scholarly journals When spring ephemerals fail to meet pollinators: mechanism of phenological mismatch and its impact on plant reproduction

2019 ◽  
Vol 286 (1904) ◽  
pp. 20190573 ◽  
Author(s):  
Gaku Kudo ◽  
Elisabeth J. Cooper
Keyword(s):  
Seed Production ◽  
Plant Reproduction ◽  
Flowering Phenology ◽  
Spring Phenology ◽  
Snow Removal ◽  
Pollination Success ◽  
Spring Ephemerals ◽  
Degree Day ◽  
Spring Ephemeral ◽  
Phenological Mismatch

The flowering phenology of early-blooming plants is largely determined by snowmelt timing in high-latitude and high-altitude ecosystems. When the synchrony of flowering and pollinator emergence is disturbed by climate change, seed production may be restricted due to insufficient pollination success. We revealed the mechanism of phenological mismatch between a spring ephemeral ( Corydalis ambigua ) and its pollinator (overwintered bumblebees), and its impact on plant reproduction, based on 19 years of monitoring and a snow removal experiment in a cool-temperate forest in northern Japan. Early snowmelt increased the risk of phenological mismatch under natural conditions. Seed production was limited by pollination success over the 3 years of the pollination experiment and decreased when flowering occurred prior to bee emergence. Similar trends were detected on modification of flowering phenology through snow removal. Following snowmelt, the length of the pre-flowering period strongly depended on the ambient surface temperature, ranging from 4 days (at greater than 7°C) to 26 days (at 2.5°C). Flowering onset was explained with an accumulated surface degree-day model. Bumblebees emerged when soil temperature reached 6°C, which was predictable by an accumulated soil degree-day model, although foraging activity after emergence might depend on air temperature. These results indicate that phenological mismatch tends to occur when snow melts early but subsequent soil warming progresses slowly. Thus, modification of the snowmelt regime could be a major driver disturbing spring phenology in northern ecosystems.

Phenology and seed production in Chenopodium rubrum, Rumex maritimus, and Rumex palustris as related to photoperiod in river forelands

1992 ◽  
Vol 70 (2) ◽  
pp. 392-400 ◽  
Author(s):  
A. J. M. Van der Sman ◽  
C. W. P. M. Blom ◽  
H. M. Van de Steeg
Keyword(s):  
Life Cycle ◽  
Seed Production ◽  
Population Level ◽  
Flowering Phenology ◽  
Chenopodium Rubrum ◽  
Axillary Shoots ◽  
Critical Photoperiod ◽  
Number Of Leaves ◽  
Rumex Maritimus ◽  
Flooded Areas

Reproductive development in three species from irregularly flooded areas of river forelands was studied in relation to time of emergence. In Chenopodium rubrum, flowering was induced earlier in plants germinated in April–May than in later cohorts. However, the period of vegetative growth diminished and the life cycle was completed in a shorter time in later germinated plants. Seed number was reduced, but seed size as well as reproductive effort per plant increased in later cohorts. Plants of both Rumex species flowered after a certain number of leaves had developed and before a critical photoperiod had passed. In earlier cohorts, the main shoot and several axillary shoots elongated and flowered. Fewer axillary shoots flowered closer to the critical photoperiod, and this resulted in a reduced seed output in later cohorts. The critical photoperiod as well as the time needed for completion of the life cycle was longer in Rumex palustris than in Rumex maritimus. It is argued that in the riparian habitat, plants of both Rumex species are only occasionally able to complete their life cycle in one growing season. Survival of these species on the population level will rely more upon adaptations towards flooding during the established phase than is the case for C. rubrum. Key words: flowering phenology, photoperiod, seed production, Chenopodium rubrum, Rumex maritimus, Rumex palustris.

scholarly journals Floral Biology and Seed Production in Cultivated North American Ginseng (Panax quinquefolius)

2000 ◽  
Vol 125 (5) ◽  
pp. 567-575 ◽  
Author(s):  
Cayetana Schluter ◽  
Zamir K. Punja
Keyword(s):  
Seed Production ◽  
North American ◽  
Age Groups ◽  
Morphological Characteristics ◽  
Floral Biology ◽  
American Ginseng ◽  
Panax Quinquefolius ◽  
Flowering Period ◽  
Pollination Success ◽  
Pollen Release

