scholarly journals Geographic variation in reproductive assurance of Clarkia pulchella

2018 ◽  
Author(s):  
Megan Bontrager ◽  
Christopher D. Muir ◽  
Amy L. Angert
Keyword(s):  
Geographic Variation ◽  
Fruit Production ◽  
Mixed Mating ◽  
Reproductive Assurance ◽  
Resource Reallocation ◽  
Temperature And Precipitation ◽  
Pollinator Community ◽  
Climatic Drivers ◽  
Plant Mating Systems ◽  
Clarkia Pulchella

AbstractClimate can affect plant populations through direct effects on physiology and fitness, and through indirect effects on their relationships with pollinating mutualists. We therefore expect that geographic variation in climate might lead to variation in plant mating systems. Biogeographic processes, such as range expansion, can also contribute to geographic patterns in mating system traits. We manipulated pollinator access to plants in eight sites spanning the geographic range of Clarkia pulchella to investigate geographic and climatic drivers of fruit production and seed set in the absence of pollinators (reproductive assurance). We examined how reproductive assurance and fruit production varied with the position of sites within the range of the species and with temperature and precipitation. We found that reproductive assurance in C. pulchella was greatest in populations in the northern part of the species’ range, and was not well-explained by any of the climate variables that we considered. In the absence of pollinators, some populations of C. pulchella have the capacity to increase fruit production, perhaps through resource reallocation, but this response is climate-dependent. Pollinators are important for reproduction in this species, and recruitment is sensitive to seed input. The degree of autonomous self-pollination that is possible in populations of this mixed-mating species may be shaped by historic biogeographic processes or variation in plant and pollinator community composition rather than variation in climate.

scholarly journals Reproductive system of a mixed-mating plant responds to climate perturbation by increased selfing

2013 ◽  
Vol 280 (1766) ◽  
pp. 20131336 ◽  
Author(s):  
N. T. Jones ◽  
B. C. Husband ◽  
A. S. MacDougall
Keyword(s):  
Population Structure ◽  
Environmental Change ◽  
Inbreeding Depression ◽  
Reproductive System ◽  
Fruit Production ◽  
Mixed Mating ◽  
Reproductive Assurance ◽  
Pollinator Visitation ◽  
Chasmogamous Flowers

How plants respond to climatic perturbations, which are forecasted to increase in frequency and intensity, is difficult to predict because of the buffering effects of plasticity. Compensatory adjustments may maintain fecundity and recruitment, or delay negative changes that are inevitable but not immediately evident. We imposed a climate perturbation of warming and drought on a mixed-mating perennial violet, testing for adjustments in growth, reproduction and mortality. We observed several plasticity-based buffering responses, such that the climatic perturbation did not alter population structure. The most substantial reproductive adjustments, however, involved selfing, with a 45% increase in self-pollination by chasmogamous flowers, a 61% increase in the number of cleistogamous flowers that produced at least one fruit and an overall 15% increase in fruit production from selfed cleistogamous flowers. Reproductive assurance thus compensated for environmental change, including low pollinator visitation that occurred independently of our climate treatment. There was also no immediate evidence for inbreeding depression. Our work indicates that plants with vegetative and reproductive flexibility may not be immediately and negatively affected by a climatic perturbation. The stabilizing effects of these reproductive responses in the long term, however, may depend on the implications of significantly elevated levels of selfing.

scholarly journals Geographic variation in reproductive assurance of Clarkia pulchella

Oecologia ◽  
2019 ◽  
Vol 190 (1) ◽  
pp. 59-67
Author(s):  
Megan Bontrager ◽  
Christopher D. Muir ◽  
Amy L. Angert
Keyword(s):  
Geographic Variation ◽  
Reproductive Assurance ◽  
Clarkia Pulchella

Floral trait variation and links to climate in the mixed-mating annual Clarkia pulchella

Botany ◽  
2018 ◽  
Vol 96 (7) ◽  
pp. 425-435 ◽  
Author(s):  
Devin E. Gamble ◽  
Megan Bontrager ◽  
Amy L. Angert
Keyword(s):  
Mating System ◽  
Common Garden ◽  
Moisture Stress ◽  
Floral Traits ◽  
Mixed Mating ◽  
Floral Trait ◽  
Local Climate ◽  
Self Fertilization ◽  
Clarkia Pulchella ◽  
Watering Treatment

