Disappearing edge: the flowering period changes the distribution of insect pollinators in invasive goldenrod patches

2018 ◽  
Vol 12 (2) ◽  
pp. 98-108 ◽  
Author(s):  
Dawid Moroń ◽  
Piotr Skórka ◽  
Magdalena Lenda
2021 ◽  
Vol 28 ◽  
pp. 90-107
Author(s):  
Irene Bottero ◽  
Simon Hodge ◽  
Jane Stout

In intensively cropped agricultural landscapes, the vegetation in edges and hedges (henceforth “field margins”) represents an important semi-natural habitat providing fundamental resources for insect pollinators. We surveyed the pollinating insects associated with two mass-flowering crops, apple and oilseed rape, and compared the insect fauna of the main crop with that in the field margins in the grass-dominated agricultural landscapes of Ireland. Different insect groups responded differently to the presence of the flowering crop, with honey and bumble bees more abundant in crops than margins during crop flowering, but more hover flies and butterflies in margins throughout. The composition of the insect assemblage also shifted over time due to taxon-specific changes in abundance. For example, solitary bees were most abundant early in the season, whereas hover flies peaked, and butterflies declined, in mid-summer. The temporal shift in insect community structure was associated with parallel changes in the field margin flora, and, although we found no relationship between insect abundance and abundance of field margin flowers, Bombus abundance and total insect abundance were positively correlated with floral diversity. After the crop flowering period, floral abundance and diversity was maintained via margin plants, but by late summer, floral resources declined. Our results confirm the importance of field margins for insect pollinators of entomophilous crops set within grass-dominated landscapes, even during the crop flowering period, and provide additional support for agri-environment schemes that protect and/or improve field margin biodiversity. The results also demonstrate that although shifts in insect and plant communities may be linked phenologically there may not always be simple relationships between insect and floral abundance and richness. 


2011 ◽  
Vol 59 (6) ◽  
pp. 582 ◽  
Author(s):  
C. Q. Nghiem ◽  
C. E. Harwood ◽  
J. L. Harbard ◽  
A. R. Griffin ◽  
T. H. Ha ◽  
...  

Floral phenology and morphology of colchicine-induced auto-tetraploid trees of Acacia mangium Willd. (AM-4x) growing in Vietnam were compared with adjacent diploid A. mangium (AM-2x) and A. auriculiformis A.Cunn. ex Benth (AA-2x). Flowering lasted for several months with a slightly later peak flowering period for A. auriculiformis (December–January), than for A. mangium (November–December). Flower spikes of AM-4x were shorter and had fewer flowers per spike than those of AM-2x, but were longer and had more flowers than AA-2x. Percentages of male to hermaphrodite flowers were less than 23% for all three species/ploidy combinations. Flowers of AM-4x had slightly shorter styles than did AM-2x, but AM-4x stigma and polyad diameters were greater. For all polyad-stigma combinations among species/ploidy levels, at least one polyad could be accommodated. AM-4x had fewer (13) ovules per ovary, compared with AM-2x and AA-2x (14–16). AM-4x set fewer (less than 3) seeds per pod than did AM-2x and AA-2x (7–8 and 5–6, respectively). Foraging behaviour of the main insect pollinators (honeybees) and examination of polyads collected from them suggested interspecific and interploidy pollination would occur. There appeared to be no phenophase or flower structure barriers to interploidy pollination.


2019 ◽  
Vol 3 (6) ◽  
pp. 723-729
Author(s):  
Roslyn Gleadow ◽  
Jim Hanan ◽  
Alan Dorin

Food security and the sustainability of native ecosystems depends on plant-insect interactions in countless ways. Recently reported rapid and immense declines in insect numbers due to climate change, the use of pesticides and herbicides, the introduction of agricultural monocultures, and the destruction of insect native habitat, are all potential contributors to this grave situation. Some researchers are working towards a future where natural insect pollinators might be replaced with free-flying robotic bees, an ecologically problematic proposal. We argue instead that creating environments that are friendly to bees and exploring the use of other species for pollination and bio-control, particularly in non-European countries, are more ecologically sound approaches. The computer simulation of insect-plant interactions is a far more measured application of technology that may assist in managing, or averting, ‘Insect Armageddon' from both practical and ethical viewpoints.


2021 ◽  
Vol 13 (9) ◽  
pp. 1630
Author(s):  
Yaohui Zhu ◽  
Guijun Yang ◽  
Hao Yang ◽  
Fa Zhao ◽  
Shaoyu Han ◽  
...  

