EFFECTS OF A SPLIT APPLICATION OF SEVIN-4-OIL® ON POLLINATORS AND FRUIT SET IN A SPRUCE–FIR FOREST

1984 ◽  
Vol 116 (3) ◽  
pp. 457-464
Author(s):  
Richard W. Hansen ◽  
Eben A. Osgood
Keyword(s):  
Fruit Set ◽  
Spruce Budworm ◽  
Split Application ◽  
Cornus Canadensis ◽  
Native Bee ◽  
Maianthemum Canadense ◽  
Pollinator Populations

AbstractCounts of four pollinating insect groups were taken in unsprayed forest localities and in areas sprayed with a split application of Sevin-4-oil® (carbaryl) for spruce budworm control. Results indicate a reduction of pollinator populations due to spraying.Fruit set, measured by fecundity ratios (fruits/flower), was determined for Cornus canadensis L., Maianthemum canadense Desf., Clintonia borealis (Ait.) Raf., and Viburnum cassinoides L. in sprayed and unsprayed areas. Fecundity values for C. canadensis and M. canadense were significantly lower in sprayed than in unsprayed areas. Fruit set of C. borealis was apparently unaffected by carbaryl spraying, but the seed/flower ratio was significantly reduced in the sprayed area. V. cassinoides fecundity values were unaffected by carbaryl application. Reductions in native bee populations probably had the greatest impact on fruit set.

The reproductive biology of boreal forest herbs. II. Phenology of flowering and fruiting

1987 ◽  
Vol 65 (10) ◽  
pp. 2047-2056 ◽  
Author(s):  
Kaius Helenurm ◽  
Spencer C. H. Barrett
Keyword(s):  
Boreal Forest ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Fruit Production ◽  
Fruit Removal ◽  
Cornus Canadensis ◽  
Forest Herbs ◽  
Pollinator Service ◽  
Maianthemum Canadense ◽  
Major Factors

The flowering and fruiting phenologies of 12 boreal forest herbs were recorded during 1979 (flowering and fruiting) and 1980 (flowering only) in spruce–fir forests of central New Brunswick. The species studied were Aralia nudicaulis, Chimaphila umbellata, Clintonia borealis, Cornus canadensis, Cypripedium acaule, Linnaea borealis, Maianthemum canadense, Medeola virginiana, Oxalis montana, Pyrola secunda, Trientalis borealis, and Trillium undulatum. Flowering in the community occurred from mid-May to the end of July. The order of flowering was maintained in the 2 years, but the degree of synchronization of inflorescences differed in several species. Fruiting in the community began in mid-July and extended beyond the end of September. The percentage of buds that ultimately bore fruit ranged from 0 (Cypripedium acaule) to 61% (Aralia nudicaulis). With the exception of Cypripedium acaule, which received little pollinator service, the self-incompatible species, Cornus canadensis, Maianthemum canadense, and Medeola virginiana, experienced the lowest levels of fruit-set. Pollen limitation and predation of developing fruit appear to be the major factors limiting percentage fruit-set in boreal forest herbs. Fruit production varied with time of flowering of inflorescences in several species, with periods of low fruit-set tending to coincide with lower densities of flowering inflorescences. Significant rates of fruit removal by herbivores occurred in all sarocochorous species. Disappearance of fruits from infructescences ranged from 31 (Medeola virginiana) to 95% (Aralia nudicaulis), with highest removal rates occurring during periods of greatest fruit availability.

The effect of aerial insecticide spraying for spruce budworm control on the fecundity of entomophilous plants in New Brunswick

1980 ◽  
Vol 58 (18) ◽  
pp. 2022-2027 ◽  
Author(s):  
G. R. Thaler ◽  
R. C. Plowright
Keyword(s):  
New Brunswick ◽  
Seed Set ◽  
Spruce Budworm ◽  
Spray Application ◽  
Kalmia Angustifolia ◽  
Cornus Canadensis ◽  
Cornus Stolonifera ◽  
Insect Visitation ◽  
Maianthemum Canadense

Eight entomophilous plants, Aralia nudicaulis L., Clintonia borealis (Ait.) Raf., Cornus alternifolia L., Cornus canadensis L., Cornus stolonifera Michx., Kalmia angustifolia L., Maianthemum canadense Desf., and Viburnum trilobum Marsh., all of which bloom shortly after forest spray application in New Brunswick, were shown by bagging experiments to be dependent on insect visitation for seed set. All species showed significantly lower fecundity in fenitrothion-treated than in unsprayed areas. No depression of fecundity in Clintonia borealis or Kalmia angustifolia was found associated with aminocarb (Matacil) spraying.