The benefits of self-fertilization can vary across environments, leading to selection for different reproductive strategies and influencing the evolution of floral traits. Although stressful conditions have been suggested to favour self-pollination, the role of climate as a driver of mating-system variation is generally not well understood. Here, we investigate the contributions of local climate to intraspecific differences in mating-system traits in Clarkia pulchella Pursh in a common-garden growth chamber experiment. We also tested for plastic responses to soil moisture with watering treatments. Herkogamy (anther–stigma spacing) correlated positively with dichogamy (timing of anther–stigma receptivity) and date of first flower, and northern populations had smaller petals and flowered earlier in response to experimental drought. Watering treatment alone had little effect on traits, and dichogamy unexpectedly decreased with annual precipitation. Populations also differed in phenological response to watering treatment, based on precipitation and winter temperature of their origin, indicating that populations from cool and dry sites have greater plasticity under different levels of moisture stress. While some variation in floral traits is attributable to climate, further investigation into variation in pollinator communities and the indirect effects of climate on mating system can improve our understanding of the evolution of plant mating.

scholarly journals Variation in reproductive effort, genetic diversity and mating systems across Posidonia australis seagrass meadows in Western Australia

AoB Plants ◽  
2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Elizabeth A Sinclair ◽  
Jane M Edgeloe ◽  
Janet M Anthony ◽  
John Statton ◽  
Martin F Breed ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating System ◽  
Western Australia ◽  
Reproductive Effort ◽  
Genetic Data ◽  
Fruit Production ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Shark Bay ◽  
Range Edge

Abstract Populations at the edges of their geographical range tend to have lower genetic diversity, smaller effective population sizes and limited connectivity relative to centre of range populations. Range edge populations are also likely to be better adapted to more extreme conditions for future survival and resilience in warming environments. However, they may also be most at risk of extinction from changing climate. We compare reproductive and genetic data of the temperate seagrass, Posidonia australis on the west coast of Australia. Measures of reproductive effort (flowering and fruit production and seed to ovule ratios) and estimates of genetic diversity and mating patterns (nuclear microsatellite DNA loci) were used to assess sexual reproduction in northern range edge (low latitude, elevated salinities, Shark Bay World Heritage Site) and centre of range (mid-latitude, oceanic salinity, Perth metropolitan waters) meadows in Western Australia. Flower and fruit production were highly variable among meadows and there was no significant relationship between seed to ovule ratio and clonal diversity. However, Shark Bay meadows were two orders of magnitude less fecund than those in Perth metropolitan waters. Shark Bay meadows were characterized by significantly lower levels of genetic diversity and a mixed mating system relative to meadows in Perth metropolitan waters, which had high genetic diversity and a completely outcrossed mating system. The combination of reproductive and genetic data showed overall lower sexual productivity in Shark Bay meadows relative to Perth metropolitan waters. The mixed mating system is likely driven by a combination of local environmental conditions and pollen limitation. These results indicate that seagrass restoration in Shark Bay may benefit from sourcing plant material from multiple reproductive meadows to increase outcrossed pollen availability and seed production for natural recruitment.

scholarly journals Reconstruction of the annual mass balance of Chhota Shigri glacier, Western Himalaya, India, since 1969

2014 ◽  
Vol 55 (66) ◽  
pp. 69-80 ◽  
Author(s):  
Mohd Farooq Azam ◽  
Patrick Wagnon ◽  
Christian Vincent ◽  
Alagappan Ramanathan ◽  
Anurag Linda ◽  
...  
Keyword(s):  
Mass Balance ◽  
Western Himalaya ◽  
Winter Precipitation ◽  
Temperature Index ◽  
Temperature And Precipitation ◽  
Chhota Shigri Glacier ◽  
Decadal Scale ◽  
Climatic Drivers ◽  
Precipitation Records ◽  
Significant Mass Loss

