Aim Many high-latitude floras contain more calcicole than calcifuge vascular plant species. The species pool hypothesis explains this pattern through an historical abundance of high-pH soils in the Pleistocene and an associated opportunity for the evolutionary accumulation of calcicoles. To obtain insights into the history of calcicole/calcifuge patterns, we studied species richness-pH-climate relationships across a climatic gradient, which included cool and dry landscapes resembling the Pleistocene environments of northern Eurasia.
Location Western Sayan Mountains, southern Siberia.Methods Vegetation and environmental variables were sampled at steppe, forest and tundra sites varying in climate and soil pH, which ranged from 3.7 to 8.6. Species richness was related to pH and other variables using linear models and regression trees.Results Species richness is higher in areas with warmer winters and at medium altitudes that are warmer than the mountains and wetter than the lowlands. In treeless vegetation, the species richness-pH relationship is unimodal. In tundra vegetation, which occurs on low-pH soils, richness increases with pH, but it decreases in steppes, which have high-pH soils. In forests, where soils are more acidic than in the open landscape, the species richness-pH relationship is monotonic positive. Most species occur on soils with a pH of 6-7.Main conclusions Soil pH in continental southern Siberia is strongly negatively correlated with precipitation, and species richness is determined by the opposite effects of these two variables. Species richness increases with pH until the soil is very dry. In dry soils, pH is high but species richness decreases due to drought stress. Thus, the species richness-pH relationship is unimodal in treeless vegetation. Trees do not grow on the driest soils, which results in a positive species richness-pH relationship in forests. If modern species richness resulted mainly from the species pool effects, it would suggest that historically common habitats had moderate precipitation and slightly acidic to neutral soils.
Pollination is a required process for survival of numerous plant species and crops. Hoverflies (Diptera: Syrphidae) play a significant role in this phenomenon. Due to raising environmental pressures, pollinator diversity and pollination services are at risk. Faunistic studies and biodiversity research are the essential elements and steps in the process of species preservation. This study aimed to analyze diversity of hoverflies in two CORINE land cover types (Broad-leaved forest and Natural grasslands), based on a recent one-year study. To achieve this goal, Shannon's diversity index (H), Shannon's equitability (E H ), and Jaccard similarity coefficient (J t ) were calculated. Values of indices and coefficients indicate which parts of Vojvodina and what land cover types can be considered as hoverfly reservoirs.
Biodiversity has strongly declined throughout the world mainly due to human
activities. Thus, standardized indicators are needed more than ever before to
effec?tively monitor anthropogenic disturbance and its impact on ecosystems.
In this study, hov?erfly species of two largest phytophagous genera
(Cheilosia and Merodon) were chosen as bioindicators to assess the quality of
15 sites located in Serbia; in or around mountains Fruska Gora, Kopaonik,
Stara Planina, Dubasnica and Pcinja region. Sufficiently close associations
with particular habitats (each having its own characteristic assemblage) make
phytophagous hoverflies perfect candidates for such a role. Syrph the Net
database was used as a useful tool for assessing quality of habitats and
detecting differences between them. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 043002: Biosensing technology and global
system for continuous research and integrated management of ecosystems]
Descriptions of the endophallus (for 10 species) and female genital segments and genitalia (for 8 species) of the genus Nicrophorus Fabricius, 1775 are presented in the paper. Figures of described structures are given. A status of N. investigator interruptus stat. n. is lowered to subspecies level, N. tennuipes (Lewis, 1887) is included in the subgenus Nicrophorus Fabricius, 1775. Status of the following taxa is restored: subgenera Acanthopsilus
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