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AbstractArthropods play an essential role in steppe ecosystems. However, studies testing the overall response of terrestrial arthropods to overgrazing are scarce. The problem is particularly worrisome in Central Asia, while, to date, only a very few broader studies have been conducted in this region. We investigated how epigeic terrestrial arthropod assemblages respond to different livestock grazing pressure in two ecozones in SE Mongolia by examining their structure using pitfall traps. We also assessed which groups can be utilised as the most efficient indicators of grazing intensity. Our analyses demonstrated that the habitat type, grazing intensity, and the interaction of these variables had a significant effect on the overall species composition and abundance. However, the grazing intensity caused different changes in the composition of arthropod communities in both studied ecozones. Contrary to the semi-desert, in the steppe habitat, the grazing had the strongest impact in the moderately grazed site. It is most likely because steppe-dwelling species are more sensitive to loss of plant biomass and changes in habitat structure. We also found that the most representative species within and from different groups can react differently to changing grazing intensities, indicating with their presence the characteristics of the respective habitat. Such differences should also be considered when elaborating the management plan of conserved species but also when applying grazing management in different habitat types. Our survey is one of the most comprehensive in Central Asia and should help implement further, more targeted studies in the corresponding habitats.

Abstract—The results of our long-term monitoring of a family of larks (Alauda arvensis L., Melanocorypha calandra L., M. leucoptera Pallas, M. yeltoniensis J.R. Forster, and Calandrella rufescens Vieillot) in the semi-desert zone of the Saratov Trans-Volga region are presented. Bird censuses were carried out at four key sites on permanent routes during the nesting period; the total length of the census transects was 792 km. Statistical indicators of the population dynamics were calculated, namely, the growth rates (Tnp) and average density values (ind./100 ha) of each lark species. A statistical multivariate factor analysis (F-test) was carried out, with the help of which we were able to reveal the influence of a whole range of factors on the lark density dynamics. Changes in habitat conditions in the key areas (Fcrit = 1.30, p = 0.003), as well as weather factors (Fcrit = 1.39, p = 0.004) of particular years, have a significant impact on the density dynamics of larks. Evaluation of the variance showed the heterogeneity of the sample (St = 0.119, p = 0.006); therefore, the average densities of larks differ significantly from each other. Thus, the structure of the lark community and the annual density of each species are the result of the environmental conditions of the habitats at each key site, and the weather conditions of particular years. [ABSTRACT FROM AUTHOR]

Water is a vital liquid for developing biological, industrial, and social processes. However, by 2020, the availability of drinking water decreased by 20% worldwide, leaving more than 2 billion people without access to high-quality water. Thus, this work was based on freshwater production from air dehumidification using silica-based supported materials in two climate zones in Colombia to deal with this lack of water. The results showed that the material synthesized based on a hygroscopic CaCl2 salt supported on silica (SHS) has a high sorption capacity and efficiency even after ten sorption/desorption cycles. The obtained water isotherms had the same tendency for 20, 30, 40, and 60 °C, showing type II behavior based on the International Union of Pure and Applied Chemistry (IUPAC) classifications from 2015. A sorption capacity of 0.85 g⋅g−1 for a relative humidity of 84% was obtained. Based on the thermodynamic properties of sorption, the process is defined as spontaneous and exothermic. For the field tests, simple equipment was designed for water sorption/capture during the night, while the desorption/condensation process occurs during the day. The exclusive use of solar energy generated productivity above 0.6 g⋅g−1 in the environmental conditions of Santa Fe-Antioquia and the Tatacoa desert in Colombia. The relative humidity was less than 80% during the entire test. The desorption temperature was lower than 40 °C, which shows the high capacity of the SHS to produce water in semi-desert conditions at low temperatures. Thus, this SHS can produce water in challenging environments, generating a positive social impact by providing fresh water to those communities that need it most.

