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Current understanding of how streamflow in terminal basins is driven by climatic and hydrogeomorphic characteristics is limited, despite the fact that these closed systems show an increased sensiti...

Land-use practices in Mongolia can lead to environmental degradation and consequently affect the structure and function of biological communities. The main aim of this study was to determine land-use effects on freshwater macroinvertebrate communities based on their response to grazing and mining, using a trait-based approach (TBA). The functional structure of macroinvertebrate communities was examined using 86 categories of 16 traits. A total of 13 physical and chemical variables were significantly different among the levels of land-use intensity. Significant declines in functional diversity were observed with increased land-use intensity. The community weighted mean of 19 trait categories for 11 traits varied significantly among different levels of land-use intensity. Traits were significantly explained by environmental variables across a land-use intensity gradient. Water temperature, gravel, nitrate, silt, and cobble were the main predictor variables and explained 28% of the total variance of the trait variation. The functional structure of the macroinvertebrate community was strongly related to environmental conditions. The TBA is an important method in assessing disturbance responses in freshwater communities of steppe and taiga regions, such as in Mongolia and other countries in Central Asia and will be useful in finding best management practices for conserving aquatic ecosystems.

Overgrazing is one of the major land-use impacts in Mongolia leading to habitat degradation and subsequent impairment of biological diversity. This study examined macroinvertebrate diversity among sites with different grazing intensities in Hövsgöl, Mongolia, to test whether the taxonomic and functional structure of the macroinvertebrate community differs among streams with different grazing intensity. The 14 551 total identified specimens comprised 78 genera in 27 macroinvertebrate families from the 6 study streams. Exponential Shannon index and weighted functional diversity were significantly higher in low grazing sites than in moderate and high grazing sites; no significant difference was found between moderate to high grazing intensity. Macroinvertebrate community composition was not significantly different between low and moderate or low and high grazing intensity sites. SIMPER analysis revealed the taxon with the highest contribution to dissimilarity among the levels of grazing. Thirteen trait categories from 8 traits differed significantly between sites with varying grazing pressure. The community-weighted means for 4 of these traits were filtered by high grazing intensity: dissemination, resistant form, current velocity, and saprobity. Although the other 4 traits differed significantly, they did not respond directly to grazing intensity. Further knowledge of traits, especially regarding physiological capabilities, is needed to better understand macroinvertebrate/environment relationships, but overall, these findings suggest that macroinvertebrate diversity components were affected by grazing.

We analyze here the nature of research in freshwater macrosystem biology (especially lotic studies) from both conceptual and current research perspectives. The boundaries of permanent and transitional lotic macrosystems from the smallest to largest spatial extents are described. We contrast ecosystem vs. macrosystem research and macroecology vs. macrosystems ecology and provide some examples of representative aquatic macrosystems ecology projects in the USA. We recommend approaches for incorporating certain large‐scale lotic concepts developed over the last 40 yr as the bases for lotic macrosystem studies. Of these, the three most appropriate in chronological order are the River Continuum Concept, the Riverine Ecosystem Synthesis, and the Stream Biome Gradient Concept. Four other concepts would be suitable for testing macrosystem hypotheses after incorporating small to large conceptual or geographic expansions of the models. We suggest future research directions in lotic macrosystem research in areas of climate change and teleconnections among distant organisms and systems and include general recommendations for conducting macrosystem‐level research.

The importance of education in science, technology, engineering, and mathematics (STEM) disciplines is again a topic of discussion among policy makers and scientists, particularly given perceived declines in STEM performance by students in the U.S. Service-learning has been used in innovative and creative ways to enhance learning in a variety of STEM-related courses. Improving STEM literacy is also a focal point of STEM education and has been explicitly linked to servicelearning projects. Herein the authors review literature linking service-learning to academic achievement in STEM-related courses. They then examine whether service-learning enhances STEM literacy in a STEM-centered communications course at an aeronautics engineering university and in two biology courses at a small rural college. Despite early calls by researchers for improved rigor in the field of service-learning research, the literature review indicates that few studies over the past 15 years employed rigorous research techniques when examining whether service-learning affects academic achievement in STEM courses. Results of mixed-methods analyses showed that service-learning enhanced science literacy in the three STEM-related courses. First, students scored significantly higher on a post-service survey of skills and content relative to the pre-survey survey at the aeronautics engineering university. Second, students earned significantly higher grades in a written report of their service-learning project relative to a non-service-oriented project in the small rural college. Third, students indicated through comments on evaluations and reflections that the service-learning projects enhanced the STEM content in the courses.

Rapidly declining diversity of freshwater species necessitates surveys to document and describe patterns in biodiversity. To this end, a survey of Chironomidae (Insecta: Diptera) was conducted in a remote watershed of western Alaska. Larval chironomids were collected from 16 stream sites in the Kuskokwim River watershed in 2009 and 2010. Twenty-seven chironomid taxa were identified. Orthocladiinae was the most diverse subfamily and was numerically dominant at all sites except a glacial runoff stream where Diamesinae was numerically dominant. Two rare chironomids were collected in the study: an undescribed species of Stilocladius and a species of Orthocladius (Mesorthocladius). The latter genus has only 2 described species in North America, one in Ohio and one in Minnesota. Results of a nonmetric multidimensional scaling analysis indicated that sites varied based on changes in elevation, conductivity, pH, and percent Diamesinae. Two high-elevation sites, one at the outflow of a lake and the other...

