The Field Elm may grow to heights of up to 35m. It normally has a regularly rounded crown and many branches. Its ideal ecological environment lies in the wetlands surrounding major rivers, where it – along with the English oak – constitutes the upper storey of damp and young hardwood riparian forests. Today, having been decimated by Dutch Elm disease in the last few decades, it has been included as one of the threatened tree species on the IUCN Red List. In the National Park, the Field Elm is most likely to be found in the hardwood riparian forests.
Description
The Field Elm is a deciduous tree with a relatively straight trunk, growing to heights of up to 35m. Its crown is variable but richly branched and occasionally shaped like a high dome. Numerous root suckers spring from its extensive root system, often leading to the formation of smaller, shrubby stocks; it also has stump suckers, water sprouts and has burls on its trunk. Its relatively smooth, dull-grey bark exhibits fine, dark cracks on younger boughs. On its trunk and stronger branches, the bark is brownish to dark brown and marked by deep lengthwise cracks. Field Elms can live for up to 500 years and, where soil conditions are amenable, can boast trunk diameters of 1.5–2m. Ulmus minor may sometimes feature characteristic corky ridges on its side branches. Buds are relatively small and plump with white downy hairs. Elm leaves may be easily differentiated from most other deciduous leaves by way of two main characteristics: first, the asymmetry of the leaf base, which is occasionally very prominent; second, the double-toothed leaf edge. The alternating leaves are distichous (in two vertical rows); their form and size may vary significantly. However, the common denominator is their oblong, oval or elliptical form; a length from 6 – 10cm; a compact and shiny dark green upper side. The Field Elm flowers starting around the end of winter (February to March), e.g. before leaves appear. Tiny (hermaphroditic – wind pollination!) flowers form, from which bunches of nut-like fruits with elliptical wings spring, measuring approx. 1.5-2.5cm long and .5–1.5cm wide. Another attribute of this species is its propensity to form root and stump suckers. The ring-porous timber has yellowish sapwood and a brown core which may turn a deep reddish-brown after drying. The timber is hard, both impact and pressure resistant, easily workable and commands a high price.
Distribution
Naturally occurring in most parts of continental Europe except in the northwest and Scandinavia, its range extends to the Caucasus Mountains and Asia Minor. Found frequently if only sporadically in Austria; there are however no incidences in Carinthia. Widespread in the Donau-Auen National Park, especially in the hardwood riparian forests.
Endangerment and Conservation Status
Elms, but in particular the Field Elm, are threatened in many countries by a dangerous fungal infection which has brought the species to the brink of extinction. The species is vulnerable in Europe but also in Austria and even more so in certain regions such as in the Alps. A marked decline in the Field Elm stock in the National Park has been observed.
Ecological Characteristics
The Field Elm is a tree species requiring the warmth and the moderate amount of light provided by colline altitudinal zones, sunny slope forests but also the riverine wetlands and the fluvial valleys of major rivers. It prefers deep, alkaline soils which are seasonally flooded or freshly saturated and rich in nutrients. In the National Park, Ulmus minor may be found most often in the young hardwood riparian forests, but it can be observed throughout the park, albeit infrequently. The Dutch Elm disease, caused by the Ceratocystis ulmi fungus and transmitted by the bark beetle, has led to the near elimination of the Field Elm from the main stand.
Special Characteristics
Since pre-historic times, the Field Elm has been closely aligned with humans and is a witness of sorts to the development of human civilization. Many parts of this tree were used as food or indirectly as forage for animals; for making art objects; and in popular medicine. Ancient heathen cults of the elm were taken over in part by the Christian religion; sometimes, particularly impressive specimens were dedicated to saints. In comparison to the role it once played, the Field Elm is no longer of such societal importance. Its timber is well-suited for the production of furniture, is hardy, and maintains its robustness – even under water. In France in 1918, it was observed that an insidious disease had infected the elm. The epidemic spread rapidly across Europe and it is estimated that over 90% of the elms in Europe have now been infected, to the extent that the extinction of this species is a genuine threat.