Arthropods play an essential role in steppe ecosystems. However, studies testing the overall response of terrestrial arthropods to overgrazing are scarce. The problem is particularly worrisome in Central Asia, while, to date, only a very few broader studies have been conducted in this region. We investigated how epigeic terrestrial arthropod assemblages respond to different livestock grazing pressure in two ecozones in SE Mongolia by examining their structure using pitfall traps. We also assessed which groups can be utilised as the most efficient indicators of grazing intensity. Our analyses demonstrated that the habitat type, grazing intensity, and the interaction of these variables had a significant effect on the overall species composition and abundance. However, the grazing intensity caused different changes in the composition of arthropod communities in both studied ecozones. Contrary to the semi-desert, in the steppe habitat, the grazing had the strongest impact in the moderately grazed site. It is most likely because steppe-dwelling species are more sensitive to loss of plant biomass and changes in habitat structure. We also found that the most representative species within and from different groups can react differently to changing grazing intensities, indicating with their presence the characteristics of the respective habitat. Such differences should also be considered when elaborating the management plan of conserved species but also when applying grazing management in different habitat types. Our survey is one of the most comprehensive in Central Asia and should help implement further, more targeted studies in the corresponding habitats. In meadow steppes and other arid habitats, livestock grazing is one of the most severe causes of desertification and leads to an overall decline in vegetation cover, plant species richness and aboveground biomass, and, consequently, most often negatively affects arthropod diversity. Although the impact of grazing on arthropod diversity has already been the subject of numerous studies, most of them were focused only on a single or small number of arthropods and were conducted outside Central Asia (e.g., there is only one paper dealing with analyses of several arthropod groups conducted in Mongolia, where over 40% of the human population depends on pastoral livestock production and up to 90% of its territory belongs to various arid areas). We hypothesise that the overall diversity of different arthropod groups will change according to the grazing intensities, and these changes will depend on the habitat type and will differ between arthropod groups. Our analyses demonstrated that the habitat type, grazing intensity, and the interaction of these two variables significantly impacted the overall species composition and abundance. Our results highlight that the different terrestrial arthropod groups and representative species of the most abundant groups can react differently to changes in grazing intensity, and such differences should be considered when elaborating the management plan of conserved species and when applying grazing management in different habitat types. Our results also highlight that the species diversity alone cannot indicate the changes in species composition along the grazing intensity, and one should also consider the individual needs of specific species while investigating the impact of grazing on arid habitats. [ABSTRACT FROM AUTHOR]

The forms of anthropogenic impact and its degree were not the same in different epochs, changing, of course, with the development of the economy of farms. In the Chechen Republic, the processes of pollution, degradation and desertification occur on more than half of the territory. As a result, the water-regulating role of forests disappeared, rivers became shallow, and many sources were depleted. The influence of human activity on the vegetation cover in the steppe and semi-desert landscape complexes of the Chechen Republic is no less powerful than in other regions, they differed not so much in the ways of influence, but in the scale of the changes caused, in some cases larger, in others less. The deforestation of forests on the territory of the Chechen Republic was carried out in two stages. The first in the middle of the 19th century, the tsarist troops reduced forests on an area of more than 70% of the territory, the forest cover decreased from 80% to 35%. The second stage covers the Soviet period, when the forests of the Black Mountains were subjected to continuous logging in the mountain forest belt, freeing up land for tobacco culture. As is known, after these deforestation, landslide processes intensified in the areas of forest information. On significant areas there was a cooling, forests were replaced by meadow plant formations. In the territories subjected to economic activity, the spread of new plant species occurs, causing radical changes in vegetation, still leaves a certain imprint on the formation of various associations. First of all, it is necessary to focus on the spread by anthropogenic activity of various weed species of grasses that grow next to cultivated ones, are unpretentious to new living conditions, adapt well, give a lot of seeds, and also have the ability to vegetative reproduction. Deforestation and fires lead not only to the disappearance of individual species, but also leave a certain imprint on the vegetation cover of adjacent meadows and steppes, the herbage of which changes in the direction of increasing xerophytization. The purpose of the study is to study the influence of anthropogenic factors on landscapes and the patterns of changes depending on the stages of development of degradation processes. [ABSTRACT FROM AUTHOR]

