An analysis of elm (Ulmus americana) mortality in a second-growth hardwood forest in southeastern Michigan

1976 ◽  
Vol 54 (10) ◽  
pp. 1120-1125 ◽  
Author(s):  
Curtis J. Richardson ◽  
Charles W. Cares
Keyword(s):  
Acer Rubrum ◽  
Dutch Elm Disease ◽  
Forest Community ◽  
Reproductive Capacity ◽  
Hardwood Forest ◽  
Importance Value ◽  
Ulmus Americana ◽  
Important Species ◽  
Quercus Macrocarpa ◽  
Second Growth

A second-growth hardwood forest containing both wet lowland and mesic upland sites in southeastern Michigan was studied 24 years after the introduction of Dutch elm disease. American elm (Ulmus americana) surprisingly had the highest importance value (IV = 61/300) (IV = relative density + relative dominance + relative frequency). Two other species (Acer rubrum and Quercus macrocarpa) closely followed elm with IVs of 41/300 and 38/300. respectively. Mortality for all trees surveyed was 20.4%. Elm comprised 86.6% of this total. Although reduced, the present IV for elm and the percentage of living individuals in each diameter class indicate that elm is still an important species in the forest community. Elm mortality reached 100% only on the poorly drained lowland pockets where densities of elm exceeded 50%. Its high reproductive capacity and dispersal rate indicate that elm will continue to exist as an important species, even if not a canopy dominant, in some types of hardwood communities.

Succession in deciduous swamp communities of southeastern Michigan formerly dominated by American elm

1976 ◽  
Vol 54 (1-2) ◽  
pp. 19-24 ◽  
Author(s):  
Burton V. Barnes
Keyword(s):  
Acer Rubrum ◽  
Dutch Elm Disease ◽  
Old Fields ◽  
Base Line ◽  
Betula Alleghaniensis ◽  
Ulmus Americana ◽  
Average Life Span ◽  
Permanent Sample Plots ◽  
Fraxinus Nigra ◽  
Carpinus Caroliniana

Fifty-six permanent sample plots were established in deciduous swamp communities of south-eastern Michigan where Ulmus americana was dominant before introduction of the Dutch elm disease. Plots were also established in old fields where elm seedlings were present. The purpose of the study was to determine the composition of the overstory, understory, and seedling layers in deciduous swamp forests and to provide a base line for determining the fate of young seedling and sapling elms, and the rate and nature of succession in the deciduous swamp communities. The major overstory species in the three swamps studied were Fraxinus nigra, Acer rubrum, and Betula alleghaniensis. These species were also dominant in the understory along with smaller numbers of Carpinus caroliniana, Ulmus americana, Tilia americana, and Fraxinus pennsylvanica. In the next generation the communities will be much as they are today. The overstory dominants are also strongly represented in the seedling layer. Ulmus americana was more abundant in this layer than in the understory. Therefore, Ulmus has not been eliminated from the deciduous swamps but makes up about 10 to 15% of the understory and seedling layers. Old fields and other open upland areas are much more important habitats for regeneration of Ulmus than swamp communities. Indications are that unlike Castanea dentata, Ulmus americana will be perpetuated for generations by seeds from young elm trees; however, the average life span of the species will be drastically reduced.

The Microscopy of Compatibility and Incompatibility in Ulmus

1985 ◽  
Vol 43 ◽  
pp. 504-505
Author(s):  
B. L. Redmond ◽  
Christopher F. Bob
Keyword(s):  
Dutch Elm Disease ◽  
Economic Losses ◽  
Hybrid Progeny ◽  
Ulmus Pumila ◽  
Ulmus Americana ◽  
American Elm ◽  
Asian Species ◽  
Ulmus Parvifolia ◽  
Initial Appearance ◽  
Chinese Elm

The American Elm (Ulmus americana L.) has been plagued by Dutch Elm Disease (DED), a lethal disease caused by the fungus Ceratocystis ulmi (Buisman) c. Moreau. Since its initial appearance in North America around 1930, DED has wrought inexorable devastation on the American elm population, triggering both environmental and economic losses. In response to the havoc caused by the disease, many attempts have been made to hybridize U. americana with a few ornamentally less desirable, though highly DED resistant, Asian species (mainly the Siberian elm, Ulmus pumila L., and the Chinese elm Ulmus parvifolia Jacq.). The goal is to develop, through breeding efforts, hybrid progeny that display the ornamentally desirable characteristics of U. americana with the disease resistance of the Asian species. Unfortunately, however, all attempts to hybridize U. americana have been prevented by incompatibility. Only through a firm understanding of both compatibility and incompatibility will it be possible to circumvent the incompatibility and hence achieve hybridization.