With the increase in the frequency of extreme weather events in recent years, apple growing areas in the Loess Plateau frequently encounter frost during flowering. Accurately assessing the frost loss in orchards during the flowering period is of great significance for optimizing disaster prevention measures, market apple price regulation, agricultural insurance, and government subsidy programs. The previous research on orchard frost disasters is mainly focused on early risk warning. Therefore, to effectively quantify orchard frost loss, this paper proposes a frost loss assessment model constructed using meteorological and remote sensing information and applies this model to the regional-scale assessment of orchard fruit loss after frost. As an example, this article examines a frost event that occurred during the apple flowering period in Luochuan County, Northwestern China, on 17 April 2020. A multivariable linear regression (MLR) model was constructed based on the orchard planting years, the number of flowering days, and the chill accumulation before frost, as well as the minimum temperature and daily temperature difference on the day of frost. Then, the model simulation accuracy was verified using the leave-one-out cross-validation (LOOCV) method, and the coefficient of determination (R2), the root mean square error (RMSE), and the normalized root mean square error (NRMSE) were 0.69, 18.76%, and 18.76%, respectively. Additionally, the extended Fourier amplitude sensitivity test (EFAST) method was used for the sensitivity analysis of the model parameters. The results show that the simulated apple orchard fruit number reduction ratio is highly sensitive to the minimum temperature on the day of frost, and the chill accumulation and planting years before the frost, with sensitivity values of ≥0.74, ≥0.25, and ≥0.15, respectively. This research can not only assist governments in optimizing traditional orchard frost prevention measures and market price regulation but can also provide a reference for agricultural insurance companies to formulate plans for compensation after frost.


Author(s):  
Keira Dymond ◽  
Juan L. Celis‐Diez ◽  
Simon G. Potts ◽  
Brad G. Howlett ◽  
Bryony K. Willcox ◽  
...  
Keyword(s):  

2016 ◽  
Vol 96 (1) ◽  
pp. 151-159 ◽  
Author(s):  
Gan Yantai ◽  
K. Neil Harker ◽  
H. Randy Kutcher ◽  
Robert H. Gulden ◽  
Byron Irvine ◽  
...  

Optimal plant density is required to improve plant phenological traits and maximize seed yield in field crops. In this study, we determined the effect of plant density on duration of flowering, post-flowering phase, and seed yield of canola in diverse environments. The field study was conducted at 16 site-years across the major canola growing area of western Canada from 2010 to 2012. The cultivar InVigor® 5440, a glufosinate-resistant hybrid, was grown at five plant densities (20, 40, 60, 80, and 100 plants m−2) in a randomized complete block design with four replicates. Canola seed yield had a linear relationship with plant density at 8 of the 16 site-years, a quadratic relationship at 4 site-years, and there was no correlation between the two variables in the remaining 4 site-years. At site-years with low to medium productivity, canola seed yield increased by 10.2 to 14.7 kg ha−1 for every additional plant per square metre. Averaged across the 16 diverse environments, canola plants spent an average of 22% of their life cycle flowering and another 27% of the time filling seed post-flowering. Canola seed yield had a negative association with duration of flowering and a positive association with the days post-flowering but was not associated with number of days to maturity. The post-flowering period was 12.7, 14.7, and 12.6 d (or 55, 68, and 58%) longer in high-yield experiments than in low-yield experiments in 2010, 2011, and 2012, respectively. We conclude that optimization of plant density for canola seed yield varies with environment and that a longer post-flowering period is critical for increasing canola yield in western Canada.


1940 ◽  
Vol 31 (2) ◽  
pp. 147-177 ◽  
Author(s):  
F. S. Parsons

Studies of the food-plant associations of Heliothis armigera have elicited the information that, for all practical purposes, egg-laying may be considered as confined to the period of florescence. Evidence of coincidence of the oviposition and flowering curves is submitted for 21 species of short-flowering crops and 8 species of long-flowering crops. All told, records taken in nearly 1,000 crops have been consulted for the conclusions drawn.As regards short-flowering species, the peaks, as well as the confines, of the oviposition and flowering curves are related closely. But oviposition on long-flowering species may decline while flowering is still in progress, or two or more waves of oviposition may be evident according to the number of moth flights spanned by the flowering period. The courses of oviposition on long-flowering species of crop in the given instances are interpreted through knowledge of the train of moth flights: although egg-laying in quantity occurs within the flowering period, peak layings frequently are not aligned with maximum flower production because the calendar times of moth flights are displaced in relation thereto.


1979 ◽  
Vol 57 (9) ◽  
pp. 997-999 ◽  
Author(s):  
R. J. Reader

In laboratory freezing trials, cold hardiness of six types of bog ericad flowers differed significantly (i.e., Chamaedaphne calyculata > Andromeda glaucophylla > Kalmia polifolia > Vaccinium myrtilloides > Ledum groenlandicum > Vaccinium macrocarpon) at air temperatures between −4 and −10 °C but not at temperatures above −2 °C. At the Luther Marsh bog in southern Ontario, low temperatures (−3 to −7 °C) would select against May flowering by the least cold hardy ericads. Availability of pollinators, on the other hand, would encourage May flowering by the most cold hardy species. Presumably, competition for insect pollinators has promoted the diversification of bog ericad flowering peaks, while air temperature, in conjunction with flower cold hardiness, determined the order in which flowering peaks were reached.


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