Overstory spread and intensification of hemlock dwarf mistletoe

1977 ◽  
Vol 7 (4) ◽  
pp. 632-640 ◽  
Author(s):  
R. B. Smith
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Western Hemlock ◽  
Dwarf Mistletoe ◽  
Dispersal Patterns ◽  
Early Autumn ◽  
Early Removal ◽  
Residual Tree ◽  
Early Damage

Development of dwarf mistletoe (Arceuthobiumtsugense (Rosendahl) G.N. Jones) on 51 western hemlock (Tsugaheterophylla (Raf.) Sarg.) trees planted in 1963 at varying distances from an infected residual tree is described. Distribution of infections in the planted trees related directly to seed-dispersal patterns, i.e., it was influenced mainly by distance and direction from the infected residual. Factors controlling the numbers of infections produced included the amount of throughfall and winter depredation of seed, germination, and infection success. From an initial dispersal of 100 seeds, an average of 37 attached firmly and were retained on the branches the next spring, 23 germinated, and 13 caused infection. The influence of early autumn frosts, death of established infections, and variation in resistance levels in the trees on the ultimate number of functioning infections is documented. It was concluded that with early removal of the overstory source, levels of infection sufficiently high to cause significant early damage on all intervening regeneration would result with about 86 evenly scattered, severely infected residuals per hectare.

HEMLOCK AND LARCH DWARF MISTLETOE SEED DISPERSAL

1966 ◽  
Vol 42 (4) ◽  
pp. 395-401 ◽  
Author(s):  
Richard B. Smith
Keyword(s):  
Seed Dispersal ◽  
Western Hemlock ◽  
Dwarf Mistletoe ◽  
Western Larch ◽  
Potential Sources ◽  
Tree Seeds ◽  
Larch Tree

During 1964-65, approximately 49,050 hemlock dwarf mistletoe seeds were dispersed from a severely infected 35-ft. western hemlock tree, and 3,750 larch mistletoe seeds were dispersed from a lightly infected 63-ft. western larch tree. Seeds were trapped over an area 5,800 ft.2 in extent around the hemlock, and over an area of 2,200 ft.2 around the larch.The peak of larch mistletoe seed dissemination was about 1 month earlier than for hemlock. Seed counts for both years and both mistletoes were highest in the southwest and least in the northeast quadrants of the trapping areas.It was firmly established that small trees, even if lightly infected, are a serious potential sources of dwarf mistletoe seed; they must be removed if satisfactory dwarf mistletoe control is to be achieved.

A model of spread and intensification of dwarf mistletoe infection in young western hemlock stands

1980 ◽  
Vol 10 (1) ◽  
pp. 42-52 ◽  
Author(s):  
W. J. Bloomberg ◽  
R. B. Smith ◽  
A. Van Der Wereld
Keyword(s):  
Seed Production ◽  
Computer Model ◽  
Tree Species ◽  
Stocking Density ◽  
Western Hemlock ◽  
Tree Crown ◽  
Field Plot ◽  
Dwarf Mistletoe ◽  
Source Tree ◽  
Residual Tree

The following relationships were quantified in a mathematical computer model to predict spread and intensification of dwarf mistletoe (Arceuthobiumtsugense (Rosendahl) G. N. Jones) infection, originating from residual trees, in regeneration of western hemlock (Tsugaheterophylla (Raf.) Sarg.): distribution of dwarf mistletoe infections in residual source trees, dwarf mistletoe seed production, escape from crown and dispersal, interception of seeds by neighboring trees, distribution of seeds within crowns, development of dwarf mistletoe infections, mortality of plants, and tree crown growth. The model included options for thinning or sanitation by removal of infected residual or regeneration trees. Predictions by the model for a 10-year period did not differ significantly (p = 0.05) from results of a field plot with respect to average number of infections per tree, percentage of infections at 1-m distances from the residual tree, and percentage of infections in each quadrant centered on residual source tree. Predictions of the effects of stocking density and sanitation or thinning on infection agreed with results obtained from experiments with other tree species.