The reproductive biology of boreal forest herbs. I. Breeding systems and pollination

1987 ◽  
Vol 65 (10) ◽  
pp. 2036-2046 ◽  
Author(s):  
Spencer C. H. Barrett ◽  
Kaius Helenurm
Keyword(s):  
Boreal Forest ◽  
Reproductive Biology ◽  
Fruit Set ◽  
Experimental Studies ◽  
Reproductive Mode ◽  
Breeding Systems ◽  
Cornus Canadensis ◽  
Forest Herbs ◽  
Maianthemum Canadense ◽  
Floral Syndromes

Detailed observations and experimental studies of the reproductive biology of 12 boreal forest herbs were conducted over a 3-year period (1978–1980) in spruce–fir forests of central New Brunswick. The species examined were Aralia nudicaulis, Chimaphila umbellata, Clintonia borealis, Cornus canadensis, Cypripedium acaule, Linnaea borealis, Maianthemum canadense, Medeola virginiana, Oxalis montana, Pyrola secunda, Trientalis borealis, and Trillium undulatum. All taxa are insectpollinated perennials and most exhibit clonal growth. Floral syndromes of the understory community are relatively unspecialized with many species possessing small white or green flowers. A total of 103 taxa of insects were collected from flowers during the 1979 season. Bombus spp. are the major pollinators of 5 of the 12 species. Syrphid flies, bee flies, and halictid and andrenid bees were also commonly observed. Controlled pollinations were undertaken to determine the breeding systems of herbs. Bagged, self-, cross- and open-pollinated treatments were used to investigate the capacity for self-pollination, compatibility status, and factors influencing fecundity in each species. A diversity of reproductive systems was revealed. Six species are completely dependent on insects for pollination, four species are weakly autogamous, one is strongly autogamous, and one appears to be apomictic. Comparisons of fruit-set and seed set from controlled self- and cross-pollinations indicate that four species are strongly self-compatible, one is dioecious, and the remainder display varying degrees of self-incompatibility. Despite this variation, outbreeding appears to be the most common reproductive mode. In several species there is evidence that low pollinator service limits fruit-set.

Heat tolerance of rhizomes of several understory species

1983 ◽  
Vol 61 (2) ◽  
pp. 452-457 ◽  
Author(s):  
Marguerite A. Flinn ◽  
Joan K. Pringle
Keyword(s):  
Temperature Tolerance ◽  
Pteridium Aquilinum ◽  
Tolerance Index ◽  
Understory Species ◽  
Chamaedaphne Calyculata ◽  
Cornus Canadensis ◽  
Shoot Number ◽  
Different Temperatures ◽  
Maianthemum Canadense ◽  
Study Sites

Rhizomes of eight understory species: Gaultheria procumbens, Maianthemum canadense, Vaccinium angustifolium, Cornus canadensis, Pteridium aquilinum, Kalmia angustifolia, Chamaedaphne calyculata, and Rhododendron canadense were subjected to treatments of 45, 50, 55 and 60 °C for 5 min in a water bath. Selection of these species for study was based on differences in the depth of the rhizomes, in habitat, and in rhizome morphology. Samples were collected from study sites located near Halifax, in the Nova Scotia Acadian Forest region.Maximum shoot growth occurred at different temperatures for the various species: 45 °C for Cornus canadensis; 50 °C for Chamaedaphne calyculata, R. canadense, and V. angustifolium; 55 °C for G. procumbens and M. canadense. Death occurred at or below 60 °C for most species. For comparative purposes, a temperature tolerance index (TTI) was calculated for each species. The TTI indicated that R. canadense and V. angustifolium showed the greatest tolerance to higher temperatures and that K. angustifolia and P. aquilinum showed the least tolerance. Mean shoot number increased significantly following spring treatments for all species except for Cornus canadensis which showed greater increase following autumn treatments.

The neutralisation of acid rain by the leaves of four boreal forest species

1988 ◽  
Vol 66 (9) ◽  
pp. 1877-1882 ◽  
Author(s):  
B. A. Gaber ◽  
T. C. Hutchinson
Keyword(s):  
Boreal Forest ◽  
Acid Rain ◽  
Cell Walls ◽  
Leaf Surface ◽  
Weather Conditions ◽  
Cornus Canadensis ◽  
Exchange Processes ◽  
Rapid Changes ◽  
Maianthemum Canadense ◽  
Rate Of Evaporation

A field study was carried out in the boreal forest of Ontario to measure the neutralisation response of the leaves of Cornus canadensis, Aralia nudicaulis, Maianthemum canadense, and Acer spicatum to simulated acid rain. Plots of each species were sprayed with pH 5.6, 3.8, or 3.2 rain, and the pH of the raindrops on the leaves and on Parafilm (control) was measured with a microelectrode at 15-min intervals until the leaves dried. Species differed in their ability to neutralise the rain, with C. canadensis consistently neutralising acidic raindrops the most. The neutralisation response varied greatly between pH treatments, with greatest neutralisation occurring at the most acidic pH treatment. Raindrop neutralisation primarily took place within the first few minutes following the spray. For this reason, the dissolution of basic particulates on the leaf surface was probably responsible for the rapid changes in raindrop pH, while slower changes may reflect cation exchange processes with the cell walls. Weather conditions determined the rate of evaporation of the raindrops, and this affected their acidity. High rates of evaporation reduced the time available for leaf surface – raindrop interactions and are probably responsible for the acidification observed in some plots.

