Search results for "systematic"
showing 10 items of 7608 documents
Seed germination and seedling allogamy in Rosmarinus officinalis: the costs of inbreeding.
2018
Self‐pollination by geitonogamy is likely in self‐compatible plants that simultaneously expose a large number of flowers to pollinators. However, progeny of these plants is often highly allogamous. Although mechanisms to increase cross‐pollination have been identified and studied, their relative importance has rarely been addressed simultaneously in plant populations. We used Rosmarinus officinalis to explore factors that influence the probability of self‐fertilisation due to geitonogamy or that purge its consequences, focusing on their effects on seed germination and allogamy rate. We experimentally tested the effect of geitonogamy on the proportion of filled seeds and how it influences ge…
Inflorescence scents of Calendula maritima, C. suffruticosa subsp. fulgida, and their hybrid
2018
Premise of research. Hybridization is an important driver of plant evolutionary processes. By attracting the same pollinators to different species, floral scents may be involved in the formation of hybrids and breakdown of species boundaries. In contrast, by attracting a different suite of pollinators to hybrids and their parents, floral scents are believed to contribute to speciation processes initiated by hybridization events. Scents may or may not differ between the hybrids and their parents, but little is known about the scent chemistry of parental species and their hybrids. Methodology. We studied the inflorescence scents of parental Calendula maritima and C. suffruticosa subsp. fulgid…
Resource profitability, but not caffeine, affects individual and collective foraging in the stingless beePlebeia droryana
2019
ABSTRACT Plants and pollinators form beneficial relationships, with plants offering resources in return for pollination services. Some plants, however, add compounds to nectar to manipulate pollinators. Caffeine is a secondary plant metabolite found in some nectars that affects foraging in pollinators. In honeybees, caffeine increases foraging and recruitment to mediocre food sources, which might benefit the plant, but potentially harms the colonies. For the largest group of social bees, the stingless bees, the effect of caffeine on foraging behaviour has not been tested yet, despite their importance for tropical ecosystems. More generally, recruitment and foraging dynamics are not well und…
Interspecific variation of inflorescence scents and insect visitors in Allium (Amaryllidaceae: Allioideae)
2019
Allium is a large monocotyledonous genus, with many species of high economic importance. Knowledge of the pollination biology and the chemical ecology of pollination in this genus is far from being complete. We studied flower visitors of some Allium species in their native habitat and how these interaction partners communicate by olfactory cues. Floral volatiles of five Mediterranean species were investigated by dynamic headspace and thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS). Floral visitors were observed and captured. The physiological activity of scent components in antennae of flower visitors and congeneric species was tested by gas chromatographic/electroantenno…
Ecological and conceptual consequences of Arctic pollution
2020
Although the effect of pollution on forest health and decline received much attention in the 1980s, it has not been considered to explain the ‘Divergence Problem’ in dendroclimatology; a decoupling of tree growth from rising air temperatures since the 1970s. Here we use physical and biogeochemical measurements of hundreds of living and dead conifers to reconstruct the impact of heavy industrialisation around Norilsk in northern Siberia. Moreover, we develop a forward model with surface irradiance forcing to quantify long‐distance effects of anthropogenic emissions on the functioning and productivity of Siberia’s taiga. Downwind from the world’s most polluted Arctic region, tree mortality ra…
The tangled cases of Deinogalerix (Late Miocene endemic erinaceid of Gargano) and Galericini (Eulipotyphla, Erinaceidae): a cladistic perspective.
2018
The Late Miocene giant erinaceid Deinogalerix from Scontrone and Gargano (Italy) is associated with many other vertebrates in deposits of a past island, the “Abruzzo-Apulia Platform”. At Gargano, Deinogalerix is accompanied by the moderately endemized Galericini Apulogalerix. This first extensive cladistic analysis is aimed at defining the relationships of Deinogalerix with characteristic members of the tribe Galericini. The analysis was performed on a matrix of 30 characters and 19 taxa and identified some smaller clades, nested within three major ones. The latter include: (i) a pentatomy of Galerix species, (ii) a polytomy of “transitional” Galerix–Parasorex species and (iii) a large clad…
Identity of the Calcarata species complex in Viola sect. Melanium (Violaceae)
2020
The Calcarata species complex in Viola sect. Melanium (Violaceae) is a group of species from Italy and neighbouring islands. The complex is of considerable evolutionary interest because several hypotheses about hybrid speciation within the group have been previously proposed. Because the Calcarata complex is not well characterized morphologically, we used 142 samples representing 92 (of c. 120) species of V. sect. Melanium plus three outgroup species. Nuclear ITS and ETS and plastid trnS–trnG intergenic spacer sequences were analysed to test the monophyly of the Calcarata complex and to infer relationships among the constituent species. Both nuclear and plastid sequences resulted in very li…
Intergenerational fitness effects of the early life environment in a wild rodent.
2019
The early life environment can have profound, long-lasting effects on an individual's fitness. For example, early life quality might (a) positively associate with fitness (a silver spoon effect), (b) stimulate a predictive adaptive response (by adjusting the phenotype to the quality of the environment to maximize fitness) or (c) be obscured by subsequent plasticity. Potentially, the effects of the early life environment can persist beyond one generation, though the intergenerational plasticity on fitness traits of a subsequent generation is unclear. To study both intra- and intergenerational effects of the early life environment, we exposed a first generation of bank voles to two early life…
Fine-scale population dynamics in a marine fish species inferred from dynamic state-space models
2017
1. Identifying the spatial scale of population structuring is critical for the conservation of natural populations and for drawing accurate ecological inferences. However, population studies often use spatially aggregated data to draw inferences about population trends and drivers, potentially masking ecologically relevant population sub‐structure and dynamics. 2. The goals of this study were to investigate how population dynamics models with and without spatial structure affect inferences on population trends and the identification of intrinsic drivers of population dynamics (e.g. density dependence). 3. Specifically, we developed dynamic, age‐structured, state‐space models to test differe…
Do phase-dependent life history traits in cyclic voles persist in a common environment?
2019
Phenotype and life history traits of an individual are a product of environmental conditions and the genome. Environment can be current or past, which complicates the distinction between environmental and heritable effects on the phenotype in wild animals. We studied genome–environment interactions on phenotype and life history traits by transplanting bank voles (Myodes glareolus) from northern and southern populations, originating from low or high population cycle phases, to common garden conditions in large outdoor enclosures. The first experiment focused on the persistence of body traits in autumn-captured overwintering populations. The second experiment focused on population growth and …