EcologyDevelopment of Dwarf Mistletoe (Arceuthobium) Infections on Western Hemlock, Shore Pine, and Western Larch

1971 ◽  
Vol 1 (1) ◽  
pp. 35-42 ◽  
Author(s):  
R. B. Smith
Keyword(s):  
Seed Dispersal ◽  
Life Span ◽  
Western Hemlock ◽  
First Year ◽  
Mature Fruit ◽  
Dwarf Mistletoe ◽  
Western Larch ◽  
The Third ◽  
Second Year ◽  
Shore Pine

Newly dispersed seeds, established infections, and individually tagged shoots of hemlock dwarf mistletoe on western hemlock and shore pine, and established infections and individual shoots of larch mistletoe on western larch were examined periodically for up to 7 years, Infections on hemlock first appeared as swellings, some of which were visible during the first year after seed dispersal. Aerial shoots appeared in the second year. By the end of the third year most infections exhibited both swellings and aerial shoots. On all three hosts, mature mistletoe fruit were produced occasionally in the fourth year but generally not until the fifth year. Most female aerial shoots bore at least one crop of flowers during their existence, however, only half produced mature fruit. Aerial shoots varied in their life span from less than 1 year up to 7 years. The average was 2 to 3 years. One female shoot on larch bore five successive crops of flowers. The fastest longitudinal growth of mistletoe endophytic system occurred on western larch and the slowest was on shore pine. All infections were nonsystemic in that the endophytic system was largely confined to the swollen portions of the hosts.

Dwarf mistletoe seed dispersal and germination in southwestern Alberta

1977 ◽  
Vol 7 (4) ◽  
pp. 589-594 ◽  
Author(s):  
John A. Muir
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Lodgepole Pine ◽  
Dwarf Mistletoe ◽  
Single Tree ◽  
In The Beginning

In 1966, numbers of seeds of dwarf mistletoe (Arceuthobiumamericanum Nutt. ex Engelm.) dispersed from two transplanted lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) decreased logarithmically with increasing distance from the trees. In two study areas in 1967–1969. dispersal of seeds from individual plants began in late August and was completed in 2–3 weeks. Differences of up to 2 weeks in the beginning and duration of dispersal were apparent between the areas. On one occasion, a difference in seed dispersal was noted between plants originating from seed collected at the two study areas and growing on a single tree at another location. Seed germination began in middle to late April, and in 4–6 weeks, 10–50% of the seeds had germinated.

Seed dispersal interactions promoting plant invasions.

2020 ◽  
pp. 90-104
Author(s):  
M. Celeste Díaz Vélez ◽  
Ana E. Ferreras ◽  
Valeria Paiaro
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Seedling Establishment ◽  
Native Species ◽  
Native Plants ◽  
Woody Species ◽  
Native Plant ◽  
Invasional Meltdown ◽  
Native Plant Species ◽  
Origin Life

Abstract Animal dispersers are essential for many non-native plants since they facilitate seed movement and might promote seed germination and seedling establishment, thereby increasing their chances of invasion. This chapter reviews the published literature on seed dispersal of non-native plant species by native and/or non-native animals. The following questions are addressed: (i) Are interactions between non-native plants and their animal dispersers evenly studied worldwide? (ii) Which are the distinctive traits (i.e. geographical origin, life form, dispersal strategy and propagule traits) of non-native plants that are dispersed by animals? (iii) Which are the most studied groups of dispersers of non-native plants around the world? (iv) Does the literature provide evidence for the Invasional Meltdown Hypothesis (non-native plant-non-native disperser facilitation)? (v) What is the role of animal dispersers at different stages of the non-native plant regeneration process? Our dataset of 204 articles indicates that geographical distribution of the studies was highly heterogeneous among continents, with the highest number coming from North America and the lowest from Asia and Central America. Most of the non-native plants involved in dispersal studies were woody species from Asia with fleshy fruits dispersed by endozoochory. More than the half of the animal dispersal agents noted were birds, followed by mammals, ants and reptiles. The dominance of bird-dispersal interactions over other animal groups was consistent across geographical regions. Although most of the studies involved only native dispersers, interactions among non-native species were detected, providing support for the existence of invasional meltdown processes. Of the total number of reviewed articles reporting seed removal, 74% evaluated seed dispersal, but only a few studies included seed germination (35.3%), seedling establishment (5.4%) or seed predation (23.5%). Finally, we discuss some research biases and directions for future studies in the area.

