scholarly journals Carex secalina (Cyperaceae), a critically endangered species of Europe: historic and new localities in Poland

2011 ◽  
Vol 78 (4) ◽  
pp. 311-320 ◽  
Author(s):  
Marlena Lembicz ◽  
Agnieszka Bogdanowicz ◽  
Julian Chmiel ◽  
Waldemar Żukowski

<em>Carex secalina</em>, a species recognized as extinct in Poland for 40 years, was re-discovered in 2000 and it’s natural populations covered by monitoring. From among nine historic localities, only for two - Jacewo and Turzany, in the vicinity of Inowrocław - the occurrence of the species was confirmed. In the course of the field studies, six new localities, not previously recorded in literature, were discovered. The sedge occupies sub-halophytic habitats in which it occurs along with halophytic species (particularly, such as <em>Glaux maritima</em> and <em>Pucinellia distans</em>) and a group of ruderal taxons. One of the newly discovered localities of <em>C. secalina</em> comprises an anthropogenic habitat. On the whole, the population sizes ranged from 20 to 350 individuals. The studies revealed a positive correlation between the size of a population and cattle pasturing, i.e. <em>C. secalina</em> forms the largest populations in the habitats remaining under the intense pressure of grazing and treading. Moreover, it was found that the high generative reproduction rate compensates the damage caused by animal grazing. The results suggest that an active protection of the sedge populations through the agricultural use of its habitats is the only effective way of securing it’s further occurrence in Poland, while including the sub-halophytic pastures with <em>C. secalina</em> in the agricultural and environmental program should be a priority task in the nearest future.

2021 ◽  
pp. 1-4
Author(s):  
Yu-Wei Tseng ◽  
Chi-Chun Huang ◽  
Chih-Chiang Wang ◽  
Chiuan-Yu Li ◽  
Kuo-Hsiang Hung

Abstract Epilobium belongs to the family Onagraceae, which consists of approximately 200 species distributed worldwide, and some species have been used as medicinal plants. Epilobium nankotaizanense is an endemic and endangered herb that grows in the high mountains in Taiwan at an elevation of more than 3300 m. Alpine herbs are severely threatened by climate change, which leads to a reduction in their habitats and population sizes. However, only a few studies have addressed genetic diversity and population genetics. In the present study, we developed a new set of microsatellite markers for E. nankotaizanense using high-throughput genome sequencing data. Twenty polymorphic microsatellite markers were developed and tested on 30 individuals collected from three natural populations. These loci were successfully amplified, and polymorphisms were observed in E. nankotaizanense. The number of alleles per locus (A) ranged from 2.000 to 3.000, and the observed (Ho) and expected (He) heterozygosities ranged from 0.000 to 0.929 and from 0.034 to 0.631, respectively. The developed polymorphic microsatellite markers will be useful in future conservation genetic studies of E. nankotaizanense as well as for developing an effective conservation strategy for this species and facilitating germplasm collections and sustainable utilization of other Epilobium species.


