scholarly journals Reproductive Success of an Endangered Plant after Invasive Bees Supplant Native Pollinator Services

Diversity ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Alyson M. DeNittis ◽  
Susan E. Meyer
Keyword(s):  
Reproductive Success ◽  
Reproductive Output ◽  
Genetic Factors ◽  
Fruit Set ◽  
First Year ◽  
Flower Number ◽  
Interplant Distance ◽  
Negative Effect ◽  
Study Sites ◽  
Africanized Honeybees

Arctomecon humilis (dwarf bear poppy) is an endangered gypsophile restricted to the St. George area in southern Utah, USA. Extirpation of the rare oligolectic bee Perdita meconis and decline of other native pollinators within the last 20 years has been largely attributed to the advent of invasive Africanized honeybees (AHBs), which have become the predominant pollinator for A. humilis. A three-year study was carried out to determine if reliance on AHBs had a negative effect on reproductive output. In the first year, pollen addition experiments were carried out in a small, isolated population to determine if pollinator scarcity or genetic factors affected reproductive output. In the subsequent two years, reproductive output studies were conducted across four populations. In all years, fruit set across study sites was exceptionally high. There was no consistent effect from flower number or interplant distance, which have historically been shown to have a significant impact on reproductive output prior to AHB arrival. The consequences and sustainability of this relatively young relationship between A. humilis and the AHB remain unclear. However, high reproductive success shows that the AHB is currently capable of adequately fulfilling pollinator services for A. humilis.

Beetle pollination and fruit predation of Xanthosoma daguense (Araceae) in an Andean cloud forest in Colombia

2004 ◽  
Vol 20 (4) ◽  
pp. 459-469 ◽  
Author(s):  
Carlos García-Robledo ◽  
Gustavo Kattan ◽  
Carolina Murcia ◽  
Paulina Quintero-Marín
Keyword(s):  
Reproductive Success ◽  
Positive Relationship ◽  
Fruit Set ◽  
Cloud Forest ◽  
Female Reproductive Success ◽  
Hand Pollination ◽  
Negative Effect ◽  
Tropical Cloud Forest ◽  
Nitidulid Beetles ◽  
Pollination Systems

This study describes a pollination system in a species of Araceae that involves three species of beetle, one of which is also a fruit predator. In a tropical cloud forest in Colombia, inflorescences of Xanthosoma daguense opened at dusk, releasing a sweet scent and raising their temperature 1–3 °C. Soon after, two species of Scarabaeidae (Dynastinae; Cyclocephala gregaria and C. amblyopsis) and one species of Nitidulidae (Macrostola costulata) arrived with pollen. Cyclocephala beetles remained inside the inflorescence for 24 h. The next night, Cyclocephala beetles left the inflorescence after picking up the freshly shed pollen, almost always moving to the nearest inflorescence available. The probability of inflorescence abortion and number of fruits set after the visit of one individual was equivalent for both Cyclocephala species. However, C. gregaria was much more abundant than C. amblyopsis, so it was the most important pollinator. There was a positive relationship between the number of dynastine visits and the number of fruits produced. Besides carrying pollen to the inflorescences, nitidulid beetles had a negative effect on female reproductive success through fruit predation. Nitidulid larvae developed inside the infructescence and preyed on up to 64% of the fruits. However, 8% of inflorescences not visited by dynastines were probably pollinated by nitidulids, because hand-pollination experiments showed that self-pollination was unlikely. Inflorescences potentially pollinated by nitidulids comprised 25% of the fruit crop in the year of our study. This interaction with a fruit predator that is also a potential pollinator resembles brood-site pollination systems in which pollinators prey on part of the fruit set (e.g. Ficus, senita cacti, Yucca), making this system substantially more complex than previously described dynastine-pollinated systems in aroids.

scholarly journals A comparative study on the reproductive success of two rewarding Habenaria species (Orchidaceae) occurring in roadside verge habitats

