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Salix gordejevii (Salicaceae) is a climax and dominant sand-fixing shrub species native to the northern China. We assessed S. gordejevii population genetic variation in different environmental gradients in Horqin Sandy Land, Northern China using inter-simple sequence repeat (ISSR) markers, and investigated the possible existence of relationships between genetic diversity and environmental gradients. The results showed that S. gordejevii populations in general have high genetic diversity. An analysis of molecular variation (AMOVA) revealed relatively high levels (> 89.91%) of within-population genetic variation. Based on cluster analysis, the 12 studied S. gordejevii populations can be clustered into three clades. Genetic diversity and differentiation of S. gordejevii populations are affected from different environmental gradients. Genetic diversity of all populations was affected by habitat environment change, and was well-correlated with the humidity gradients. These results have important implications for restoration and management of degraded ecosystems in arid and semi-arid areas.
The specific conditions in habitats in the immediate vicinity of roads provide a suitable environment for noxious weeds and invasive species that spread through them to the landscape. Echinochloa crus-galli and Digitaria sanguinalis are problematic weeds of wide-row crops. The field experiment focused on the impact of the roadside habitat salinization on the occurrence, growth and reproduction of these two species. Quantitative vegetative and generative characteristics of the plants were determined. Measurements were carried out at three distances from the edge of the road and on control plots.
The results showed that the growth and reproduction of E. crus-galli and D. sanguinalis occur in the period when the values of soil environmental variables correspond to values of non-saline soil according to the criteria for soil salinity assessment. Despite this fact, the average salinity of soil along roadside was still higher than in soil of further distances and we found these levels of salinity to be well tolerated by the study species. Therefore, we conclude that roadsides with the same or higher salt content represent a suitable location for the occurrence and reproduction of E. crus-galli and D. sanguinalis, thus being temporary locations that enable their further spreading to the countryside.
Military training areas, where ecosystems are shaped under a complex disturbance regime, are recognized to be favourable pieces of land for maintaining high biological diversity. Our study focused on explosion craters – a small-scale disturbance type of high severity, and their effect on species diversity including vascular plants, bryophytes and lichens. The research was carried out on an active military training area in Nowa Dęba (SE Poland). The examined vegetation represented open communities on nutrient-poor soils with a wide range of soil moisture conditions. We compared 76 pairs of vegetation samples, each pair consisting of a crater and a closely located control plot of the same size. Out of 135 species recorded (72 vascular plants, 33 mosses, 9 liverworts, 22 lichens), 37 were found only in craters, while 19 occurred only in control plots. Both, species number and diversity were significantly higher for craters than controls. In general, the positive effect of cratering on all studied groups rises from dry to wet habitats. The highest increase of diversity was observed in relation to bryophytes in the moist habitats. Moreover, craters within habitats of higher moisture turned out to be more resistant to alien colonization and at the same time were characterized by significantly higher number of red-listed species compared to the control plots. Differences in species composition between craters and undisturbed plots were most visible in moderately moist habitats. We found several species with a strong preference for craters, and the plants of the highest indicative value are Atrichum tenellum and Dicranella cerviculata.
This study (conducted in western Poland) was aimed at recognizing the importance of straw heaps (SH) and manure heaps (MH) located in cultivated fields for fungal diversity in farmland. Fungi (24 species and 1 sterile form) were found in 19.1% of SH (N = 89) and 60.4% of MH (N = 169). The estimated species richness (Chao2) was 29.8 ± 12.7 and 18.1 ± 2.5 (SD), respectively. Species composition of fungal communities differed significantly between SH and MH. The studied ephemeral habitats contributed markedly to fungal diversity, both locally and on the national scale. The occurrence of fungi in SH was significantly positively related to heap size, while fungal species number in MH depended most strongly on the degree of shielding, linked with proximity of woods or shelterbelts. The results show that both the reduction of SH and MH numbers in farmlands (required by the Nitrates Directive) and landscape simplification are unfavorable for fungal diversity.
