Animal and vegetation patterns in natural and man-made bog pools: implications for restoration

1. Peatlands have suffered great losses following drainage for agriculture, forestry, urbanisation, or peat mining, near inhabited areas. We evaluated the faunal and vegetation patterns after restoration of a peatland formerly mined for peat. We assessed whether bog pools created during restoration are similar to natural bog pools in terms of water chemistry, vegetation structure and composition, as well as amphibian and arthropod occurrence patterns. 2. Both avian species richness and peatland vegetation cover at the site increased following restoration. Within bog pools, however, the vegetation composition differed between natural and man‐made pools. The cover of low shrubs, Sphagnum moss, submerged, emergent and floating vegetation in man‐made pools was lower than in natural pools, whereas pH was higher than in typical bog pools. Dominant plant species also differed between man‐made and natural pools. 3. Amphibian tadpoles, juveniles and adults occurred more often in man‐made pools than natural bog pools. Although some arthropods, including Coleoptera bog specialists, readily colonised the pools, their abundance was two to 26 times lower than in natural bog pools. Plant introduction in bog pools, at the stocking densities we applied, had no effect on the occurrence of most groups. 4. We conclude that our restoration efforts were partially successful. Peatland‐wide vegetation patterns following restoration mimicked those of natural peatlands, but 4 years were not sufficient for man‐made pools to fully emulate the characteristics of natural bog pools.     

Hydrology,Physiochemistry, and Amphibians in Natural and Created Vernal Pool Wetlands

This study compared the hydrology, physiochemistry, and amphibian biomass between a complex of created vernal pools and a complex of natural vernal pools in 2007 in central Ohio, United States. Hydrologic connectivity of surface water and groundwater differed between the natural and the created pool complexes. Surface inundation duration for created pools exceeded that of natural pools, although spring water depths were similar. Dissolved oxygen (p= 0.05) and hourly temperature (p= 0.00) were 1.2% and 1.1% higher, respectively, in the created pools, and conductivity was 1.5% higher (p= 0.00) in the natural pools. Amphibian dip net results found no significant difference in biomass between natural and created pools or family (hylid, ranid, and ambystomatid) biomass in both pool types. Amphibian families were evenly represented by both capture methods in the created wetlands; however, the distribution of families was not even in natural pools and the proportion of ranids was four times greater for samples obtained by funnel traps than dip netting. Eleven years after construction, the created vernal pools did not mimic natural pools in surface inundation and groundwater–surface water exchange, dissolved oxygen, and water temperature. The created pools are perched wetlands and are never likely to mimic reference pool hydrology. Dissolved oxygen and temperature differences are likely due to the separation of surface water and groundwater in the created pools. However, the created pools exhibited a higher taxa diversity than the natural pools due to a more even distribution of organisms between the three families.     

A Long‐Term Comparison of Hydrology and Plant Community Composition in Constructed Versus Naturally Occurring Vernal Pools

Successful restoration of ephemeral wetlands worldwide is particularly challenging, given the often‐precise relationship between hydrological features and plant community dynamics. Using a long‐term experiment in vernal pool restoration, we compare hydrological and vegetative characteristics of constructed pools with those of adjacent, naturally occurring reference pools. Although constructed and reference pools were similar in maximum water depth and duration of inundation at the beginning of our experiment in 2000, constructed pools were shallower and inundated for shorter periods by 2009. Native vernal pool species were able to establish populations in many constructed pools, and seeding sped their establishment. Comparing seeded plots in constructed pools with unseeded plots in reference pools, we found no significant difference in the cover of seeded species, native species, or exotic species in most years. In recent years, however, native species have declined in both constructed and reference pools. Finally, the cover of native vernal pool species was positively and non‐linearly associated with both water depth and seeding treatment. We conclude that the establishment of appropriate hydrological conditions was necessary, but not sufficient to promote successful performance of vernal pool species in constructed pools. Constructed pools with hydrologic conditions similar to those of reference pools were more likely to support populations of native vernal pool plant species, but only seeded pools were similar to reference pools in abundance of native cover. Most importantly, hydrological conditions in experimental pools have worsened since their construction, which may hamper persistence of native species in this restoration effort.     