The article provides a predictive assessment of longevity of Ulmus pumila L. stands in the Astrakhan Zavolzhye. The effi and expediency of renewable logging for rejuvenation and increasing the longevity of plantings in the semi-desert were confi The classifi of ecotopes of the Astrakhan Zavolzhye on suitability for cultivation of protective and shadow elm plantings on pasture lands was developed and presented. In the Caspian region, Ulmus pumila became widespread in forest reclamation of semi-desert lands in the 1950s. Since then, till the beginning of the 1990s, Bogdinskaya research agroforestry experimental station laid on the sandy massifs about 1 thousand hectares of Ulmus pumila L. plantings, which currently amounts to 1824 %. The long-term practice of using protective shade Ulmus pumila umbrellas has shown their signifi ecological effect on functioning pastures. The aim of the research was to develop an improved technology for creating long-lived protective shade stands of Ulmus pumila on degraded pastures of the Astrakhan Zavolzhye. The research was carried out using generally accepted methods of stand forest taxation by A.P. Anuchin (1961), 1. Bitvinskas (1974) and A.S. Manaenkov (2001). Soil conditions were studied by drilling sounding to 3 m depth. The results of the research revealed that the longevity of wood species in the dry-steppe zone was determined mainly by two factors: productive moisture in the soil and salinity level. The most favorable growing conditions for Ulmus pumila were unsalted (to a depth of at least 3 m) brown sandy soils, sandy loam soils, dark-colored swale soils with periodic redistributed accumulation of moisture. In arid conditions of the Astrakhan Zavolzhye in island plantations (group of trees, umbrellas, 0.51 ha parts of forest area) and optimal growing conditions without logging and reforestation, Ulmus pumila lives up to 6070 years.

The tail autotomy in the population of steppe runners (Eremias arguta deserti (Gmelin, 1789)) living in semi-deserts of the southeastern part of the Lower Volga region was studied. The proportion of lizards with the signs of tail autotomy was used as an indicator of predation pressure. It was found that the number of lizard individuals with autotomized (regenerated) tails increased throughout the research period (2017–2019). The correlation between the total abundance of lizards and the number of individuals with tail autotomy exhibits a direct and statistically insignificant dependence. The data obtained suggest that predators are low abundant, both in the study area and in the surrounding territories, and, thus, they have no considerable influence on the size of the population of lizards. No autotomy as a result of intra- and interspecific contacts was recorded. In the spring field seasons, the lizard individuals with autotomized (regenerated) tails were mainly mature males and females. In the autumn periods, they were exclusively underyearlings. In the population under consideration, lizards with the signs of tail autotomy were more frequent among the migrating individuals. There were no quantitative differences in the presence of tail autotomy between males and females.

The useful plant species play a decisive role of support and subsidy, in the livelihoods of the inhabitants of rural communities. In the case of the Yaqui ethnic group, the ethnobotanical heritage they have is an identity and referential element whose traits have been transmitted generationally, giving them internal cohesion through common signs, in addition to contributing to preserve the culinary, medicinal and ceremonial culture. The objective of this research is to identify native and introduced plants with use value in the Yaqui community of Vicam Town, Guaymas, Mexico. The research was carried out under a participatory action research approach and protocols used in ethnobotanical studies. Sixty semi-structured surveys with open-ended questions and some questions of one answer were applied. 42 plants with different uses are identified: fuel, medicinal, food, forage, construction, ceremonial or religious, ornamental and living fences. The plants that they recognize as useful are used in different ways, and depending on the species, it is the morphological part taken advantage of. It was found that according to the species the leaves, the flower, the fruit, the stem, the root and the seed are used. The foregoing exemplifies that the Yaqui ethnic group is able to take advantage of their ancestral knowledge for the use of the plants present in the region.

Studies on the feeding biology of Lesser Kestrel (Falco naumanni) have limited in Turkey. The aim of this study was to contribute to the knowledge of its feeding ecology in arid areas. In this study, pellet compositions of Lesser Kestrel were examined. Compositions of 17 pellets of Falco naumanni were used in the study. 182 preys which belong to 8 different taxa were found in the diet composition. Insecta (f= 59.34%) and Arachnida (f= 37.36%) taxa were the main preys in the diet composition of Falco naumanni. Solpugidae (Arachnida) (f= 35.16%) had the high prey rate in the dietary composition. The significant ratio of members of Solpugidae was similar to the results of the other semi-arid and arid areas. [ABSTRACT FROM AUTHOR]

Southern Siberia and western Mongolia are characterized by very cold, dry winters, and short, warm summers with modest or little precipitation. In the driest region that we investigated (119 mm annual precipitation), the upper part of two catenas had a larger fraction of microbial biomass in soil organic matter (6–12%) than the four other catenas (<4%) in less dry regions (260 and 442 mm). All six catenas had values ≤4% at the lowest position near the shore of saline lakes. Respiration per unit microbial biomass was similar within and among the catenas, except for the lowest position in three catenas, where enhanced values indicated microbial stress, probably due to high salinity. [ABSTRACT FROM AUTHOR]

