scholarly journals Pollination biology of the urban populations of an ancient forest, spring ephemeral plant

2016 ◽  
Vol 85 (2) ◽  
Author(s):  
Maciej A. Ziemiański ◽  
Marcin Zych

Habitat fragmentation, caused by, among all, agriculture and urbanization, is one of the most important drivers of plant biodiversity decline worldwide. One of the signs of deteriorating zoogamous plant reproduction is pollen limitation, often associated with a decline in pollinator diversity and abundance. Various authors predict that the most vulnerable taxa are outbreeding plant species characterized by specialist pollination systems. We have, therefore, focused on self-incompatible <em>Corydalis solida</em>, an ancient forest, spring ephemeral plant, growing in three remnant urban populations in the city of Warsaw (Poland). Over two years, we checked for pollen limitation and recorded insect diversity and abundance for <em>C. solida</em> flowers. Our study populations composed of self-incompatible individuals were mainly visited by generalist pollinators, and produced more seeds when supplementally pollinated. Pollen limitation, however, was greater during 1 year with an early spring onset, when we observed a decline in floral visitors diversity and activity. This was probably an effect of phenological mismatch between plants and their pollinators, in this case, mostly social bees, i.e., over-wintered bumblebee queens and <em>Apis mellifera</em>. We conclude that for outbreeding zoogamous spring ephemerals, such as <em>C. solida</em> serviced by generalist pollinators, changing climatic conditions may override the effects of habitat fragmentation and influence their reproductive success.

Botany ◽  
2012 ◽  
Vol 90 (11) ◽  
pp. 1125-1132 ◽  
Author(s):  
Antoine Bernatchez ◽  
Line Lapointe

Allium tricoccum Aiton is a common spring ephemeral of hardwood deciduous forests of northeastern North America. It takes advantage of the short period of high light conditions between snowmelt and canopy closure to complete its vegetative life cycle and accumulate carbohydrate reserves for the following year. Previous studies on other spring ephemerals have shown that growth of these species is enhanced when grown at low temperature, typical of very early spring. We thus quantified the effect of three growth temperature regimes, i.e., 18 °C day – 14 °C night, 12 °C day – 8 °C night, and 8 °C day – 6 °C night, which have previously been tested on Erythronium americanum, another spring ephemeral. Gas exchange, chlorophyll a fluorescence, and plant biomass were measured repeatedly throughout the growth season. Growth was greatest under the 12 °C day – 8 °C night temperature regime, consistent with enhanced net photosynthetic rates (Pn), photochemical quenching (qP), and photochemical efficiency of photosynthesis (ΦPSII) at this temperature regime throughout the season. Pn was similar at 18 °C day – 14 °C night and 8 °C day – 6 °C night, but leaves had a greater duration at 8 °C day – 6 °C night; however, bulb biomass was not greater at 8 °C day – 6 °C night than at 18 °C day – 14 °C night. This study corroborates the general sensitivity of spring ephemerals to warmer temperatures. It also highlights species differences that might be caused by their specific carbon metabolism at the bulb level.


Author(s):  
Zh. M. Novak ◽  

Different weather conditions provide unequal growth and development of plants, in addition, biotypes react differently to changes in external environmental factors. Scientists from Ukraine and other countries analyze varieties and samples of spring barley for the purpose of determine donors of useful traits in different soil and climatic conditions. For the purpose of combine a number of useful traits in one genotype, hybridization between geographically distant biotypes is used. Uman National University of Horticulture has a collection of spring barley samples by different geographic origin. The analyze of breeding material by biometric traits, which will allow us to determine the level of manifestation of each of them in different conditions of 2018–2020 and to determine the donors of useful traits for the further breeding process, was carried out. The weather conditions of the years of research were very different. 2018 was the most unfavorable year for early spring crops. The reason for this was the presence of snow cover until the end of March. After that were strong heat and lack of precipitation. 2019 and 2020 were more favorable for spring barley due to the long cool spring. In addition, in 2020, May and June characterized by increased rainfall. The average plant height of the studied biotypes ranged from 50 to 64 cm. Most samples had the lowest plant height 40–57 cm in 2018, and the highest – in 2020 – from 54 to 88 cm. The average spike length of the analyzed samples was 5.9–8.1 cm. There was not dependence between conditions of the research year and spike length. The number of spikelets per spike was naturally determined by the research conditions. The lowest indicators were observed in 2018 — from 7.0 to 12.0 units, while in 2019 — 16.6–23.9 units, and in 2020 — 20.2–27.7 units. The variation of plant height of the analyzed samples was medium and significant with coefficients from 13.7 to 32.6 %. There was a slight, medium and significant variation of the length of the ear (V = 2.9–23.6 %). The index of number of spikelets per spike most varied — the coefficients of variation were 32.6–55.5 %.