Assemblages of dytiscid predators and culicid prey in relation to environmental factors in natural and clear-cut boreal swamp forest pools

Assemblages of diving beetles (Dytiscidae) and mosquito immatures (Culicidae) were studied during 1987–1988 in 40 small, more or less temporary, snowmelt pools in spruce swamp forest and clearings at the Arctic Circle in Sweden. Larger pools were warmer than smaller ones, and clearing pools were warmer than forest pools. Temperature differences between pools remained high until late July. Twenty-one dytiscid species, representing three guilds, occurred in the pools, and individual pools had 1–13 species. Ten species occurred in both habitats. A few stenotopic species of boreal swamp forests had in clearing pools apparently been replaced by some species with a preference for more productive, often man-made habitats. Six Aedes species were collected in the clearing pools. Five of these were found in the forest pools, of which three had no mosquito larvae. Dytiscid assemblages in both habitats and culicid assemblages in clearing pools showed strong nested patterns.Abundance and species richness of both culicids and dytiscids were higher in clearing than in forest pools with an area >2 m² after that the effects of pool area had been accounted for (MANCOVA). In both habitats, abundance and species richness of both culicids and dytiscids were strongly and positively correlated with a linear combination of pool area, depth and temperature (Canonical Correlation). Increasing drought frequency of pools had a negative, less significant effect on the biota. In the clearing, the abiotic correlations with abundance were somewhat weakened chiefly by the relatively low abundance values from the largest pool.Distribution and mean abundance of individual dytiscid species were positively related in the clearing pools. Flying dytiscids were trapped in the larger (1.6 m²), but not in the smaller (0.07 m²) artificial pools, and the immigration rate was markedly higher on clearings than in forest. Dug pools were colonized faster on clearings than in forest. Even the flightless Hydroporus melanarius colonized dug pools during the first year.     

Calcium pools mobilized by calcium or inositol 1,4,5-trisphosphate are differentially localized in rat heart and brain.

Calcium-induced calcium release (CICR) pools have been demonstrated in brain and heart microsomes biochemically and autoradiographically by the sensitivity of 45Ca2+ accumulation to Mg2+, ATP, ruthenium red, caffeine, and tetracaine. The CICR pool colocalizes with [3H]ryanodine binding sites, supporting the notion that [3H]ryanodine labels CICR pools. Sites of CICR pools in the brain contrast with those of inositol 1,4,5-trisphosphate (IP3)-sensitive Ca2+ pools with reciprocal localizations between the two Ca2+ pools in several structures. Thus, in the hippocampus CA-1 is enriched in IP3-sensitive Ca2+ pools, whereas CICR pools are highest in CA-3 and the dentate gyrus. The corpus striatum and cerebellum are enriched in IP3 pools, whereas the medial septum and olfactory bulb have high CICR densities. In cardiac tissue, CICR is localized to atrial and ventricular muscle, whereas IP3 pools are concentrated in coronary vessels and cardiac conduction fibers. The reciprocal enrichment of IP3 and CICR Ca2+ pools implies differential regulation of Ca2+ hemostasis in these tissues.     

Breeding birds associated with seasonal pools in the northeastern United States

ABSTRACT Seasonal pools in the northeastern United States provide habitat for amphibians and invertebrates, but little is known about their importance as habitat for birds. We examined avian community composition at seasonal pools in Rhode Island to test the hypothesis that seasonal pools would support a greater abundance and diversity of birds than nearby upland sites. From mid‐May to June 2008, we conducted point counts at 33 paired sets of seasonal pools and upland sites that were 150 m apart. Bird abundance and diversity was significantly higher at seasonal pools than upland sites, whereas community composition as measured by evenness was similar. We also found that the mean abundance of birds was significantly greater at urban pools than rural pools. Our results suggest that birds preferentially use seasonal pools, particularly in more urban settings, adding to the body of evidence that supports the protection and restoration of small isolated wetlands in urban landscapes.     

