ABSTRACT
Global agricultural landscapes are witnessing a concerning decline in biodiversity, and this trend is predicted to persist. To safeguard these biodiversity-rich areas, it is crucial to pinpoint hotspots effectively. In doing so, we used various species of avian predators as suitable sentinel animals due to their mobility and dependence on prey diversity and abundance. Between 2019 and 2021, we tracked 62 individuals from four bird of prey species using GPS loggers in Estonian farmland. Dividing the study area into 50 m grids and overlaying them with tracked individuals' locations enabled us to differentiate between hotspots of their activity and control sites. We conducted surveys on amphibian, bird, small mammal and plant abundance and diversity to determine if avian predator activity hotspots correlated with overall biodiversity. Our findings revealed significantly higher diversity and abundance in the surveyed groups within activity hotspots compared to control sites. These hotspots continued to be frequently used by raptors in the subsequent year, albeit not two years later. In conclusion, multispecies GPS telemetry of avian predators emerges as an objective, dependable and spatially accurate biodiversity indicator. With the accumulation of movement data, we anticipate increased interest and adoption of this approach in biodiversity monitoring.
ABSTRACT
Carex pulicaris is considered an endangered species, and further losses are forecast under the influence of even moderate climate change. Local studies indicate that temporal declines in C. pulicaris abundance are positively correlated to decreases in precipitation and increases in air temperature. Determining ecological properties on larger scales than local ones can help develop effective protection programs for the species. We hypothesize that the local relationships observed between C. pulicaris abundance and precipitation, air temperature and soil properties will be confirmed in a spatially-oriented large-scale study performed in situ. Therefore, the present study takes a novel, large-scale integrated approach to (1) precisely characterize the ecological requirements of C. pulicaris within its eastern distribution range, and (2) determine the influence of its community type, soil properties and climatic conditions on its abundance. It was found that C. pulicaris is not a dominant or codominant species in the studied phytocoenoses in the eastern distribution range. Five natural vegetation groups including C. pulicaris, with significantly diverse species compositions, were resolved: well supported Estonian, Polish, Slovak and Radecz groups, and a weakly-supported Ambiguous group. The abundance of C. pulicaris was found to be positively correlated with the composition of the geographically-diversified plant communities and atmospheric precipitation, and to be also negatively associated with latitude and soil pH. Although the species is adapted to a relatively wide range of soil types, such adaptation requires appropriate substrate moisture level and light conditions. The species prefers moist organic and mineral soils and grows on both acid and neutral medium, characterized by a narrow C:N ratio, with various amounts of digestible total P, Mg and N, and low levels of digestible K. Climate change, manifested by reduced rainfall, may be one of the most important predictors negatively affecting the occurrence of C. pulicaris.
ABSTRACT
BACKGROUND: Carex buxbaumii and C. hartmaniorum are sister species of the clade Papilliferae within the monophyletic section Racemosae. An unambiguous identification of these species is relatively difficult due to the interspecific continuum of some morphological characters as well as the intraspecific variability. The study was aimed at determining the range of variability, both morphological and genetic, within and between these two closely related and similar species. METHODS: The sedges were collected during botanical expeditions to Armenia, Estonia, the Netherlands, and Poland. The morphological separation of the two species and their populations was tested using the Discriminant Function Analysis (DFA). The genetic variability of the 19 Carex populations was assessed in the presence of eight Inter Simple Sequence Repeat (ISSR) primers. RESULTS: Results of the study indicate a considerable genetic affinity between the two sedge species (mean Si = 0.619). However, the populations of C. hartmaniorum are, morphologically and genetically, more homogenous than the populations of C. buxbaumii. Compared to C. hartmaniorum, C. buxbaumii usually has wider leaf blades, a shorter inflorescence, a lower number of spikes which are shorter, but wider, and longer bracts and utricles. The AMOVA showed a larger variation between the populations of C. buxbaumii, representing 25.65% of the total variation in the taxon. Two populations of C. buxbaumii (from Poland and Estonia) are separated from the remaining populations, both genetically and morphologically; their individuals show shorter utricles and glumes, compared to the typical specimens of C. buxbaumii, and correspond with the morphology of putative infraspecific taxa described by Cajander (var. brevisquamosa and var. confusa). CONCLUSIONS: The taxonomic status of the putative infraspecific taxa within C. buxbaumii requires further studies throughout the distribution range of C. buxbaumii, addressing habitats, morphology and genetics (including a chromosome count or a combination of different genetic methods), particularly as the variability in C. buxbaumii may be associated with the species' polyploid origin.
