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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That spring, mineral is a spring having a high mineral content.?

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Your search for populations (Keyword) returned 110 results for the whole karstbase:
Showing 16 to 30 of 110
The natural populations of Stenasellus virei Dollfus (trgoglobic Crustacea Asellota)., 1973, Magniez Guy
Many cavernicolous and phreatic localities are known for the species Stenasellus virei. Some of these, which harbor a rather abundant population have been studied for several years. The endemic populations from permanent waters of some fossil karstic systems seem to have an abnormal composition. They include especially large individuals (juvenile stages being rare). They differ from the phreatic populations, which exhibit a normal distribution in size groups with a normal percentage of juveniles. These differences in the structure of populations may result from physical differences between the habitat in free waters of caves and in phreatic water, and from differences between the associations of species that these two types of hypogean habitat may support.

Observations on Stenasellus virei in its natural biotopes (Crustacea Isopoda Asellota of Subterranean Waters)., 1974, Magniez Guy
Thanks to intensive exploration and to new methods for capturing aquatic underground fauna. 117 localities are now known for Stenasellus virei. The description of some typical biotopes suggests that the species lives as well in karstic waters as in phreatic ones, inside the different environment of the hydrogeological classification of subterranean waters. St. virei buchneri and St. v. hussoni are almost cavernicolous. St. v. angelieri is distributed in the underground waters of Catalonia. St. v. boui is located in the underflow of Salat river basin. St. v. virei is widely distributed in the alluvial water-level of Garonne and Ebro rivers basins. The dispersion of St. virei into the alluvial environment explains the process of colonization of continental underground waters. It explains also the existence of an apparently insulated population into the sink-hole of Padirac. The actual distribution of the five subspecies is explained by important restrictions of the area in quaternary glacial ages, followed by local (in the water-level of the tributaries of Garonne river) spreading during postglacial time. The postglacial reconquest of the Salat river underflow by this species seems to have been responsible for the latest subspeciation (St. v. boui). The endemic populations of fossil karstic systems seem to have an abnormal composition. They include unusually large adults, juvenile stages being rare. They differ from the phreatic populations, which exhibit a normal distribution is size groups, with a formal percentage of juveniles. These differences between karstic and interstitial populations may result from the fact that in caves, Sr. virei is often insulated from its original phreatic biocoenosis: an intraspecific competition between size classes has taken the place of normal heterospecific struggle for existence.

Interaction between competition and predation in cave stream communities., 1975, Culver David C.
Predation by salamander larvae (Gyrinophilus porphyriticus) reduces the density of one of its prey (the isopod Asellus recurvatus) but increases the density of the other (the amphipod Crangonyx antennatus in a Virginia cave stream. This happens because predation on the isopod reduces its competitive effect on the amphipod. Both prey populations tend to occur more frequently in refugia when predators are present. In another cave where there are no prey refugia, the predator reduces the density of both species. It appears that it is easier for a predator to invade a community than to reach a stable equilibrium with the prey, if the prey have refugia, persistence of the prey system and the predator/prey system is constrained more by low population sizes than by the instability of the interaction coefficients.