Effects of pool isolation on trophic ecology of fishes in a highland stream

The objective of this study was to examine the effects of pool isolation on fish diet and to answer three questions: Were food resources different or reduced in isolated compared with connected pools? Were fishes more selective and did they increase resource partitioning in isolated pools? Would individuals exhibit increased gastrointestinal tract (GIT) length in isolation to aid nutrient absorption? Benthic macroinvertebrate density and richness were significantly lower in isolated pools compared with connected pools; fishes became more selective and partitioned resources more in isolated pools and all three species showed an increase in GIT length in isolated pools compared with connected pools. With a changing climate predicted to increase intermittency within headwater streams, the results show that these fishes have the adaptive ability to respond and continue to survive.     

Hydroperiods of created and natural vernal pools in central Ohio: A comparison of depth and duration of inundation

Water levels were recorded weekly from six natural vernal pools and 10 created vernal pools at two forested wetland complexes in central Ohio. Vernal pool median water depth and duration of inundation were significantly greater at the created vernal pools than at the natural vernal pools (α = 0.05, P < 0.05). The average period of inundation for created pools was 309 ± 32 days, compared with 250 ± 16 days for natural pools. The created pools produced a range of inundation times, from 163 to 365 days in length, with three pools permanently inundated.     

A review of vertebrate community composition in seasonal forest pools of the northeastern United States

Seasonally-flooded wetlands occur throughout the world and provide important foraging, resting, and breeding habitat for a broad array of organisms. This review summarizes our current understanding of vertebrate community composition at seasonal forest pools in the northeastern United States. These wetlands typically have hydroperiods that range from temporarily flooded to intermittently exposed, which reduces densities of many potential predators (e.g., fish). Current research has shown that pool hydroperiod, canopy closure, vegetation structure within pools, presence of potential predators, and landscape structure surrounding pools are the key factors determining vertebrate diversity at seasonal forest pools. Of 25 species of amphibians in the region, frogs (10 of 12 species) are more likely to breed in seasonal forest pools than salamanders (6 of 13 species). Seven of 10 amphibian species that breed in seasonal forest pools are state-listed as threatened or endangered. Among 27 species of reptiles, 3 of 15 species of snakes, and 6 of 12 species of turtles utilize seasonal pools during at least one stage of their annual cycle. Seasonal forest pools are important foraging and basking habitat for three species of turtles listed as threatened or endangered. Compared to other vertebrate taxa, most species of mammals are habitat generalists, with 50 of 63 mammal species potentially foraging at seasonal pools during part of their annual cycle. Chiroptera (bats; all 9 species) are believed to actively forage at seasonal pools and some Insectivora, particularly Sorex palustris Richardson and S. fumeus (Miller) and Condylura cristata (L.), are detected regularly at seasonal pools. Breeding birds are less likely to utilize seasonal pools than other vertebrate taxa, although 92 of 233 species might forage or breed near seasonal pools. Several species of Anatidae, Rallidae, and some Passeriformes use seasonally flooded pools. All vertebrates that use seasonal forest pools use other habitats during some stage in their life cycle; thus gaining a clear understanding of their habitat requirements is critical to their long-term persistence.     

The effects of trout on water striders in stream pools

Summary Observations made in Rattlesnake Creek, Santa Barbara County, California, U.S.A. indicate that rainbow trout (Salmo gairdneri) affect the microdistribution of adult water striders (Gerris remigis). Gerrids occupied all areas of stream pools lacking trout but stayed in margins of pools containing trout. To test the hypothesis that the presence of trout controlled the distribution of water striders within pools, trout were removed from some pools and transferred to pools lacking trout. Undistrubed pools with and without trout served as controls for the trout transferrals. The results supported the hypothesis; within one week, gerrids moved to the edge of pools where trout were added and to the middle of pools where trout were removed. Time budgets and gut analyses suggest that local patterns of gerrid distribution were maintained by harrassment of gerrids by trout. At times trout had significant effects on components of gerrid fitness.     