2021 ◽  
Author(s):  
Ilan N. Rubin ◽  
Iaroslav Ispolatov ◽  
Michael Doebeli

AbstractOne of the oldest and most persistent questions in ecology and evolution is whether natural communities tend to evolve toward saturation and maximal diversity. Robert MacArthur’s classical theory of niche packing and the theory of adaptive radiations both imply that populations will diversify and fully partition any available niche space. However, the saturation of natural populations is still very much an open area of debate and investigation. Additionally, recent evolutionary theory suggests the existence of alternative evolutionary stable states (ESSs), which implies that some stable communities may not be fully saturated. Using models with classical Lokta-Volterra ecological dynamics and three formulations of evolutionary dynamics (a model using adaptive dynamics, an individual-based model, and a partial differential equation model), we show that following an adaptive radiation, communities can often get stuck in low diversity states when limited by mutations of small phenotypic effect. These low diversity metastable states can also be maintained by limited resources and finite population sizes. When small mutations and finite populations are considered together, it is clear that despite the presence of higher-diversity stable states, natural populations are likely not fully saturating their environment and leaving potential niche space unfilled. Additionally, within-species variation can further reduce community diversity from levels predicted by models that assume species-level homogeneity.Author summaryUnderstanding if and when communities evolve to saturate their local environments is imperative to our understanding of natural populations. Using computer simulations of classical evolutionary models, we study whether adaptive radiations tend to lead toward saturated communities in which no new species can invade or remain trapped in alternative, lower diversity stable states. We show that with asymmetric competition and small effect mutations, evolutionary Red Queen dynamics can trap communities in low diversity metastable states. Moreover, limited resources not only reduces community population sizes, but also reduces community diversity, denying the formation of saturated communities and stabilizing low diversity, non-stationary evolutionary dynamics. Our results are directly relevant to the longstanding questions important to both ecological empiricists and theoreticians on the species packing and saturation of natural environments. Also, by showing the ease evolution can trap communities in low diversity metastable stats, we demonstrate the potential harm in relying solely on ESSs to answer questions of biodiversity.


2021 ◽  
pp. 62-67
Author(s):  
I.V. Tkachenko ◽  

Objective: The aim of our work was to study the potential ecotoxicological hazard of a new chemical from the class of tetramic and tetronic acid derivatives - the insecticide spiromesifen, taking into account its physico-chemical properties and impact on the environmental objects. Materials and methods: An assessment of the potential danger of spiromesifen use for ecosystems was carried out on the basis of the calculation of the ecotoxicological hazard (ecotox) by N.N. Melnikov’s method. The field studies were carried out in different agro-climatic zones of Ukraine. The treatment of vineyards and apple trees was carried out at the maximum consumption rates of spiromesifen. Results: According to the literary data and our research, it was found that in the soil-and-climatic conditions of Ukraine, the ecotoxicological risk, when using the new insecticide spiromesifen, is 10,000 times and 7,000 times low than the analogous characteristics of DDT. Ecotox abamectin is 154 times low than ecotox DDT. This makes preparations, based on these substances, more promising and competitive among other pesticides in agricultural use. We can conclude that spiromesifen does not pose a threat to terrestrial ecosystems and health of the population.


2018 ◽  
Vol 108 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Erin E. Gunnink Troth ◽  
Jeffrey A. Johnston ◽  
Alan T. Dyer

Among root pathogens, one of the most documented antagonisms is the suppression of Cochliobolus sativus by Fusarium (roseum) species. Unfortunately, previous studies involved single isolates of each pathogen and thus, provided no indication of the spectrum of responses that occur across the respective species. To investigate the variability in interactions between Cochliobolus sativus and Fusarium pseudograminearum, field and greenhouse trials were conducted that included monitoring of spring wheat plant health and monitoring of pathogen populations via quantitative real-time polymerase chain reaction. The interactions between two isolates of C. sativus and four isolates of F. pseudograminearum were explored in three geographically distinct wheat fields. To complement field trials and to limit potentially confounding environmental variables that are often associated with field studies, greenhouse trials were performed that investigated the interactions among and between three isolates of C. sativus and four isolates of F. pseudograminearum. Across field locations, C. sativus isolate Cs2344 consistently and significantly reduced Fusarium populations by an average of 20.1%. Similarly, F. pseudograminearum isolate Fp2228 consistently and significantly reduced C. sativus field populations by an average of 30.9%. No interaction was detected in the field between pathogen species with regards to disease or crop losses. Greenhouse results confirmed a powerful (>99%), broadly effective suppression of Fusarium populations by isolate Cs2344. Among greenhouse trials, additional isolate–isolate interactions were observed affecting Fusarium populations. Due to lower C. sativus population sizes in greenhouse trials, significant Fusarium suppression of C. sativus was only detected in one isolate–isolate interaction. This study is the first to demonstrate suppression of Fusarium spp. by C. sativus in field and greenhouse settings. These findings also reveal a complex competitive interaction between these two pathogen species that was previously unknown.