Observations on the biology of Stenasellus virei (Crustacea Isopoda Asellota of subterranean waters), 1975, Magniez Guy
St. virei has been bred in the laboratory for many years (1960-1974). Most of the St.v.hussoni were captured in karstic waters, near the Moulis subterranean laboratory. Some St.v.virei from the Padirac sink-hole; St.v.buchneri from Cantabrian caves; St.v.boui and St.v.virei from phreatic waters; and St.buili and St.breuili have also been bred. Since Stenasellids are unable to swim, very low aquariums are used, with a bed of cave clay, some calcareous stones, dead wood and dead elm tree leaves. Little depth of water is necessary. Stenasellus was originally carnivorous, being able to capture and devour living prey, such as Chironomid larvae, but the populations of cave waters have developed a different diet: silt, guano, plant remains..., because they have been often insulated from their original phreatic biocenosis. Nevertheless, the existence of cannibalism among them points out that the predatory behaviour has not completely disappeared. Adult St.virei can be fed with Cerophyl. Some observations on the burrowing activity and on the reactions to light, temperature and salt water have been made. All postmarsupial molts of Stenasellus occur in two steps (isopodian molts). The intramolt is extremely long (from 83 h 30 mi for the first molt of the free young), to 8-12 days, for the adult male and female, 14 days for female reproductive molts and 16-21 days for the molts of aged or senile individuals). The intermolts last from 2 1/2 months (first intermolt of the free young), to 9-12 months (non-reproductive ones of the adult) and 12-18 months (average: 15-16), for reproductive 9 intermolts. The normal lifespan of karstic subspecies of St.virei and related species must be estimated as 12 years (males) and 15 years (females). All these values are 10-20 times longer than these of an epigean Asellid of the same size (Asellus aquaticus). The reproductive cycle has been studied. The adult female is larger than the male. There is no precopulatory pairing ("nuptial ride"d 6-7 years or more, fur the female. In the juvenile male, the morphogenesis of I and Il pleopods takes place normally on intermolts 4-9 and lasts 3 years or more. On intermolt 10, it seems that the male is able to mate.

Lethargy in the cavernicolous Chiroptera in Central Africa., 1976, De Faveaux Michel Anciaux
From his personal research undertaken in the subterranean field (natural and artificial cavities) in Shaba (ex-Katanga, in S.E. Zaire) and Rwanda, the author briefly defines the macroclimate of the prospected regions as well as the microclimate of the subterranean habitat (humidity and temperature). A reversible hypothermia has been noticed in the dry season only (from May till August) in eleven species of troglophile Chiroptera belonging to the following families: Rhinolophidae (7 species of Rhinolophus), Hipposideridae (only Hipposideros ruber) and Vespertilionidae (Miniopterus inflatus rufus, Miniopterus schreibersi arenarius & M.s. natalensis, Myotis tricolor). No sign of lethargy has been noticed in the Megachiroptera (Lissonycteris angolensis, Rousettus aegyptiacus leachi), Emballonuridae (Taphozous perforatus sudani), Hipposideridae (Cloeotis percivali australis) or Nycteridae (3 species of Nycteris). There could be correlations between lethargy and breeding if one takes into account the phenomena of late ovulation and delayed implantation. The entry into lethargy is not caused by the scarcity of food. It does not concern all the individuals of a colony or in various populations of a cave. The degree of humidity appears to be more important than the temperature as far as the conditions for hibernation are concerned.

Remarks about the psammic Asellid Proasellus walteri (Chappuis, 1948) (Crustacea, Isopoda, Asellota)., 1976, Henry Jean Paul
P. walteri, an eyeless species of tiny size and thin body, shows numerous original characters. By its general morphology, it is one form of Asellid best adapted to the phreatic waters where it exists in large settlements. It is also able to live in the psammic biotope in a manner similar to Microparasellids. The females lay only 6 to 10 normal sized eggs. There is no indication of oostegits outside the breeding period. In some populations, the small number of eggs, correlated with the small size, seems to be compensated by a sex-ratio favorable so the females.

The dynamics of population in the Isopod Proasellus slavus ssp.n. and the larvae of Chironomids in the hyporheic water of the river Drava with regard to pollution., 1976, Lattingerpenko Romana, Mestrov Milan, Tavcar Vlatka
If we sum up the data and observations derived from our researches on the Drava river, we conclude after consideration of surface water fauna and after comparison of chemical parameters that it influences the hyporheic water of a rough gravel-sandy alluvium more than 2 m deep, while in the compact sandy substratum it has less influence. The next conclusion is that the horizontal and vertical distribution of Proasellus slavus ssp.n. in the alluvium of the Drava river, depends upon the granulation of substratum, with reference so the largeness of interstices; that the populations vary in density and structure according to the nature of water which irrigates these alluviums; and finally upon the quantity of detritus which this water contains. Concerning the influence of the sewage waters the effect of a sudden action of very polluted water is not known but it is certain that the increasing of decaying material to the alfa-meso saprobial level of the river water does not threaten either the existence or the development of the populations of Proasellus slavus ssp.n.