The effects of trout on epibenthic odonate naiads in stream pools

• 1 In a southern Califomian stream naiads of a lestid damselfly (Archilestes grandis Rambur) were much less abundant, moved less, exhibited fewer conspicuous behaviours, were more likely to occur in refuge areas, and had different diets in pools containing versus pools lacking rainbow trout (Oncorhynchus mykiss Richardson). To determine if trout were responsible for these patterns, we removed trout from some stream pools and added them to pools lacking trout, with unmanipulated trout and troutless pools acting as controls.
• 2 The abundance and emergence of A. grandis were drastically reduced, and the proportion of lestid populations in refuge areas greatly increased, when trout were added to pools; however, the removal of trout had less drastic effects on lestid abundance and distribution, Aeshna walkeri (Kennedy) was also more abundant in pools lacking than in pools containing trout.
• 3 Trout manipulations affected lestid behaviour, with swimming being observed only in troutless pools and movement tending to be greater in pools lacking rather than containing trout.
• 4 One week after manipulations started, the number of prey items per lestid gut was higher in troutless control than in trout addition pools. Ostracods and chironomids were more abundant, and mayflies were less abundant, in the diets of lestids from pools lacking versus containing trout. Comparisons of the environmental abundances of prey taxa and lestid diet composition indicated that lestid selectivities for Caenis were higher, and those for Paraleptophlebia, ostracods, and Eubrianax lower, in trout than in troutless pools.
• 5 Although similar at the beginning of manipulations, head widths of lestids in troutless control pools were greater than those in trout addition pools after 3 weeks.

     

Behavioral Adaptations of Moose to Roadside Salt Pools

Abstract: Sodium has many fundamental physiological functions in animals but is rare in boreal ecosystems where moose (Alces alces) thrive. In Québec (Canada), sodium is readily available in aquatic vegetation and in salt pools that form along highways. We do not know if moose are adopting specific behaviors to access sodium sources or if they simply use the sodium sources they encounter during their movements. We tested the hypothesis that moose modify both space and habitat use to gather sodium from salt pools. We expected moose to use salt pools mostly in spring and early summer, when needs are greatest and before aquatic vegetation has fully developed. We fitted 47 moose with Global Positioning System telemetry collars and collected data for 2 to 36 months between 2003 and 2006. We rarely located moose at salt pools (0.12% among the 95,007 locations collected). As we expected, use of salt pools was highest in late spring and in early summer, and we observed a time lag between peak use of salt pools compared to use of lakes and waterways, indicating moose fulfilled their sodium requirements in salt pools before aquatic vegetation was available. Moose selected salt pools over lakes and waterways when these 2 sodium sources were present in their home range and moved rapidly over large distances to reach them. Our results were consistent with moose using salt pools when they are likely to be sodium deficient. Salt pools were less accessible, required long-distance movements, and were located in habitually avoided areas along highways. Elimination of roadside salt pools should be considered among strategies to reduce cervid-vehicle collision risks in boreal environments.     

Habitat scale, female cannibalism, and male reproductive success in three-spined sticklebacks (Gasterosteus aculeatus)

We studied the effects of habitat scale (pool size) on the riskof egg cannibalism and the breeding behavior of three-spinedsticklebacks (Gasterosteus aculeatus). Laboratory experimentsshowed that in pools with similar population density, a largerfraction of males nested in pools of 4.8-m² surface area thanin 15-m² pools. Breeding males in the 4.8-m² pools also hadbigger territories, obtained more eggs, and were more aggressivetoward intruders than those in the 15-m² pools. The numbersof raids attempted on nests were similar in the two pool sizes.However, raiding-shoal sizes were larger, and hence individualsin these larger shoals were more succesful at overwhelming maleterritorial defenses in the 15-m² pools than in the 4.8-m² pools.At the field site, a salt marsh containing hundreds of tidepools of different sizes, sticklebacks settled at similar densitiesin small (<30 m² surface area) and large (>355 m²) pools.This resulted in significantly more fish being present in largepools than in small pools, a concomitant increase in the amountof nest raiding, and a decrease in individual male reproductivesuccess in large compared to small pools. A photogrammetry analysisof the salt-marsh pools suggests that the majority of fish breedingat the site will be subjected to a high risk of cannibalismbecause most fish nest in large pools. We conclude that spatialscale has a major influence on this species' breeding behaviorand reproductive success.     