1990 ◽  
Vol 25 (4) ◽  
pp. 526-534 ◽  
Author(s):  
Mark A. Coffelt ◽  
Peter B. Schultz

The anholocyclic life cycle of the aphid Takecallis arundinaria (Essig) on golden stem bamboo, Phyllostachys aurea (Carrie're) was investigated in 1987 – 1988. Aphid populations peaked from March – May, declined from June – October, and peaked again in December. Aphid population dynamics were strongly influenced by climatic conditions. When aphid populations were at constant or rising levels, significantly more nymphs were found in the southern and eastern quadrants, than in the northern and western quadrants. This directionality may have allowed T. arundinaria populations to be exposed to increased sunlight and decreased winds during the winter and early spring periods. Alate viviparae had a mean fecundity of 147 nymphs and a longevity of 46.5 days. Predators were few and no parasites were found. An alternate host study revealed no aphids on yellow sticky traps placed on nine woody plant species.


Botany ◽  
2017 ◽  
Vol 95 (5) ◽  
pp. 457-467 ◽  
Author(s):  
Pierre-Paul Dion ◽  
Julie Bussières ◽  
Line Lapointe

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.


2013 ◽  
Vol 61 (1) ◽  
pp. 37-42
Author(s):  
L. Marton ◽  
C. Szőke ◽  
J. Pintér

The climatic conditions in Hungary and in the countries to which seed is exported makes the study of maize cold tolerance and constant improvements in the cold tolerance of Martonvásár hybrids especially important. An improvement in the early spring cold tolerance of maize would allow it to be grown in more northern areas with a cooler climate, while on traditional maize-growing areas the profitability of maize production could be improved by earlier sowing, leading to a reduction in transportation and drying costs and in diseases caused by Fusarium sp. The recognition of this fact led Martonvásár researchers to start investigating this subject nearly four decades ago. The phytotron has proved an excellent tool for studying and improving the cold tolerance of maize. The review will give a brief summary of the results achieved in the field of maize cold tolerance in the Martonvásár institute in recent decades.


1997 ◽  
Vol 8 (3) ◽  
pp. 121-143 ◽  
Author(s):  
Kauri Mikkola

Based on a query and on a literature review, the population trends of Finnish Lepidoptera since Kaisila's (1962) thorough overview are analysed. Changes in the belt of three coastal biogeographical provinces (V-EK) show significant correlations with those in three inland provinces (St-ES). Furthermore, positive trends in these belts are reflected as new provincial finds north of them. The spatial synchrony is supposedly caused by spatially conelated climatic conditions. This is supported by evidence of synchronous trends in species grouped according to their overwintering stages (Marttila 1991, Bruun 1992). The increased migration rate, indicated by the new provincial finds, is probably a consequence of high population densities, and does not explain the synchrony itself. Kaisila's division into expansive and fluctuant species is considered to be a historical rather than a biological characterization. During the 19th century, the reporting of new lepidopteran species was delayed by about 50 years if they were night-active vs. day-active. The low numbers of observers and slow development of collecting methods have caused further analytical uncertainties. Some of Kaisila's expansive species may actually have been inhabitants of Finland for long periods of time. At present, drainage of peatlands and overgrowth of meadows are the most adverse environmental changes causing a decline of lepidopterans, particularly of the butterflies. Increase of bushiness and reeds appear to have positively affected many geometrid and noctuid species. The high incidence of new provincial finds and of species new to the country in the 1990s as well as positive trends in late-autumn and early-spring species supposedly reflect the ongoing climatic change. The Finnish lepidopteran fauna is undergoing a dynamic phase: around 30 recent invaders and 40 older expansive species are spreading, while fewer are retreating; the declining species are mainly habitat specialists while the expansive ones are generalists, mainly feeding on bushes and trees. Fewer expansions are evident among micro- than macrolepidopterans.


