data jungle adventures

Thanks to national and regional greening initiatives, the landscaping and greening sector in KSA is flowering, leading to a much needed capacity development associated with plant production, plant material import, propagation and transport. This may lead to the propagation of and sales of non-native invasive plants such as Prosopis juliflora.

• Recently the National Centre for Vegetation Cover Development and Combating Desertification (NCVC) hatched an applied science project to reduce the impact of invasive plants, increase awareness and control plants in-situ. Additional initiaives include research from multiple universities:
• King Khaled University (KKU) is supporting research on invasive species. One of the recent studies weights benefits from Nicotiana glauca (false tobacco) and Prosopic juliflora against risk for the local environment.
• King Abdullah University focusses on marine invasive species, modelling of their distributions, citizen science and awareness, and monitoring (2021).

Regulations

While an invasive species list has not been released by a public authority, the Green Saudi and Middle East Initiatives plan to unify and push for setting clear regulations to control and manage invasive species. We suppose that the NCVC project will lead to a national plant species list, regulations on land management, transport and production.

MEWA (Ministry of environment, water, and agriculture) is probably most suited to steer communications, regulate, and manage compliance on the national and regional levels. For now a positive list for ‘the most important local plants suitable for landscaping’ has been published by MEWA.

Species list

Invasive and naturalised species list have been mainly published through scientific articles and websites.

• The website plant diversity of Saudi Arabia lists invasive species based on Thomas et al. 2016. 
• The Global Biodiversity Information Facility (GBIF) has listed a 131 invasive plants species sourced from a collaboration of Thomas et al. and a research group from New Zealand.

Species	Geographical Distribution	Habit
Alternanthera pungens	Southwestern Mountains	Herb
Amaranthus albus	Central, Eastern and Western regions	Herb
Amaranthus hybridus	Throughout Saudi Arabia	Herb
Amaranthus spinosus	Southwestern mountains	Herb
Annona squamosa	Southwestern mountains (Jabal Fayfa)	Tree
Argemone mexicana	Southwestern mountains	Herb
Argemone ochroleuca	Southwestern mountains	Herb
Astrocylindropuntia subulata (Presence not confirmed)	Southwestern mountains	Shrub
Atriplex suberecta	Central and eastern regions	Herb
Bidens aurea	Southwestern mountains	Herb
Cenchrus echinatus	Central, eastern western and northern regions	P. grass
Cenchrus setigerus	Southwestern mountains	P. grass
Dysphania carinata (=Chenopodium carinatum)	Southwestern mountains	Herb
Chenopodium atrovirens	Central region	Herb
Chenopodium desiccatum ssp.  leptophylloides	Central region	Herb
Cuscuta campestris	Central , eastern and  northern regions	Herb
Cylindropuntia rosea	Southwestern region	Shrub
Datura ferox	Southwestern region	Herb
Datura innoxia	Through out Saudi Arabia	Herb
Datura metel	Southwestern region	Herb
Datura stramonium	Southwestern region	Herb
Dysphania ambrosioides	Central and southwestern r	Herb
Eclipta prostrata	Central	Shrub
Encelia farinosa	Southwestern region	Shrub
Euphorbia cyathophora	Eastern Province	P. Herb
Euphorbia heterophylla	Eastern province	P. herb
Euphorbia hirta	Throughout Saudi Arabia	Herb
Euphorbia hypercifolia	Central and Western regions	Herb
Euphorbia maculata	Central region	Herb
Euphorbia prostrata	Central region	Herb
Euphorbia tirucalli	Southwestern region	Shrub/Tree
Galinsoga parviflora	Southwestern region	Shrub
Heliotropium curassavicum	Eastern, central and southwestern regions	Herb
Ipomoea carnea ssp. fistulosa	Tihama, SW region	Shrub
Jatropha curcas	Southwestern region	Shrub
Lantana camara	Southwestern mountains	Shrub
Leucaena leucocephala	Central, eastern and southern reigons	Tree
Malvastrum coromandelianum	Central region	P. Herb
Nicotiana glauca	Asir and Jazan Mountains	Shrub
Operculina turpethum	Southwestern region	P. Herb
Opuntia dellenii	Southwestern region	Shrub
Opuntia ficus-indica	Southwestern region	Shrub
Opuntia stricta	Southwestern region	Shrub
Parthenium hysterophorus	Southwestern region	Herb
Paspalum dilatatum	Southwestern region	Annual
Physalis peruviana	Tihama, SW region	Herb
Physalis stepelioides	Tihama, SW region	Herb
Potamogeton perfoliatus	Central region	P. Herb
Prosopis juliflora	All regions in Saudi Arabia	Tree
Prosopis koelziana	Central region	Tree
Senna occidentalis	Central and western regions	Shrub
Senna obtusifolia	Southwestern region	Shrub
Sesuvium portulacastrum	Eastern and central region	P. Herb
Sesuvium verrucosum	Central and Western region	Herb
Tagetes minuta	Southwestern region	P. Herb
Trianthema portulacastrum	Southwestern region	Herb
Tridax procumbens	Southwestern region	Herb
Verbesina encelioides	Southwestern region	Herb
Xanthium spinosum	Southwestern region	P. Herb

Updated list of KSA

Thomas et al. 2016 published an updated list of the invasive species where some species were removed and others were added. Here is a glimpse on both:

• Removed species: Cenchrus setigerus, Euphorbia prostrata, Opuntia dellenii, Parthenium hysterophorus, Prosopis koelziana
• Added species: Cenchrus gracillimus, Cirsium vulgare, Erigeron bonariensis, Erigeron canadensis, Euphorbia prostrata Aiton, Flaveria trinervia, Ipomoea cairica, Salsola kali

For each of the added species, Thomas et al. indicate the altitudinal variations (in meters), the impact on domestic herds, mode of dispersal (shoes, water, wind, soil, clothes, moving vehicles, etc.), and the propagation mode (seeds, vegetative, or both).

Impactful?

By definition invasive species are that group of aliens that impacts the native environment significantly. In a hyper-arid context where plant diversity and abundance may appear sparse to the untrained eye, the impact of an alien may be perceived as positive. This discussion depends on context and angle. While benefits to us humans may be obvious, risk of the destruction of endemic ecosystems, plants, communities, and trophic networks is imminent.

Awareness can be brought to the example of invasive plants in local nurseries along with planting guides and manuals that do not classify impactful invaders.