scholarly journals Animal movement drives variation in seed dispersal distance in a plant–animal network

2019 ◽  
Vol 286 (1894) ◽  
pp. 20182007 ◽  
Author(s):  
E. Rehm ◽  
E. Fricke ◽  
J. Bender ◽  
J. Savidge ◽  
H. Rogers
Keyword(s):  
Seed Dispersal ◽  
Animal Movement ◽  
Bird Species ◽  
Dispersal Distance ◽  
Dispersal Patterns ◽  
Long Distance ◽  
Gut Passage ◽  
Dispersal Distances ◽  
Seed Dispersal Distance ◽  
Passage Times

Frugivores play differing roles in shaping dispersal patterns yet seed dispersal distance is rarely quantified across entire communities. We model seed dispersal distance using gut passage times and bird movement for the majority (39 interactions) of known bird–tree interactions on the island of Saipan to highlight differences in seed dispersal distances provided by the five avian frugivores. One bird species was found to be a seed predator rather than a disperser. The remaining four avian species dispersed seeds but differences in seed dispersal distance were largely driven by interspecific variation in bird movement rather than intraspecific variation in gut passage times. The median dispersal distance was at least 56 m for all species-specific combinations, indicating all species play a role in reducing high seed mortality under the parent tree. However, one species—the Micronesian Starling—performed 94% of dispersal events greater than 500 m, suggesting this species could be a key driver of long-distance dispersal services (e.g. linking populations, colonizing new areas). Assessing variation in dispersal patterns across this network highlights key sources of variation in seed dispersal distances and suggests which empirical approaches are sufficient for modelling how seed dispersal mutualisms affect populations and communities.

scholarly journals Frugivory and seed dispersal of golden lion tamarin (Leontopithecus rosalia (Linnaeus, 1766)) in a forest fragment in the Atlantic Forest, Brazil

2008 ◽  
Vol 68 (2) ◽  
pp. 241-249 ◽  
Author(s):  
MJ. Lapenta ◽  
P. Procópio-de-Oliveira ◽  
MCM. Kierulff ◽  
JC. Motta-Junior
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Atlantic Forest ◽  
Forest Fragment ◽  
Consistent Effect ◽  
Leontopithecus Rosalia ◽  
Lion Tamarin ◽  
Seed Disperser ◽  
Golden Lion Tamarin ◽  
Field L

The influence of the golden lion tamarin (Leontopithecus rosalia) as a seed disperser was studied by monitoring two groups of tamarins from December 1998 to December 2000 (871.9 hours of observations) in a forest fragment in south-east Brazil. The tamarins consumed fruits of 57 species from at least 17 families. They ingested the seeds of 39 species, and 23 of these were put to germinate in the laboratory and/or in the field. L. rosalia is a legitimate seed disperser because the seeds of all species tested germinated after ingestion, albeit some in low percentages. These primates do not show a consistent effect in final seed germination, because they benefit some species while damaging others. Feces were examined for seeds that had been preyed upon or digested.

scholarly journals REGULATION OF SEED-GERMINATION TIMING BY MOIST CHILLING IN WESTERN HEMLOCK

1982 ◽  
Vol 92 (2) ◽  
pp. 173-182 ◽  
Author(s):  
ROBERT K. CAMPBELL ◽  
STANLEY M. RITLAND
Keyword(s):  
Seed Germination ◽  
Western Hemlock ◽  
Moist Chilling ◽  
Germination Timing
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