1986 ◽  
Vol 64 (1) ◽  
pp. 227-232 ◽  
Author(s):  
A. A. Reznicek ◽  
P. M. Catling

Carex subimpressa, originally described as a hybrid of C. hyalinolepsis and C. lanuginosa, has been reported over a wide area and beyond the range of C. hyalinolepis. Consequently it has been accorded specific rank. Various aspects of morphology reflected in scatter diagrams as well as intermediate stomatal structure revealed through scanning electron microscopy and sectioning support the hybrid origin as originally proposed. This is further supported by field studies of natural populations where both putative parents were invariably present. Reports from beyond the range of one or both parents are the result of misidentification. The diagnostic character combination includes sparsely pubescent perigynia 4.2–6.4 mm long, with relatively short beaks, leaves 4.5–11 mm wide, and ligules 1.8–9 mm long.


2016 ◽  
Vol 283 (1843) ◽  
pp. 20161380 ◽  
Author(s):  
Ryan P. Kovach ◽  
Brian K. Hand ◽  
Paul A. Hohenlohe ◽  
Ted F. Cosart ◽  
Matthew C. Boyer ◽  
...  

Evolutionary and ecological consequences of hybridization between native and invasive species are notoriously complicated because patterns of selection acting on non-native alleles can vary throughout the genome and across environments. Rapid advances in genomics now make it feasible to assess locus-specific and genome-wide patterns of natural selection acting on invasive introgression within and among natural populations occupying diverse environments. We quantified genome-wide patterns of admixture across multiple independent hybrid zones of native westslope cutthroat trout and invasive rainbow trout, the world's most widely introduced fish, by genotyping 339 individuals from 21 populations using 9380 species-diagnostic loci. A significantly greater proportion of the genome appeared to be under selection favouring native cutthroat trout (rather than rainbow trout), and this pattern was pervasive across the genome (detected on most chromosomes). Furthermore, selection against invasive alleles was consistent across populations and environments, even in those where rainbow trout were predicted to have a selective advantage (warm environments). These data corroborate field studies showing that hybrids between these species have lower fitness than the native taxa, and show that these fitness differences are due to selection favouring many native genes distributed widely throughout the genome.


1968 ◽  
Vol 100 (7) ◽  
pp. 769-776 ◽  
Author(s):  
E. D. A. Dyer ◽  
D. W. Taylor

AbstractField studies were carried out on effect of attack by unmated spruce beetles, Dendroctonus obesus (Mann.) on log attractiveness. Test logs were screen-covered or sprayed with insecticide. Trays beneath logs, with glass-barrier traps beside them, were used to measure response of beetles from natural populations.About 89% of the beetles attracted at six replicate sites were taken at logs containing introduced females. Males always predominated in responses to these logs. After the initial flight, about equal numbers of each sex responded to logs without introduced females. Response to the latter dropped to a low level after the initial flight, but beetles continued to respond well to logs attacked by females throughout the flight period. Use of increased attractiveness to logs following introduction of female beetles shows promise as a means of studying, directing, or controlling infestations of the spruce beetle.


2020 ◽  
Author(s):  
Joshua Niklas Ebner ◽  
Danilo Ritz ◽  
Stefanie von Fumetti

AbstractIdentifying when and where environmental change induces molecular responses in natural populations is an important goal in contemporary ecology. It can aid in identifying molecular signatures of populations experiencing stressful conditions and potentially inform if species are approaching the limits of their tolerance niches. Achieving this goal is hampered by our limited understanding of the influence of environmental variation on the molecular systems of most ecologically relevant species as the pathways underlying fitness-affecting plastic responses have primarily been studied in model organisms under controlled laboratory conditions. In this study, we establish relationships between protein abundance patterns and the abiotic environment by profiling the proteomes of 24 natural populations of the caddisfly Crunoecia irrorata. We subsequently relate these profiles to natural variations in the abiotic characteristics of their freshwater spring habitats which shows that protein abundances and networks respond to abiotic variation according to the functional roles these proteins have. We provide evidence that geographic and past and present environmental differences between sites affect protein abundances and identifications, and that baseline reaction norms are ubiquitous and can be used as information rather than noise in comparative field studies. Taking this natural variation into account is a prerequisite if we are to identify the effects environmental change has on natural populations.