Native species in lakes commonly are affected by cultural eutrophication and introductions of nonnative species. The effects of these disturbances on benthic communities in large lakes have been understudied, despite the integral role that benthos play in maintaining habitat complexity and ecosystem processes. Lake Tahoe has experienced progressive eutrophication and introductions of nonnative species over the past several decades, but how its unique benthic communities have been affected is unclear. The density of Lake Tahoe’s benthic fauna was compared between 1960s surveys and our recent (2008–2009) survey, and the association of zoobenthos with macrophytes was examined for contemporary and historical samples. The density of benthic invertebrates and the occurrence of macrophytes in benthic samples have declined dramatically since collections made in the 1960s. Lakewide densities of benthic invertebrate taxa endemic to Lake Tahoe have declined by 80 to 100%, and the community structure of benth...

Lake Hovsgol is a large, ancient, asymmetrical grabenlake located in north central Mongolia. The lake is longalong its north/south axis and the west shore of the lake islined by steep mountains with little human activity; where-as the east shore of the lake is lined by shallow hills char-acterized by pastoral land use. Lake Hovsgol is a pristinelake with high concentrations of dissolved oxygen, lowconcentrations of nutrients, and deep blue color(Kozhova

The purpose of this study was to document gamma diversity of Chironomidae in Outer Mongolia by documenting alpha and beta diversity of chironomids from streams sites within Gorkhi Terelj National Park and in the surrounding area. Pupal exuviae of Chironomidae were collected from streams using standardized, semi-quantitative sampling methods so that patterns in community structure could be compared to patterns in the study sites. Gamma diversity for the twelve sites in this study was 98 species, including 26 new records for Mongolia; alpha diversity of Chironomidae ranged from 3 to 37 species. Beta diversity ranged from 0–0.44 and mean beta diversity was 0.17. Species diversity did not correlate to distance between sites. The Chao 1 species estimator estimated 126 species of Chironomidae from the streams in Gorkhi Terelj National Park. Ad hoc analysis comparing chironomid communities from Gorkhi Terelj National Park and Lake Hovsgol area stream and lake sites increased the estimated number of spe...

Paraboreochlus minutissimus (Strobl 1894) and Trichotanypus posticalis (Lund- beck 1898) have been collected from Gorkhi Terelj, Outer Mongolia resulting in the first record for these species and for the subfamily Podonominae (Diptera: Chironomidae) in this country. Both species were collected in habitats similar to their described habitats from Europe and North America. A review of their biogeography indicates that Trichotanypus are restricted to the more northern part of the Holarctic region and will likely be restricted to northern Mongolia; whereas Paraboroechlus has a more southern Holarctic distribution and future surveys may result in finding it in southern Mongolia, just north of the Gobi Desert.

Relative to their scarcity, large, deep lakes support a large proportion of the world's freshwater species. This biodiversity is threatened by human development and is in need of conservation. Direct comparison of biodiversity is the basis of biological monitoring for conservation but is difficult to conduct between large, insular ecosystems. The objective of our study was to conduct such a comparison of benthic biodiversity between three of the world's largest lakes: Lake Tahoe, USA; Lake Hovsgol, Mongolia; and Crater Lake, USA. We examined biodiversity of common benthic organism, the non-biting midges (Chironomidae) and determined lake trophic status using chironomid-based lake typology, tested whether community structure was similar between the three lakes despite geographic distance; and tested whether chironomid diversity would show significant variation within and between lakes. Typology analysis indicated that Lake Hovsgol was ultra-oligotrophic, Crater Lake was oligotrophic, and Lake Tahoe was borderline oligotrophic/mesotrophic. These results were similar to traditional pelagic measures of lake trophic status for Lake Hovsgol and Crater Lake but differed for Lake Tahoe, which has been designated as ultra-oligotrophic by traditional pelagic measures such as transparency found in the literature. Analysis of similarity showed that Lake Tahoe and Lake Hovsgol chironomid communities were more similar to each other than either was to Crater Lake communities. Diversity varied between the three lakes and spatially within each lake. This research shows that chironomid communities from these large lakes were sensitive to trophic conditions. Chironomid communities were similar between the deep environments of Lake Hovsgol and Lake Tahoe, indicating that chironomid communities from these lakes may be useful in comparing trophic state changes in large lakes. Spatial variation in Lake Tahoe's diversity is indicative of differential response of chironomid communities to nutrient enrichment which may be an indication of changes in trophic state within and across habitats.

