Bog Pools Research Articles

INSECT COMMUNITIES OF NEWFOUNDLAND BOG POOLS WITH EMPHASIS ON THE ODONATA

AbstractThe arthropod and annelid fauna of a series of small, acidic pools in a domed, ombrotrophic bog on the Avalon Peninsula, Newfoundland, was studied over the ice-free season of 1986. Pools were assigned to four classes on the basis of their surface area (<1; 1.1–10; 10.1–100; >100 m2) and at least two 1-m2 (entire pool if area <1 m2) substrate samples, plankton samples, and moss samples were taken from pools of each size class biweekly. One hundred and thirty-one taxa, most identified to the species level, were collected. Taxa varied in abundance between pools of various size classes and, using Cluster Analysis and TWINSPAN, two principal communities were identified. Oligochaetes, beetles, and mosquitoes dominated small, astatic pools and odonates, chironomids, and several other taxa predominated in large, stable, vegetated pools. Water level stability is postulated to be the principal factor determining this community structure. Within large pools, odonate larvae were the dominant predators and comprised the majority of the standing crop. Odonate larvae have life cycles of 2 or more years; their slow growth is probably due to prey limitation. Odonate larvae potentially exert a powerful predation pressure within the large pool community, and may be the principal biotic factor determining abundance and distribution of prey taxa within the bog pool system.

Classification of lake basins and lacustrine deposits of Estonia

Based on extensive data from a long-term investigation, a new genetic classification of lake basins is proposed for Estonia. Eight lake groups are distinguished, tectonic-denudation, glacial, chemical, fluvial, coastal (neotectonic), telmatogenic, cosmogenic and artificial, containing 13 subgroups and 19 basin types. Also proposed is a new lithological classification of Estonia's organic and calcareous lake sediments, based on analyses of more than 2000 sediment samples from 90 contemporary and 50 late-glacial (extinct) lakes. Of the ca. 1150 Estonian lake basins that formed on mineral substrate, the two largest basins are of preglacial, tectonic-denudation origin, later modified by glaciers. Eight hundred lakes are of glacial origin, and 300 of other origins in the Holocene. In addition, ca 20 000 bog pools formed on peat in the Holocene. Only minerogenous sedimentation occurred in the lakes in the late-glacial period. After that, organic (gyttjas) and/or calcareous sediments have formed. Azonal factors have been largely responsible for the wide variation in Estonia's lacustrine deposits.

Systematics and biology for a new Nearctic genus in the caddisfly family Phryganeidae (Trichoptera)

Discovery of the larval and pupal stages of the northern North American species Fabria complicata (Banks) reveals that the pupal mandibles are degenerate and that a silken sieve membrane is not constructed across the anterior opening of the case at pupation. Supporting this relationship with the small aberrant group of adecticous genera in the Phryganeidae are several other derived structural characters of larvae (long antennae, mesonotal sclerites) and adults (complex structure of segments IX and X of male genitalia), and of case-making behaviour (discrete rings instead of a continuous spiral). However, because complicata cannot be interpreted as monophyletic with any of these genera, recognition of a new genus, Beothukus, is required. Larvae of the population of B. complicatus studied in Newfoundland were found in small sphagnum bog pools where pH ranged from 4.2 to 4.9, and fed on algae, insects, and crustaceans; the species is univoltine at this site. Beothukus complicatus (Banks) is a noteworthy species because it is one of the few Trichoptera known to live in bog pools of low pH, and because it is another of the exceptions invalidating the widespread perception that all Trichoptera have decticous pupae.

IMMATURE STAGES AND BIOLOGY OF THE NORTH AMERICAN CADDISFLY GENUS PHANOCELIA BANKS (TRICHOPTERA: LIMNEPHILIDAE)

AbstractLarvae of Phanocelia canadensis (Banks) were found inhabiting the floating sphagnum fringe of acidic bog ponds. Phanocelia canadensis has a 1-year life cycle with autumnal emergence. This is the first morphological and biological information available for immature stages of this genus.