DNA precursor asymmetries, replication fidelity, and variable genome evolution.

Balanced pools of deoxyribonucleoside triphosphates (dNTPs) are essential for DNA replication to occur with maximum fidelity. Conditions that create biased dNTP pools stimulate mutagenesis, as well as other phenomena, such as recombination or cell death. In this essay we consider the effective dNTP concentrations at replication sites under normal conditions, and we ask how maintenance of these levels contributes toward the natural fidelity of DNA replication. We focus upon two questions. (1) In prokaryotic systems, evidence suggests that replication is driven by small, localized, rapidly replenished dNTP pools that do not equilibrate with the bulk dNTP pools in the cell. Since these pools cannot be analyzed directly, what indirect approaches can illuminate the nature of these replication-active pools? (2) In eukaryotic cells, the normal dNTP pools are highly asymmetric, with dGTP being the least abundant nucleotide. Moreover, the composition of the dNTP pools changes as cells progress through the cell cycle. To what extent might these natural asymmetries contribute toward a recently described phenomenon, the differential rate of evolution of different genes in the same genome?     

Difficulties with estimating and interpreting species pools and the implications for understanding patterns of diversity

Evidence has been accumulating that species pools play a major role in regulating variations in small-scale diversity. However, our ability to unambiguously estimate and interpret species pools remains a major impediment to understanding the processes that control patterns of diversity. Two main approaches have been employed to evaluate the relationships between species pools and species diversity. The direct approach has been to estimate the actual sizes of species pools by sampling discrete areas at larger spatial scales and then relating these estimates to samples taken at smaller scales. The indirect approach has been to search for correlations between abiotic environmental factors and patterns of diversity that are indicative of gradients in species pools. Both of these approaches have substantial predictive capability but also have limitations that impair our ability to draw unambiguous interpretations about causal factors. A primary difficulty for the direct approach is in deciding which species in the larger pool of potential species are actually capable of living in a sample. In this regard, the indirect approach requires fewer assumptions and has the ability to detect previously unsuspected gradients in species pools. As with the direct approach, assessing the causes for observed gradients in species pools remains a limitation for the indirect approach. Consideration of experimental studies of potential niches suggests that it may be valuable to distinguish between potential and observed species pools if the role of competitive exclusion is to be fully assessed. This paper concludes by arguing for (1) an increased use of multivariate studies that examine the effects of species pools indirectly and (2) further experimental studies designed to determine potential species pools.     

中国美利奴细毛羊BAC文库的三维PCR筛选

本研究利用中国美利奴细毛羊全基因组BAC文库,构建了可供快速筛选的两级水平的混合池,一级混合池和二级混合池(Primary pools and secondary pools).一级混合池基于每一384-well盘而构建,由盘、行,列三维混合池组成,二级混合池基于整个BAC文库而构建.设计了一种基于PCR技术的快速筛选方法,先筛选二级混合池m再根据结果筛选相应的一级混合池.利用此方法只需一步共66个PCR反应即可从BAC丈库中7.4万个克隆中筛选出1个阳性克隆,或三步100个以内的PCR反应筛选出多个阳性克隆.以绵羊基因组多态性分子标记BF94-1为引物,用一步共66个PCR反应成功筛选到1个阳性克隆373D13.     

