in Lake Champlain in 1929. Therefore, there has been at least one early unsuccessful introduction of Alewife into Lake Champlain and there may have been others that escaped notice. Changing lake conditions may have allowed Alewife to recently become established.

We report the extirpation of Notropis bifrenatus (Bridle Shiner) from Maryland. This once widespread species has not been observed in this state since 1984 despite recent and extensive collection efforts in areas of historical occurrence. Based on these results, the status of the Bridle Shiner in Maryland was changed from endangered to endangered/extirpated in 2010.

After the complete destruction of a Sterna antillarum (Least Lern) nesting colony on Lovells Island in Boston Harbor in 2007, we set remote-sensing cameras over artificial tern nests in an effort to identify potential nest predators. In addition to Corvus brachyrhynchos (American Crows) and Rattus norvegicus (Brown Rats), Oryctolagus cuniculus (European Rabbits) were photographed burying eggs and destroying artificial nests. These observations indicate that introduced European Rabbits on islands may have a direct impact on nesting terns.

We describe a successful nest defense strategy of an adult Gavia immer (Common Loon) during an attempted predation event by a Nevison vison (American Mink) at Umbagog National Wildlife Refuge, NH. It is suspected that mink occasionally depredate loon nests, but defense strategies have not been described previously.