Background The present paper includes the results of a year-round pitfall trapping survey of ground beetles in the region of Lake Elton, Volgograd Area, Russia. The main objectives of the project lie in studying the local fauna of Carabidae in the Lake Elton region, as well as their demographic structure and dispersal potential of the local populations of particular carabid species. A total of ten model habitats: six zonal (characteristic of that particular biogeographic area) and four azonal (present in a variety of biogeographical areas) were studied. In each model habitat, ten pitfall traps were set from 10 May 2006 until 10 May 2007 and were checked at 10-day intervals except for the period with negative temperatures (from 1 November 2006 until 31 March 2007). During the period of observation, 51,314 specimens of Carabidae, belonging to 149 species, were trapped. The resulting sampling-event dataset includes 24,291 plot-based observations (= sampling events), some of them containing zero records of particular species in a certain habitat and time. New information This is the first sampling-event dataset of a year-round pitfall trapping survey (from May 2006 until May 2007) of ground-beetle communities and the demographic structure of local populations of particular species in the Lake Elton region, Volgograd Area, Russia. [ABSTRACT FROM AUTHOR]

The useful plant species play a decisive role of support and subsidy, in the livelihoods of the inhabitants of rural communities. In the case of the Yaqui ethnic group, the ethnobotanical heritage they have is an identity and referential element whose traits have been transmitted generationally, giving them internal cohesion through common signs, in addition to contributing to preserve the culinary, medicinal and ceremonial culture. The objective of this research is to identify native and introduced plants with use value in the Yaqui community of Vicam Town, Guaymas, Mexico. The research was carried out under a participatory action research approach and protocols used in ethnobotanical studies. Sixty semistructured surveys with open-ended questions and some questions of one answer were applied. 42 plants with different uses are identified: fuel, medicinal, food, forage, construction, ceremonial or religious, ornamental and living fences. The plants that they recognize as useful are used in different ways, and depending on the species, it is the morphological part taken advantage of. It was found that according to the species the leaves, the flower, the fruit, the stem, the root and the seed are used. The foregoing exemplifies that the Yaqui ethnic group is able to take advantage of their ancestral knowledge for the use of the plants present in the region. [ABSTRACT FROM AUTHOR]

Abstract—This work was carried out in the Dzhanibek and Bokey Orda districts of the West Kazakhstan region of the Republic of Kazakhstan in two key areas. The possibility to study the relationship between the distribution of the abundance of various lark species and their nesting habitats detected using high-resolution satellite images, ground geobotanical descriptions, and bird counts on routes with a variable width of the accounting band was evaluated. The image heterogeneity in a snapshot was analyzed by cluster analysis in the ILWIS software (Heckbert quantization algorithm) using three rasters as variables: infrared and red channel images and NDVI. The correlation between the number of some lark species and the share of some plant associations in the band of accounting routes was established using correlation analysis and approximation of empirical distributions by theoretical ones. A reliable relationship was established between the distribution of three lark species living in the Trans-Volga semi-desert of the Caspian lowland with certain plant associations which they prefer to use as nesting stations. [ABSTRACT FROM AUTHOR]

The short-lived thallose liverwort Riccia lamellosa (Ricciaceae) is first recorded for Azerbaijan, hence bridging the distribution gap between the Russian Caucasus, Iran and Iraq. Its site conditions in the semi-desert landscape of Qobustan south of Bakı are reported and illustrated. An updated list of Riccia species of the Caucasus ecoregion is provided. [ABSTRACT FROM AUTHOR]