Morphological characteristics of flowers, duration of flowering, degree of self-pollination, and extent of berry and seed production in North American ginseng (Panax quinquefolius L.) were studied under controlled environmental conditions as well as under field conditions. A comparison was also made between plants of 3 and 4 years of age at two field locations. The duration of flowering was ≈4 weeks and was similar in plants of both age groups grown in the two environments; however, 4-year-old plants produced an average of 40% more flowers (≈100 per plant in total) compared to 3-year-old plants. Flowers were comprised of five greenish-colored petals, five stamens, and an inferior ovary consisting of predominantly two fused carpels and stigmatic lobes. Anthers dehisced in staggered succession within individual flowers, and flowering began with the outermost edge of the umbel and proceeded inwards. At any given time during the 4-week flowering period, ≈10% of the flowers in an umbel had recently opened and were producing pollen. Stigma receptivity was associated with separation of the stigmatic lobes; this occurred at some time after pollen release. Growth of pollen tubes through the style in naturally pollinated flowers was most evident when the stigmatic lobes had separated. The proportion of flowers that developed into mature berries (pollination success rate) was in the range of 41% to 68% for both 3-year-old and 4-year-old plants. However, when the inflorescence was bagged during the flowering period, berry formation was increased by 13% to 21% in 4-year-old plants, depending on location. A majority of the berries (92% to 99%) contained one or two seeds in an almost equal frequency, with the remaining berries containing three seeds. In 4-year-old plants, the frequency of two-seeded berries was increased by ≈13% by bagging the inflorescence. These observations indicate that P. quinquefolius is highly self-fertile and that several physiological and environmental factors can affect seed production.

Does seed production of spring ephemerals decrease when spring comes early?

2004 ◽  
Vol 19 (2) ◽  
pp. 255-259 ◽  
Author(s):  
Gaku KUDO ◽  
Yoko NISHIKAWA ◽  
Tetsuya KASAGI ◽  
Shoji KOSUGE
Keyword(s):  
Seed Production ◽  
Spring Ephemerals

scholarly journals Phenological change in a spring ephemeral: implications for pollination and plant reproduction

2016 ◽  
Vol 22 (5) ◽  
pp. 1779-1793 ◽  
Author(s):  
Zachariah J. Gezon ◽  
David W. Inouye ◽  
Rebecca E. Irwin
Keyword(s):  
Plant Reproduction ◽  
Spring Ephemeral

Variable flowering phenology and pollinator use in a community suggest future phenological mismatch

2014 ◽  
Vol 59 ◽  
pp. 104-111 ◽  
Author(s):  
Theodora Petanidou ◽  
Athanasios S. Kallimanis ◽  
Stefanos P. Sgardelis ◽  
Antonios D. Mazaris ◽  
John D. Pantis ◽  
...  
Keyword(s):  
Flowering Phenology ◽  
Phenological Mismatch

scholarly journals Late canopy closure delays senescence and promotes growth of the spring ephemeral wild leek (Allium tricoccum)

Botany ◽  
2017 ◽  
Vol 95 (5) ◽  
pp. 457-467 ◽  
Author(s):  
Pierre-Paul Dion ◽  
Julie Bussières ◽  
Line Lapointe
Keyword(s):  
Light Availability ◽  
Growing Season ◽  
Tree Canopy ◽  
Strong Impact ◽  
Bud Burst ◽  
Growth And Survival ◽  
Spring Ephemerals ◽  
Spring Ephemeral ◽  
Tree Leaf ◽  
Allium Tricoccum

Spring ephemerals take advantage of the high light conditions in spring to accumulate carbon reserves through photosynthesis before tree leaves unfold. Recent work has reported delayed leaf senescence under constant light availability in some spring ephemerals, such as wild leek (Allium tricoccum). This paper aims to establish whether tree canopy composition and phenology can influence the growth of spring ephemerals through changes in their phenology. Wild leek bulbs were planted in 31 plots in southern Quebec, Canada, under canopies varying in composition and densities. Light availability and tree phenology were measured, along with other environmental conditions, and their effect on the growth of wild leeks was assessed with a redundancy analysis. Higher light availability resulted in better growth of wild leeks. The plants postponed their senescence under trees with late bud-burst, and thus better bulb growth and seed production were achieved. The tree litter and temperature and moisture levels of the soil also influenced the growth and survival of wild leeks. Thus, tree leaf phenology appears to have a strong impact on the growth of spring ephemerals by modulating the length of their growing season and their photosynthetic capacity. This underlines the importance of considering the variation of light availability throughout the growing season in the study of spring ephemerals.

