Acer negundo

Boxelder Maple

The Boxelder Maple (Acer negundo) is a medium-sized tree that originally comes from North America, but is also found in Europe as an invasive neophyte. It was introduced to Europe as early as the 17th century, as it was popular as an ornamental tree due to its adaptability and rapid growth. The Boxelder Maple can reach a height of 10 to 15 metres and forms a spreading crown. The leaves are pinnate and consist of three to seven leaflets with serrated edges. Yellowish-green flowers appear in hanging panicles in spring, followed by winged fruits in autumn. In Europe, Ash Maple is considered a problematic species due to its invasive properties and ability to displace native plants. As it is already a large-scale established species, the focus is limited to controlling the further spread of Acer negundo and preventing its expansion, especially in riparian forests.

Types of damage

Ecological damage

Boxelder Maple forms dense stands and competes successfully for nutrients, water and light, which can reduce biodiversity. Native vegetation can be suppressed or displaced by Boxelder Maple, leading to changes in ecosystems. Especially in riparian forests, Acer negundo can prevent the natural regeneration of vegetation and contributes to a reduction of species in the herbaceous layer.

Damage to health

Although Acer negundo does not cause any direct health damage to humans, the plant's high pollen production can lead to allergic reactions. People who are allergic to pollen can experience increased allergic symptoms such as hay fever, respiratory problems and eye irritation from the Boxelder Maple.

Region of origin

North America

Introduction vectors

Horticulture

Acer negundo was often planted in gardens, parks and other landscaped areas as an ornamental tree. Nowadays, however, it spreads mainly by natural means.

Current distribution

Based on the FlorKart Database of the Federal Agency for Nature Conservation, as of 2013

Miscellaneous

Family

Soapberries (Sapindaceae) comprise about 2000 species spread over 140 genera. Characteristic are their pinnate or palmate leaves and the often brightly coloured, diverse fruits. The fruit forms range from capsules to berries. Many species have economic importance, such as the sugar maple (maple syrup), lychee, guaraná (source of caffeine) or the horse chestnut.

Climate change

Acer negundo has already filled its potentially suitable habitat under current climate conditions. It does not benefit from climate change because in the future its potentially suitable habitat will become smaller. The environmental factors that most influence its spread are precipitation in autumn, soil type, precipitation in winter, rail infrastructure and temperature in summer.

Positive effects

The Boxelder Maple is characterised by a very high maximum photosynthesis rate. Especially in cities (where it is sometimes planted as an ornamental tree), it can thus contribute more to air quality than other plants.
Dispersion forecast

Indicates the proportion of land suitable for habitat under current and future climate conditions (2060-2080) under three emission scenarios (RCP26, RCP45 & RCP85).

Habitat suitability maps

Instructions for use: Click here

Habitat suitability under current climate conditions

These habitat suitability maps show for Acer negundo where suitable habitat conditions exist.

The map on the left shows this for current climate conditions. Below this are maps for the time classes 2040-2060 and 2061-2080, in which three different emission scenarios can be selected.

The slider at the top left allows you to adjust the opacity of the map to make orientation easier.

By clicking on the respective quadrant, information on the environmental conditions present in it can be called up.

The methodology is explained here .

Habitat suitability 2040 - 2060

2040-2060: In the RCP2.6 scenario, GHG emissions are expected to peak by 2040 through comprehensive mitigation measures and to decline rapidly thereafter. By 2060, global warming would stabilise at about 1.5°C above pre-industrial levels. Subtle changes in precipitation patterns could vary regionally, with some areas facing increased drought and others increased precipitation.

2040-2060: Under RCP4.5, GHG emissions would continue to increase until 2040, but stabilise at a high level thereafter. By 2060, there could be a global temperature increase of about 2°C above pre-industrial levels. This scenario would likely cause moderate changes in precipitation patterns, with potential regional differences.

2040-2060: Under RCP8.5, which assumes continued intensive use of fossil fuels, greenhouse gas emissions would rise sharply by 2060. The global temperature increase could be around 2.5-3°C. In this scenario, significant changes in precipitation patterns could occur, with an increased likelihood of extreme weather events.
Habitat suitability 2061 - 2080

2060-2080: By 2080, global warming could be limited to below 2°C in the RCP2.6 scenario, provided emission reductions are consistently pursued. Impacts on precipitation patterns would likely stabilise, although regional variance would remain significant.

2060-2080: In the RCP4.5 scenario, global temperatures would continue to increase and could be around 2.5°C above pre-industrial levels by 2080. Changes in precipitation patterns would likely increase and regional differences could become more pronounced.

2060-2080: Under RCP8.5, global temperatures could rise by more than 4°C above pre-industrial levels by 2080. Precipitation patterns would be expected to change significantly, with further increases in the frequency and intensity of extreme weather events. This would have far-reaching impacts on ecological and socio-economic systems.