Bog Development and Landform Dynamics in Central Sweden and South-Eastern Labrador, Canada

(1) Stratigraphic analysis, detailed surveying, and radiocarbon dating were used to document the development of Hammarmossen, a raised mire in central Sweden, and to contrast the structure, development, and dynamics of landforms there with those on Gilbert bog in south-eastern Labrador, Canada. (2) A series of basal radiocarbon dates from transects of peat cores across Hammarmossen shows that peat started to accumulate approximately 5500 years B.P. and spread radially across a glacial outwash plain throughout the late Holocene. The implications of this pattern of development for models of bog hydrology and growth and for interpretations of the process of paludification, e.g. by Malmstrom, are discussed. (3) On both Swedish and Labrador mires the distribution, shape and development of open-water pools are closely controlled by the topography of the peat surface. The largest and deepest pools occur on the flattest surfaces, where water outflow is slow. Pool development results from hydrological controls on relative rates of peat accumulation in hummocks and hollows. (4) Pools were initiated throughout the last 4000 years of bog development. On Hammarmossen a deep layer of algal gyttja partly fills the pools, whereas on Labrador bogs algal sediment is absent, and the pool floors are degrading peat and peat detritus. This contrast in stratigraphy of bog pools in Sweden and Labrador follows a similar pattern for pools on minerotrophic mires (fens) in the two areas. (5) Once formed, pools undergo similar dynamics in the two regions. Pool depth increases as peat accumulation on hummocks exceeds sedimentation in pools. Lateral expansion of pools occurs through marginal flooding, controlled by differential rates of accumulation and by the breakdown of peat ridges separating adjacent pools. Pools may be drained through surface erosion or through subsurface piping. Erosion of the bog from the mire margin towards the centre may gradually fragment the peat mass. Under very wet conditions raised bogs are inherently unstable systems on which water-dominated landforms increase through time until stream erosion gradually dissects the mire.

Emergence phenology and ecology of aquatic and semi‐terrestrial insects on a boreal raised bog in Central Finland

Emergence of peatland insects was studied in Central Finland by sampling insects on a raised bog with tent traps from five different surfaces: muddy hollow without vegetation; hollow covered with Sphagnum; deep (0.7–0.9 m) open‐water pool; shallow (about 0.3 m) pool with bottom covered by Carex vegetation; shallow (about 0.3 m) pool with bare muddy bottom. The material was collected at two‐days intervals from 13 May until 31 August in 1981.Biomass emerging from the sites varied considerably. In general, aquatic sites were clearly more productive than semi‐terrestrial sites. Corrected total biomass values for deep pools, shallow Carex pools, and shallow mud pools were 2.471, 1.066, and 0 514 g m−2, respectively. The corresponding values for muddy and Sphagnum hollows were 0.208 and 0.236 g m−2, respectively.All chironomids, chaoborids and trichopterans from the aquatic sites were identified to species, and their emergence phenology and habitat preferences are discussed. 14 species were considered as eurytopic littoral species, 9 species showed strong preference for the bog pools or polyhumic lakes, and 8 species were of diverse origin. Differences in emergence patterns and habitat preferences are probably connected with species‐specific resistances to freezing and oxygen and nutrient requirements. The role of emerging insects in the peatland food webs, especially as food for breeding birds, is briefly discussed.

The Absence of Antipredator Behaviour in the Larvae of Leucorrhinia dubia (Odonata) and the Consequences for Their Distribution

Acidified bog ponds were the only previously reported habitat of larvae of the dragonfly Leucorrhinia dubia (Van der Lind.) (Odonata: Libellulidae). To study its present range of habitats, twenty lakes in southwestern Sweden were sampled. Ten of the lakes supported fish, the other ten lakes were fishless and acidified. L. dubia was found to occur in all ten fishless lakes but in none of the lakes which contained fish. To test the hypothesis that fish predation was the factor behind the distribution of L. dubia, a laboratory study was made where perch (Perca fluviatilis L.) was shown to discover and catch significantly more L. dubia than other dragonfly larvae from lakes with fish. When exposed to a simulated fish attack larvae of L. dubia tried to escape, whereas most larvae of two other genera from lakes with fish feigned death. This result, together with earlier studies on diel activity of L. dubia, supports my opinion that L. dubia is more susceptible to fish predation than are larvae of certain other genera from lakes with fish.