Remarks on the biology and ecology of Stenasellus virei Dollfus (Crustacea Isopoda Asellota of subterranean waters)., 1976, Magniez Guy
Recent observations indicate that a laying season seems to exist, in karstic as well as in phreatic populations. Nevertheless, a single female cannot lay each year, because the reproductive intermolt averages 15-16 months and is always followed by one (9-10 months) or several non-reproductive intermolts. So, the minimum laying rhythm of female St. virei is biennial. The cavernicolous population (St. v. virei) of the Padirac swallow-hole is not a relict, but a colony separated from the main settlement of the alluvial waters of the Dordogne river. On the contrary, it is possible to find, close to each other, karstic and phreatic populations which belong to different subspecies (St. v. hussoni and St. v. boui) and live independently.

The effect of cave entrances on the distribution of cave-inhabiting terrestrial Arthropods., 1976, Peck Stewart B.
Populations of cave invertebrates are generally considered to be food-limited. The cave entrance is a major source of food input into the community in the form of decaying organic matter. Thus, the densities of scavenging terrestrial cave invertebrates should be related to the distance from the cave entrance because this represents a measure of food abundance. A test showed this expectation to be true in Crossings Cave, Alabama. A population density peak occurred 10 m inside the cave where the dark zone and detritus infall regions meet. The greatest population peak occurred at 100 m where densities of crickets and their guano are highest. The pattern should hold for most caves, but the actual distances will vary in each site depending on its circumstances. When the fauna was removed from the cave, the remnant had not regained community equilibrium a year later. Removal of the dominant scavenger, a milliped, allowed other species populations to expand because of decreased competitions.

Variation among populations of the troglobitic Amphipod Crustacean Crangonyx antennatus Packard living in different habitats. I. Morphology., 1977, Dickson Gary W.
Populations of the troglobitic (i.e., obligatory cavernicole) amphipod Crangonyx antennatus living in two distinct aquatic habitats were examined for possible morphological variation. Collections were made seasonally for one year in six Lee Co., Virginia caves, three with mud-bottom pools and three with small gravel-bottom streams. Environmental parameters thought to influence population variation were recorded for each of the six caves. Body length of mature amphipods was found to be greater in the mud-bottom pool habitats, whereas stream amphipods possessed more first antennal segments per unit body length. Variation was also observed in integument coloration; stream amphipods were characterized by a brownish integument and pool amphipods a whitish integument. Differences in the type and amount of available food in the two habitats is considered the most important environmental parameter affecting morphological variation. The population variation noted between habitats is believed indicative of the adaptive flexibility of this vagile troglobitic species.

Mayan Urbanism: Impact on a Tropical Karst Environment, 1979, Deevey Es, Rice Ds, Rice Pm, Vaughan Hh, Brenner M, Flannery Ms,
From the first millennium B.C. through the 9th-century A.D. Classic Maya collapse, nonurban populations grew exponentially, doubling every 408 years, in the twin-lake (Yaxha-Sacnab) basin that contained the Classic urban center of Yaxha. Pollen data show that forests were essentially cleared by Early Classic time. Sharply accelerated slopewash and colluviation, amplified in the Yaxha subbasin by urban construction, transferred nutrients plus calcareous, silty clay to both lakes. Except for the urban silt, colluvium appearing as lake sediments has a mean total phosphorus concentration close to that of basin soils. From this fact, from abundance and distribution of soil phosphorus, and from continuing post-Maya influxes (80 to 86 milligrams of phosphorus per square meter each year), which have no other apparent source, we conclude that riparian soils are anthrosols and that the mechanism of long-term phosphorus loading in lakes is mass transport of soil. Per capita deliveries of phosphorus match physiological outputs, approximately 0.5 kilogram of phosphorus per capita per year. Smaller apparent deliveries reflect the nonphosphatic composition of urban silt; larger societal outputs, expressing excess phosphorus from deforestation and from food waste and mortuary disposal, are probable but cannot be evaluated from our data. Eutrophication is not demonstrable and was probably impeded, even in less-impacted lakes, by suspended Maya silt. Environmental strain, the product of accelerating agroengineering demand and sequestering of nutrients in colluvium, developed too slowly to act as a servomechanism, damping population growth, at least until Late Classic time