The world largest alpine permafrost region, the Tibetan Plateau, will experience amplified warming under global climate change scenarios. Studying its environmental evolution in the geological past is crucial to further our understanding of mechanism and thresholds of climate change. Here we present a 3.5-million-year-long, high-altitude vegetation and climate record from the Kunlun Pass Basin to reconstruct the transition from the sustained warm, high carbon dioxide environment of the Pliocene to the cool glacial and interglacial periods of the Pleistocene, 4.31 to 0.85 million years (Ma) ago. The Early Pliocene pollen record indicates the occurrence of patches of broadleaved and coniferous forests in a semi-desert shrubland at this high-altitude site. Pollen derived quantitative climate estimates based on modern pollen rain transfer functions suggest a moister climate before 4.0 Ma with mean annual temperatures (MATs) > 14 °C warmer than today. The retreat of broadleaved and coniferous forests from the Kunlun Pass Basin area is linked to stepwise cooling at ∼4.0 Ma and during the Plio-Pleistocene transition between 2.7 and 2.6 Ma. Pollen derived climate estimates and Δ 47 -palaeothermometry indicate an abrupt cooling of ∼4–8 °C resulting in the onset of permafrost condition on the Tibetan Plateau after 2.7 Ma. An expansion of Chenopodioideae dominated xerophytic shrublands after 3.8 Ma and 2.15 Ma indicates a reduction in precipitation on the NE Tibetan Plateau, which appears to be linked to a weakening of the East Asian Summer Monsoon at the Plio-Pleistocene transition. The reconstructed cooling at the Kunlun Pass Basin site reflects the regional expression of global climate change with high-elevation temperature amplification hence rejecting the notion of a major tectonic uplift of the Tibetan Plateau during the Plio-Pleistocene. • A high-altitude (∼ 5000 m a.s.l.), 3.5-million-year-long vegetation record. • Retreat of forests after 4.0 Ma in response to global cooling. • Expansion of semi-desert shrubland and alpine meadows after 3.8 Ma and 2.7 Ma. • Multiproxy climate estimates indicate the onset of alpine permafrost after 2.7 Ma. [ABSTRACT FROM AUTHOR]

36 grasshopper species were showed for environs of the Dzhanybek Research Station. Features of their phenology and biotopical preference were investigated. Structure of grasshopper communities in common types of biotopes is discussed. Calling songs of 20 species of the subfamily Gomphocerinae are described. It is shown that species inhabiting the same biotope could have strong overlap of food and microhabitat niches, but they have different acoustic niches. In some cases, interspecific competition for the acoustic dimension of the biotope is important factor limiting biotopical distribution of grasshoppers

Corsac foxes ( Vu lpes corsac ) and red foxes ( V. vulpes ) range widely across northern and central Asia, occupying a variety of arid biotopes. In Mongolia, both species live sympatrically throughout most of the country, but few details of their habitat associations exist. We examined the biotope of corsac and red foxes in Ikh Nart Nature Reserve in Dornogobi Aimag, Mongolia, which lies at the confl ue nce of steppe and semi-desert vegetation zones. We evaluated the extent to which both species occur in these two zones and the habitats within them based on locations of scats ( n = 1 ,967), opportunistic sightings ( n = 2 19), and captures ( n = 3 5) collected from August 2004 to August 2007. Corsac and red foxes occurred in both steppe and semi-desert zones and all habitat types in the reserve. However, corsacs occurred more frequently than expected in steppe zone and red foxes occurred more than expected in semi-desert zone. Corsac locations associated positively with steppe habitats, including grass, shrub, and semi-shrub plains, whereas red fox locations fell mainly in drier, more rugged semi-desert habitats, suggesting ecological separation exists between species. As corsac and red foxes appear to be declining in Mongolia, our results suggest that protection efforts in Ikh Nart should focus on steppe habitats for corsacs and semi-desert habitats for red foxes.

The present study aims at describing and analyzing the floristic composition and vegetation types, as well as evaluating the impact of waste water pollution on the plant diversity and community structure in Al-Marj plain, North Libya. Forty-two stands, distributed among pol-luted and non-polluted sites, were selected seasonally for this study. A total of 156 species were recorded (92 in the polluted and 121 in the non-polluted sites). Eight vegetation groups were resulted after the application of TWINSPAN and DCA as classification and ordi-nation techniques: four represented the polluted sites, two for the non-polluted sites and other two were mixed groups. Group II ( Sarcopoterium spinosum - Pistacia len-tiscus), which represents the polluted sites, had the highest values of soil moisture, sa-linity, sulphate, calcium and potassium; while group VI ( Juniperus phoenicea - Olea europaea) inhabiting the non-polluted site, had the lowest value of organic matter, salinity and magnesium. Group VII ( Foeniculum vulgare - Nicotiana glauca), representing the non-polluted site, was the most diverse, while VG III ( Ricinus communis - Chrysanthemum coronarium), characterizing the polluted one, was the least. Heavy metal analysis, in both soil and waste water, indicated that the con-centrations of Pb, Cd, Cr, Cu and Ni in the polluted sites were significantly higher than that in the non-polluted ones. The diagram resulting from CCA showed effectiveness of most soil variables, except carbonates, sodium, magnesium and chlorides. The impact of waste water discharge led to the emergence of new invasive species, which may severely affects the plant diversity and community structure of this hot spot of biodiversity in Libya. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Much attention has been paid to differences in leaf form and composition among vegetation types, but less to the frequently substantial variation within vegetation types. We focused on the extent to which correlations between variables are the same in both succulent-poor and succulent-rich vegetation in semi-arid SE Spain. Mean foliar [N] of perennials varied among species over a 5-fold range. Across species, [N] was positively correlated with specific leaf area (i.e., leaf area divided by dry mass; SLA) and with water concentration at saturation (WCS) in the grasslands, excluding the one succulent species. In succulent-rich vegetation on marl, SLA was correlated with [N] but not WCS, and there was a wedge-shaped relationship between [N] and WCS. Foliar [N] and [P] were positively correlated in the grasslands, but not in succulent-rich vegetation on marl. The N/P quotient varied from 8 to 29, with mean 14 in grassland on limestone and mean 26 in grassland on deep soil over gypsum. Our chief finding is that most correlations among SLA, WCS, [N] and [P] found in the non-succulent vegetation are not found in the succulent-rich vegetation. The results are discussed in relation to global patterns and the problems of defining succulence. [ABSTRACT FROM AUTHOR]