Chamelea gallina reproductive biology and Minimum Conservation Reference Size: implications for fishery management in the Adriatic Sea

BMC Zoology ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Giada Bargione ◽  
Fortunata Donato ◽  
Giulio Barone ◽  
Massimo Virgili ◽  
Pierluigi Penna ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Adriatic Sea ◽  
Seawater Temperature ◽  
Reproductive Capacity ◽  
Great Effort ◽  
Important Species ◽  
Spawning Period ◽  
The Past ◽  
Chamelea Gallina ◽  
Size At Sexual Maturity

Abstract Background The striped venus clam Chamelea gallina is an economically important species in Adriatic Sea fisheries. The use of hydraulic dredging for its catch has a long history in Italy and its management faced several stages of development in the last 40 years. A great effort has been made in the past two decades to move from poorly or weakly managed fisheries to a well-structured co-management system to improve the sustainability of this fishery. However, a prerequisite for appropriate resource management is a sound knowledge of the biology and reproductive strategy of the species. Results We investigated three major biological features– the gametogenic cycle, size at sexual maturity and partial fecundity – by microscopic, histological and video analysis techniques. We demonstrated that its breeding season is driven by rises in seawater temperature and chlorophyll-a concentration and that its spawning period lasted from March to September. Size at sexual maturity was reached very early in the life cycle. As regards partial fecundity – the number of mature oocytes potentially released by females with ripe gonads in a single release event – varied in relation to size. Nevertheless, the reduction on the Minimum Conservation Reference Size (MCRS) from 25 to 22 mm (Delegated Regulation (EU) 2020/2237) lead to a 40% reduction in the number of emitted eggs. Conclusions We suggest that the ability of Adriatic clam stocks to withstand the strong fishing pressure of the past 40 years and the present one is due to their high reproductive potential and multiple spawning events combined with the effect of management measures (closed areas/seasons, quota, MCRS) and technical constraints on the gear and the sieve on board. Moreover, since the reduced MCRS for Venus shells is still larger than the size at maturity, it will probably not be detrimental to the reproductive capacity of the stock.

Xylella fastidiosa. [Distribution map].

2006 ◽  
Author(s):  
Keyword(s):  
New York ◽  
South Carolina ◽  
Prunus Persica ◽  
Xylella Fastidiosa ◽  
Acer Rubrum ◽  
Prunus Dulcis ◽  
Wild Plants ◽  
Distribution Map ◽  
Ulmus Americana ◽  
Platanus Occidentalis

Abstract A new distribution map is provided for Xylella fastidiosa Wells et al. Bacteria. Hosts: Grapevine (Vitis vinifera and others), peach (Prunus persica), Citrus, almond (Prunus dulcis), lucerne (Medicago sativa), some wild trees (including Acer rubrum, Platanus occidentalis, Quercus rubra, Ulmus americana), other wild plants and weeds. Information is given on the geographical distribution in Europe (France, Italy), Asia (Taiwan), North America (Canada (Ontario), Mexico, USA (Alabama, Arizona, Arkansas, California, Delaware, District of Columbia, Florida, Georgia, Indiana, Kentucky, Louisiana, Maryland, Mississippi, Missouri, Montana, Nebraska, New Jersey, New Mexico, New York, North Carolina, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, Washington, West Virginia)), Central America and Caribbean (Costa Rica), and South America (Argentina, Brazil (Bahia, Goias, Minas Gerais, Parana, Rio de Janeiro, Rio Grande do Sul, Santa Catarina, Sao Paulo, Sergipe), Paraguay, Venezuela).

La végétation forestière du secteur nord-ouest de la vallée du Saint-Laurent, Québec

1988 ◽  
Vol 66 (4) ◽  
pp. 793-804 ◽  
Author(s):  
Claude St-Jacques ◽  
Daniel Gagnon
Keyword(s):  
Acer Saccharum ◽  
Acer Rubrum ◽  
Ecological Factors ◽  
Detrended Correspondence Analysis ◽  
Forest Community ◽  
North West ◽  
The North ◽  
Two Factors ◽  
Community Types ◽  
And Cluster Analysis

The forest vegetation of the north-west section of the St. Lawrence Valley in Quebec was sampled within 68 quadrats. The location of the quadrats was selected by means of a stratified random sampling plan. Ordination (detrended correspondence analysis) and cluster analysis (TWINSPAN) allowed the identification of 11 forest community types. The ecological factors most closely associated with the distribution of these communities are soil drainage and richness. These two factors are strongly related to the types of surface deposits. Communities dominated by Acer saccharum are found on well drained and nutrient-rich moraines. On the contrary, communities dominated by Acer rubrum and the majority of coniferous forests are found on poorly drained and nutrient-poor soils. Two floristically distinct community types, the Fraxinus – Tilia americana forests and the Tsuga canadensis – Acer saccharum forests, are found on poorly drained marine deposits with edaphically identical lower horizons. However, the pH and major cation concentrations of the upper soil horizons are much lower under the cover of the hemlock forests than under the cover of the ash – basswood forests.

Sign in / Sign up

Export Citation Format

Share Document