Quantitative Evaluation of the Behavioral Extraction of Aquatic Invertebrates from Samples of Sphagnum Moss

The difficulty of hand-sorting aquatic invertebrates from sphagnum moss led to the development of a behavioral extraction procedure. The method involves vertical temperature and dissolved oxygen gradients in a column of water with a sphagnum sample immersed at the top. When sphagnum was used as an artificial substrate in Southern Indian Lake, Manitoba, overall extraction efficiency was 85% (SD ± 1.5%, n = 4). Invertebrates in samples from the edge of the floating sphagnum mat surrounding bog ponds in New Brunswick were extracted with an overall efficiency of 75% (SD ± 15%, n = 17). Taxa not extracted by the procedure were represented by an average of fewer than two organisms in samples containing 289 (SD ± 153) organisms. Efficiencies for the more abundant groups of aquatic invertebrates ranged from 73 to 96%. Mean sorting time was reduced from >16 hr to <2 hr per sample. The method's high efficiency allows both quantitative and qualitative assessment of aquatic invertebrate populations in sphagnum and ot...

Dissolved organic matter in colored water from mountain bog pools in Japan II. Biological decomposability

Dissolved organic matter in colored water from mountain bog pools in Japan II. Biological decomposability

Dissolved organic matter in colored water from mountain bog pools in Japan I. Seasonal changes in the concentration and molecular weight distribution

Dissolved organic matter in colored water from mountain bog pools in Japan I. Seasonal changes in the concentration and molecular weight distribution

Peatland water chemistry in Central Ontario in relation to acid deposition

Thirty-one peatlands from two areas of central Ontario were sampled to assess the influence of acid deposition on peatland water chemistry. Factor analysis differentiated peatland water chemistry along three major axes of chemical variation, interpreted as axes of organic concentration, mineral concentration, and deposition influence. Water from the surface mats had a higher organic concentration than water from open pools. Mineral influence in peatland waters was reflected by higher concentrations of Ca, Mg, Na, and silica in fen pools compared to bog pools. The influence of high acid deposition in the Wanapitei study area was indicated by high concentrations of sulphate, Ni, Mn, and Cu, and lower pH compared to an area that has received less acidic deposition (Ranger). Regression analyses indicated that H+ variation in bogs could be largely explained by organic C concentration, but that sulphate concentration was also positively associated with acidity, while Ca was negatively associated with acidity.

CHIRONOMIDAE (DIPTERA) OF PEATLANDS AND MARSHES IN CANADA

AbstractA survey of the literature has revealed that the Chironomidae are one of the most abundant and diverse groups of insects present in Canadian peatlands and marshes. A total of 104 named species of Chironomidae has been recorded from Canadian bogs, fens, and marshes. At least 207 species are present if all unnamed species are included in the total. However, until more information is available about the distribution of chironomid species, particularly those from fens, it is not possible to determine if any species (other thanMetriocnemus knabiCoq.) are restricted to these habitats. Although several studies have been conducted in marshes and bog pools, the saturated peat habitats of fens and bogs have been little studied.Most information on chironomids within peatlands and marshes is based on emergence trapping of adults, and there have been few attempts to study the ecologically important immature stages. Several aspects of chironomid ecology pertinent to peatlands and marshes are presented, based primarily on information gathered from other shallow-water habitats. The ecological and economic importance of chironomids within these habitats remains largely unknown. Most effort to date has been expended on faunal surveys, and any attempt to study chironomid ecology within peatlands and marshes would add greatly to existing knowledge.