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wenliu Zhang ◽  
Jiangyun Gao
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Plant Density ◽  
Flowering Plant ◽  
Floral Display ◽  
Pollinator Behaviour ◽  
Factors Affecting ◽  
Nectar Sugar ◽  
Viable Seeds ◽  
Viable Embryo

Abstract Background Most orchid species have been shown to be severely pollination limited, and the factors affecting reproductive success have been widely studied. However, the factors determining the reproductive success vary from species to species. Habenaria species typically produce nectar but exhibit variable fruit set and reproductive success among species. Here, we investigated the influence of the flowering plant density, inflorescence size, breeding system, and pollinator behaviour on the reproductive success of two rewarding Habenaria species. Results Our observations indicated that Habenaria limprichtii and H. petelotii co-occur in roadside verge habitats and present overlapping flowering periods. Both species were pollination limited, although H. limprichtii produced more fruits than H. petelotii under natural conditions during the 3-year investigation. H. petelotii individuals formed distinct patches along roadsides, while nearly all H. limprichtii individuals clustered together. The bigger floral display and higher nectar sugar concentration in H. limprichtii resulted in increased attraction and visits from pollinators. Three species of effective moths pollinated for H. limprichtii, while Thinopteryx delectans (Geometridae) was the exclusive pollinator of H. petelotii. The percentage of viable seeds was significantly lower for hand geitonogamy than for hand cross-pollination in both species. However, H. limprichtii may often be geitonogamously pollinated based on the behaviours of the pollinators and viable embryo assessment. Conclusions In anthropogenic interference habitats, the behaviours and abundance of pollinators influence the fruit set of the two studied species. The different pollinator assemblages in H. limprichtii can alleviate pollinator specificity and ensure reproductive success, whereas the more viable embryos of natural fruit seeds in H. petelotii suggested reducing geitonogamy by pollinators in the field. Our results indicate that a quantity-quality trade-off must occur between species with different breeding strategies so that they can fully exploit the existing given resources.

scholarly journals Impact of “non-lethal” tarsal clipping on bumble bees (Bombus vosnesenskii) may depend on queen stage and worker size

2021 ◽  
Author(s):  
John M. Mola ◽  
Clara Stuligross ◽  
Maureen L. Page ◽  
Danielle Rutkowski ◽  
Neal M. Williams
Keyword(s):  
Genetic Material ◽  
Population Monitoring ◽  
First Year ◽  
Negative Effects ◽  
Worker Size ◽  
Monitoring Tools ◽  
Individual Survival ◽  
Body Sizes ◽  
Negative Effect ◽  
Worker Caste

Abstract Recent bumble bee declines have prompted the development of novel population monitoring tools, including the use of putatively non-lethal tarsal clipping to obtain genetic material. However, the potential side effects of tarsal clipping have only been tested in the worker caste of a single domesticated species, prompting the need to more broadly test whether tarsal clipping negatively affects sampled individuals. To determine if tarsal clipping reduces queen survivorship and colony establishment, we collected wild queens of Bombus vosnesenskii and clipped tarsi from a single leg of half the individuals. We reared captive queens and estimated survivorship and nest establishment success. We also clipped tarsi of workers from a subset of colonies across a range of body sizes. We found no consistent negative effect of clipping on queen survival. In the first year, clipped nest-searching queens suffered heavy mortality, but there was no effect on foraging queens. The following year, we found no effect of clipping on queen survival or establishment. Clipping did not reduce overall worker survival but reduced survivorship for those in the smallest size quartile. Implications for insect conservation Our findings suggest tarsal clipping does not have consistent negative effects on individual survival. However, our results varied with queen behavioral state, year, and worker size, suggesting differences within and among species and interactions with landscape stressors warrant further study. In the interim, we recommend researchers and conservationists minimize the use of tarsal clipping for sensitive species, populations, or small workers except in cases of exceptional scientific need.

scholarly journals Spatial distribution of the Barbary Partridge (Alectoris barbara) in Sardinia explained by land use and climate