1998 ◽  
Vol 64 (9) ◽  
pp. 3256-3263 ◽  
Author(s):  
M. T. Brandl ◽  
S. E. Lindow

ABSTRACT Erwinia herbicola 299R produces large quantities of indole-3-acetic acid (IAA) in culture media supplemented withl-tryptophan. To assess the contribution of IAA production to epiphytic fitness, the population dynamics of the wild-type strain and an IAA-deficient mutant of this strain on leaves were studied. Strain 299XYLE, an isogenic IAA-deficient mutant of strain 299R, was constructed by insertional interruption of the indolepyruvate decarboxylase gene of strain 299R with the xylE gene, which encodes a 2,3-catechol dioxygenase from Pseudomonas putidamt-2. The xylE gene provided a useful marker for monitoring populations of the IAA-deficient mutant strain in mixed populations with the parental strain in ecological studies. A root bioassay for IAA, in which strain 299XYLE inhibited significantly less root elongation than strain 299R, provided evidence that E. herbicola produces IAA on plant surfaces in amounts sufficient to affect the physiology of its host and that IAA production in strain 299R is not solely an in vitro phenomenon. The epiphytic fitness of strains 299R and 299XYLE was evaluated in greenhouse and field studies by analysis of changes in the ratio of the population sizes of these two strains after inoculation as mixtures onto plants. Populations of the parental strain increased to approximately twice those of the IAA-deficient mutant strain after coinoculation in a proportion of 1:1 onto bean plants in the greenhouse and onto pear flowers in field studies. In all experiments, the ratio of the population sizes of strain 299R and 299XYLE increased during periods of active growth on plant tissue but not when population sizes were not increasing with time.


2021 ◽  
Vol 16 (4) ◽  
pp. 0
Author(s):  
Vladimir Kotov

We develop and analyze a population model allowing us to examine a system, where people coexist with artificial beings (robots) and the both consume the same resource entering the system. The robot population consists of friendly and aggressive robots that differ in their attitudes towards people. We propose a system of differential equations, which define a dynamics of the populations of people, friendly robots and aggressive robots, and discuss different scenarios of the system evolution including those that lead to disappearance of the human population. We determine conditions that ensure a more or less prosperous future for humanity. We analyze the behavior of the system for different time dependences of the rate of the resource flow (a constant function, a step-like function, constant functions with undershoots and overshoots, a periodic function, monotonically increasing and decreasing functions). Our analysis shows that the dynamics of the rate of the resource flow defines the changes of the tendencies of the population sizes. Among the obtained solutions, there are solutions that lead to an equilibrium between populations. For people this equilibrium may be regarded as favorable if robots prefer to benefit from communication with people, but not from their extermination. However, equilibrium solutions imply a constant or slowly changes of the rate of the resource flow. Short-term changes of the rate of the resource flow modify the balance between the human population and the robot population. Accumulation of the changes can even lead to disappearance of one of the populations. Qualitative analyzes of the proposed system of differential equations along with computer simulations allow us to conclude that there are some necessary conditions for a well-being of the humans and robots. These conditions are as follows. Firstly, the benefit of the robot from communicating with people has to be higher than the benefit from their extermination. Secondly, to prevent the appearance of the aggressive robots the humanity has to regulate effectively the size of its own population. Thirdly, people have to be able to restrict their needs while maintaining the reproduction rate.


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