AbstractThis study presents a reconstruction of the mass balance (MB) of Chhota Shigri glacier, Western Himalaya, India, and discusses the regional climatic drivers responsible for its evolution since 1969. The MB is reconstructed by a temperature-index and an accumulation model using daily air-temperature and precipitation records from the nearest meteorological station, at Bhuntar Observatory. The only adjusted parameter is the altitudinal precipitation gradient. The model is calibrated against 10 years of annual altitudinal MB measurements between 2002 and 2012 and decadal cumulative MBs between 1988 and 2010. Three periods were distinguished in the MB series. Periods I (1969-85) and III (2001-12) show significant mass loss at MB rates of -0.36±0.36 and -0.57±0.36mw.e.a-1 respectively, whereas period II (1986-2000) exhibits steady-state conditions with average MBs of -0.01 ±0.36mw.e.a–1. The comparison among these three periods suggests that winter precipitation and summer temperature are almost equally important drivers controlling the MB pattern of Chhota Shigri glacier at decadal scale. The sensitivity of the modelled glacier-wide MB to temperature is -0.52 m w.e. a–1 °C–1 whereas the sensitivity to precipitation is calculated as 0.16mw.e.a-1 for a 10% change.

Context-dependent autonomous self-fertilization yields reproductive assurance and mixed mating

Nature ◽  
2004 ◽  
Vol 430 (7002) ◽  
pp. 884-887 ◽  
Author(s):  
Susan Kalisz ◽  
Donna W. Vogler ◽  
Kristen M. Hanley
Keyword(s):  
Mixed Mating ◽  
Reproductive Assurance ◽  
Self Fertilization ◽  
Context Dependent

Patterns of geographic variation in the skull of Nearctic Ermine (Mustela erminea)

1990 ◽  
Vol 68 (6) ◽  
pp. 1241-1249 ◽  
Author(s):  
Judith L. Eger
Keyword(s):  
Geographic Variation ◽  
North American ◽  
Geographic Distance ◽  
Glacial Refugia ◽  
Clinal Variation ◽  
Shape Variation ◽  
Mustela Erminea ◽  
Temperature And Precipitation ◽  
Glacial Stage ◽  
Species Groups

A. H. Macpherson suggested that much of the current geographic diversity in species and species groups of arctic mammals resulted from isolation in glacial refugia during the Wisconsin glacial stage. The present study evaluates this refugium hypothesis using a statistical assessment of geographic variation in 13 craniometric characters of Nearctic Mustela erminea. There is significant geographic variation among samples of North American ermine. Most of the skull character variance in this species reflects differences in size and is clinal. Variation in skull size is better explained by temperature and precipitation variables than by geographic distance, suggesting that environmentally ordered selection for size has been superimposed on any size differentiation that occurred during isolation in refugia. Variation in skull shape shows a relatively low correlation with climatic variables, and partitioning tests on shape variation reveal discontinuities consistent with the refugium hypothesis. Distinctive groups of samples reflect possible refugial populations in Eastern Beringia, in periglacial refugia south of the Wisconsin ice in eastern North America, and in one or more western North American refugia.

Climatic change caused larger variation of spring phenology in temperate semi-dry grasslands in China

2020 ◽  
Author(s):  
Xuancheng Zhou ◽  
Yongshuo Fu ◽  
Yaru Zhang
Keyword(s):  
Limiting Factor ◽  
Entire Study Period ◽  
Temperate Grasslands ◽  
Spring Phenology ◽  
Entire Study ◽  
Dry Grassland ◽  
Dry Grasslands ◽  
Temperature And Precipitation ◽  
Highly Sensitive ◽  
Climatic Drivers

<p>Vegetation phenology is highly sensitive to climate change. Previous studies focusing on the trends of phenological events have found that temperature and precipitation primarily regulate the dates of spring phenology in temperate grasslands. However, the variation of spring phenology and its controlling factors are still unclear. In this study, we investigated the start of the growing season (SOS) in temperate semi-dry grasslands in China using five methods, and determined the variation of SOS and its primary factor over the study period 1982-2015. We found that, in line with previous studies, the SOS date did not change significantly during the entire study period 1982-2015, but its variation increased significantly from the first subperiod (1982-1998, Std: 8.8±1.1 day) to the second (1999-2015, Std: 10.3±1.1 days), the latter of which coincides with fast warming. The larger variation in SOS may be caused by the different climatic drivers on phenology in different areas. The fluctuation of temperature was significantly increased over the study area and subsequently may result in a larger variation of SOS. Furthermore, precipitation and soil moisture has increased until the mid-1990s, which may lead to the removal of water as a limiting factor and increase the response of semi-dry grassland spring phenology to temperature, and finally result in larger variation in SOS.</p>