2021 ◽  
Vol 67 (4) ◽  
Author(s):  
Gianpasquale Chiatante ◽  
Marta Giordano ◽  
Anna Vidus Rosin ◽  
Oreste Sacchi ◽  
Alberto Meriggi
Keyword(s):  
Land Use ◽  
Conservation Status ◽  
Distance Sampling ◽  
Strong Relationship ◽  
European Population ◽  
Factors Affecting ◽  
Brood Rearing ◽  
Management Actions ◽  
Negative Effect ◽  
Study Sites

AbstractMore than half of the European population of the Barbary Partridge is in Sardinia; nonetheless, the researches concerning this species are very scarce, and its conservation status is not defined because of a deficiency of data. This research aimed to analyse the habitat selection and the factors affecting the abundance and the density of the Barbary Partridge in Sardinia. We used the data collected over 8 years (between 2004 and 2013) by spring call counts in 67 study sites spread on the whole island. We used GLMM to define the relationships between the environment (topography, land use, climate) both the occurrence and the abundance of the species. Moreover, we estimated population densities by distance sampling. The Barbary Partridge occurred in areas at low altitude with garrigue and pastures, avoiding woodlands and sparsely vegetated areas. We found a strong relationship between the occurrence probability and the climate, in particular, a positive relation with temperature and a negative effect of precipitation, especially in April–May, during brood rearing. Furthermore, dry crops positively affected the abundance of the species. We estimated a density of 14.1 partridges per km2, similar to other known estimates. Our findings are important both because they increase the knowledge concerning this species, which is considered data deficient in Italy, and because they are useful to plan management actions aimed to maintain viable populations if necessary.

Reproductive success of Acacia longifolia (Fabaceae, Mimosoideae) in native and invasive populations

2015 ◽  
Vol 63 (5) ◽  
pp. 387 ◽  
Author(s):  
Marta Correia ◽  
Sílvia Castro ◽  
Susana Rodríguez-Echeverría
Keyword(s):  
Reproductive Success ◽  
Seed Size ◽  
Fruit Set ◽  
Lower Number ◽  
Open Pollination ◽  
Native Range ◽  
Reproductive Assurance ◽  
Acacia Species ◽  
Self Compatibility ◽  
Selfing Ability

The reproductive biology of exotic species affects their capacity to become naturalised and invasive in non-native areas. Selfing is a common trait in many invasive plants probably because it provides reproductive assurance under low availability of pollination vectors and sexual partners. Nonetheless, the predominantly self-incompatible Australian Acacia species are among the most aggressive plants worldwide. To address whether there have been changes in selfing ability and natural reproductive success of A. longifolia during invasion, we compared one population in the invaded area (Portugal) with one population in the native range (Australia). We specifically assessed floral traits, fruit set and offspring traits for selfing and open-pollination treatments. Within each pollination treatment, no differences were found between areas, suggesting that the level of self-compatibility has not changed during invasion. However, the number of aborted seeds and seed size were significantly different between pollination treatments in Australia but not in Portugal. There were significant differences in the number of seeds per pod and in seed weight between ranges. A lower number of aborted seeds, a higher number of fully developed seeds and a greater seed size were found in the invaded area for both pollination treatments. In spite of the low selfing ability of A. longifolia in the invaded area, there was an increase in the quantity and size of the seeds produced in the new region, even for self-pollinated fruits, which might contribute to A. longifolia invasiveness.

scholarly journals The effect of pollen source on seed traits and dispersability in the heterocarpic annual Crepis sancta

2020 ◽  
Author(s):  
Efrat Dener ◽  
Hagai Shemesh ◽  
Itamar Giladi
Keyword(s):  
Reproductive Success ◽  
Reproductive Output ◽  
Seed Traits ◽  
Dispersal Strategy ◽  
Physiological Constraints ◽  
Dispersal Traits ◽  
Distant Neighbor ◽  
The Common ◽  
Nonsignificant Effect ◽  
Crepis Sancta