scholarly journals Wildness and Wild Spaces in Residential Yards: Changing Neighborhood Norms to Support Pollinator Populations

2021 ◽  
Vol 13 (22) ◽  
pp. 12861
Author(s):  
Andrea K. Burr ◽  
Damon M. Hall ◽  
Nicole Schaeg
Keyword(s):  
Management Practices ◽  
Urban Habitat ◽  
Cultural Preferences ◽  
Insect Pollinator ◽  
Native Bee ◽  
Residential Yards ◽  
Bee Communities ◽  
Yard Maintenance ◽  
Global Food ◽  
Pollinator Populations

Insect pollinator populations, critical to the global food supply, are declining. Research has found robust bee communities in cities, which are supported by diverse urban habitat and foraging resources. Accounting for 35–50% of urban green space, U.S. private residential yards can serve as important forage and nesting sources for pollinators. Incorporating wild attributes and wildness, such as native vegetation and less intensive yard-management practices, is key. However, urban vegetation, and its effects on local native bee populations, is shaped by social and cultural preferences, norms, aesthetics, values, and identities. The perfect lawn ideal of a highly manicured turfgrass yard dominates neighborhood landscapes and is often at odds with the habitat needs of pollinators. As part of a three-year study investigating the sociocultural drivers of residential vegetation choices in St. Louis, MO, USA, we interviewed 85 decisionmakers in order to understand choices about private residential yard maintenance. This paper presents an emergent finding concerning how residents conceptualize and talk about the urban-yard aesthetic, using the terms "wild" and "wildness", which reflect a range of levels in the demand for urban wild spaces in their neighborhoods. The discourse of wildness offers a nontechnical route for understanding the connections between the ecological consequences of urbanization, with human attitudes towards nature that shape the biological functioning of human-generated habitats.

Chemical changes in simulated raindrops following contact with leaves of four boreal forest species

1988 ◽  
Vol 66 (12) ◽  
pp. 2445-2451 ◽  
Author(s):  
Brigitte A. Gaber ◽  
Thomas C. Hutchinson
Keyword(s):  
Boreal Forest ◽  
Dry Deposition ◽  
Ion Concentration ◽  
Forest Species ◽  
Ion Concentrations ◽  
Cornus Canadensis ◽  
Rapid Changes ◽  
Maianthemum Canadense ◽  
Forest Plant Species

Simulated raindrops of pH 5.6 or 3.2 were sprayed on four boreal forest plant species in situ, and raindrops were subsequently collected from their leaves for chemical analysis. The purpose was to understand better the changes involved in foliar neutralisation of acidic raindrops. The species used were Cornus canadensis, Aralia nudicaulis, Maianthemum canadense, and Acer spicatum. Samples were analysed for Ca2+, Mg2+, Na+, K+, [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], Cl−, and F−, as well as pH. Changes in leaf raindrop ion concentrations were greater when sprayed with the pH 3.2 than with the pH 5.6 rain. Both increases and decreases in ion concentration were found, indicating leaching and (or) dissolution of particulates on the leaf or retention by the canopy, respectively. Rapid changes in ion concentrations suggest surface deposits play an important role in leaf raindrop neutralisation. Increases in [Ca2+] and [Mg2+] in raindrops with greater neutralisation are evidence that cation exchange may also be occurring (r2 = 0.170 and 0.321, respectively, at pH 3.2; p < 0.01). There were significant negative correlations between changes in [H+] and changes in[Formula: see text], [Formula: see text], and [Formula: see text] (r2 = 0.562, 0.525, and 0.297, respectively, at pH 3.2;p < 0.01). Most of the other ions measured also showed significant correlations with changes in [H+], but generally the correlation could account for only a small percentage of the observed results (low r2). Dry deposition was also measured.

HONEY BEES, APIS MELLIFERA (HYMENOPTERA: APIDAE), AS POLLINATORS OF LOWBUSH BLUEBERRY, VACCINIUM ANGUSTIFOLIUM, ON NEWFOUNDLAND COASTAL BARRENS

1983 ◽  
Vol 115 (12) ◽  
pp. 1647-1651 ◽  
Author(s):  
Derek Lomond ◽  
David J. Larson
Keyword(s):  
Honey Bees ◽  
Fruit Set ◽  
Test Field ◽  
Control Field ◽  
Lowbush Blueberry ◽  
Short Period ◽  
Native Pollinator ◽  
The Difference ◽  
Avalon Peninsula ◽  
Pollinator Populations

AbstractFlower production, fruit set, and pollinator activity were measured in two 1-year postburn blueberry fields on the coastal barrens of the Avalon Peninsula, Newfoundland. Honey bees were stocked at a density of 1.7 colonies/ha in one field while the control field lacked honey bees. Bloom production was similar in the two fields but fruit set was 54% in the test compared with 39% in the control field. Native pollinator (bee) populations were similar between fields but total pollinator populations were much higher in the test field with the difference contributed by honey bees. On the coastal barrens, where native pollinator populations are low and bloom exists in abundance for a short period of time, under-pollination may limit fruit set under some conditions and thus honey bees may have value in increasing fruit yield.

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