Seed mass, seed production, germination and seedling traits in two phenological types of Bidens pilosa (Asteraceae)

2004 ◽  
Vol 52 (5) ◽  
pp. 647 ◽  
Author(s):  
Diego E. Gurvich ◽  
Lucas Enrico ◽  
Guillermo Funes ◽  
Marcelo R. Zak
Keyword(s):  
Seed Production ◽  
Seedling Growth ◽  
Germination Rate ◽  
Seed Mass ◽  
Flowering Phenology ◽  
Early Type ◽  
Normal Type ◽  
Bidens Pilosa ◽  
Seedling Traits ◽  
Seed Sources

Bidens pilosa L. is a summer annual that shows a particular phenological pattern in the Córdoba mountains, Argentina. Some individuals start flowering 1 month after germination (early type), but most of the population starts flowering 4 months after germination (normal type). The aims of this study were to (1) analyse whether differences in flowering phenology affect seed mass and seed production, and (2) assess whether possible differences in seed traits of the two parental phenological types would affect germinability, germination rate, seedling growth and flowering phenology of offspring under laboratory conditions. The study showed that the numbers of seeds per capitulum and per plant were greater in the normal type than in the early type plants. This can be related to plant height, since in the field, normal-type plants are larger than early type plants. However, early type plants produced heavier seeds than normal-type plants. Germination rate was faster in the early type seeds, but total germination was higher in the normal ones. Seedling growth, in terms of height and the date of first flowering, did not differ between the phenological types of parental seed sources. Our results showed that differences in flowering phenology were associated with seed mass and seed production differences. Seed mass appears to be related to germination characteristics but not to seedling growth nor to flowering phenology of offspring.

scholarly journals Climate Effects on Vertical Forest Phenology of Fagus sylvatica L., Sensed by Sentinel-2, Time Lapse Camera, and Visual Ground Observations

2021 ◽  
Vol 13 (19) ◽  
pp. 3982
Author(s):  
Lars Uphus ◽  
Marvin Lüpke ◽  
Ye Yuan ◽  
Caryl Benjamin ◽  
Jana Englmeier ◽  
...  
Keyword(s):  
Climate Change ◽  
Fagus Sylvatica ◽  
Deciduous Forest ◽  
Canopy Temperature ◽  
Time Lapse ◽  
Canopy Height ◽  
Spring Phenology ◽  
Phenological Mismatch ◽  
Fagus Sylvatica L ◽  
Sentinel 2

Contemporary climate change leads to earlier spring phenological events in Europe. In forests, in which overstory strongly regulates the microclimate beneath, it is not clear if further change equally shifts the timing of leaf unfolding for the over- and understory of main deciduous forest species, such as Fagus sylvatica L. (European beech). Furthermore, it is not known yet how this vertical phenological (mis)match—the phenological difference between overstory and understory—affects the remotely sensed satellite signal. To investigate this, we disentangled the start of season (SOS) of overstory F.sylvatica foliage from understory F. sylvatica foliage in forests, within nine quadrants of 5.8 × 5.8 km, stratified over a temperature gradient of 2.5 °C in Bavaria, southeast Germany, in the spring seasons of 2019 and 2020 using time lapse cameras and visual ground observations. We explained SOS dates and vertical phenological (mis)match by canopy temperature and compared these to Sentinel-2 derived SOS in response to canopy temperature. We found that overstory SOS advanced with higher mean April canopy temperature (visual ground observations: −2.86 days per °C; cameras: −2.57 days per °C). However, understory SOS was not significantly affected by canopy temperature. This led to an increase of vertical phenological mismatch with increased canopy temperature (visual ground observations: +3.90 days per °C; cameras: +2.52 days per °C). These results matched Sentinel-2-derived SOS responses, as pixels of higher canopy height advanced more by increased canopy temperature than pixels of lower canopy height. The results may indicate that, with further climate change, spring phenology of F. sylvatica overstory will advance more than F. sylvatica understory, leading to increased vertical phenological mismatch in temperate deciduous forests. This may have major ecological effects, but also methodological consequences for the field of remote sensing, as what the signal senses highly depends on the pixel mean canopy height and the vertical (mis)match.

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