Abstract Aims The evolution and expression of dispersal-related traits are intertwined with those of other life-history functions and are manifested within various physiological constraints. Such a relationship is predicted between inbreeding levels and dispersability, which may be anatomically and ontogenetically linked so that the selection pressures on one may affect the other. While both the effect of inbreeding on reproductive success and on dispersal strategies received much attention, only a few studies considered both simultaneously. Furthermore, such studies often rely on two dichotomic representations of breeding and dispersal: using selfing vs. outcrossing as a representation of breeding level, and dispersal ratio as the sole representation of dispersal strategy. Methods Here we used pollination experiments in the heterocarpic Crepis sancta (Asteraceae) to expand in two different manners on the common practice of using dichotomic representations of breeding and dispersal. First, we used pollination treatments that represent a continuum from selfing through pollination by kin to pollination by a distant neighbor. Second, we measured a whole set of continuous morphological and dispersal-related traits, in addition to measurements of reproductive success and dispersal ratio. Important findings The proportion of developed capitula and the number of both dispersed and non-dispersed achenes were significantly lower in the self-pollination treatment in comparison to the out-crossed treatments. The effect of pollen sources on dispersal ratio was not statistically significant, though self-pollinated plants rarely produced non-dispersing seeds. Achene’s biomass increased with distance between parent plants, but pappus width did not, leading to a nonsignificant effect of pollination on falling velocity. Overall, pollen source affected mainly traits that were associated with reproductive output, but it had no clear effect on predominately dispersal-related traits. Such differences in the response of reproduction and dispersal traits to variation in pollen source suggest that dispersal-related selection is probably weak and/or masked by other forces.

PRIOR MATHEMATICS PERFORMANCE, STATISTICS ANXIETY, SELF-EFFICACY AND EXPECTATIONS FOR PERFORMANCE IN STATISTICS: A SURVEY OF SOCIAL SCIENCES STUDENTS IN A CARIBBEAN INSTITUTION OF HIGHER EDUCATION

2021 ◽  
Vol 20 (1) ◽  
pp. 4
Author(s):  
TALIA RANDA ESNARD ◽  
FAREENA MARYAM ALLADIN ◽  
KEISHA CHANDRA SAMLAL
Keyword(s):  
Social Sciences ◽  
Self Efficacy ◽  
Academic Discipline ◽  
Relative Effect ◽  
Mathematics Performance ◽  
First Year ◽  
Statistics Anxiety ◽  
Negative Effect ◽  
Performance Statistics ◽  
First Year University

The objectives of this study were to examine (i) the expectation for performance (EFP) in statistics of first year university students, (ii) the relative effect of previous mathematics performance (PMP), perceived statistical self-efficacy (SSE), and statistics anxiety (SA) for understanding these expectations, and (iii) whether students’ EFP scores differ based on sex and academic discipline. Findings point to average to high EFP in statistics, with no differences in these levels based on sex or academic discipline. PMP had little effect on students’ EFP, but, moderate effects on their levels of SA. While SSE positively affected both students’ SA, this measure produced a negative effect on their EFP in statistics. Both SSE and SA negatively affected students’ EFP in statistics, but with minimally higher levels for the latter.

The importance of recruitment patterns versus reproductive output in the persistence of a short-range endemic shrub in a highly fragmented landscape of south-western Australia

2012 ◽  
Vol 60 (7) ◽  
pp. 643 ◽  
Author(s):  
Neil Gibson ◽  
Colin Yates ◽  
Margaret Byrne ◽  
Margaret Langley ◽  
Rujiporn Thavornkanlapachai
Keyword(s):  
Short Range ◽  
Reproductive Output ◽  
Fruit Set ◽  
Seedling Recruitment ◽  
Fragment Size ◽  
Fragmented Landscape ◽  
Recruitment Failure ◽  
Degree Of Isolation ◽  
Number Of Seeds ◽  
Significant Mortality