Seven bays and four streams were sampled for surface floating pupal exuviae of Chironomidae (Insecta: Diptera) from the Lake Hovsgol watershed, Mongolia in July of 1997. A total of 52 taxa were identified with 12 species being new records for Mongolia and 1 species being a new record for the Lake Hovsgol Region. Communities of emerging chironomidae were compared between lake bay and lake affluent stream environments to determine whether affluent stream chironomids were recruited in the ultra-oligotrophic lake bays. Hierarchical cluster analyses were used to classify sites for this comparison. Bays and streams were classified together based on physical and habitat data, but formed distinctly different classes based on the chironomid community data. These two classification schemes were incongruent at a correlation of -.01. Stream sites and bay sites were comprised of either rheophilic or limnophilic chironomid communities, respectively, resulting in their separate classifications. One bay site loc...

Fourteen species of Chironomidae (Diptera) are recorded for the first time from the Hovsgol Nuur region, Mongolia, increasing the total number of chironomid species from this country to 166 (Table 1). Two major studies have contributed the most data on distribution of Chironomidae in Mongolia. The first study, summarized by Kozhova et al. (1994) and Erbaeva and Safronov (in press), was based on 20 years of research on Hovsgol Nuur, an ancient lake in Northern Mongolia. The second study, by Sasa and Suzuki (1997), described many new species and listed many species of Chironomidae from Central and Southwestern Mongolia. In addition, Reiss (1971) described and listed species of Chironomidae collected from sites throughout the country and Hayford and Ferrington (in press) studied the distribution of chironomids in Hovsgol Nuur. The current valid name-author-date and biogeographic region distribution for Mongolian Chironomidae were obtained from Ashe and Cranston (1990) and are listed with the Mongolian distribution for each species in Table 1. Of the 118 species of Chironomidae listed from the Hovsgol Nuur Region, fourteen are new records for Mongolia (Table 1). Collections were made during June and July of 1995-1997 as part of a joint United States, Mongolian, and Russian expedition to the Hovsgol Nuur Region. Adults were collected using malaise traps and sweep nets and pupal exuviae were collected using methods modified from Ferrington (1987). Eight of the fourteen newly recorded species, Ablabesmyia nr. cinctipes (Johannsen), Cricotopus (Cricotopus) cylindraceus (Kieffer), Heterotrissocla dius subpilosus (Kieffer), Parakiefferiella nr. smolandica (Brundin), Psectrocladius (Psectrocladius) schlienzi Wiilker, Psectrocladius (Psectrocladius) sordidellus (Zetterstedt), Dicrotendipes lobiger (Kieffer), and Dicrotendipes septimacullipennis (Goetghebuer) were collected from the shore of Modon Hui, an island in Hovsgol Nuur. Six species, Krenosmittia camptophleps (Edwards), Parametriocnemus boreoalpinus Gouin, Rheosmittia spinicornis (Brundin), Saetheria reissi Jackson, Cladotanytarsus vanderwalei (Edwards), and Corynocera ambigua (Zetterstedt) were collected from sandy bottom streams flowing into Hovsgol Nuur. Most of the Chironomidae in Mongolia have a cosmopolitan distribution (Table 1). Forty-seven species have a Holarctic distribution, with some additionally found in the Oriental and Neotropical regions. Seventy-nine species have a Palaearctic distribution, with some of these additionally found in the Oriental, Afrotropical and Australasian regions. Species with a Palaearctic distribution tended to have a West Palaearctic distribution, with very few species having an East Palaearctic distribution. This distribution is similar to that of caddisflies reported by Morse et al. (in press), with the exception that most caddisflies were also found in the nearby East Palaearctic region. Nearly 20% of the species of Chironomidae found in Mongolia are endemic, with most described by Sasa and Suzuki (1997). However, note that specific type localities are not clear. Thus, it is uncertain where some species were originally collected. Distribution records for species within Mongolia come primarily from the Hovsgol Nuur region or from sites close to Ulaanbaatar. Currently, two studies are underway to collect Chironomidae in central (Selenge River basin) and western (saline lake district) Mongolia, which should vastly increase the known species of Chironomidae from this country.

Surveys for symbiotic fungi in the guts of aquatic insect larvae (Trichomycetes: Harpellales) in Tasmania, Australia, resulted in the discovery of four new species: two in Gripopterygidae (Plecoptera) nymphs, Plecopteromyces leptoperlarum and P. trinoto- perlarum, and two associated with Diptera larvae, Smittium magnosporum in Thaumaleidae and Stachy- lina dolichospora in Chironomidae. Previously de- scribed species of Harpellales from other localities are reported and new host records summarized. A key to all Tasmanian species of Harpellales is provid- ed.

The two genera of Harpellales (Tricho- mycetes) found most frequently in Chironomidae (midge) larvae, namely Smittium in the hindgut and Stachylina in the midgut, are easily distinguished in most instances. However, cases are reported in which Smittium trichospores extrude prematurely as they pass through the midgut, with the sporangiospore at- taching to the peritrophic membrane and thereby leading to very limited thallic growth that resembles an immature Stachylina thallus. This development ap- pears to be common in Smittium longisporum and Sm. perforatum, and may occur less frequently in some other species of Smittium. Methods to identify such "false" Stachylina thalli are discussed.