Author(s):  
N. V. Danilova

Climate change is a change of climatic conditions in the global atmosphere and on the Earth in general (or within its individual zones or territories) caused directly or indirectly due by the human activity on the planet, which are overlaid on the natural climatic variations (fluctuations) and ob-served during comparable periods of time.    Both the climate of Ukraine and the global climate are changing, but warming within our terri-tory progresses even faster than in other regions of the Northern Hemisphere. Ukraine in general and southern regions in particular are becoming increasingly vulnerable to climate change – droughts, extremely high temperatures, inefficient precipitation, reduced irrigated area cause of precipitation amount and regime, severer and more long-lasting droughts, reduced water availability. The majority of arable land in Ukraine are located in zones of unstable and insufficient humidity, it is quite possible that for plant growing, especially for growing winter crops and early spring crops, climate change will rather have a positive effect than negative one. Among the main types of cereals millet is the most common one. It is valuable for its groats, which is known by its high eating quality. Millet as a fast-growing crop having a certain agrotechnical importance: it is used as a backup crop for re-sowing dead winter crops and is suitable for stubble and post-harvest sowing, it also can be used as a cover culture for perennial grass. Millet is one of the most drought-resistant and heat-resistant crops. It is able to withstand heat injuries which is very important in arid areas and during dry years, when other grain crops have reduced yield. Millet suffers less from pests and diseases than other crops. The task was to evaluate the agro-climatic conditions of millet crops formation in the central part of Ukraine under conditions of climate change. The study of the impact of climate change on the formation of millet productivity for different time intervals was performed by comparing the data of the RCP scenario and the average long-term climatic and agro-climatic parameters. The in-fluence of agroclimatic conditions on the dynamics of increase of agroecological yield of different levels is also assessed.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12252
Author(s):  
Yajun Chen ◽  
Zhixin Guo ◽  
Lili Dong ◽  
Zhenxuan Fu ◽  
Qianjiao Zheng ◽  
...  

Rapid rise in temperature in summer causes severe injury to cool-season turfgrass of both native species and introduced ones in Heilongjiang of Northeast China. The objectives of this study were to compare physiological responses to seasonal heat stresses and turf performances between native and introduced commercial Poa accessions. Three Chinese native Poa species (i.e., P. pratensis, P. sibirica and P. sphondylodes) and three USA Kentucky bluegrass cultivars (ie. ‘Midnight’, ‘Moonlight’ and ‘BlueChip’) were evaluated under field conditions in 2017 and 2018. All accessions showed unique characteristics and considerable seasonal differences in response to temperatures. However, performances over all accessions were largely similar in early spring and autumn. In summer, native P. pratensis performed similar to ‘Midnight’, ‘Moonlight’ or ‘BlueChip’, with respect to such traits or parameters as quality, coverage, color intensity, growth rate, osmolytes, ROS and anti-oxidant production. Native P. pratensis could be used as a new turf resource for further improvement and application under the specific climatic conditions in Heilongjiang; native P. sphondylodes may be used in repairing damaged environments or for alternative seasonal greenness.


Agriculture ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Erick D. Smith

Southern highbush blueberries (SHB; Vaccinium corymbosum interspecific hybrid) are a low chill species of blueberry that are commercially grown in sub-tropical climates. Due to the nature of SHB, the flowering and fruit set occur in mid-winter to early spring and are susceptible to freeze damage. The most effective use of freeze protection is based on climatic conditions. Identification of advective or radiative freeze, intensity of the freeze event, and the equipment deployed are the key elements for deciding if the crop can be protected and justifying the expense to operate the system. Of the various methods used in frost protection, applying overhead irrigation water is the most promising. During a freeze event, an application of 6.3 mm ha−1 (0.10 in A−1) of water per hour is required to protect blueberries from −2.8 °C (27 °F) temperature with winds from 0 to 16 km h−1 (0 to 10 mph). This is 25.4 kL h−1 ha−1 (2715 gal h−1 A−1) of water. Overhead irrigation freeze protection is dependent on large volumes of water. This paper will review methods of freeze/frost protection, importance of weather patterns, and critical temperatures based on phenology of flowering to fruit set.


Author(s):  
Anayansi Ivette Ramírez Ramírez ◽  
Tania Arellano Lezama ◽  
Zadi Méndez Roblero1 ◽  
Guadalupe Idilia Delgado Tiburcio ◽  
Jaime Gallegos-Sánchez

Objective: To describe the seasonal variations throughout the year (day length), as one of the main environmental cues used by ewes to determine the most favorable time for breeding. Design/methodology/approach: A description of the main factors affecting ewe reproduction (photoperiod, suckling, postpartum period, nutrition, sociosexual effects) was assessed by a review of documentary information. Results: The inhibition of reproductive activity during one time of the year is a common process in most animal species to prevent births from occurring at an unfavorable time for the survival of the offspring. The seasonality of reproduction (northern latitude) allows births to occur in late winter or early spring when climatic conditions are the most favorable for the offspring development. Limitations/implications: The duration of the anestrus season (seasonal or postpartum) is influenced by the photoperiod and other factors. In Mexico, a small percentage of Criollo and Pelibuey ewes show a short duration of seasonal anestrus; that is, they show almost continuous annual reproductive activity. Therefore, to improve the reproductive efficiency of ewes, it is important to precisely determine the factors that affect their reproduction to improve management and increase the profits in the production units. Findings/Conclusions: Photoperiod is the main environmental factor regulating the annual reproductive cycle of the ewes, it occurs through very complex and varied mechanisms that communicate the visual system with the gonads through nervous and endocrine pathways.


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