Calothamnus quadrifidus subsp. teretifolius A.S.George & N.Gibson is a short-range endemic shrub whose habitat has been greatly reduced by clearing for agriculture. Reproductive output was high in all populations sampled, although there were large differences among populations in fruit set, the number of seeds per fruit and seed germination. These traits showed no relationship to population size, degree of isolation, or fragment size, which contrasts strongly with the patterns found in a widespread congener. Demographic studies in remnants with an intact understorey showed stable adult populations with continuous seedling recruitment. In contrast, there was consistent widespread failure of seedling and juvenile recruitment in degraded roadside remnants that also showed significant mortality of reproductive adults. In these degraded remnants, recruitment failure appears to be the primary cause of species decline.

scholarly journals Attitudes and Reactions of Medical Students to the Dissection Room

2021 ◽  
Vol 15 (5) ◽  
pp. 917-919
Keyword(s):  
Longitudinal Study ◽  
Medical Students ◽  
Coping Strategy ◽  
Skin Irritation ◽  
First Year ◽  
Human Cadaver ◽  
Cadaver Dissection ◽  
Negative Effect ◽  
Human Cadavers ◽  
Loss Of Appetite

Background: Students get their first experiences of dissecting human cadavers in the practical classes of anatomy. These experiences may help in their profession, but may also create some problems for students Aims: To find out the attitudes and reactions of medical students to the dissection room. Methods: A longitudinal study was conducted on 309 first year MBBS students at the local college of Lahore with no previous experience of cadaver dissection. Students were filled a questionnaire. The questionnaire designedwas based to identify the feelings and problems faced by the students in their first exposure to the human cadaver. Results: Almost 25% students experience no symptom on first entry into the dissecting room. The commonest symptoms of 75% students were insomnia, dizziness, sweating, loss of appetite and palpitation. Other symptoms reported were breathlessness, skin irritation, irritation of the eye, etc. Focusing on task was the main coping strategy used by majority of students. Conclusion: The majority of the students initially experience nausea and fear that may reduce with time while excitement and interest had increased on ensuing exposure to dissection.Study concluded that the negative effect of dissection room on students is less than the benefits of dissection of cadaver. Anticipation felt by the students to learn dissecting the cadaver was relatively high. Keywords: Cadaver, Dissection room, Medical students.

scholarly journals Do abundance and proximity of the alien Impatiens glandulifera affect pollination and reproductive success of two sympatric co-flowering native species?

2012 ◽  
Vol 10 ◽  
pp. 130-139
Author(s):  
Valérie Cawoy ◽  
Mathieu Jonard ◽  
Carolin Mayer ◽  
Anne-Laure Jacquemart
Keyword(s):  
Reproductive Success ◽  
Native Species ◽  
Natural Populations ◽  
Pollen Deposition ◽  
Impatiens Glandulifera ◽  
Insect Behaviour ◽  
Native Flora ◽  
Visitation Rates ◽  
Aconitum Napellus ◽  
Negative Effect

In invasion ecology, potential impacts of aliens on native flora are still under debate. Our aim was to determine the pollinator mediated effects of both proximity and abundance of an alien species on the reproductive success of natives. We chose the highly invasive Impatiens glandulifera and two native species: Epilobium angustifolium and Aconitum napellus ssp. lusitanicum. These species share characteristics allowing for pollination interactions: similar biotopes, overlapping flowering periods and same main pollinators. The effects of abundance (5, 25 and 100 individuals) and proximity (0 and 15 m) of the alien on visitation rate, insect behaviour, pollen deposition and reproductive success of both natives were investigated during 2 flowering seasons. We used centred visitation rates as they can be directly interpreted as a positive or negative effect of the invasive.Both abundance and proximity of the alien increased bumblebee visitation rates to both natives. On the other hand, abundance of the exotic species had a slight negative effect on honeybee visits to natives while its proximity had no effect. The behaviour of bumblebees changed as visitors left significantly more often the native plants for I. glandulifera when its abundance increased. As a consequence of this “inconstancy”, bees deposited considerable quantities of alien pollen on native stigmas. Nevertheless, this interspecific pollen transfer did not decrease seed set in natives. Self-compatibility and high attractiveness of both native species probably alleviate the risk of altered pollinator services and reproductive success due to the invader in natural populations.

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