Ailanthus altissima, κοινώς βρωμοκαρυδιά ή βρωμούσα

Foliage (Photo: Chuck Bargeron, The University of Georgia, www.forestryimages.org)

Είναι πράσινο, και όταν λουλουδιάζει φαντάζει όμορφο...
αλλά το βρωμοκάρυδο (Ailanthus altissima) στην πραγματικότητα ειναι παράσιτο.

Το δέντρο αυτό είναι από τα πιο επιθετικά που υπάρχουν, μας έρχεται από την Κίνα κι έχει εποικίσει όλο τον κόσμο, εξωθώντας τα γηγενή δέντρα.

Δεν είναι άλλο από τη βρωμοκαρυδιά (εξού και η βρώμα...) και κατά το επιστημονικό του Ailanthus altissima και κατά την ταπεινή μου άποψη είναι από τα σημαντικότερα προβλήματα που μπορεί να αντιμετωπίσει η ελληνική φύση.

Όχι άμεσα γιατί προς στιγμή περιορίζεται σε περιοχές γύρω από πόλεις και χωριά, αλλά στο μέλλον δεν ξέρει κανείς τί μπορεί να γίνει...


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παράθεση από σχετικό άρθρο της ελευθεροτυπίας

"Ailanthus altissima, κοινώς βρωμοκαρυδιά) εκκρίνει στο ριζικό του σύστημα ουσίες οι οποίες χρησιμοποιούνται ως βάση ζιζανιοκτόνων! ..."


(Photo: by loco)

Taxonomic name: Ailanthus altissima (P. Mill.) Swingle
Synonyms:
Common names: Chinese sumac (English), stinking shumac (English), tree of heaven (English-USA)
Organism type: tree, shrub

Ailanthus altissima is a very aggressive plant, a prolific seed producer (up to 350,000 seeds in a year), grows rapidly, and can overrun native vegetation. It also produces tonns that prevent the establishment of other plant species. The root system is aggressive enough to cause damage to sewers and foundations.

(Photo: by loco)

Description
Ailanthus altissima is a small to medium-sized tree in the mostly tropical Quassia family. It has smooth, grey bark and leaves are compound, 1-4 feet in length, alternate, odd-pinnate, with 11-25 lanceolate leaflets. Most leaflets have one to three coarse teeth near their base. Mature trees can reach 80 feet or more in height. Flowers occur in panicles at the ends of branches and the male flowers produce a strong odour described as the smell of burnt peanut butter. The leaves when crushed also produce a distinctive odour. Seeds are centred in a papery sheath called a samara. The samaras are slightly twisted or curled, and twirl as they fall to the ground. The wood of A. altissima is soft, weak, coarse-grained, and creamy white to light brown in colour.

Similar Species
Carya illinoinensis, Juglans nigra, Rhus typhina
More

Occurs in:
agricultural areas, natural forests, ruderal/disturbed, urban areas

(Photo: by loco)


Habitat description

Ailanthus altissima establishes itself readily on disturbed sites, such as railroad embankments, highway medians, fencerows, and roadsides. In naturally forested areas, A. altissima may become established in areas disturbed by storms or infestations. A. altissima has the ability to grow in poor soils and under stressful environmental conditions. It grows in full sun and thrives in poor growing conditions. Germination rates are high, provided soil has adequate moisture. It is well adapted to heavy clays and other soils with low nutrient and oxygen content.

General impacts
All over the United States, A. altissima has become a pest of agricultural, urban and forested areas. Seedlings and root suckers of A. altissima grow rapidly and spread prolifically and thus quickly out-compete many native species for sunlight and space. It also produces a toxin in its bark and leaves. As it accumulates in the soil, the toxin inhibits the growth of other plants. The root system is capable of damaging sewers and foundations.

Uses
The wood is often used in China for lumber, fuelwood and other products. In the U.S. it is occasionally used for low-grade lumber, pulpwood and fuelwood. The toxin produced in the bark and leaves of A. altissima is being studied as a possible source for a natural herbicide. It is used in traditional herbal medicine in China.

Notes
Male flowers are conspicuous and ill smelling, attracting many insects. Female flowers are less odorous and less conspicuous.

Geographical range
Native range: Native to a region extending from Northern China through parts of East Asia to Australia, Ailanthus altissima has been introduced to throughout the United States. It is now widely distributed across the United States, occurring in forty-two states, from Maine to Florida and west to California.

Introduction pathways to new locations
Natural dispersal: Spreads easily due to its rapid growth and prolific seed production
Nursery trade: Was commonly available from nurseries by 1840

Saplings growing in recently cut-over area (Photo:Chris Evans, The University of Georgia, www.forestryimages.org)

Local dispersal methods

Escape from confinement: Escapes from cultivation because of rapid growth
On animals (local): Samaras, (papery sheath in which the seeds are centered), can be borne on the wind great distances from the parent plant.

Management information
Preventative measures: A Risk assessment of Ailanthus altissima for Australia was prepared by Pacific Island Ecosystems at Risk (PIER) using the Australian risk assessment system (Pheloung, 1995). The result is a score of 12 and a recommendation of: reject the plant for import (Australia) or species likely to be a pest (Pacific).

Nutrition
Ailanthus altissima is well adapted to heavy clays and other soils with few nutrients.

Reproduction
Ailanthus altissima reproduces both sexually (seeds) and asexually (vegetative sprouts). Flowering occurs late in the spring (June in the middle Atlantic region of eastern United States). The species is dioecious (trees have either male or female flowers). A single tree can produce around 325,000 to 350,000 seeds a year. Trees grow quickly, as stump sprouts grow up to 3cm per day.

Lifecycle stages
Established trees produce numerous suckers from the roots and sprout vigorously from cut stumps and root fragments. Seedlings establish a taproot three months after germination. A. altissima probably lives for no more than 100 years in North America (usually less) but the root system and its sprouts can persist for a longer time.

Reviewed by: Phil Pannill, Maryland Dept. of Natural Resources - Forest Service.

Compiled by: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)

Last Modified: Monday, 28 November 2005

πηγές & περισσότερες πληροφορίες:

http://rapidshare.com/files/131589585/03Burch.pdf.html

http://www.issg.org/database/species/ecology.asp?fr=1&si=319

http://en.wikipedia.org/wiki/Ailanthus_altissima

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