Quaternary Paleoclimatology of the Black Sea basin, 1979, Schrader Hans Joachim,
The occurrence of polyhaline, mesohaline and oligohaline diatom, silicoflagellate, ebridian and chrysomonad populations in late Quaternary Black Sea sediments (DSDP Leg 42B) forms the basis for reconstruction of surface water paleosalinities in the Black Sea basin over the last 3 million years. Four major periods with increased salinites are separated by extended freshwater periods. Based on paleosalinites, indicators of trophic freshwater conditions and changes in diatom species diversity, a correlation is made to the northern Europian glacial--interglacial stratigraphy and this correlation is used to place paleoenvironmental events into a chronostratigraphy. The `synchronous' late Quaternary occurrence of sediments rich in organic carbon in both the Eastern Mediterranean and the Black Sea supports this interpretation.Three different stages in the interaction between the Black Sea and the Eastern Mediterranean Sea are defined: Stage A (exchange of freshwater and marine water similar to the present day flux) during the Holocene, Eemian, Holsteinian and Pliocene; Stage B (freshwater conditions with only occasional marine spills) during the Saalian, the Waalian, the Tiglian and the Praetiglian; and Stage C (freshwater conditions with no inflow of marine waters) during the Weichselian, the Elsterian and Eburonian

Notes of the Determination of Bat Populations Using Photographic Measurements, 1980, Warden, Tom

Variation among Populations of the Troglobitic Amphipod Crustacean Crangonyx antennatus Packard (Crangonyctidae) Living in Different Habitats, III: Population Dynamics and Stability., 1981, Dickson Gary W. , Holsinger John R.
Populations of the troglobitic amphipod Crangonyx antennatus from caves in Lee Co., Virginia (U.S.A.) were investigated on both a short and long term basis. The dynamics of populations living in two distinct aquatic cave habitats (mud-bottom pools and gravel-bottom streams) were compared seasonably for one year. Sex ratios indicated a larger number of females in both pool and stream habitats. The majority of males in both habitats were found to be sexually mature throughout the year investigated. Seasonal fluctuations in female maturity were observed in both habitats, with larger numbers collected in June and August. In addition, a larger number of ovigerous females were observed in the spring, indicating the possibility of a circannian reproductive cycle in both pools and streams. The structure of populations from the caves studied appears to reflect a controlled recruitment of females from immature to mature stages. In order to determine the stability of population structure, collection data from a pool and a stream habitat for a l0-year period were analyzed. Population structures were found to be relatively stable over long periods in both habitats, with immature females comprising the dominant population class.

Structure et Fonctionnement des Ecosystmes du Haut-Rhone Franais; VIII: Hydrologie de deux stations phratiques dont l'eau alimente des bras morts., 1981, Gibert J. , Ginet Rene, Mathieu J. , Reygrobellet Jean Luc
We have been working since 1975 on phreatic stations providing two old meanders of the French river Rhone with interstitial water. The hydrological characteristics are quite different (see diagrams in the text):; The one (station 2) is a particular under-flow circulating laterally to the river ("paracoulement"), which is closely subordinate with the varying level of the Rhone.; The other (station 8) is the confluence of continental phreatic water proceeding from a Northeastern plateau (the "Dombes") with the hyporheic of the river Ain (eastern tributary of the Rhone). The Rhone has no influence on the characteristics of this second interstitial flow. The physico-chemical disparity of these stations clearly appeared during two extremely opposite climatic periods; the inferences on resident populations are considered.

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