Abstract: Because of their high proportion in the plant kingdom polyploid taxa are considered to have had evolutionary advantages over their diploid ancestors. These advantages may have included new characteristics that enable polyploids to occupy a broader range of habitats. In this context, we assess the ecological range of Artemisia sieberi, a canopy dominant within an important vegetation type in Iran. We assess the extent to which ploidy covaries with geographical and ecological distribution and look for ecologically-significant differences in the functional characteristics of diploids and polyploids. Populations of A. sieberi were sampled widely in Iran and soil characteristics, climate and anatomical and phytochemical plant attributes were measured. Also, in parallel, an independent genetic assessment of populations was carried out using genetic fingerprinting. Two ploidy levels were identified: 75% of the 34 populations of A. sieberi populations sampled were tetraploid (2n = 4x = 36) with the remainder diploid (2n = 2x = 18). Plants of differing ploidy also differed anatomically, genetically and chemically. Tetraploid populations had larger cells and lower stomatal densities and a different essential oil composition. They also appear ecologically distinct, occupying more fertile, mesic habitats than diploids. Genetic fingerprinting revealed the existence of two genetically differentiated subgroups independent of ploidy but with some geographic and ecological pattern. We conclude that diploids and tetraploids have a different ecological distribution and that the absence of mixed diploid-tetraploid populations is a reflection of differing fitness in different habitats. We suspect that a key ecological difference between diploids and tetraploids is the increased stomatal size of tetraploids, possibly resulting from the increased genome and hence cell size following polyploidisation. Polyploid-formation may be constrained in arid habitats by problems of water-use efficiency associated with the larger stomata originally produced. [Copyright &y& Elsevier]

Abstract: Generalist predators in agroecosystems may immigrate into the crop fields from the surrounding environment or may be agrobiont species that maintain stable populations in crop fields but are scarce in natural habitats. This study compared pest consumption of two main spider groups in wheat fields of a semi-desert agroecosystem of Israel, the immigrant spiders of the family Theridiidae (Enoplognatha spp.) and the agrobiont family Linyphiidae, to identify their potential role in biological control. The consumption of pest (aphids and Hessian flies) and non-pest arthropods (Collembola) was examined using PCR-based molecular gut content analysis. We describe the development of one new set of primer pairs targeting Hessian flies. We also used existing aphid- and collembolan-specific primers to test the hypotheses that agrobiont spiders are more likely to consume the most common prey species, while immigrant species will utilize pest prey more frequently than agrobionts. Our results indicated that a significantly higher proportion of immigrating Enoplognatha consumed aphids as compared to the agrobiont linyphiids, which mostly consumed collembolans. The results suggest that Enoplognatha have some degree of prey selection toward the crop pests (aphids). We therefore conclude that immigrant spiders may be particularly important biological control agents in the semi-arid wheat agroecosystem in Israel. [Copyright &y& Elsevier]