Eutrophication of heathland ponds at a site in Southern England: Causes and effects, with particular reference to the Amphibia

Chemical and biological features of bog pools at a heathland site in south-east England were investigated. The heath is one of the largest remaining in Britain, and the only locality where all 12 species of native herpetofauna coexist. The ponds showed considerable variation with respect to water chemistry, and several ion sources causing eutrophication of some of the pools were identified. Species richness and abundance were greater in the eutrophicated ponds, which generally had pHs of 5·0–6·5 and calcium concentrations of 4–10 mg litre −1, than in the purely rain-fed bog pools with pHs of 3·8–4·3 and calcium concentrations of 1–5 mg litre −1. Palmate newts Triturus helveticus occurred in all pond types, but were rarest in the purely rain-fed ones; the other five amphibians were confined to eutrophicated pools, with the rare natterjack Bufo calamita breeding only in ponds enriched by calcium-rich solid debris (limestone or concrete fragments). The significance of these findings with regard to recent natterjack declines on heathland is discussed.

THE POTENTIAL IMPORTANCE OF AN INCREASED ATMOSPHERIC NITROGEN SUPPLY TO THE GROWTH OF OMBROTROPHIC SPHAGNUM SPECIES

SUMMARYAtmospheric nitrate deposition varies across Northern Britain, and has increased approximately fourfold since the last century in the Manchester Region. Ombrotrophic mires depend on an atmospheric supply of elements, and some components of nitrogen deposition at two mire sites in northern Britain were investigated. The sites differed in proximity to major pollution sources. Growth of Sphagnum cuspidatum Hoffm, in bog pools was less in the polluted site and this was associated with a marked increase in tissue nitrogen concentration. Field experiments in which S. cuspidatum plants from unpolluted sites were exposed solely to atmospheric deposition in artificial bog pools showed that much of this large increase in nitrogen concentration could have resulted from atmospheric deposition alone. Concentrations of nitrate and ammonium within the range observed in bulk deposition at the polluted site reduced the growth of S. cuspidatum in a laboratory experiment. The results are discussed in relation to a general increase in atmospheric nitrogen deposition, and its potential importance to plant growth.

Influence of the surface microlayer on nutrients, chlorophyll and algal diversity of a small eutrophic bog pond

Nutrients, chlorophyll, phaeophytin and algal abundances were investigated in the surface microlayer and at subsurface depths in a small eutrophic bog pond. Nutrient levels were consistently higher in the microlayer while algal abundance was sometimes higher but sometimes lower in the microlayer than at near subsurface depths. Algal diversity values were strongly influenced by the depth of flagellate blooms, and in contrast to previous studies, diversity in the microlayer was higher than at near subsurface depths. These results are discussed in terms of weather parameters, affinity of algal species for the surface and differences between microlayer ecology in shallow and deep water systems.

Associations of Chironomidae (Diptera) of shallow, acid, humic lakes and bog pools in Atlantic Canada, and a comparison with an earlier paleoecological investigation

The composition of benthos in a series of 29 lake and peat pool sites is examined especially in relation to a successional gradient. The results indicate a sharp distinction between the fauna of peat pools and lakes. Chironomus, Psectrocladius, Monopsectrocladius, and Zalutschia are characteristic of bog lakes at the latter stages of their evolution and peat pools. Procladius and Tanytarsus dominate in most lakes. Between weakly acidic and strongly acidic lakes a sharp boundary exists for many other components of the benthos. Chaoborus occurs in strongly acidic lakes. Amphipoda, and Ephemeroptera are limited to weakly acidic or circum-neutral waters.

Tolerance ofSphagnumto water level

Four species of Sphagnum which occur on ombrotrophic mires were grown at different levels above the water table. In one experiment the species were grown at constant water levels in a bog pool and, in another, at fluctuating water levels in a transplant experiment. A general trend was found of decreasing photosynthetic capacity with increasing height above the water table. This indicates that the hollow species (S. balticum and S. tenellum) are unable to tolerate the hummock sites, whereas the hummock species (S. fuscum and S. rubellum) could well survive the environmental conditions of the hollows but are absent because of biotic factors.