Nematode communities of the gastrointestinal tract in three species of wild ducks: mallard (Anas platyrhynchos), tufted duck (Aythya fuligula) and common scoter (Melanitta nigra), from the area of Western Pomerania in Poland, were compared. Nematodes were the most numerous group in the helminth fauna of the common scoter, the second most abundant group in the mallard and the least numerous group among parasites found in the tufted duck. A total of 5348 nematodes belonging to 14 species were isolated from 366 examined ducks. Six nematode species (represented by 607 individuals) were found in mallard, 5 species (493 individuals) in tufted duck and 7 species (3576 individuals) in common scoter. Nematofauna of tufted duck was characterized by the highest species evenness, while the nematofauna of common scoter presented the greatest species diversity. The analysis of fauna similarity showed one common parasitic species (Epomidiostomum uncinatum) for mallard and common scoter, and three species (Tetrameres ryjikovi, T. spinosa and Echinuria hypognatha) for tufted duck and common scoter. Regarding the spatial distribution of nematodes most of them primarily reside in the proventriculus (84% of all nematodes in mallard and 40% in tufted duck) and gizzard (56.6% of all nematodes in tufted duck and 74% in common scoter), whereas, only individuals of the species Eucoleus contortus and Capillaria anatis were located in the oesophagus and intestine.
The results confirm that the phylogenetic differences of the three duck species, as well as the differences in their ecology are accompanied by differences in the structure of parasitic nematode community.
Spiders are among the most important predators in forest litter layer that control food chain and decomposition process. However, little is known about the changes in litter-spider communities from wind-exposed to wind-shielded areas during monsoon seasons, and their roles in litter arthropod distribution and decomposition processes. In the present study, the densities and diversities of the spider communities in litter were examined at the two locations in monsoon and non-monsoon seasons in southern Taiwan. Enclosures with/without the spider Ctenus yaeyamensi were set up to compare litter arthropod distribution and decomposition rates in litterbags in different sampling units. It was found that the mean density of litter spiders was significantly greater in wind-shielded area than wind-exposed area. There was a marked impact of structure and depth of litter layers on guild composition, but not on the diversity indices of the litter spider communities. The litter invertebrates and decomposition rates did not differ between enclosures with/without spiders. However, there was a marked difference in litter arthropod abundance between monsoon and non-monsoon seasons in wind-exposed areas. The decomposition rate was remarkably greater in non-monsoon seasons than in monsoon seasons, whereas there were no marked differences between wind-shielded and wind-exposed locations. It was concluded that litter arthropod distribution and related decomposition were affected by variation of monsoon seasons but not by spider presence/absence in Nanjenshan Rain Forest.
We studied species composition and seasonal co-existence of coprophagous Scarabaeoidea from two study sites in karst meadows in sub-Mediterranean Slovenia. Each site consisted of three habitat patches with different impact of grazing (S1, the active part of the pasture; S2, the overgrown part of the pasture, mainly spiny shrubs; S3, a meadow with some overgrown patches of shrubs outside the fenced pasture). Four pitfall trapping events per month were conducted from March until November to test for temporal, spatial and habitat-related segregation of species. Primary results show a high level of temporal segregation of species within and between the guilds (Aphodiidae – dwellers, Geotrupidae – tunnelers, Scarabaeidae – tunnelers, Scarabaeidae – rollers). Temporal segregation of monthly samples was evident between Aphodiidae – dwellers (most active at the beginning and end of the season, with a month of complete inactivity during hot summer) and Scarabaeidae – tunnelers (present all the time, but with least species and specimens at the beginning and end of season). Intra-guild competition was most prominent for Aphodiidae – dwellers and Geotrupidae – tunnelers, where species show high rate of temporal avoidance to minimize interspecies competition for the same food source. Finally, geographical (site-related) and habitat-related (S1, S2, S3) differences were found in species composition, species richness and abundance, however for the latter two parameters only at habitat level (more species at S1, but higher abundances at S2 and S3). The results imply that the pronounced temporal and spatial segregation facilitate higher biodiversity in space and time, and allow more species to co-exist at the same sites over time.
We compared population structure and trophy hunting statistics of Himalayan ibex (Capra sibirica) in two community-controlled hunting areas (CCHAs) of northern Pakistan with varying duration of trophy hunting and isolated populations of C. sibirica. Based on fixed-point direct count method during winter 2016–2017, 939 ibexes were counted in Khyber and 346 in Hussaini, with a density of 7.5 and 3.2 animals km-2, respectively. Though the populations of C. sibirica at both the study sites have increased compared to the past estimates, we found variations in population structures and horn sizes, presumably as a result of trophy hunting. The sex ratios are skewed toward females in Khyber (87 males/100 females) and towards males in Hussaini (115 males/100 females). The trophy size males were 7% of the population in Khyber and 11% in Hussaini. Mean group (herd) size in Khyber was 28 (range = 1–117) and Hussaini was 20 (range = 1–79). Mean horn size of the trophies harvested in Khyber was 102 cm (± range = 91–114) compared to 108 cm (range = 99–121) in Hussaini. Stringent regulatory measures are suggested to determine the number of permits.
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