We describe Algaria nataliei, a new genus and species from the Worcester-Robertson Karoo region, Western Cape Province, South Africa. Particularly distinctive features of the new genus are the strongly dimorphic leaves with the upper toothed to laciniate-margined, apically notched on one side, and long-awned and the lower entire, weakly but distinctly cucullate and with the costa ending in the apex, the laminal cells bulging ventrally and smooth to weakly papillose but flattened dorsally and strongly papillose, the immersed macrostomous eperistomate capsules with flat to umbonate opercula and flattened or indented bases, and long-conic to mitrate, prorate-papillose calyptrae. [ABSTRACT FROM AUTHOR]

Abstract: A better understanding of the relation between suspended sediment concentration and water discharge is gained by recognizing, amongst other things, the different impacts of two types of rainfall event: wandering, discrete, convective or convectively-enhanced, high intensity storms; and ubiquitous, multi-celled, low intensity, frontal storms. In the Levant, the first type is characteristic of autumn and spring and the flushing of sediment by the instant onset of high intensity rainfall produces a clockwise hysteresis in the suspended sediment–water discharge relation. The second type is characteristic of winter and can be marked by either anticlockwise or no hysteresis in the suspended sediment–water discharge relation; sedimentary flushing is rarely apparent. Suspended sediment concentrations in flash floods resulting from convective storms are high (typically 104–105 mg l−1) but correlation with water discharge is low (r =0.57). In contrast, frontal storm runoff carries lower suspended sediment concentrations (typically 103–104 mg l−1) and correlation with water discharge is better (r =0.78). This division assists in interpreting the high degree of scatter evident in the overall suspended sediment concentration–water discharge relation, but it reveals that much is yet to be learned about the interplay of the disposition of cellular storm tracks and sediment source areas. [Copyright &y& Elsevier]

Giant earth mounds (heuweltjies) formed by the southern harvester termite Microhodotermes viator occupy a large proportion of the land surface of the Succulent karoo, Nama-karoo and Fynbos biomes. Microhodotermes viator is associated with specific vegetation types and low winter rainfall, prompting the hypothesis that rainfall and vegetative productivity govern the distribution and population densities of M. viator. Using an analysis of aerial photographs, the density of termite mounds at 34 sites in 10 vegetation types was determined across the full range of their distribution. The number of mounds ranged from 143 to 704 km−2 with a mean of 297. When all sites were considered together, mound density was not related to temperature, altitude, rainfall and vegetative productivity [as measured by the normalized difference vegetation index (NDVI)]. However, if the single Fynbos and five Coastal Renosterveld sites (with rainfall >350 mm year−1) were excluded from the analysis, then mound density was significantly related to both rainfall and NDVI values. A separate analysis of the relationship between mound density, rainfall and soil fertility was undertaken. There was a significant relationship between rainfall and mound density for sites occurring on soils of high-fertility status but not for sites occurring on soils of low-fertility status. These results suggest that soil fertility and vegetation composition are parameters that influence the effect of rainfall and vegetative productivity on termite mound distribution and density. Finally, the positive relationship between rainfall and mound density in areas with <350 mm year−1 suggests that M. viator populations are in equilibrium with climatic conditions. This provides further evidence that heuweltjies are constructed by their current occupants, M. viator, and are not the product of an extinct termite species as has been suggested previously. [ABSTRACT FROM AUTHOR]

Abstract: A survey for entomopathogenic nematodes was conducted in oak-juniper woodlands of four mountain ranges (Santa Rita, Santa Catalina, Pinaleño, and Chiricahuas), in southeastern Arizona. From a total of 120 soil samples, 23.3% were EPN-positive. Of them 78.5% were positive for Steinernema spp. and 21.5% were positive for Heterorhabditis spp. An integrated approach, combining both traditional (morphological) and molecular methods, was used for examining the diversity of species of these entomopathogenic nematodes. Two named-species S. oregonense and S. riobrave are reported for the first time in Arizona, expanding their currently known geographic range. In addition to this, three undescribed Steinernema and three Heterorhabditis spp. were recovered. Insular evolution, in part, could account for the geographic distribution of entomopathogenic nematodes in Arizona. [Copyright &y& Elsevier]

Abstract: This study evaluates some simple procedures for measuring ammonia (NH3) emission from wind speed, NH3 concentration and an estimate of atmospheric stability using the backward Lagrangian stochastic (bLS) dispersion technique. The bLS technique, which requires measurements from only one height may prove useful when carrying out experiments simultaneously in a small field with several small plots. Commercial software exists that facilitates easy use of the bLS technique. Our study shows the bLS to be reliable using average wind speed at one height and average NH3 concentration derived from horizontal flux measurements of NH3 using passive flux samplers. The bLS technique underestimated the emission by 16–24% when applied at a measurement height of 0.5–1.55m, but the inclination of bLS estimates versus integrated horizontal flux estimates was not different from 1 (P &#60;0.01). The emission of NH3 from urea applied to dry prairie soil was 29% of the nitrogen applied, emphasising the need of developing techniques for reducing NH3 emission from zero tillage arable soils. [Copyright &y& Elsevier]