Management of Roadside Salt Pools to Reduce Moose-Vehicle Collisions

ABSTRACT Wildlife-vehicle collisions cause numerous human fatalities and injuries, and generate considerable expenses in property damage each year. Certain characteristics of the road and its surroundings are known to have an impact on collision probability. Roadside salt pools increase the risk of collision by attracting moose (Alces alces) to the side of the road. In the Laurentides Wildlife Reserve of Québec, Canada, roadside salt pools were drained and filled with rocks to deter moose from drinking. We surveyed 12 roadside salt pools during 3 consecutive summers (2003–2005) from mid-May to mid-August. Seven salt pools were managed in autumn 2004, and 5 pools were left untreated. We equipped all 12 sites with electronic apparatus that allowed us to detect moose attendance and study their behavior. We also measured physical, chemical, and environmental characteristics of these pools and other unvisited pools in order to correlate moose attendance with specific habitat criteria. We found that moose mostly attended roadside salt pools from mid-June to mid-July, with a decrease in August. Moose attendance was significantly correlated with visual obstruction toward the road and water availability. Management of the pools caused a decrease in mean length of time moose spent at them. Number of visits decreased significantly at night (by 90%), which was when most visits occurred, but not during the day. The proposed management practice prevented all visiting moose from drinking brackish water. These results suggest that moose should eventually lose interest in treated salt pools, therefore decreasing the risk of moose-vehicle collisions on the road.     

Spatial and temporal patterns in the fish assemblages of individual pools in a midwestern stream (U.S.A.)

Synopsis The composition and consistency of fish assemblages in 14 adjacent pools (6–120 m long) of a clear-water, limestone and gravel creek in midwestern U.S.A. were quantified in eight snorkeling surveys over 19 months, to establish a baseline of natural variation in the system at this scale. The fauna of the stream was dominated numerically by minnows (Cyprinidae), sunfish and black bass (Centrarchidae), and topminnows (Fundulidae). The pool fish fauna of the total 1 km reach (including all 14 pools) was highly consistent throughout the study, despite two major floods. Assemblages in individual pools generally were consistent, but there was more variation within pools than at the scale of the entire reach. Throughout the study, most individual pools remained within discrete subsets of the total occupied multivariate space in a principal components analysis based on fish species abundances. Sunfishes (Lepomis spp.) and bass (Micropterus spp.) were more consistent in their distribution among pools than were minnows (Cyprinidae) or a topminnow (Fundulus). There were 25 significant correlations in occurrence of species pairs among stream pools, out of 91 possible comparisons of the 14 most abundant taxa in the reach. Many pools contained assemblages either dominated by large centrarchids or by abundant cyprinids and juvenile centrarchids, but intermediate assemblages also were observed. The dynamics of distribution of fish species and fish assemblages among individual stream pools are likely influenced by a combination of species-specific behaviors and habitat selection, predator constraints on use of individual pools by small fishes, riffles as size-selective barriers to fish movements between pools, dispersal of young-of-the-year fishes, and abiotic phenomena like floods. Individual stream pools appear to be discrete habitat units for fishes, and do represent an appropriate scale for biologically meaningful studies of fish assemblages or their effects on streams.Department of Zoology, University of Oklahoma     

Molecular evidence for trans‐stadial transmission of Anaplasma platys by Rhipicephalus sanguineus sensu lato under field conditions

This study investigated the transmission of Anaplasma platys by Rhipicephalus sanguineus sensu lato (Ixodida: Ixodidae). Engorged nymphs (n = 404) removed from A. platys‐infected dogs were incubated at 28 °C until moulting. Unfed adults were obtained and divided into 48 pools. Unfed ticks collected from the grounds of the dog shelter, comprising 1800 larvae (n = 18 pools), 3100 nymphs (n = 62 pools) and 85 adults (n = 10 pools, including three male and seven female pools) were sorted into 90 pools. All pools were screened by polymerase chain reaction for the 16S rRNA gene of A. platys. Of 48 pools of unfed adults obtained from engorged nymphs, 12 were positive for A. platys; the infection rate maximum likelihood estimate (MLE) was 3.36 [95% confidence interval (CI) 1.84–5.68]. Anaplasma platys was detected in five of 23 male pools (MLE 2.82, 95% CI 1.06–6.20) and seven of 25 female pools (MLE 3.83, 95% CI 1.72–7.57). Of seven pools of unfed adult females collected from the shelter grounds, one was positive for A. platys (MLE 1.74, 95% CI 0.11–8.22). Among 62 unfed nymph pools, eight were infected with A. platys (MLE 0.27, 95% CI 0.13–0.52). No A. platys DNA was detected in the larva pools. The present results reveal molecular evidence for the trans‐stadial transmission of A. platys by R. sanguineus s.l.