Alien flora of Oman: invasion status, taxonomic composition, habitats, origin, and pathways of introduction

Abstract

We present the first inventory and status assessment of the alien flora of Oman, mainly based on field data collected from 1998 to 2021. The study provides (i) a comprehensive account of alien vascular plant species occurring in the wild in Oman, with information on their taxonomic composition. For each species information is given on (ii) invasion status (casual, naturalized or invasive), biogeography, habitat and life-form characteristics, and pathways of introduction. Further, we (iii) explain the differences in the alien species composition in different parts of the country, and (iv) analyse the drivers of plant invasions in Oman. Out of the 111 alien species reported (7.7% of the total Oman vascular flora), 34 species are casuals and 77 naturalized; of the latter seven are considered invasive. The moderate number of alien plant species is likely a result of the country’s arid climate, with extremely high summer temperatures and low annual precipitation in most of its area, and the relatively long isolation of the country. The families richest in alien plant species are Fabaceae (17 species), Asteraceae (14 species) and Poaceae (12 species). More alien plants were found in northern Oman (82 species) than in southern Oman (60 species), and very few species are recorded from the central desert (7 species). The main habitats colonized were man-made habitats, either ruderal or agricultural. Most species alien to Oman are native to South America (49 species) or North America (43 species). This inventory provides a knowledge base for developing a national management strategy for alien vascular plants in Oman.

Plant–soil feedback and plant invasion: effect of soil conditioning on native and invasive Prosopis species using the plant functional trait approach

“…To test how soil conditioning with native and invasive species will affect the plant performance and production and soil properties, we ran a two-phase experiment that included a soil-conditioning phase and a feedback phase in the greenhouse at the Sultan Qaboos University, Muscat, Oman (23°36′0.95″N, 58°10′5.29″E) ( Figure 1 ). To carry out this study, we used two species, P. cineraria (L.) Druce, which is a plant native to Oman, and P. juliflora (Sw.) DC., which is an invasive species in Oman and is currently competing with P. cineraria and other native species ( Supplementary Figure 1 ) ( Pickering and Patzelt, 2008 ; Patzelt et al., 2022 ). Seeds were collected directly from the field, and the two species have comparable germination and establishment rates.…”

“…In Oman, invasive plant species are posing a serious risk to ecosystems and biodiversity ( Patzelt et al., 2022 ). Prosopis juliflora (Sw.) DC.…”

“…Prosopis juliflora (Sw.) DC. is among the invasive plants that are currently posing a severe threat to the natural ecosystem all over the Sultanate of Oman, and it has become difficult to manage due to the lack of knowledge about how these plants are so successful invaders ( Patzelt et al., 2022 ). P. juliflora , which is commonly called mesquite, is an evergreen tree natively found in central and northern South America; as it has a high ecological adaptability, it is vigorously invading plenty of natural areas in Oman due to its ability to adapt and grow under harsh arid environmental conditions ( Shackleton et al., 2015 ).…”

“…Additionally, it is suggested that P. juliflora affects the nearby native species due to its ability to produce allelopathic chemicals that limit the growth of other native species and alter soil nutrients ( El-Keblawy and Abdelfatah, 2014 ; Shackleton et al., 2015 ; Bibi et al., 2023 ). P. juliflora competing with other native species, e.g., Prosopis cineraria (L.) Druce trees, which is one of the species native to Oman and is a valuable species that helps in improving soil nutrients, provides fodder for domestic animals, has a variety of medicinal and cosmetic uses, and is a potential species for biodiesel production ( Pickering and Patzelt, 2008 ; Giustra et al., 2022 ; Patzelt et al., 2022 ). Understanding such interplay between the invasion process and PSF will help in managing this invasive species in Oman.…”

Naturalization of Pineapple-weed (Matricaria discoidea DC.) in the Indian Trans-Himalayan region of Ladakh

“…In fact, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES 2019), has recognized IAS as one of the ve major drivers of biodiversity loss. Historically, human-mediated activities have introduced a large pool of species outside their native distribution ranges (van Kleunen et al 2015), and most of these species fail to establish self-sustaining natural populations in their non-native ranges (Patzelt et al 2022). However, a small fraction of introduced alien species do establish by maintaining natural populations without direct human intervention and are referred to as naturalized species; further only a subset of these naturalized species spread rapidly and exert negative ecological and economic impacts and are referred to as invasive species (Richardson et al 2012).…”