The Physiological Ecology of Larval Lestes disjunctus Selys (Zygoptera:Odonata)

Lestes disjunctus is a common damselfly found in small, densely vegetated temporary ponds such as the Rocky Mountain 'bog pond' studied. Hatch occurs at ice melt in May, growth is rapid and emergence is in late July. Dissolved oxygen (DO) and temperature vary considerably during this time. During a 'typical' late July day temperature and DO may range from minima at dawn of 12°C and 3.1 ppm (lowest 1.8 ppm) to maxima at 1700 h of 22°C (highest 25.5°C) and 7.6 ppm. One mode of adaptation to such variable temperature conditions is low Q10. However, Lestes' Q10S (2.4-3.6) suggest that like most aquatic poikilotherms, it does not gain competitional advantage through unique thermal adaptation. Logic suggests that respiratory regulation would be a beneficial adaptation to variable DO. However, L. disjunctus is not a good regulator of respiration either. Oxygen intake decreases a temperature-dependent 15-27% from a normal environmental high DO to its low-O2 critical point. However, daytime DO variation only cause...

Factors Structuring Fish Assemblages Along a Bog Lake Successional Gradient

Three alternate and distinct fish assemblages were identified in 43 northern Wisconsin lakes encompassing a gradient from bog ponds to small, oligotrophic lakes having little bog character. Multivariate analysis of physical/chemical variables identified three general environmental factors that influence community type and species richness. These factors are: (1) habitat size and heterogeneity; (2) lake productivity— pH; and (3) winter oxygen concentrations. Ordination of lake fish assemblages along these environmental gradients revealed that two factors, lake pH and winter anoxia, were especially crucial in determining assemblage type. Maintenance of these discrete assemblages is also the result of biotic interactions (exclusion of cyprinids due to predation or competition from centrarchids). A centrarchid assemblage dominated lakes across a wide range of habitat types and pH, providing winter anoxia does not occur. Lakes with low winter oxygen concentrations harbor a cyprinid assemblage if the pH is above 5.2—5.4. Lakes that are acidic and also have low winter oxygen contain only two physiologically hardy species comprising the Umbra—Perca assemblage: central mudminnow (Umbra limi) and yellow perch (Perca flavescens). Five fishless lakes had physical and chemical characteristics similar to lakes with an Umbra—Perca assemblage. Within the fish assemblages, no subgroups of closely associated species were evident. For Umbra—Perca lakes, few environmental differences were evident between lakes having (1) no fish, (2) central mudminnows only or, (3) yellow perch and central mudminnows. The sequential loss of species along a gradient from oligotrophic seepage lakes to bog ponds reflected the increased harshness of the chemical environment and the loss of near—shore habitat zones. Species that are specialized zooplanktivores, that utilize hard—bottom substrates for spawning for feeding activities, or that are intolerant of low pH were limited to lakes with little bog character. Lakes in intermediate stages of succession contain acid—tolerant species that are food and habitat generalists. Lakes near the final stages of senescence contained only yellow perch and central mudminnows. The location of bog lakes at the lower end of several environmental gradients makes them valuable sites for studying the influence of environmental factors and biotic interactions on the structure of aquatic communities.

Treatment of New York's Adirondack Lakes by Liming

Abstract Since 1959 the New York State Department of Environmental Conservation has used neutralizing agents to raise the pH of New York lakes. Initial experimental lake treatments were used to neutralize bog and kettle ponds. These treatments successfully raised the pH of these ponds, but fish production was limited by low dissolved oxygen in some of these ponds. Therefore, neutralization did not always produce acceptable fish habitat. The more recent operational lake neutralization program is an effort to mitigate the impact of acidic deposition. This program has utilized a variety of neutralizing agents and dispersal systems. Pending better knowledge of the ecological effects of lake neutralization, it is used only to protect extraordinary fishery resources in New York.