Land degradation was investigated in a mountainous semi-arid area at the coast of southeastern Cuba in 2001. The study area included two villages and part of a nature reserve. Degree of degradation was investigated by walking across the study area to delineate different land use classes. Further information about the area was collected by interviewing 24 farmers and conducting rankings with key persons of the study villages.Six land use classes were distinguished: village areas, highly, moderately, and little degraded areas, areas with high tree density and areas with natural vegetation. Grazing was found to be the main cause of degradation in the study area, followed by wood cutting and forest fires. Impact of grazing was found to be highest near the villages, decreasing with greater distance towards the mountains. Woody vegetation is mostly cut to provide firewood or charcoal for the local population. The vegetation of the Nature Reserve is only affected to smaller degrees by grazing and wood cutting due to geographical factors limiting access.Some management options to combat land degradation, such as better stoves to reduce lavish use of firewood, seem to be feasible, but most options are limited by lack of finances, lack of personal responsibility or the failure to see short-term effects. Although villagers’ perception of degradation factors such as over-grazing is low, local initiatives to conserve their natural environment exist. [Copyright &y& Elsevier]

Data are presented on the changes in distribution and abundance of the Mongolian saiga Saiga tatarica mongolica in the last few decades, based on an analysis of the literature and the authors’ field observations. The subspecies has suffered a considerable decline in its range because of hunting and competition with domesticated stock. In 1997 a survey was made of almost all the known range, which consists of two disjunct areas and covers a total of 2200 sq km. A total of 609 animals was recorded and analysis of the census results suggests that c. 1300 saiga remain in total. The authors recommend strengthening the nature reserve established in 1993 in the Shargyn Gobi, and creating several sanctuaries outside this area, where Mongolian saiga from the main remaining population could be reintroduced. These measures would enhance prospects for the survival of this endemic subspecies of the semi-deserts of western Mongolia. [ABSTRACT FROM AUTHOR]

and 8 taxa of its allied genera, Australian Astereae. Statistical tests regarding correlations between changes in chromosome number, total chromosome length, mean chromosome length, karyotypic asymmetry and chromosome length heterogeneity and changes in habit were performed based on the matK molecular phylogenetic tree. The reductions in chromosome number and total chromosome length, and the increases in mean chromosome length, chromosome length heterogeneity and karyotypic asymmetry were found to be correlated with the change in habit from perennial to annual. A reduction in total chromosome length is favored to shorten the mitotic cell cycle and to produce smaller cells conducive to more rapid development of smaller annuals under the time-limited environment. Stepwise dysploidal reductions in chromosome number were achieved through the translocation of large chromosome segments onto other chromosomes, followed by the loss of a centromere, resulting in one fewer linkage group and one fewer haploid chromosome. The correlations between the dysploidal reduction in chromosome number and the increases in mean chromosome length, length heterogeneity and asymmetry in karyotype can be attributed to this mode of chromosomal change. These changes occurred independently in several different lineages in Brachyscome. [ABSTRACT FROM AUTHOR]

The water relations of three native and four exotic shrub species occurring in semi-arid Central Otago, New Zealand were examined. Water potentials at midday were low in the native Kunzea ericoides, while those in the exotic Lupinus arboreus remained high, but there were no other obvious distinctions between the field water potentials of the native and exotic species. An examination of the relation between water potential and water content, however, showed a low potential at full turgor in the native Coprosma propinqua, while the exotic species Rosa rubiginosa and L. arboreus both showed large changes in water potential for relatively small changes in water content after turgor had been lost. The exotics R. rubiginosa and Thymus vulgaris showed a rapid loss of water content in drying conditions; the exotic 'broom' Cytisus scoparius and the native 'broom' Carmichaelia compacta showed the lowest rates. It is concluded that there is no overall difference between the mechanism of adaptation of the native and exotic species; the exotic species that invaded are those that were pre-adapted to the conditions. [ABSTRACT FROM AUTHOR]