Mating strategies dictate the importance of insect visits to native plants in urban fragments

2020 ◽  
Vol 68 (1) ◽  
pp. 26
Author(s):  
E. L. Eakin-Busher ◽  
P. G. Ladd ◽  
J. B. Fontaine ◽  
R. J. Standish
Keyword(s):  
Reproductive Success ◽  
Plant Species ◽  
Native Species ◽  
Mating Systems ◽  
Mating Strategies ◽  
Mixed Mating ◽  
Native Plant ◽  
Native Woodland ◽  
Plant Mating Systems ◽  
Plant Mating

Plant species conservation relies on their reproductive success and likelihood of population persistence. Knowledge of plant mating systems, particularly the relationship between plants and their pollinators, is fundamental to inform conservation efforts. This knowledge could be critical for prioritising efforts in human-dominated fragmented landscapes such as the world’s biodiversity hotspots, where reproductive success can be compromised due to habitat loss, limited access to pollinators or other factors. Yet, fundamental data on plant mating systems are lacking for many Australian plants. Here we determined the mating systems of native plant species growing in native woodland fragments within Perth’s urban landscape in south-western Australia. We manipulated insect access to flowers and pollen transfer on five locally common native species, then observed floral visitors and examined reproductive success. Hemiandra pungens and Patersonia occidentalis had mixed mating systems with some ability to self-pollinate, whereas Dianella revoluta and Jacksonia sericea were reliant on insects for outcross pollination. The fruits and seeds produced by Tricoryne elatior were too low to draw conclusions about its mating system. The introduced honey bee (Apis mellifera) was the sole visitor to the mixed mating species, whereas native bees visited D. revoluta and J. sericea (one bee species each). Overall, our data suggest that D. revoluta and J. sericea are more vulnerable to fragmentation than H. pungens and P. occidentalis. Although insects contributed significantly to the reproductive output of the two former plant species, our observations suggested low frequency and richness of insect visitors to these urban fragments. More research is required to determine the generality of our findings. A comparative study in larger native woodland fragments would help estimate the effect of fragmentation on insect pollinators and consequences for the insect-reliant plant species.

Costs and benefits of the mixed-mating system of Narcissus serotinus (Amaryllidaceae) in the conservation of small fragmented populations

Botany ◽  
2014 ◽  
Vol 92 (2) ◽  
pp. 113-122 ◽  
Author(s):  
Isabel Marques ◽  
David Draper ◽  
José María Iriondo
Keyword(s):  
Inbreeding Depression ◽  
Floral Biology ◽  
Mixed Mating ◽  
Reproductive Assurance ◽  
Evolutionary Potential ◽  
Mixed Mating System ◽  
Fragmented Populations ◽  
Large Populations ◽  
Fruit And Seed Set ◽  
Plant Pollinator

Small fragmented populations often exhibit reduced plant–pollinator interactions and scarce outcrossing opportunities. In this context, mixed-mating systems can be advantageous since selfing can provide reproductive assurance, but they may also carry relevant costs such as those involved in inbreeding depression. This study examines the advantages and costs of selfing in Narcissus serotinus L., a mixed-mating geophyte that currently occurs in several fragmented populations in Portugal, that resulted from the construction of the largest European dam. Observation of pollinators revealed that cross-pollination is less frequent in small than in large populations. Manual self-pollinations significantly increased fruit and seed set in small-size populations, also suggesting limited insect pollination. The existence of selfing may provide reproductive assurance in small-size populations of N. serotinus where outcrossing pollination is reduced. Although floral biology and experimental pollinations showed that N. serotinus is capable of autonomous selfing, four of the six fitness traits studied showed significant inbreeding depression in all populations. The high levels of inbreeding depression found in N. serotinus suggest that the initial reproductive assurance advantage of selfing may be counterbalanced by lower survival of the resulting individuals and a decrease in the evolutionary potential of the populations.

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